数控专业外文翻译----数控技术发展

Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC).Prior to the advent of NC, all machine tools were manual operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator . Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems though the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool, For a machine tool to be numerically controlled , it must be interfaced with a device for accepting and decoding the p2ogrammed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operator , and it has done so . Numerical control machines are more accurate than manually operated machines , they can produce parts more uniformly , they are faster, and the long-run tooling costs are lower . The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3.Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide variety of par4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies , NC was born in the laboratories of the Massachusetts Institute of Technology . The concept of NC was developed in the early 1950s with funding provided by the U.S Air Force .In its earliest stages , NC machines were able to make straight cuts efficiently and effectively.However ,curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is the straight lines making up the step ,the smoother is 4he curve . Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tape reader was used to interpret the instructions written on the tape for the machine .Together, all /f this represented giant step forward in the control of machine tools . However ,there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium . It was common for the paper containing the programmed instructions to break or tear during a machining process, This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to rerun thought the reader . If it was necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 separate times . Fragile paper tapes simply could not withstand the rigors of shop floor environment and this kind of repeated use.This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most important of these was that it was difficult or impossible to change the instructions entered on the tape . To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape thought the reader as many times as there were parts to be produced . Fortunately, computer technology become a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as numerical control (DNC) solve the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions . In direct numerical control, machine tools are tied, via a data transmission link, to a host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However ,it is subject to the same limitation as all technologies that depend on a host computer. When the host computer goes down , the machine tools also experience down time . This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known as data management . The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connectDigital Signal ProcessorsThere are numerous situations where analog signals to be processed in many ways, like filtering and spectral analysis , Designing analog hardware to perform these functions is possible but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis of signals.The act of sampling an signal into thehat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . Today there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usage group. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both specialised DSP’s for certain fields like motor-control or modems ,and general high-performance DSP’s that can perform broad ranges of processingtasks. Development kits an` software are also available , and there are companies making software development tools for DSP’s that allows the programmer to implement complex processing algorithms using simple “drag ‘n’ drop” methodologies.DSP’s more or less fall into t wo categories depending on the underlying architecture-fixed-point and floating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Another important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “general purpose” register , making them quite tricky to program and more importantly ,making C-compilers inherently inefficient. Floating-point DSP’s behave more like common general-purpose CPU’s ,with register-files.There are thousands of different DSP’s on the market, and it is difficult task finding the most suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest manufacturers against it.The “big four” manufacturers of DSPs: Texas Instruments, Motorola, AT&T and Analog Devices.Digital-to-analog conversionIn the case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplifier or similar audio equipment . This digital to analog conversion (DCA) is performed by a circuit with the same name & Different DCA’s provide different performance and quality , as measured by THD (Total harmonic distortion ), number of bits, linearity , speed, filter characteristics and other things.The TMS320 family DQP of Texas InstrumentsThe TLS320family consists of fixed-point, floating-point, multiprocessor digital signal processors (D[Ps) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The’ F/C240 is a number of the’C2000DSP platform , and is optimized for control applications. The’C24x series of DSP controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The following characteristics make the TMS320 family the right choice for a wide range of processing applications:--- Very flexible instruction set--- Inherent operational flexibility---High-speed performance---Innovative parallel architecture---Cost effectivenessDevices within a generation of the TMS320 family have the same CPU structure but different on-chip memory and peripheral configurations. Spin-off devices use new combinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save circuit board space.The 16-bit ,fixed-point DSP core of the ‘C24x devices provides analog designers a digital solution that does not sacrifice the precision and performance of their system performance can be enhanced through the use of advanced control algorithms for techniquessuch as adaptive control , Kalman filtering , and state control. The ‘C24x DSP controller offer reliability and programmability . Analog control systems, on the other hand ,are hardwired solutions and can experience performance degradation due to aging , component tolerance, and drift.The high-speed central processing unit (CPU) allows the digital designer to process algorithms in real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with the extensive development time and provides the same ease of use as traditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other general-purp ose‘C2xx generation ,source code compatible with the’C2x generation , and upwardly source code compatible with the ‘C5x generation of DSPs from Texas Instruments.The ‘C24x architecture is also well-suited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances in a system or an estimation technique that could eliminate state sensors in a system.The ‘C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixed-signal peripherals includes:---Timers---Serial communications ports (SCI,SPI)---Analog-to-digital converters(ADC)---Event manager---System protection, such as low-voltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow’s embedded control marke tplace.The TMS320F/C240 is the first standard device introduced in the ‘24x series of DSP controllers. It sets the standard for a single-chip digital motor controller. The ‘240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The ‘ 240 has the architectural features necessary for high-speed signal processing and digital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The ‘240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced processing power of the ‘240 include:---Industrial motor drives---Power inverters and controllers---Automotive systems, such as electronic power steering , antilock brakes, and climatecontrol---Appliance and HV AC blower/ compressor motor controls---Printers, copiers, and other office products---Tape drives, magnetic optical drives, and other mass storage products---Robotic and CNC milling machinesTo function as a system manager, a DSP must have robust on-chip I/O and other peripherals. The event manager of the ‘240 is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for high-precision and high-efficiency full variable-speed control of all motor types. Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable dead-band function and a space vector PWM state machine for 3-phase motors that provides state-of-the-art maximum efficiency in the switching of power transistors.There independent up down timers, each with it’s own compare register, suppo rt the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.Open-Loop and Closed-Loop ControlOpen-loop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open -loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house; but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the open-loop control.An electric washing machine is another typical example of an open-loop system , because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes continuously and turn itsedt off when the desired degised of cleanliness is reached.Closed-Loop Control SystemsWhat is missing in the open-loop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and compared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closed-loop system. human being are probably the most complex and sophisticated feedback control system in existence. A humanbeing may be considered to be a control system with many inputs and outputs, capable of carrying out highly complex operations.To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closed-loop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closed-loop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig & . In complex systems there may be multitude of feedback loops and element blocks.数控在先进制造技术领域最根本的观念之一是数控（NC）。

原文：The digital control process technology is summarized1. digital control programming reaches such developmentThe digital control programming is the segment that be able to obviously bring into play the beneficial result in at the moment CAD/CAPP/CAM's system the most most , such is living to achieve to design the process automation and raise process accuracy and processes the quality and cuts down the product development cycle and so on the respect is brining into play the significant action . Being living possess the greats quantity applications such as aviation industry and auto industry and so on territorys . Since giving birth to the intense demand of practice , wide-ranging research has wholly been carried on to the digital control programming technique in the home and abroad , and acquires the plentiful and substantial fruit . The next reaches such to the digital control programming and develops to act as some to introduce .1.1 basic concept of digital control programmingThe digital control programming is through the spare parts drawings up the full process that obtains the digital control processing program . Its main mission is that the sword spot ( Cutterlocationpoint abbreviate CL's spot ) in the sword is processed away in the calculation .The point of intersection that sword the spot was oridinarily get to the cutting tool axial line against the cutting tool face still will be give out the sword shaft vector in much processs1.2 digital control programming technique development surveyMIT designed one kind of special language that is used in the inflexible spare parts digital control processing program establishments to the program problem in order to resolve in the digital control process , andis called APT ( AutomaticallyProgrammedTool ) in the 50's .Well-developed editions such as after APT time and again develops , takeed shape such as APTII and APTIII ( the stereoscopic cutting action is employd ) and APT ( the algorithm improves , add much coordinates surface processes the programming meritorous service capacity ) and APTAC ( Advancedcontouring ) ( add cuts the database administration system ) and APT/SS ( SculpturedSurface ) ( add engraves the camber processes the programming meritorous service capacity ) and so on .Adoping APT language drawing up digital control order to have easy the refineing of order , and gos away the strongs point such as sword control is agile and so on , and causes the digital control process the programming , and moves upward up yet possess much not suitable points to geometry element .APT through " assemble language " grade to the machine tool order : Adoping language definition spare parts geometry form shape , and is difficult to depict complex geometry form shape , and lack audio-visual quality of geometry ;The certification measure that the figure audio-visual that is short of to spare parts form shape and the cutting tool movement locus displays and the cutting tool locus ;Being difficult to effectively join with CAD's data bank and CAPP's system ;Not to act as easily up the high automation , the integrationizationIn view of the APT's language defect , in 1978 , France attained the system that the large rope airplane corporation starts development gathers assemble three dimensions design , analysis and NC's process integration , and is called in the interest of CATIA .Having ariseed alikely the systems such as EUCLID and NPU/GNCP and so on soon afterwards very quickly , the geometry moldswholly valid settlements of these systems and the spare parts geometry form shape display is designed mutually and mends generates the cutting tool locus , and the problems such as the imitation to go away the sword process displays and certification and so on promoteed CAD and CAM developing to the integration orientation . The approximately idea that system ( CIMS ) and parallel project ( CE ) was manufacture in the calculating machine integration take shape up the 80's gradually on the base that the CAD/CAM's integration being living is approximately attend school . At the moment , and the necessaries that CE developed in order to adapt to CIMS , the digital control programming system to integrationization and intelligentization the development .Being living the integration respect , with the development accords with the STEP ( StandardfortheExchangeofProductModelData ) criterion parameterization feature moldmaking and systematically gives priority to , having carried on the highly effective work of greats quantity at the moment is the home and abroad development heatpointBeing living the intelligentization respect , the work has start only a short while ago , and still awaits that we leave hard2、NCs' cutting tool locus generates the method study developing actualityDigital control programming core work is generateing the cutting tool locus , afterwards by such scattered one-tenth sword spot , places that the handle comes into being the digital control processing program afterwards viaing .The next cutting tool locus comes into being the means and actes as some and introduce2.1 baseding on a little and string , surface and part of the body NC's sword track formation meansCAD's technique moves through the two dimension mapping , andudergo the three dimensions wires frame and camber and the solid modelling generation , now the parameterization feature reacing is always moldded .Is living two dimension mapping together with three dimensions wires frame phase , in case the opening processes , the rough sketch is processed the digital control process is main with spot and string act as drive target , the plane area process and so on .This kind of level that personnel staff was requireed manipulating in the process is taller , complex mutually .Being living camber and the solid modelling generation , entity process had ariseed to based on .The entity process target is an entity ( oridinarily blendes for CSG and BREP express ) , its ( moreover , intersects , falls short of to operate ) but get yield through some fundamental parts of the body habitually after the set operation .The entity is processed not merely usable rough machining and semi precision work to the spare parts , and the great area cuts Yu Liang , and the effectiveness is processed in the raise , but also usable research together with development to digital control baseding on the feature programming system , is the feature process baseEntity process oridinarily possess entity rough sketch process and the entity area and processes two kinds .The entity process realization means slices law ( SLICE ) in the interest of the straturm , in immediate future slices by the process entity in the way of one series of level , afterwards to obtains the intersection comes into being the isometry string dos worthwhile the sword the going away locus .The original slave system needs the angle depart , the digital control process that the ACIS's geometry moldmaking being living achieved thiskind to based on a little on the terrace and the string and surface and entity Feature NC's sword track formation means 2.2 baseding onThe parameterization feature molds to possess the specified development particular period , yet baseds on that feature cutting tool locus formation means research starts only a short while ago .The feature processes to cause digital control programming personnel staff to be out to let drop the step geometry message to those ( in case : Spot , string , surface and entity ) manipulate , but transforing to carry on the digital control programming in the interest of directly to accords with the feature that engineers and technicians are used to , and liftd the programming effectiveness enormouslyW.R.Mail and A.J.Mcleod are living in their research to give out one to based on feature NC's code generating sub system , and this systematic work rule is : Spare parts every one process wholly may be regarded as to adjust to make up the total that the spare parts form shape feature group processed .In immediate future the queen completees spare parts process is not processed that to the feature adjusting entirely form the shape in that way either form shape feature component .But each form shape feature either form shape feature series NC's code may generate voluntarily .The system opened up at the moment merely is applicable to 2.5D's spare parts processThe LeeandChang opened up one kind of raised liberal camber feature cutting tool locus of means autogeneration in the way of fictitious border system .This systematic work rule is : Being living to inlay inner place the raised liberal camber into one the minimal long and square , so raised liberal camber feature is transformd into the hollow feature .Minimal the long and square incorporation against the end product pattern constituteed to be called one kind of indirect produce pattern on the fictitious pattern .That the cutting tool locus formation means separates into completees three paces : ( 1 ) and the cutting action polyhedron feature ;( 2 ) and cuts the liberal camber feature ;( 3 ) and the cutting action intersects the featureJongYunJung researcies baseds on the non- cutting action cutting tool locus formation problem of feature .The article process baseding on the feature locus separates into rough sketch process and processes two types with the inside area , and the definition this two types of process cutting action orientations , attains the aim that the entirety optimizes the cutting tool locus by means of decreasing the cutting action cutting tool locus .Type who talked about these fundamental features gos away sword way and cutting tool selection and process order and so on to main being aimed at of article some kinds of fundamental features ( hollow inner place Kong and step , trough ) , and averting repeatedly going away the sword by means of IP ( InterProgramming ) technique , with the non- cutting action cutting tool locus of optimization .Besides JongYunJong still is living , and his doctor in 1991 researcied tabrication feature extraction and baseds on feature cutting tool and the cutting tool way in the dissertationThe feature process base is an entity process , and surely of course also may think the entity process being more high-quality .Yet feature process distinct entity process , and entity process possess it oneself the limitations .Feature process chiefly possess below difference against entity process :Through approximately attends school says that the feature is the meritorous service capacity key element to make up the spare parts , and the operation that accords with engineers and technicians is used to , by engineers and technicians are know intimately ;The entity is the geometry target on low straturm , and is a geometric object that obtains after a series of Booleans calculation , and does not have whatever meritorous service capacity semantic information ;It frequently is adjusting the once only process of entire spare parts ( entity ) that the entity is processed .Yet in reality the spare parts is not very much probably merely once processed through in the way of the sword , frequently will go through a series of workmans of rough machining and semi precision work and precision work and so on stage , the place of spare parts difference oridinarily will be employd the difference cutting tool and process ;Now and then not only the spare parts will be employd up turning , but also employ up mill .Hence entity process is chiefly used spare parts rough machining and semi precision work .But but the feature on processing through essentially resolved the above-mentioned issue ;Feature process havees even more intellect .May regulate some kinds of settled admittedly process meanss as to the specially designated feature , particularly those have been living , and STEP's criterion the person who regulates the feature still more is such in this way .In case we wholly draw up the specially designated process means to all standards feature , it is you can imagine that spare parts that in thatway sufficiently succeed through the standard feature to those are processed such convenient quality .In case CAPP systematically be able to supply the relevant technology feature , NCP's system may decrease inputing mutually , and havees even more intellect enormously in that way .But these entity process can not achievedFeature process is favour of achieving through comprehensive integration of CAD , CAPP , NCP and CNC's system , and achieves the two-way going from place to place of message , in the interest of CIMS and even parallel project ( CE ) are settleed the well base ;It be helpless that but the entity is processed to theseNC's sword track formation means 2.3 being on active service in several main CAD/CAM's systems is analysedActive duty CAM constitutes reaching the main meritorous service capacityThat at the moment comparatively more mature CAM's system is main with two kinds of shapes achieves CAD/CAM's system integration : Integration CAD/CAM's system ( in case : UGII , Euclid and Pro/ENGINEERs and so on ) and independent relatively CAM's system ( in case : Mastercam and Surfcams and so on ) . Unitary less than the former data format is directly gaind the produce geometric model through CAD's system , but the latter is main gains the produce geometric model by means of the neutral papers through else CAD's systems . However , no matter is what the CAM's system growed the shape , wholly consising of five modules , in immediate future mutually technology parameter input module and cutting tool locus formation module and cutting tool locus compiler module and three dimensions process that dynamic imitation module and afterwards places the processing module . Next merely some famous CAD/CAM's system NC's process meanss are holied discussions .UGII's process means is analysedOridinarily think that UGII is the best in trade circle , and havees representativeness digital control software most .That such havees the distinguishing feature most is the cutting tool locus formation means that such meritorous service capacity is powerful .Consists of turning , milling and string cuts and so on the consummate process means .In it milling chiefly possess the below meritorous service capacity :And PointtoPoint: Completeing the different openings processesAnd PanarMill: Plane is milled .Consising of that the one-way walkes surely , the two-way row are slice , and the hoop is slice along with rough sketch process to await And FixedContour: Admittedly much projectionss are areed processed stably .Dominateeing on being living on the single camber either much camber the removing of cutting tool in the way of the projection means , and that the control cutting tool is removed may be the cutting tool locus that has generateed , a series of either suite stringAnd VariableContour: Variable projection is processedAnd Parameterline: Await that the parameter string is processed .The successive process of single camber either much camber may be adjustAnd ZigZagSurface: Cutting out processAnd RoughtoDepth: Rough machining .The depth is reachd assigning in the rough machining by Mao PiAnd CavityMill: The many stages depth mould cavity processes .Rough machining that particularly is applicable to the male contact with the hollow standardAnd SequentialSurface: The camber occuies simultaneously the workman .In accordance the spare parts and guides that and the thinking of check adjust the removing suppling the largesttest degree control of cutting toolEDSUnigraphics still consists of greats quantity else the respects meritorous service capacitys , and did not enumerate one by one here STRATA's process means is analysedSTRATA is a digital control programming system development environment , and it is establishing ACIS's geometry model building terrace onIt supplys two kinds of programming development environments in the interest of consumer , in immediate future NC's command language interface and the NC's operation C++ storehouse . It may back three to mill , and turning and string cut NC and process , and may back wire frame , camber and the entity geometry model building . Such NC's cutting tool locus formation means is baseding on the physical model . STRATA is baseded on , and what supplys the process means in entity NC's cutting tool locus formation type storehouse consists of : ProfileToolpath: Rough sketch processAreaClearToolpath: The area on plane processesSolidProfileToolpath: The entity rough sketch is processedSolidAreaClearToolpath: The area on entity plane processesSolidFaceToolPath: The entity face processesSolidSliceToolPath: The entity severs process on planeLanguagebasedToolpath: Baseding on , language cutting tool locus generatesElse CAD/CAM software , in case Euclid the person who awaits the NC's meritorous service capacity is each has his strong point , yet suchfundamental substance is almost alike , the not natural difference .2.4 main problem of systematic sword track formation means of active duty CAMIn accordance tradition CAD/CAM's system and CNC's system work means , CAM's system is with directly either the indirect means gains the produce geometry data model through CAD's system ( by means of neutral papers ) . CAM's system is with spot , string , surface in the three dimensions geometrics model and either the entity is the drive target , the cutting tool locus is processed in the formation , and afterwards the shape with the cutting tool locating file viaes the handle is placed , with the NC's code shape supplys to CNC's machine tool , the some respects problems under being living in entire CAD/CAM and the CNC's system operation process to be :CAM systematically can only gain produce low tier of geometry message through CAD's system , and can not seize voluntarily meritorous service capacity and the semantic information of produce geometry shape information and produce higher level .Hence manufacturing engineering master that entire CAM's process have to be living is very experience haves a hand in secondly , and completees mutually by means of the figure .In case : Manufacturing engineering master .The entire system automation degree is leted dropBeing living in the CAM's system generation cutting tool locus , equal also merely embodying low straturm geometry message ( right line and arc geometry locating information ) , along with the a little process control information ( as moving forward ) to rate , main shaft rotation speed and trading sword and so on .Hence , can not obtain the process technology parameter that haves something to do with against generateing the cutting tool locus yetThe produce data between CAM's system every module are not unitied , and the independence is opposite to each other to every module .For instance the cutting tool locating file is merely keep the minutes the cutting tool locus and is not keep the minutes the relevant process technology parameter , the dynamic imitation of three dimensions merely keeps the minutes that the cutting tool locus interference against runs into , but keep the minutes interference and process target and correlation process technology parameter that runs into happen against suchThe CAM systematically is an independence system .Not thering is the unitary produce data model between CAD's system together with the CAM's system , even if being the integrated CAD/CAM's system of integration in , one-way and unity is enjoyed also being only to message in all . CAM systematically can not sufficiently comprehend and complete message utilizing CAD's system to have something to do with the produce , feature message that especially haves something to do with against process , equal CAD's system can not gain the process data message that CAM systematically come into being yet . This is give parallel project implementation to bring the hardship3、digitals control techniques of simulation3.1 calculating machine imitation approximately idea and applicationThe angle through the project is see , and the imitation is the system by means of the test to the system model leave to research in the existing either design .Analysing the complex dynamic target , the imitation is one kind of valid means , may decrease the hazard , cuts down design and manufactures cycle , and practise thrift the investment .Calculating machine imitation is draing support from the calculatingmachine , and utilizes the system model to adjust actually systematically testing the process which researcied .It is swiftly developed in the wake of the calculating machine technique development , and is living in the imitation to passess the more and more significant position .Three foundation maneuveies between the key element that the calculating machine imitation process may be notify by means of the picture 1 are depictd :The model building maneuver is by means of viewing either examination to the actual system , and is living to over look the less important element to reach on the base that examine the variable , and the means in the way of physics either mathematics is depictd , thereby obtains the similar pattern of actual system simplification .The meritorous service with the actual system of the pattern here be able to together with between the parameter ought to have similarity and homologous qualityThe imitation pattern is the mathematical model to the system ( simplifying the pattern ) carries on the specified algorithm handle , and causes such become the appropriate shape ( in case turns into iterative operation pattern by the numerical integration ) afterwards , yet becomes " computation module computational mode " that be able to be receiveed by the calculating machine .The imitation pattern is two simplification patterns to the actual systemThe imitation test is shall system imitation pattern be living the process rund in the calculating machine .The imitation is researching actual system one kind of technique by means of the test , may clarify systematically immanent structure variable and the ambient condition effect by means of the technique of simulationCalculating machine technique of simulation main expressing of development tendency be living two respects : Application territory enlargement and imitation calculating machine intelligentization .The calculating machine technique of simulation not merely is living tradition project technique territory ( respects such as aviation , spaceflight and chemical industry and so on ) subsequent development , but also broadens up community economy and living beings and so on much non- project territorys , moreover , technique such as parallel processing , artificial intelligence , knowledge base and expert system and so on the development is affecing the imitation calculating machine development Digital control process imitation utilizes the calculating machine imitation practice process , being the forceful means to verify digital control processing program dependability and the calculation cutting action process , in order to decrease work attempies surely , and lifts production efficiency3.2 digital control technique of simulation research present situationThe APT process spare parts are completeed near the digital control order program control .In the interest of right quality to guarrantee the digital control order , guard against in process to intervene happenning , and is living in the actual manufacture , and constantly adopts attempting the anxious means to examine with what runs into .Yet this kind of means requiring a lot of labor expense is anticipateed , the cost expansively causes the manufacturing cost move upward , addd produce process time and production cycle .Adoping once more the locus to display the law afterwards , in immediate future in order to mark needle either pencil or writing brush replace the cutting tool , with colouring plank either paper replaces the work imitation cutting tool movement locus two dimension figure ( alsomay display the two dimension semi process locus ) , possess the considerably great limitations .Three dimension and the many-dimensionss as to the work are processed , the cutting action locus that the inspection that the stuff that also possess use easily to cut replaces the work ( in case , paraffin wax , lumber , midified resin and plastic material and so on ) comes is processed .Yet APT and the process field is very important occupied in the attempt .For this reason , people are living always to research replace gradually attempting the anxious calculating machine emulation mode , and is living to attempt to slice that the respects such as environment modeling and imitation calculation and graphic display and so on acquire the significant progress , and develops to raise pattern accurateness and imitation calculation real timeization and improvement real feeling of graphic display and so on orientations at the momentThrough attempies the pattern distinguishing feature sliceeing the environment seeing , NC's cutting action process imitation branch geometry imitation and mechanics imitation at the moment two respects .Geometry imitation is not consider that cutting action parameter and cutting force reach else the physics elements effects , the imitation cutting tool work geometric object movement , and with right quality of certification NC's order .The problem such as it may decrease either remove as a result of the machine tool injury that the program error causes and clamping apparatus damage either the cutting tool rolls over to snap and the spare parts are reported something as worthless and so on ;May decrease moreover through the product design up time manufacturing , and cut down the manufacturing cost .Cutting action process mechanics imitation pertains to the physics imitation category , and its dynamic mechanics property by means of the imitation cutting action process is forecast that the cutting tool breakage and cutting tool vibration and control cuts the parameter , thereby attains to optimize the cutting action process aimThe geometry technique of simulation development is in the wake of geometry model building technique development but development , and consists of that quality graphic display and the ration is intervened verifying two respects .At the moment the means in common use possess the immediate solid modelling law , and the means of figure image space baseding on is requestted the intersection law with the scattered vector3.3 immediate solid modelling lawThis kind of enveloping solid that the means is the work part of the body against the cutting tool movement takes shape is underway that the entity Boolean falls short of operating , and the work part of the body three dimensions patterns are continuously replaceed in the wake of the cutting action processSungurtekin and Velcker opened up a miller simulation system .The three dimensions patterns that ought to systematically adopt CSG's law to keep the minutes Mao Pi utilize some fundamental primitives like cuboid , the cylindrical body and taper part of the body , and the set operation , particularly operating , the area by Mao Pi and a series of cutting tool scannings is keep the minutes , afterwards usies the set difference and operates through Mao Pizhong's order take-offing the scanning area .Traverse when the so-called area by has sweep is cutting the cutting tool to move along some locuss area .Per length of Mao Pixing's shape that NC's code afterwards。

NC Technology1、Research current situation of NC lathe in our timesResearch and development process to such various kinds of new technologies as numerical control lathe,machining center,FMS,CIMS,etc.of countries all over the world,linked to with the international economic situation closely.The machine tool industry has international economy to mutually promote and develop,enter21alert eras of World Affairs,the function that people's knowledge plays is more outstanding, and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine,its key position and strategic meaning are more obvious. Within1991-1994years,the economic recession of the world,expensive FMS,CIMS lowers the temperature,among1995-2000years,the international economy increases at a low speed,according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market(EMO,IMTS,JIMTOF,China CIMT of Japan of U.S.A.of Europe),have the analysis of the exhibit,there are the following several points mainly in the technical research of NC lathe in our times:（1）、Pay more attention to new technology and innovationWorldwide,are launching the new craft,new material,new structure,new unit,research and development of the new component in a more cost-effective manner,developmental research of for instance new cutter material,the new electric main shaft of main shaft structure,high speed,high-speed straight line electrical machinery,etc..Regard innovating in improvement of the processing technology as the foundation,for process ultra and hard difficult to cut material and special composite and complicated part,irregular curved surface,etc.research and develop new lathe variety constantly.（2）、Improve the precision and research of machine toolingIn order to improve the machining accuracy of the machining center,areimproving rigidity of the lathe,reduction vibration constantly,dispel hotly and out of shape,reduce the noise,improve the precision of localization of NC lathe,repeat precision,working dependability,stability,precision keeping,world a lot of country carry on lathe hot error,lathe sport and load out of shape software of error compensate technical research,take precision compensate,software compensate measure improve,some may make this kind of error dispel60%already.And is developing retrofit constantly,nanometer is being processed.（3）、Improve the research of the machine tooling productivityWorld NC lathe,machining center and corresponding some development of main shaft,electrical machinery of straight line,measuring system,NC system of high speed,under the prerequisite of boosting productivity.（4）、What a lot of countries have already begun to the numerical control system melt intelligently,openly,study networkedlyA、elligent research of the numerical control systemMainly showing in the following aspects:It is intelligent in order to pursue the efficiency of processing and process quality,the self-adaptation to the processing course is controlled,the craft parameter produces research automatically;Join the convenient one in order to improve the performance of urging and use intelligently,to the feedback control,adaptive operation,discerning automatically load selects models automatically,since carries on research whole definitely,etc.of the electrical machinery parameter;There are such research of the respect as intelligent automatic programming,intelligent man-machine interface,intelligence diagnosing,intelligent monitoring,etc..B、The numerical control system melts and studies openMainly showing in the following aspects:The development of the numerical control system is on unified operation platform,face the lathe producer and support finally,through changing,increasing or cutting out the structure target(numerical control target),form the seriation,and can use users specially conveniently and the technical know-how is integrated in the control system,realize the open numerical control system of different variety,different grade fast,form leading brand productswith distinct distinction.System structure norm of the open numerical control system at present,norm,disposing the norm,operation platform,numerical control systematic function storehouse and numerical control systematic function software developing instrument,etc.are the core of present research to pass through.C、Meeting the manufacture system of the production line,demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment,it is a basic unit of realizing the new manufacture mode too.2、Classification of the machining center（1）Process according to main shaft space position when it classifies to be as follows,horizontal and vertical machining center.Horizontal machining center,refer to the machining center that the axis level of the main shaft is set up.Horizontal machining center for3-5sport coordinate axis,a common one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round(turn the workingbench round),it can one is it is it finish other4Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work pared with strength type machining center it,the structure is complicated,the floor space is large,quality is large,the price is high.Vertical machining center,the axis of the main shaft of the vertical machining center,in order to set up vertically,its structure is mostly the regular post type,the workingbench is suitable for processing parts for the slippery one of cross,have3 rectilinear motion coordinate axis generally,can find a room for one horizontal numerical control revolving stage(the4th axle)of axle process the spiral part at workingbench.The vertical machining center is of simple structure,the floor space is small,the price is low,after allocating various kinds of enclosures,can carry on the processing of most work pieces.Large-scale gantry machining center,the main shafts are mostly set up vertically, is especially used in the large-scale or with complicated form work piece,is it spend the many coordinate gantry machining center to need like aviation,aerospaceindustry,some processing of part of large-scale steam turbine.Five machining centers,this kind of machining center has function of the vertical and horizontal machining center,one is it after inserting,can finish all five Taxi processing besides installing the surface to install in work piece,the processing way can make form of work piece error lowest,save2times install and insert working,thus improve production efficiency,reduce the process cost.(2)Classify by craft useIs it mill machining center to bore,is it mill for vertical door frame machining center,horizontal door frame mill the machining center and Longmen door frame mill the machining center to divide into.Processing technology its rely mainly on the fact that the door frame is milled,used in case body,shell and various kinds of complicated part special curve and large processes,curved surface of outline process, suitable for many varieties to produce in batches small.Complex machining center,point five times and compound and process mainly, the main shaft head can be turned round automatically,stand,lie and process,after the main shaft is turned round automatically,realize knowing that varies in the horizontal and vertical direction.(3)Classify by special functionSingle workingbench,a pair of workingbench machining center;Single axle,dual axle,three axle can change machining center,main shaft of case;Transfer vertically to the tower machining center and transfer;One hundred sheets of storehouses adds the main shaft and changes one one hundred sheets of machining centers;One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers;One hundred sheets of storehouses adds the manipulator and adds one pair of main shafts to transfer to the tower machining center.3、Development trend of the current numerical control latheAt present,the advanced manufacturing technology in the world is risingconstantly,such application of technology as ultrafast cutting,ultraprecision processing,etc.,the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe,have put forward higher demand to the process technology of numerical control.Nowadays the numerical control lathe is being developed in several following directions.（1）.The speed and precision at a high speed,high accuracy are two important indexes of the numerical control lathe,it concerns directly that processes efficiency and product quality.At present,numerical control system adopt-figure number, frequency high processor,in order to raise basic operation speed of system. Meanwhile,adopt the super large-scale integrated circuit and many microprocessors structure,in order to improve systematic data processing ability,namely improve and insert the speed and precision of mending operation.Adopt the straight line motor and urge the straight line of the lathe workingbench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feedforward control technology,make it lag behind error reduce greatly,thus improve the machining accuracy cut in corner not to track.For meet ultrafast demand that process,numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one,realize frequency conversion motor and lathe main shaft integrate,bearing,main shaft of electrical machinery adopt magnetism float the bearing,liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing,etc..At present,ceramic cutter and diamond coating cutter have already begun to get application.（2）.Multi-functional to is it change all kinds of machining centers of organization(a of capacity of storehouse can up to100of the above)automatically to furnished with,can realize milling paring,boring and pares,bores such many kinds of processes as paring,turning,reaming,reaming,attacking whorl,etc.to process at the same time on the same lathe,modern numerical control lathe adopt many main shaft,polyhedron cut also,carry on different cutting of way process to one different position of part at the same time.The numerical control system has because adopted many CPU structure and cuts off the control method in grades,can work out partprocessing and procedure at the same time on a lathe,realize so-called"the front desk processes,the backstage supporter is an editor".In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface,can network,realize data communication,numerical control of lathe,can control many numerical control lathes directly too.（3）.Intelligent modern numerical control lathe introduce the adaptive control technology,according to cutting the change of the condition,automatic working parameter,make the processing course can keep the best working state,thus get the higher machining accuracy and roughness of smaller surface,can improve the service life of the cutter and production efficiency of the equipment at the same time. Diagnose by oneself,repair the function by oneself,among the whole working state, the system is diagnosed,checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time.While breaking down,adopt the measure of shutting down etc.immediately,carry on the fault alarm,brief on position,reason to break down,etc..Can also make trouble module person who take off automatically,put through reserve module,so as to ensure nobody demand of working environment.For realize high trouble diagnose that requires,its development trend adopts the artificial intelligence expert to diagnose the system.（4）.Numerical control programming automation with the development of application technology of the computer,CAD/CAM figure interactive automatic programming has already get more application at present,it is a new trend of the technical development of numerical control.It utilize part that CAD draw process pattern,is it calculate the trailing punishing to go on by cutter orbit data of computer and then,thus produce NC part and process the procedure automatically,in order to realize the integration of CAD and CAM.With the development of CIMS technology, the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present,it,and CAD/CAM systematic programming great difference their programming necessary processing technology parameter needn't by artificial to participate in most,get from CAPP database in system directly.（5）.The dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time.The numerical control system will adopt the circuit chip of higher integrated level,will utilize the extensive or super large-scale special-purpose and composite integrated circuit,in order to reduce the quantity of the components and parts,to improve dependability.Through the function software of the hardware,in order to meet various kinds of demands for controlling the function,adopt the module, standardization,universalization and seriation of the structure lathe noumenonn of the hardware at the same time,make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on..Still through operating and starting many kinds of diagnostic programs of diagnosing,diagnosing, diagnosing off-line online etc.automatically,realize that diagnoses and reports to the police the trouble to hardware,software and various kinds of outside equipment in the system.Utilize the warning suggestion,fix a breakdown in time;Utilize fault-tolerant technology,adopt and design the important part"redundantly",in order to realize the trouble resumes by oneself;Utilize various kinds of test,control technology,exceed Cheng,one one hundred sheets of damages,interfering,cutting out,etc.at the time of various kinds of accidents as production,carry on corresponding protection automatically.（6）.Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine,electric device for an organic whole.Adopt the super large-scale integrated component,multi-layer printed circuit board mainly at present,adopt the three-dimensional installation method,make the electronic devices and components must use the high density to install,narrow systematic occupying the space on a larger scale.And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube,will make the operating system of numerical control miniaturize further.So can install it on the machine tool conveniently,benefit the operation of the numerical control lathe correctly even more.。

外文原文：NUMERICAL CONTROLNumerical control(N／C)is a form of programmable automation in which the processing equipment is controlled by means of numbers，letters，and other symbols．The numbers，letters，and symbols are coded in an appropriate format to define a program of instructions for a particular workpart or job．When the job changes，the program of instructions is changed．The capability to change the program is what makes N／C suitable for low-and medium-volume production．It is much easier to write programs than to make major alterations of the processing equipment．There are two basic types of numerically controlled machine tools：point—to—point and continuous—path(also called contouring)．Point—to—point machines use unsynchronized motors，with the result that the position of the machining head Can be assured only upon completion of a movement，or while only one motor is running．Machines of this type are principally used for straight—line cuts or for drilling or boring．The N／C system consists of the following components：data input，the tape reader with the control unit，feedback devices，and the metal—cutting machine tool or other type of N／C equipment．Data input，also called“man—to—control link”，may be provided to the machine tool manually，or entirely by automatic means．Manual methods when used as the sole source of input data are restricted to a relatively small number of inputs．Examples of manually operated devices are keyboard dials，pushbuttons，switches，or thumbwheel selectors．These are located on a console near the machine．Dials ale analog devices usually connected to a syn-chro-type resolver or potentiometer．In most cases，pushbuttons，switches，and other similar types of selectors aye digital input devices．Manual input requires that the operator set the controls for each operation．It is a slow and tedious process and is seldom justified except in elementary machining applications or in special cases．In practically all cases，information is automatically supplied to the control unit and the machine tool by cards，punched tapes，or by magnetic tape．Eight—channel punched paper tape is the most commonly used form of data input for conventional N ／C systems．The coded instructions on the tape consist of sections of punched holes called blocks．Each block represents a machine function，a machining operation，or a combination of the two．The entire N／C program on a tape is made up of an accumulation of these successive data blocks．Programs resulting in long tapes all wound on reels like motion-picture film．Programs on relatively short tapes may be continuously repeated by joining the two ends of the tape to form a loop．Once installed，the tape is used again and again without further handling．In this case，the operator simply loads and unloads the parts．Punched tapes ale prepared on type writers with special tape—punching attachments or in tape punching units connected directly to a computer system．Tape production is rarely error-free．Errors may be initially caused by the part programmer，in card punching or compilation，or as aresult of physical damage to the tape during handling，etc．Several trial runs are often necessary to remove all errors and produce an acceptable working tape．While the data on the tape is fed automatically，the actual programming steps ale done manually．Before the coded tape may be prepared，the programmer，often working with a planner or a process engineer, must select the appropriate N／C machine tool，determine the kind of material to be machined，calculate the speeds and feeds，and decide upon the type of tooling needed. The dimensions on the part print are closely examined to determine a suitable zero reference point from which to start the program．A program manuscript is then written which gives coded numerical instructions describing the sequence of operations that the machine tool is required to follow to cut the part to the drawing specifications．The control unit receives and stores all coded data until a complete block of information has been accumulated．It then interprets the coded instruction and directs the machine tool through the required motions．The function of the control unit may be better understood by comparing it to the action of a dial telephone，where，as each digit is dialed，it is stored．When the entire number has been dialed，the equipment becomes activated and the call is completed．Silicon photo diodes，located in the tape reader head on the control unit，detect light as it passes through the holes in the moving tape．The light beams are converted to electrical energy，which is amplified to further strengthen the signal．The signals are then sent to registersin the control unit, where actuation signals are relayed to the machine tool drives．Some photoelectric devices are capable of reading at rates up to 1000 characters per second．High reading rates are necessary to maintain continuous machine—tool motion；otherwise dwell marks may be generated by the cutter on the part during contouring operations．The reading device must be capable of reading data blocks at a rate faster than the control system can process the data．A feedback device is a safeguard used on some N／C installations to constantly compensate for errors between the commanded position and the actual location of the moving slides of the machine tool．An N／C machine equipped with this kind of a direct feedback checking device has what is known as a closed-loop system．Positioning control is accomplished by a sensor which，during the actual operation，records the position of the slides and relays this information back to the control unit．Signals thus received ale compared to input signals on the tape，and any discrepancy between them is automatically rectified．In an alternative system，called an open—loop system，the machine is positioned solely by stepping motor drives in response to commands by a controllers．There are three basic types of NC motions, as follows:Point-to-point or Positional Control In point-to-point control the machine tool elements ( tools,table,etc.) are moved to programmed locations and the machining operations performed after the motions are completed. The path or speed of movement between locations is unimportant; only the coordinates of the end points of the motions are accurately controlled. This type of control is suitable for drill presses and some boring machines, where drilling, tapping, or boring operations must beperformed at various locations on the work piece. Straight-Line or Linear Control Straight-Line control systems are able to move the cutting tool parallel to one of the major axes of the machine tool at a controlled rate suitable for machining. It is normally only possible to move in one direction at a time, so angular cuts on the work piece are not possible, Consequently, for milling machines, only rectangular configurations can be machined or for lathes only surfaces parallel or perpendicular to the spindle axis can be machined. This type of controlled motion is often referred to as linear control or a half-axis of control. Machines with this form of control are also capable of point-to-point control.Continuous Path or Contouring Control In continuous path control the motions of two or more of the machine axes are controlled simultaneously, so that the position and velocity of the can be tool are changed continuously. In this way curves and surfaces can be machined at a controlled feed rate. It is the function of the interpolator in the controller to determine the increments of the individual controlled axes of the machines necessary to produce the desired motion. This type of control is referred to as continuous control or a full axis of control.Some terminology concerning controlled motions for NC machines has been introduced. For example, some machines are referred to as four-or five-or even six-axis machines. For a vertical milling machine three axes of control are fairly obvious, these being the usual X, Y, Z coordinate directions. A fourth or fifth axis of control would imply some form of rotary table to index the work piece or possibly to provide angular motion of the work head. Thus, in NC terminology an axis of control is any controlled motion of the machine elements ( spindles, tables, etc ). A further complication is use of the term half-axis of control; for example, many milling machines are referred to as 2.5-axis machine. This means that continuous control is possible for two motions (axes )and only linear control is possible for the third axis. Applied to vertical milling machines, 2.5axis control means contouring in the X, Y plane and linear motion only in the Z direction. With these machines three-dimensional objects have to be machined with water lines around the surface at different heights. With an alternative terminology the same machine could be called a 2CL machine (C for continuous, L for linear control ). Thus, a milling machine with continuous control in the X, Y, Z directions could be termed be a three-axis machine or a 3c machine, Similarly, lathes are usually two axis or 2C machines. The degree of work precision depends almost entirely upon the accuracy of the lead screw and the rigidity of the machine structure．With this system．there is no self-correcting action or feedback of information to the control unit．In the event of an unexpected malfunction，the control unit continues to put out pulses of electrical current．If，for example，the table on a N／C milling machine were suddenly to become overloaded，no response would be sent back to the controller．Because stepping motors are not sensitive to load variations，many N／C systems are designed to permit the motors to stall when the resisting torque exceeds the motor torque．Other systems are in use，however，which in spite of the possibility of damage to the machine structure or to themechanical system，ale designed with special high—torque stepping motors．In this case，the motors have sufficient capacity to“overpower’’the system in the event ofalmost any contingency．The original N／C used the closed—loop system．Of the two systems，closed and open loop，closed loop is more accurate and，as a consequence，is generally more expensive．Initially，open—loop systems were used almost entirely for light-duty applications because of inherent power limitations previously associated with conventional electric stepping motors．Recent advances in the development of electrohydraulic stepping motors have led to increasingly heavier machine load applications．MILLINGMilling is a basic machining process in which the surface is generated by the progressive formation and removal of chips of material from the workpiece as it is fed to a rotatingcutter in a direction perpendicular to the axis of the cutter．In some cases the workpiece isstationary and the cutter is fed to the work．In most instances a multiple—tooth cutter is used so that the metal removal rate is high，and frequently the desired surface is obtained in a single pass ofthe work．The tool used in milling is known as a milling cutter．It usually consists of a cylindrical body which rotates on its axis and contains equally spaced peripheral teeth that intermittently engage and cut the workpiece．In some cases the teeth extend part way across one or both ends of the cylinder．Because the milling principle provides rapid metal removal and can produce good surface finish，it is particularly well—suited for mass-production work，and excellent milling machines have been developed for this purpose．However，very accurate and versatile milling of a general-purpose nature also have been developed that are widely used in job-shop and tool and die work．A shop that is equipped with a milling machine and an engine lathe can machine almost any type of product of suitable size．Types of Milling Operations．Milling operations can be classified into two broad categories，each of which has several variations：1．In peripheral milling a surface is generated by teeth located in the periphery of the cutter body；the surface is parallel with the axis of rotation of the cutter．Both flat and formed surfaces san be produced by this method．The cross section of the resulting surface corresponds to the axial contour of the cutter．This procedure often is called slab milling．2．In face milling the generated flat surface is at right angles to the cutter axis and is the combined result of the actions of the portions of the teeth located on both the periphery and the face of the cutter．The major portion of the cutting is done by the peripheral portions of the teeth with the face portions providing a finishing action．The basic concepts of peripheral and face milling are illustrated in Fig．16—1．Peripheral milling operations usually are performed on machines having horizontal spindles，whereas face milling is done on both horizontal—and vertical-spindle machines.Surface Generation in Milling．Surfaces can be generated in milling by twodistinct1y different methods depicted in Fig．16-2．Note that in up milling the cutter rotates against the direction of feed the workpiece，whereas in down milling the rotation is in the same direction as the feed．As shown in Fig．16—2，the method of chip formation is quite different in the two cases．In up milling the chip is very thin at the beginning，where the tooth first contacts the work，and increases in thickness,becoming a maximum where the tooth leaves the work．The cutter tends to push the work along and lift it upward from the table．This action tends to eliminate any effect of looseness in the feed screw and nut of the milling machine table and results in a smooth cut．However，the action also tends to loosen the work from the clamping device so that greater clamping forcers must be employed. In addition the smoothness of the generated surface depends greatly on the sharpness of the cutting edges．In down milling，maximum chip thickness occurs close to the point at which the tooth contacts the work．Because the relative motion tends to pull the workpiece into the cutter，all possibility of looseness in the table feed screw must be eliminated if down milling is to be used．It should never be attempted on machines that are not designed for this type of milling．Inasmush as the material yields in approximately a tangential direction at the end of the tooth engagement，there is much less tendency for the machined surface to show tooth marks than when up milling is used．Another considerable advantage of down milling is that the cutting force tends to hold the work against the machine table，permitting lower clamping force to be employed．This is particularly advantageous when milling thin workpiece or when taking heavy cuts．Sometimes a disadvantage of down milling is that the cutter teeth strike against the surface of the work at the beginning of each chip．When the workpiece has a hard surface，such as castings do，this may cause the teeth to dull rapidly．Milling Cutters．Milling cutters Can be classified several ways．One method is to group them into two broad classes，based on tooth relief，as follows：1．Profile-cutters have relief provided on each tooth by grinding a small land back of the cutting edge．The cutting edge may be straight or curved．2．In form or cam-relieved cutters the cross section of each tooth is an eccentric curve behind the cutting edge，thus providing relief．All sections of the eccentric relief，parallel with the cutting edge，must have the same contour as the cutting edge．Cutters of this type are sharpened by grinding only the face of the teeth，with the contour of the cutting edge thus remaining unchanged．Another useful method of classification is according to the method of mounting the cutter．Arbor cutters are those that have a center hole so they can be mounted on an arbor．Shank cutters have either tapered or straight integral shank．Those with tapered shanks can be mounted directly in the milling machine spindle，whereas straight—shank cutters are held in a chuck．Facing cutters usually are bolted to the end of a stub arbor．Types of Milling Cutters．Plain milling cutters are cylindrical or disk—shaped，having straight or helical teeth on the periphery．They are used for milling flat surfaces．This type of operation is called plain or slab milling．Each tooth in a helical cutter engages the work gradually，and usually more than one tooth cuts at a giventime．This reduces shock and chattering tendencies and promotes a smoother surface．Consequently, this type of cutter usually is preferred over one with straight teeth．Side milling cutters are similar to plain milling cutters except that the teeth extend radially part way across one or both ends of the cylinder toward the center．The teeth may be either straight or helical．Frequently these cutters are relatively narrow，being disklike in shape. Two or more side milling cutters often are spaced on an arbor to make simultaneous．parallel cuts，in an operation called straddle milling．Interlocking slotting cutters consist of two cutters similar to side mills，but made to operate as a unit for milling slots．The two cutters are adjusted to the desired width by inserting shims between them．Staggered-tooth milling cutters are narrow cylindrical cutters having staggered teeth，and with alternate teeth having opposite helix angles．They are ground to cut only on the periphery，but each tooth also has chip clearance ground on the protruding side．These cutters have a free cutting action that makes them particularly effective in milling deep slots．Metal-slitting saws are thin，plain milling cutters，usually from 1／32 to 3／16 inch thick，which have their sides slightly "dished”to provide clearance and prevent binding.They usually have more teeth per inch of diameter than ordinary plain milling cutters and are used for milling deep，narrow slots and for cutting-off operations．中文译文：数控技术数控是可编程自动化技术的一种形式，通过数字、字母和其他符号来控制加工设备。

数控技术外文文献翻译(含：英文原文及中文译文)英文原文The development trend of numerical control technology AbstractThe current trends in the development of numerical control technology and equipment in the world and the status quo of the development and industrialization of CNC equipment technology in China are briefly introduced. On this basis, we discuss the development of CNC technology and equipment in China under the new environment of China's accession to the WTO and further opening to the outside world. The importance of improving the level of China's manufacturing informatization and international competitiveness, and put forward some views on the development of China's CNC technology and equipment from both strategic and strategic aspects.The technological level and degree of modernization of the equipment industry determine the level of the entire national economy and the degree of modernization. Numerical control technology and equipment are the development of emerging high-tech industries and cutting-edge industries (such as information technology and its industries, biotechnology and its industries, aviation, aerospace, etc.) (Defense Industry Industry) enabling technology and basic equipment. Marx oncesaid that “the difference between various economic times is no t what is produced but how it is produced and what labor data it is used to produce”. Manufacturing technology and equipment are the most basic production materials for human production activities, and numerical control technology is the core technology of today's advanced manufacturing technologies and equipment. In the manufacturing industry of the world today, CNC technology is widely used to improve manufacturing capabilities and levels, and to improve the adaptability and competitiveness of dynamic markets. In addition, various industrialized countries in the world have also listed numerical control technology and numerical control equipment as strategic materials of the country. They not only take significant measures to develop their own numerical control technologies and their industries, but also have the key technology and equipment of “high-precision” numerical control. Our country adopts a policy of blockade and restriction. In short, the vigorous development of advanced manufacturing technologies centered on numerical control technology has become an important way for all developed countries in the world to accelerate economic development and improve their overall national strength and national status.Numerical control technology is a technology that uses digital information to control mechanical movement and work process. Numerical control equipment is a mechatronic product formed by thepenetration of new technologies represented by numerical control technology into traditional manufacturing industries and emerging manufacturing industries, namely, so-called digital equipment. Its technical scope covers many fields: (1) machinery manufacturing technology; (2) information processing, processing, and transmission technology; (3) automatic control technology; (4) servo drive technology;(5) sensor technology; (6) software Technology and so on. Keywords: CNC technology, machinery manufacturing, information processing, sensors1 Development Trends of Numerical Control TechnologyThe application of numerical control technology has not only brought about revolutionary changes in the traditional manufacturing industry, but also made manufacturing a symbol of industrialization. With the continuous development of numerical control technology and the expansion of application fields, he has made important contributions to the national economy and people's livelihood (IT, automotive The development of light industry, light industry, medical care, etc. is playing an increasingly important role, because the digitalization of the equipment required by these industries is a major trend of modern development. From the current trend of numerical control technology and its equipment development in the world, its main research hotspots are the following aspects [1~4].1.1 New trends in high-speed, high-precision processing technology and equipmentEfficiency and quality are the mainstays of advanced manufacturing technology. High-speed, high-precision machining technology can greatly improve efficiency, improve product quality and grade, shorten production cycle and increase market competitiveness. To this end, the Japanese Advanced Technology Research Institute will list it as one of the five major modern manufacturing technologies. The International Association of Production Engineers (CIRP) has identified it as one of the central research directions for the 21st century.In the passenger car industry, the production cycle of 300,000 vehicles per year is 40 seconds per vehicle, and multi-species processing is one of the key issues that must be addressed for car equipment. In the aviation and aerospace industries, the parts processed by them are mostly thin-walled. With thin ribs, the rigidity is poor, and the material is aluminum or aluminum alloy. These ribs and walls can be processed only when the high cutting speed and cutting force are small. Recently, the method of “hollowing out” large-size aluminum alloy billets has been used to manufacture large parts such as wings and fuselage to replace multiple parts and assembled by numerous rivets, screws, and other coupling methods to obtain strength, stiffness, and reliability of components. improve. All of these require high-speed, high-precision andhigh-flexibility for processing equipment.From the standpoint of EMO2001, the feed rate of high-speed machining centers can reach 80m/min, or even higher, and the airspeed can reach around 100m/min. At present, many automobile plants in the world, including China's Shanghai General Motors Corporation, have adopted a part of the production line consisting of a high-speed machining center to replace the combined machine tools. The HyperMach machine tool feed rate of CINCINNATI, USA is up to 60m/min, the speed is 100m/min, the acceleration is 2g, and the spindle speed has reached 60,000r/min. It takes only 30 minutes to machine a thin-walled aircraft part, and the same part takes 3h for general high-speed milling and 8h for normal milling; the spindle speed and acceleration of the twin-spindle lathe of DMG, Germany, reach 12*!000r/mm respectively. And 1g.In terms of machining accuracy, in the past 10 years, the machining accuracy of ordinary CNC machine tools has increased from 10μm to 5μm, precision machining centers have increased from 3~5μm to 1~1.5μm, and ultra-precision machining precision has begun to enter the nanometer level. (0.01μm).In terms of reliability, the MTBF value of foreign numerical control devices has reached more than 6000 hours, and the MTBF value of the servo system has reached more than 30,000 hours, showing very highreliability.In order to achieve high-speed, high-precision machining, the supporting functional components such as electric spindles and linear motors have been rapidly developed and the application fields have been further expanded.1.2 Rapid development of 5-axis simultaneous machining and compound machiningThe use of 5-axis simultaneous machining of 3D surface parts allows cutting with the best geometry of the tool, resulting in not only a high degree of finish, but also a significant increase in efficiency. It is generally considered that the efficiency of a 5-axis machine tool can be equal to 2 3-axis linkage machines. Especially when using ultra-hard material milling tools such as cubic boron nitride for high-speed milling of hardened steel parts, 5-axis simultaneous machining can be compared with 3-axis linkage. Processing to play a higher efficiency. In the past, due to the complexity of the 5-axis linkage CNC system and the host machine structure, the price was several times higher than that of the 3-axis linkage CNC machine tool, and the programming technology was more difficult, which restricted the development of 5-axis linkage machine tools.At present, due to the emergence of electric spindles, the structure of the composite spindle head that realizes 5-axis simultaneous machining isgreatly simplified, its manufacturing difficulty and cost are greatly reduced, and the price gap of the numerical control system is reduced. As a result, the development of composite spindle head type 5-axis linkage machine tools and compound machine tools (including 5-sided machine tools) has been promoted.At the EMO2001 exhibition, the new 5-axis machine tool of Nippon Machine Tool Co., Ltd. adopts a compound spindle head, which can realize the processing of four vertical planes and processing at any angle, so that 5-sided machining and 5-axis machining can be realized on the same machine tool. It can realize the processing of inclined surface and inverted cone. Germany DMG company exhibited DMUV oution series machining center, which can be processed in five-face machining and five-axis linkage in a single clamping. It can be directly or indirectly controlled by CNC system control or CAD/CAM.1.3 Intelligentization, openness, and networking have become major trends in the development of modern digital control systemsThe 21st century CNC equipment will be a certain intelligent system. The intelligent content is included in all aspects of the CNC system: in order to pursue the processing efficiency and processing quality in the intelligent, such as the process of adaptive control, process parameters automatically Generated; To improve the driving performance and the use of convenient connection intelligent, such as feed-forward control,adaptive calculation of motor parameters, automatic identification load automatic selection model, self-tuning, etc.; simplify the programming, simplify the operation of intelligent, such as smart The automatic programming, intelligent man-machine interface, etc.; as well as the contents of intelligent diagnosis, intelligent monitoring, convenient system diagnosis and maintenance.In order to solve the problems of traditional CNC system closure and industrial application of CNC application software. At present, many countries have conducted research on open numerical control systems such as NGC of the United States, OSACA of the European Community, OSEC of Japan, and ONC of China. The openness of numerical control systems has become the future of CNC systems. The so-called open CNC system is the development of CNC system can be in a unified operating platform, for machine tool manufacturers and end users, by changing, adding or cutting structure objects (CNC function), to form a series, and can be convenient to the user's special The application and technology are integrated into the control system to quickly realize open numerical control systems of different varieties and different grades to form brand-name products with distinctive personality. At present, the architecture specification, communication specification, configuration specification, operation platform, numerical control system function library and numerical control system function software development toolof open CNC system are the core of current research.Networked CNC equipment is a new bright spot in the international well-known machine tool exposition in the past two years. The networking of CNC equipment will greatly satisfy the requirements of information integration for production lines, manufacturing systems, and manufacturing companies. It is also the basic unit for realizing new manufacturing models such as agile manufacturing, virtual enterprise, and global manufacturing. Some famous domestic and foreign CNC machine tools and numerical control system manufacturing companies have introduced relevant new concepts and prototypes in the past two years. For example, at the EMO 2001 exhibition, the “Cyber Production Center” exhibited by Japan's Mazak company Mazak Production Control Center (CPC); Okuma Machine Too l Company, Japan exhibited “ITplaza” (Information Technology Plaza, IT Plaza); Open Manufacturing Environment (Open Manufacturing Environment, OME), exhibited by Siemens, Germany Etc., reflecting the trend of the development of CNC machine tools to the direction of the network.1.4 Emphasizing the Establishment of New Technology Standards and Specifications1.4.1 About Design and Development of CNC SystemsAs mentioned above, the open CNC system has better versatility, flexibility, adaptability, and expandability. The United States, theEuropean Community, and Japan have implemented strategic development plans one after another, and have conducted the open architecture system specification (OMAC). , OSACA, OSEC) research and development, the world's three largest economies in the short term carried out almost the same set of scientific plans and norms, indicating that the arrival of a new revolution in digital technology. In 2000, China began to conduct research and development of the regulatory framework for China's ONC numerical control system.1.4.2 About CNC StandardsCNC standards are a trend in the development of manufacturing informatization. The information exchange in the 50 years since the birth of CNC technology was based on the ISO 6983 standard. That is how the G and M codes describe how to process. The essential feature is the processing-oriented process. Obviously, he has been unable to meet the high speed of modern CNC technology. The need for development. For this purpose, a new CNC system standard ISO14649 (STEP-NC) is being researched and developed internationally. Its purpose is to provide a uniform data model that can describe the entire life cycle of a product without relying on a neutral mechanism of a specific system. , in order to achieve the entire manufacturing process, and even the standardization of product information in various industrial fields. The emergence of STEP-NC may be a revolution in CNC technology. It will have aprofound impact on the development of CNC technology and even the entire manufacturing industry. First, STEP-NC proposes a brand-new manufacturing concept. In the traditional manufacturing concept, NC machining programs are concentrated on a single computer. Under the new standard, NC programs can be distributed on the Internet. This is the direction of open and networked CNC technology. Secondly, STEP-NC CNC system can also greatly reduce the processing drawings (about 75%), processing program preparation time (about 35%) and processing time (about 50%).At present, European and American countries attach great importance to the research of STEP-NC, and Europe has initiated STEP-NC's IMS plan ( Participation in this program comes from 20 CAD/CAM/CAPP/CNC users, vendors and academic institutions in Europe and Japan. STEPTools of the United States is the developer of global manufacturing data exchange software. He has developed a SuperModel for the information exchange of CNC machine tools. Its goal is to describe all machining processes with a unified specification. This new data exchange format has now been validated on prototype prototypes equipped with SIEMENS, FIDIA and European OSACA-NC numerical control systems.2 Basic Estimates of China's CNC Technology and Its Industrial DevelopmentCNC technology in China started in 1958. The development process in the past 50 years can be roughly divided into three stages: the first stage from 1958 to 1979, which is the closed development stage. At this stage, the development of numerical control technology is relatively slow due to the limitations of foreign technology and China's basic conditions. The second stage is the introduction of technology during the “sixth and fifth” periods of the country, the “seventh five-year plan” period, and the “eighth five-year plan period,”and it will be digested and absorbed to initially establish the stage of the national production system. At this stage, due to the reform and opening up and the country’s attention, as well as the improvement of the research and development environment an d the international environment, China’s CNC technology has made great progress in research, development, and localization of products. The third stage is the implementation of industrialization research in the later period of the "Eighth Five-Year Plan" and the "Ninth Five-Year Plan" period of the country, entering the stage of market competition. At this stage, the industrialization of domestically-manufactured CNC equipment has achieved its essenceSexual progress. At the end of the “Ninth Five-Year Plan” period, the domestic market share of domestic CNC machine tools reached 50%, and the number of domestically-manufactured numerical control systems (pervasive models) also reached 10%.Looking at the development process of CNC technology in China in the past 50 years, especially after four five-year plans, the overall results are as follows:a. It lays the foundation for the development of CNC technology and basically masters modern CNC technology. China has now basically mastered the basic technologies from numerical control systems, servo drives, numerical control mainframes, special planes and their accessories. Most of these technologies already have the basis for commercial development. Some technologies have been commercialized and industrialized.b. Initially formed a CNC industrial base. Based on the research results and the commercialization of some technologies, we have established numerical control system production plants such as Huazhong Numerical Control and Aerospace Numerical Control which have mass production capabilities. Lanzhou Electric Machinery Factory, Huazhong Numerical Control and a number of servo systems and servo motor manufacturers, as well as a number of CNC machine manufacturers such as Beijing No. 1 Machine Tool Plant and Jinan No. 1 Machine Tool Plant. These production plants have basically formed China's CNC industrial base.c. Established a basic team of CNC research, development and management talents.Although significant progress has been made in the research, development, and industrialization of numerical control technology, we must also soberly realize that the research and development of high-end numerical control technologies in China, especially the status quo of the technological level of industrialization and the actual needs of China There is a big gap. Although our country's development speed is very fast in the vertical direction, the horizontal ratio (compared with foreign countries) not only has a gap in the level of technology, but also has a gap in the development speed in certain aspects, that is, the gap in the technological level of some highly sophisticated numerical control equipment has expanded. From the international point of view, the estimated level of China's numerical control technology and industrialization is roughly as follows:a. On the technical level, it will be about 10 to 15 years behind the advanced level in foreign countries, and it will be even bigger in terms of sophisticated technology.b. At the industrialization level, the market share is low, the variety coverage is small, and scale production has not yet been established; the specialized production level of functional components and the complete set capacity are low; the appearance quality is relatively poor; the reliability is not high, and the degree of commercialization is insufficient; The domestic CNC system has not established its own brand effect, andthe user's confidence is insufficient.c. On the ability of sustainable development, the research and development and engineering capabilities of pre-competitive numerical control technology are weak; the application of numerical control technology is not strong; the research and formulation of related standard specifications is lagging behind.The main reasons for analyzing the above gaps are as follows:a. Awareness. Insufficient understanding of the arduous, complex and long-term characteristics of the domestic CNC industry process; Insufficient estimates of market irregularities, foreign blockades, killings, and systems; and insufficient analysis of the application level and capabilities of CNC technology in China.b. Systematic aspects. From the point of view of technology, attention has been paid to the issue of CNC industrialization. It has been a time to consider the issue of CNC industrialization from the perspectives of system and industry chain; there is no complete supporting system of high-quality supporting systems, perfect training, and service networks. .c. Mechanisms. Bad mechanisms have led to brain drain, which in turn has restricted technological and technological route innovations and product innovations, and has constrained the effective implementation of planning. It is often planned to be ideal and difficult to implement.d. Technical aspects. Enterprises have little ability to independentlyinnovate in technology, and the engineering ability of core technologies is not strong. The standard of machine tools is backward, the level is low, and the new standard of CNC system is not enough.3 Strategic Thinking on the Development of CNC Technology and Industrialization in China3.1 Strategic ConsiderationsChina is a manufacturing country, and we must try to accept the transfer of the front-end rather than the back-end in the industrial transfer of the world. That is to master the advanced manufacturing core technologies, otherwise, in the new round of international industrial restructuring, China's manufacturing industry will further “empty core”. At the expense of resources, the environment, and the market, we may obtain only the international "processing centers" and "assembly centers" in the world's new economic structure, rather than the status of manufacturing centers that master core technologies. This will seriously affect our country. The development of modern manufacturing.We should pay attention to numerical control technology and industrial issues from the perspective of national security strategy. First of all, we must look at social security because manufacturing industry is the industry with the largest number of employed people in China. Manufacturing industry development can not only improve the people’s living standards, but also ease the country’s The pressure of employmentguarantees social stability. Secondly, from the perspective of national defense security, Western developed countries classify high-precision numerical control products as national strategic materials and implement embargoes and restrictions on China. The “Toshiba Incident” and the “Cox Report” "This is the best illustration.3.2 Development StrategyFrom the perspective of China’s basic national conditions, taking the country’s strategic needs and the market demand of the national economy as the guide, and aiming at improving the comprehensive competitiveness and industrialization le vel of China’s manufacturing equipment industry, we can use systematic methods to choose to dominate the early 21st century in China. The key technologies for the development and upgrade of the manufacturing equipment industry and supporting technologies and supporting technologies for supporting industrialization development are the contents of research and development and the leap-forward development of the manufacturing equipment industry. Emphasizing the market demand as the orientation, that is, taking CNC terminal products as the mainstay, and driving the CNC industry with complete machines (such as large-scale CNC lathes, milling machines, high-speed, high-precision and high-performance CNC machine tools, typical digital machines, key equipment of key industries, etc.). development of. The focus is on the reliability and production scale of CNC systems andrelated functional components (digital servos and motors, high-speed spindle systems and accessories for new equipment, etc.). Without scale, there will be no high-reliability products; without scale, there will be no cheap and competitive products; of course, CNC equipment without scale in China will be difficult to come to the fore. In the research and development of high-precision equipment, we must emphasize the close integration of production, learning, research, and end-users, and aim at “doing, using, and selling off” as a goal, and implement national research on the will of the country to solve the urgent need of the country. . Before the competition, CNC technology emphasizes innovation, emphasizes research and development of technologies and products with independent intellectual property rights, and lays a foundation for the sustainable development of China's CNC industry, equipment manufacturing industry, and even the entire manufacturing industry.中文译文数控技术的发展趋势摘要本文简要介绍了当今世界数控技术及装备发展的趋势及我国数控装备技术发展和产业化的现状, 在此基础上讨论了在我国加入WTO 和对外开放进一步深化的新环境下, 发展我国数控技术及装备、提高我国制造业信息化水平和国际竞争能力的重要性, 并从战略和策略两个层面提出了发展我国数控技术及装备的几点看法。

NC technology development trends——数控技术发展趋势1 NC system developments at home and abroadWith the rapid development of computer technology, the traditional beginning of a fundamental change manufacturing, the industrial developed countries spent huge sums of money on the modern manufacturing technology research and development, to create a new model. In modern manufacturing systems, CNC technology is the key to technology, which combines microelectronics, computers, information processing, automatic detection, automatic control, such as the integration of advanced, a high-precision, high-efficiency, flexible automation, and other characteristics, the manufacturing industry Flexible automation, integrated, intelligent play the pivotal role. At present, NC technology is undergoing a fundamental change, from a special closed-loop control mode to general-purpose real-time dynamic open all closed-loop control mode. In the integrated on the basis of the CNC systems ultra-thin, ultra-light; on the basis of the intelligent, integrated computers, multimedia, fuzzy control, neural network and other technical disciplines, NC system to achieve high-speed, high-precision, Efficient control, automatic processing can be amended to regulate compensation and the parameters for an online intelligent fault diagnosis and treatment of the network based on the CAD / CAM and CNC systems integration as one machine network, makes the central government centralized control of the group control processing.For a long time, China''s CNC system for traditional closed architecture, but only as a non-intelligent CNC machine controller. Process variables based on experience in the form of pre-fixed parameters, processing procedures before the actual processing by hand or through CAD / CAM and automatic programming system prepared. CAD / CAM and CNC have no feedback control link, the entire manufacturing process CNC is a closed ring-opening implementing agencies. In a complex and changing environment under the conditions of processing tool in the process of composition, workpiece material, spindle speed, feed rate, tool path, cutting depth, step, allowance and other processing parameters, not at the scene circumstances under external interference and real-time dynamic random factors, not by random amendment feedback control link CAD / CAM settings volume, in turn, affect the work of CNC machining efficiency and product quality. Clearly, the traditional fixed CNC system that controlled mode and closed architecture, limiting the CNC to the developmentof more intelligent control variables, can no longer meet the increasingly complex manufacturing process, therefore, the CNC technology in the potential for change inevitable.2 NC technology development trends2.1 Performance development direction(1) high-speed high-precision efficient speed, accuracy and efficiency of machinery manufacturing technology is the key performance indicators. As a result of the high-speed CPU chips, RISC chip, as well as multi-CPU control system with high-resolution detector of the absolute exchange digital servo system, taken at the same time improve the machine dynamic and static characteristics of effective measures, the high-speed high-precision machine has been efficient greatly enhanced.(2) Flexible includes two aspects: CNC system itself flexibility, NC system is modular in design, functional coverage, can be cut and strong, and easy to meet the needs of different users; group control system flexibility, with a control system pursuant to the requirements of different production processes, materials flow and information flow automatically dynamically adjusted to maximize their group control system performance.(3) Process of composite and multi-axis to reduce the process time for the main purpose of supporting the composite processing, and are moving towards multi-axis, multi-function control of the direction of series development. NC Machine Tool Technology composite refers to the workpiece in a single machine on a fixture, through an automatic tool change, rotating spindle head or turntable, and other measures to accomplish multiple processes, multi-surface machining compound. Axis CNC technology, Siemens 880-axis control system for up to 24 axes.(4) Real-time Intelligent early for the real-time system is usually relatively simple ideal environment, and its role is to scheduling tasks, to ensure that the task be completed within a specified time limit. And artificial intelligence is used to model the realization of mankind''s various intelligent behaviors. To the development of science and technology today, real-time systems and artificial intelligence combined with each other towards artificial intelligence is a real-timeresponse, a more realistic field of development, and also in the real-time system with intelligent behavior, the more complex application development, resulting in the Intelligent real-time control of this new area. NC technology in the field, real-time intelligent control of the research and application of development along several main branches: adaptive control, fuzzy control, neural network control, experts control, learning control, feed-forward control. For example, in CNC programming system with expert systems, fault diagnosis expert system parameters automatically set and tool management and automatic compensation, such as adaptive conditioning systems, in high-speed processing of the integrated motion control ahead of the introduction of budget projections and functional, dynamic Feedforward functions in pressure, temperature, position, velocity, control, fuzzy control, the control of the NC system performance greatly improved, so as to achieve optimal control purposes.2.2 functional development direction(1) The user interface is graphical user interface with the CNC system of dialogue between the user interface. Since different users interface requirements are different, thus the development of the workload of great user interface, user interface software developed into the most difficult part of. At present INTERNET, virtual reality, visualization in scientific computing and multimedia technologies, such as the user interface has put a higher demand. Graphical user interface greatly facilitates the use of non-professional users, it can be carried out through the window and menu operation, ease of programming and blueprint for rapid programming, three-dimensional dynamic three-dimensional color graphics, graphics, simulation, graphics, dynamic tracking and simulation, and the different directions view and partial display ratio scaling function can be achieved.(2) visualization in scientific computing visualization in scientific computing can be used for efficient data processing and interpretation of data, so that the exchange of information is no longer limited to using the written word and language, and can direct the use of graphics, image, animation, video and other information. Visualization technology and virtual environment technology, to further broaden the application areas, such as a drawing design, virtual prototyping technology, which shorten product design cycles, improving product quality, reduce production cost is of great significance. NC technology in the areas of visualizationtechnology can be used for CAD / CAM, such as automatic programming design parameters automatically set, tool compensation and tool management of dynamic data processing and display, as well as the processing of visual simulation, and other presentations.(3) interpolation, and a variety of methods of compensation interpolation methods such as multiple linear interpolation, circular interpolation, cylindrical interpolation, space elliptical surface interpolation, thread interpolation, polar coordinates interpolation, 2 D +2 helical interpolation , NANO interpolation, interpolation NURBS (non-uniform rational B-spline interpolation), spline interpolation (A, B, C kind), such as polynomial interpolation. A variety of functions such as compensation gap compensation vertical compensation quadrant error compensation, and measurement systems pitch error compensation, andspeed-related feedforward compensation and temperature compensation, with nearly smooth and exit, as well as the opposite point of the cutter radius compensation.(4) high-performance PLC contents contents performance CNC system PLC control module can be directly used ladder diagram or high-level language programming, with intuitive online debugging and online help function. Programming tools include the standard used lathe and milling machine PLC user program an example, users may PLC user program standards on the basis of editorial changes, thus easily build their own applications.(5) application of multimedia technology of multimedia technology-computers, audio-visual and communication technology, and it has the computer integrated voice,text, images and video information. In NC technology, multimedia technology can be applied to information processing integrated, intelligent, real-time monitoring system in the field and production equipment fault diagnosis, monitoring of process parameters such as production has a significant value.2.3 Development of the Architecture(1) integration of a highly integrated CPU, programmable RISC chips and large-scale integrated circuits FPGA, EPLD, CPLD and ASIC ASIC chips that can improve the CNC system integration and hardware and software operating speed. Application FPD flat panel display technology can improve display performance. Flat-panel displays with high science and technology content, light weight, small size, lowpower consumption and portability advantages can be realized Supersized, a counterweight to the emerging and CRT display technology, display technology in the 21st century the mainstream. Application of advanced packaging and interconnect technologies, semiconductors and surface mount technology integration. By increasing the density of integrated circuits, reducing the length and number of interconnection products to reduce prices, improve performance, reduce component size, improve the reliability of the system.(2) easy to implement modular hardware modular NC systems integration and standardization. According to various functional requirements, the basic modules, such as CPU, memory, position servo, PLC, the input and output interfaces, and communications modules, making the standard Series products, through functional building-block approach to cutting the number of steps and modules, a NC system at different grades.(3) machine interconnection network for remote control of unmanned operation. Machine through networking, can be in any one machine on the other machine programming, configuration, operation, operating, different machine can be displayed on the screen each machine on the screen.(4) general-open the closed-loop control mode to adopt a common computer component Bus, modular, open, embedded architecture, ease of cutting, expansion and upgrading, can be composed of different grades, different types, different degree of integration CNC system. Closed-loop control mode is the traditional CNC system only for single closed-open-loop control mode proposed. The manufacturing process is a multi-variable control and the role of integrated processing complex process, including processing, such as size, shape, vibration, noise, temperature and thermal deformation, and other factors, therefore, to achieve the process of multi-objective optimization, Multivariable must adopt the closed-loop control, real-time processing in the dynamic adjustment process variables. Processing the adoption of open universal real-time closed-loop control mode the whole dynamic, easy real-time intelligent computer technology, network technology, multimedia technology, CAD / CAM, servo control, adaptive control, dynamic data management and dynamic tool compensation, dynamic simulation and other high technology into one, a tight closed-loop manufacturing process control system to achieve integrated, intelligent, network-based.3 PCNC new generation of intelligent CNC systemResearch and Development adapted to the current complexity of the manufacturing process, with the structure of the closed-loop control system, a new generation of intelligent PCNC CNC system has become possible. PCNC NC intelligent system will be a new generation of intelligent computer technology, network technology, CAD / CAM, servo control, adaptive control, dynamic data management and dynamic tool compensation, dynamic simulation and other high technology into one, a tight closure of the manufacturing process Central control system.数控技术的发展趋势- 数控技术发展趋势1国内外数控系统开发随着计算机技术的飞速发展，从根本上改变传统的制造业开始，工业发达国家用于现代制造技术的研究和开发巨额资金，以创建一个新的模式。

（数控加工）机械类数控外文翻译外文文献英文文献数控NumericalControlOneofthemostfundamentalconceptsintheareaofadvancedmanufacturingte chnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachinetools weremanualoperatedandcontrolled.Amongthemanylimitationsassociatedwith manualcontrolmachinetools,perhapsnoneismoreprominentthanthelimitation ofoperatorskills.Withmanualcontrol,thequalityoftheproductisdirectlyre latedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrepresentst hefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufacturin gsystemsthoughtheuseofprerecorded,writtensymbolicinstructions.Rathert hanoperatingamachinetool,anNCtechnicianwritesaprogramthatissuesoperat ionalinstructionstothemachinetool,Foramachinetooltobenumericallycontr olled,itmustbeinterfacedwithadeviceforacceptinganddecodingthep2ogramm edinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanoperato r,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanmanuallyo peratedmachines,theycanproducepartsmoreuniformly,theyarefaster,andthe long-runtoolingcostsarelower.ThedevelopmentofNCledtothedevelopmentofs everalotherinnovationsinmanufacturingtechnology:1.Electricaldischargemachining.sercutting.3.Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduceawidev arietyofpar4s,eachinvolvinganassortmentofundertaketheproductionofprod uctsthatwouldnothavebeenfeasiblefromaneconomicperspectiveusingmanuall ycontrolledmachinetoolsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesoftheMas sachusettsInstituteofTechnology.TheconceptofNCwasdevelopedintheearly1 950swithfundingprovidedbytheU.SAirForce.Initsearlieststages,NCmachine swereabletomakestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobeprogra mmedtoundertakeaseriesofhorizontalandverticalstepstoproduceacurve.The shorteristhestraightlinesmakingupthestep,thesmootheris4hecurve.Eachli nesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgrammedT ools(APT)languageforNCthatusesstatementssimilartoEnglishlanguagetodef inethepartgeometry,describethecuttingtoolconfiguration,andspecifythen ecessarymotions.ThedevelopmentoftheAPTlanguagewasamajorstepforwardint hefurtherdevelopmentofNCtechnology.TheoriginalNCsystemwerevastlydiffe rentfromthoseusedpunchedpaper,whichwaslatertoreplacedbymagneticplasti ctape.Atapereaderwasusedtointerprettheinstructionswrittenonthetapefor themachine.Together,all/fthisrepresentedgiantstepforwardinthecontrolo fmachinetools.However,therewereanumberofproblemswithNCatthispointinit sdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwascomm onforthepapercontainingtheprogrammedinstructionstobreakortearduringam achiningprocess,Thisproblemwasexacerbatedbythefactthateachsuccessivet imeapartwasproducedonamachinetool,thepapertapecarryingtheprogrammedin structionshadtorerunthoughtthereader.Ifitwasnecessarytoproduce100copi esofagivenpart,itwasalsonecessarytorunthepapertapethoughtthereader100 separatetimes.Fragilepapertapessimplycouldnotwithstandtherigorsofshop floorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagnetictape.Whereasthepapertape carriedtheprogrammedinstructionsasaseriesofholespunchedinthetape,theT hismostimportantofthesewasthatitwasdifficultorimpossibletochangethein structionsenteredonthetape.Tomakeeventhemostminoradjustmentsinaprogra mofinstructions,itwasnecessarytointerruptmachiningoperationsandmakean ewtape.Itwasalsostillnecessarytorunthetapethoughtthereaderasmanytimes astherewerepartstobeproduced.Fortunately,computertechnologybecomearea lityandsoonsolvedtheproblemsofNC,associatedwithpunchedpaperandplastic tape.Thedevelopmentofaconceptknownasnumericalcontrol(DNC)solvethepaper andplastictapeproblemsassociatedwithnumericalcontrolbysimplyeliminati ngtapeasthemediumforcarryingtheprogrammedinstructions.Indirectnumeric alcontrol,machinetoolsaretied,viaadatatransmissionlink,toahostcompute randfedtothemachinetoolasneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedtapeandplasticta pe.However,itissubjecttothesamelimitationasalltechnologiesthatdependo nahostcomputer.Whenthehostcomputergoesdown,themachinetoolsalsoexperie ncedowntime.Thisproblemledtothedevelopmentofcomputernumericalcontrol.Thedevelopmentofthemicroprocessorallowedforthedevelopmentofprogra mmablelogiccontrollers(PLC)andmicrocomputers.Thesetwotechnologiesallo wedforthedevelopmentofcomputernumericalcontrol(CNC).WithCNC,eachmachi netoolhasaPLCoramicrocomputerthatservesthesamepurpose.Thisallowsprogr Csolvedtheproblems associateddowntimeofthehostcomputer,butitintroducedanotherproblemknow nasdatamanagement.Thesameprogrammightbeloadedontendifferentmicrocompu terswithnocommunicationamongthem.Thisproblemisintheprocessofbeingsolv edbylocalareanetworksthatconnectDigitalSignalProcessorsTherearenumeroussituationswhereanalogsignalstobeprocessedinmanywa ys,likefilteringandspectralanalysis,Designinganaloghardwaretoperformt hesefunctionsispossiblebuthasbecomelessandpractical,duetoincreasedper formancerequirements,flexibilityneeds,andtheneedtocutdownondevelopmen t/testingtime.Itisinotherwordsdifficultpmdesignanaloghardwareanalysis ofsignals.Theactofsamplingansignalintothehatarespecialisedforembeddedsignal processingoperations,andsuchaprocessoriscalledaDSP,whichstandsforDigi talSignalProcessor.TodaytherearehundredsofDSPfamiliesfromasmanymanufacturers,eachonedesignedforaparticularprice/performance/usagegroup.Man yofthelargestmanufacturers,likeTexasInstrumentsandMotorola,offerboths pecialisedDSP’sforcertainfieldslikemotor-controlormodems,andgeneralh igh-performanceDSP’sthatcanperformbroadrangesofprocessingtasks.Devel opmentkitsan`softwarearealsoavailable,andtherearecompaniesmakingsoftw aredevelopmenttoolsforDSP’sthatallowstheprogrammertoimplementcomplex processingalgorithmsusingsimple“drag‘n’drop”methodologies.DSP’smoreorlessfallintotwocategoriesdependingontheunderlyingarch itecture-fixed-pointandfloating-point.Thefixed-pointdevicesgenerallyo perateon16-bitwords,whilethefloating-pointdevicesoperateon32-40bitsfl oating-pointwords.Needlesstosay,thefixed-pointdevicesaregenerallychea per.Anotherimportantarchitecturaldifferenceisthatfixed-pointprocessor stendtohaveanaccumulatorarchitecture,withonlyone“generalpurpose”reg ister,makingthemquitetrickytoprogramandmoreimportantly,makingC-compil ersinherentlyinefficient.Floating-pointDSP’sbehavemorelikecommongene ral-purposeCPU’s,withregister-files.TherearethousandsofdifferentDSP’sonthemarket,anditisdifficulttas kfindingthemostsuitableDSPforaproject.Thebestwayisprobablytosetupacon straintandwishlist,andtrytocomparetheprocessorsfromthebiggestmanufact urersagainstit.The“bigfour”manufacturersofDSPs:TexasInstruments,Motorola,AT&Ta ndAnalogDevices.Digital-to-analogconversionInthecaseofMPEG-Audiodecoding,digitalcompresseddataisfedintotheDS Pwhichperformsthedecoding,thenthedecodedsampleshavetobeconvertedbacki ntotheanalogdomain,andtheresultingsignalfedanamplifierorsimilaraudioe quipment.Thisdigitaltoanalogconversion(DCA)isperformedbyacircuitwitht hesamename&DifferentDCA’sprovidedifferentperformanceandquality,asmea suredbyTHD(Totalharmonicdistortion),numberofbits,linearity,speed,filt ercharacteristicsandotherthings.TheTMS320familyDQPofTexasInstrumentsTheTLS320familyconsistsoffixed-point,floating-point,multiprocesso rdigitalsignalprocessors(D[Ps),andfoxed-pointDSPcontrollers.TMS320DSP haveanarchitecturedesignedspecificallyforreal-timesignalprocessing.Th e’F/C240isanumberofthe’C2000DSPplatform,andisoptimizedforcontrolapp lications.The’C24xseriesofDSPcontrollerscombinesthisreal-timeprocess ingcapabilitywithcontrollerperipheralstocreateanidealsolutionforcontr olsystemapplications.ThefollowingcharacteristicsmaketheTMS320familyth erightchoiceforawiderangeofprocessingapplications:---Veryflexibleinstructionset---Inherentoperationalflexibility---High-speedperformance---Innovativeparallelarchitecture---CosteffectivenessDeviceswithinagenerationoftheTMS320familyhavethesameCPUstructure butdifferenton-chipmemoryandperipheralconfigurations.Spin-offdevicesu senewcombinationsofOn-chipmemoryandperipheralstosatisfyawiderangeofne edsintheworldwideelectronicsmarket.Byintegratingmemoryandperipheralso ntoasinglechip,TMS320devicesreducesystemcostsandsavecircuitboardspace .The16-bit,fixed-pointDSPcoreofthe‘C24xdevicesprovidesanalogdesi gnersadigitalsolutionthatdoesnotsacrificetheprecisionandperformanceof theirsystemperformancecanbeenhancedthroughtheuseofadvancedcontrolalgo rithmsfortechniquessuchasadaptivecontrol,Kalmanfiltering,andstatecont rol.The‘C24xDSPcontrollerofferreliabilityandprogrammability.Analogco ntrolsystems,ontheotherhand,arehardwiredsolutionsandcanexperienceperf ormancedegradationduetoaging,componenttolerance,anddrift.Thehigh-speedcentralprocessingunit(CPU)allowsthedigitaldesignert oprocessalgorithmsinrealtimeratherthanapproximateresultswithlook-upta bles.TheinstructionsetoftheseDSPcontrollers,whichincorporatesbothsign alprocessinginstructionsandgeneral-purposecontrolfunctions,coupledwit htheextensivedevelopmenttimeandprovidesthesameeaseofuseastraditional8 -and16-bitmicrocontrollers.Theinstructionsetalsoallowsyoutoretainyour softwareinvestmentwhenmovingfromothergeneral-purpose‘C2xxgeneration, sourcecodecompatiblewiththe’C2xgeneration,andupwardlysourcecodecompa tiblewiththe‘C5xgenerationofDSPsfromTexasInstruments.The‘C24xarchitectureisalsowell-suitedforprocessingcontrolsignal s.Itusesa16-bitwordlengthalongwith32-bitregistersforstoringintermedia teresults,andhastwohardwareshiftersavailabletoscalenumbersindependent lyoftheCPU.Thiscombinationminimizesquantizationandtruncationerrors,an dincreasesp2ocessingpowerforadditionalfunctions.Suchfunctionsmightinc ludeanotchfilterthatcouldcancelmechanicalresonancesinasystemoranestim ationtechniquethatcouldeliminatestatesensorsinasystem.The‘C24xDSPcontrollerstakeadvantageofansetofperipheralfunctions thatallowTexasInstrumentstoquicklyconfigurevariousseriesmembersfordif ferentprice/performancepointsorforapplicationoptimization.Thislibraryofbothdigitalandmixed-signalperipheralsincludes:---Timers---Serialcommunicationsports(SCI,SPI)---Analog-to-digitalconverters(ADC)---Eventmanager---Systemprotection,suchaslow-voltageandwatchdogtimerTheDSPcontrollerperipherallibraryiscontinuallygrowingandchanging tosuittheoftomorrow’sembeddedcontrolmarketplace.TheTMS320F/C240isthefirststandarddeviceintroducedinthe‘24xserie sofDSPcontrollers.Itsetsthestandardforasingle-chipdigitalmotorcontrol ler.The‘240canexecute20MIPS.Almostallinstructionsareexecutedinasimpl ecycleof50ns.Thishighperformanceallowsreal-timeexecutionofverycomple8controlalgorithms,suchasadaptivecontrolandKalmanfilters.Veryhighsampl ingratescanalsobeusedtominimizeloopdelays.The‘240hasthearchitecturalfeaturesnecessaryforhigh-speedsignalp rocessinganddigitalcontrolfunctions,andithastheperipheralsneededtopro videasingle-chipsolutionformotorcontrolapplications.The‘240ismanufac turedusingsubmicronCMOStechnology,achievingalogpowerdissipationrating.A lsoincludedareseveralpower-downmodesforfurtherpowersavings.Someapplic ationsthatbenefitfromtheadvancedprocessingpowerofthe‘240include: ---Industrialmotordrives---Powerinvertersandcontrollers---Automotivesystems,suchaselectronicpowersteering,antilockbrake s,andclimatecontrol---ApplianceandHVACblower/compressormotorcontrols---Printers,copiers,andotherofficeproducts---Tapedrives,magneticopticaldrives,andothermassstorageproducts---RoboticandCNCmillingmachinesTofunctionasasystemmanager,aDSPmusthaverobuston-chipI/Oandotherp eripherals.Theeventmanagerofthe‘240isunlikeanyotheravailableonaDSP.T hisapplication-optimizedperipheralunit,coupledwiththehighperformanceD SPcore,enablestheuseofadvancedcontroltechniquesforhigh-precisionandhi gh-efficiencyfullvariable-speedcontrolofallmotortypes.Includeintheeve ntmanagerarespecialpulse-widthmodulation(PWM)generationfunctions,suchasaprogrammabledead-bandfunctionandaspacevectorPWMstatemachinefor3-ph asemotorsthatprovidesstate-of-the-artmaximumefficiencyintheswitchingo fpowertransistors.Thereindependentupdowntimers,eachwithit’sowncompareregister,sup portthegenerationofasymmetric(noncentered)aswellassymmetric(centered) PWMwaveforms.Open-LoopandClosed-LoopControlOpen-loopControlSystemsThewordautomaticimpliesthatthereisacertainamountofsophistication inthecontrolsystem.Byautomatic,itgenerallymeansThatthesystemisusually capableofadaptingtoavarietyofoperatingconditionsandisabletorespondtoa classofinputssatisfactorily.However,notanytypeofcontrolsystemhastheau ually,theautomaticfeatureisachievedbyfeed.gthefeedbackstructure,itiscalledanopen-loopsystem,whichisthesimp lestandmosteconomicaltypeofcontrolsystem.inaccuracyliesinthefactthato nemaynotknowtheexactcharacteristicsofthefurther,whichhasadefinitebear ingontheindoortemperature.Thisalcopointstoanimportantdisadvantageofth eperformanceofanopen-loopcontrolsystem,inthatthesystemisnotcapableofa daptingtovariationsinenvironmentalconitionsortoexternaldisturbances.I nthecaseofthefurnacecontrol,perhapsanexperiencedpersoncanprovidecontr olforacertaindesiredtemperatureinthehouse;butidthedoorsorwindowsareop enedorclosedintermittentlyduringtheoperatingperiod,thefinaltemperatureinsidethehousewillnotbeaccuratelyregulatedbytheopen-loopcontrol.Anelectricwashingmachineisanothertypicalexampleofanopen-loopsyst em,becausetheamountofwashtimeisentirelydeterminedbythejudgmentandesti mationofthehumanoperator.Atrueautomaticelectricwashingmachineshouldha vethemeansofcheckingthecleanlinessoftheclothescontinuouslyandturnitse dtoffwhenthedesireddegisedofcleanlinessisreached.Closed-LoopControlSystemsWhatismissingintheopen-loopcontrolsystemformoreaccurateandmoread aptablecontrolisalinkorfeedbackfromtheoutputtotheinputofthesystem.Ino rdertoobtainmoreaccuratebontrol,thecontrolledsignalc(t)mustbefedbacka ndcomparedwiththereferenceinput,andanactuatingsignalproportionaltothe differenceoftheoutputandtheinputmustbesentthroughthesystemtocorrectth eerror.Asystemwithoneormorefeedbackpat(slikethatjustdescribediscalled aclosed-loopsystem.humanbeingareprobablythemostcomplexandsophisticate dfeedbackcontrolsysteminexistence.Ahumanbeingmaybeconsideredtobeacont rolsystemwithmanyinputsandoutputs,capableofcarryingouthighlycomplexop erations.Toillustratethehumanbeingasafeedbackcontrolsystem,letusconsidert hattheobjectiveistoreachforanobjectonaperformthetask.Theeyesserveasas ensingdevicewhichfeedsbackcontinuouslythepositionofthehand.Thedistanc ebetweenthehandandtheobjectistheerror,whichiseventuallybroughttozeroa sthehandreachertheobject.Thisisatypicalexampleofclosed-loopcontrol.However,ifoneistoldtoreachfortheobjectandthenisblindolded,onecanonlyrea chtowardtheobjectbyestimatingitsexactposition.ItisAsantherillustrativ eexampleofaclosed-loopcontrolsystem,showstheblockdiagramoftherudderco ntrolsystemofThebasicalementsandtheblocadiagramofaclosed-loopcontrols ystemareshowninfig.Ingeneral,theconfigurationofafeedbackcontrolsystem maynotbeconstrainedtothatoffig&.Incomplexsystemstheremaybemultitudeof feedbackloopsandelementblocks.数控在先进制造技术领域最根本的观念之壹是数控（NC）。

外文原文：NC machineNC machine tool was developed as a new automation tool in the 50s of the 20th century, which use NC technique to solve mechanical cutting process. Following the advanced developing of the modern manufacture, NC machine tool was one of the most important basic equipments as FMC, FMS and CIMS. As the key technology of NC machine tool, NC technology is one of the professional technologies engineering college students should master.One The number of tool machine controls a technique to include tool machine and count to control system and outer circle technique，It constitutes to see form：Number's controlling tool machine is generally lain quality by control, the number control device, servo system and measure feedback device and tool machine host to constitute. Now to each constitute parts of brief introductions as follows:.1st, control mediumWhen the numerical control engine bed processes, needs each kind of control information must depend on some kind of middle carrier carry home and the transmission，This kind of carrier being called as control medium, The control medium is saves acts completely and the cutting tool which the numerical control processing needs is opposite in the work piece positional information intermedium, it is recording the components processing procedure.The control medium has many kinds of, like punched tape, punch card, magnetic tape and floppy disk and so on, also may need each kind of informationthrough the correspondence connection direct input, uses what kind of control medium to be decided by the numerical control installment type.2nd, numerical control installmentThe numerical control installment is the numerical control engine bed core, is the high-tech intensity product. It integrated the microelectronic technology, the information technology, the automatic control technology, the actuation technology, the monitoring examination technology, the software engineering technology and the machine-finishing craft knowledge.The numerical control engine bed is precisely under its control, according to the procedure, which assigns automatically to the machine parts carries on the processing. From 50's in 20 centuries the number controlled tool machine to publish, number's controlling device is already developed CNC by NC.Especially microprocessor and microcomputer make the calculator number control function and credibility of device to raise continuously after counting to control to equip up the successful application, the cost descends continuously, and its high performance price ratio promoted number control the quick development of tool machine.The installment is composed by the hardware and the software. The CNC hardware is a special purpose computer, realizes partial or the complete numerical control function by the software, Through changes the software to be very easy to change or to expand its function.The installment basic skills work includes: Input, decoding, cutting tool compensation, feed rate processing, interpolation, position control, processing, demonstration and diagnosis and so on, It has the main function is as follows:(1) Multi-coordinates control (Multiple spindle linkage);(2)Realizes many kinds of function interpolation;(3) Many kinds of procedure input (Man-machine conversation, manual data feeds, by higher authority computer and other computer equipment excuse input), As well as edition and revision(4) Information transformation;(5)Compensation (Cutting tool radius compensation, cutting tool length compensation, transmission gap compensation, pitch error compensation and so on);(6) multi-processing Options;(7)The breakdown from examines the demonstration(8) Communications and networking.3rd, The servo systemThe tool machine servo system is the conjunction link that the number controls device and tool machine, It is based on mobile components of the machine location and speed as the control of automatic control systems, NC device used to accept (or computing) interpolation generation of feed or feed pulse displacement, Driving Machine executive body movement. It includes spindle drive modules (mainly speed control), feed-driven modules, the spindle motor and feed motor, etc.. In general, CNC servo system requirements of a good rapid corresponding performance, feed rate scope, sensitive and accurate tracking and command functions and speed, in the larger context of a good job stability. What to use is the direct current servo system and communicates now servo system, and communicate the servo system is replacing the direct current servo system.4th, the diagraph feedback equip.The device can be included in the servo system. It consists of measuring element and the corresponding circuit, whose main role is to detect the speed and displacement, Information and feedback control system to form closed loop control. No feedback device measurement systems become open-loop system. The common element is measured pulse encoder, resolve, lnductosyn, grating, and the magnetic-foot Laser Displacement Monitoring System.5th, The host machineHost NC machine is the mainstay, including bed, box, rail, spindle, feed institutions mechanical parts. The numerical control engine bed structure has following several characteristics:As a result of the high-performance spindle feed servo drives, simplifying the CNC machine mechanical transmission structure, Drive a short chain.CNC machine tools with high mechanical structure of the dynamic characteristics of dynamic stiffness, damping precision, wear resistance and thermal deformation properties, continuous adaptation processing automation;More efficient use of transmission pieces, such as ball screws, linear motion guide, such as hydrostatic guideway.Three, NC Machine features1st, the characteristics of CNC machine toolsModification of processing objects adaptability, As the NC processing machineparts change, only the need to re-establishment procedures, replacement of a new perforated paper tape or manually input we will be able to realize the processing of parts. It is different from traditional machines, not manufacture, replacement of a large number of tools, fixtures and equipment, no more re-adjustment machine. Therefore NC machine tools can quickly from a processing components into a processing components, which has single pieces, Trial Production small batch of new products and provide great convenience. It reduces the preparation cycle, and save a lot of equipment. For the use of point-to-point control system porous parts processing, when necessary design modifications, change some of the hole locations and size, only partial changes to delete the corresponding porosity zones, spent a very short time on the product can be modified to create new products, and Results for the products constantly attacking provide favorable conditions.2nd, the high precision machiningCNC machine tools are based on figures given in the form of instructions for processing. Since the NC device pulse equivalent up to 0.001mm，and feed chain drive space and reverse screw pitch error NC devices, etc. can be compensated, therefore, NC machine tools can achieve higher precision. For small and medium-sized CNC machine tools, positioning accuracy can be achieved 0.03mm general, repetitive positioning accuracy of 0.01mm. Because the transmission system with CNC machine tools and the structure has reached a very high stiffness and thermal stability, and improved its manufacturing precision, CNC machine tools, especially the automatic processing methods to avoid the producer human operational error, with a number of machined dimensional consistency, and the rate of qualified products, processing quality is quite stable.The introduction of point-to-point control of the drilling system, eliminating the need for the use of drilling template and the drilling package Drilling Template Error coordinates the impact would cease to exist。

NC technology development trends1 NC system developments at home and abroadWith the rapid development of computer technology, the traditional beginning of a fundamental change manufacturing, the industrial developed countries spent huge sums of money on the modern manufacturing technology research and development, to create a new model. In modern manufacturing systems, CNC technology is the key to technology, which combines microelectronics, computers, information processing, automatic detection, automatic control, such as the integration of advanced, a high-precision, high-efficiency, flexible automation, and other characteristics, the manufacturing industry Flexible automation, integrated, intelligent play the pivotal role. At present, NC technology is undergoing a fundamental change, from a special closed-loop control mode to general-purpose real-time dynamic open all closed-loop control mode. In the integrated on the basis of the CNC systems ultra-thin, ultra-light; on the basis of the intelligent, integrated computers, multimedia, fuzzy control, neural network and other technical disciplines, NC system to achieve high-speed, high-precision, Efficient control, automatic processing can be amended to regulate compensation and the parameters for an online intelligent fault diagnosis and treatment of the network based on the CAD / CAM and CNC systems integration as one machine network, makes the central government centralized control of the group control processing.For a long time, China''s CNC system for traditional closed architecture, but only as a non-intelligent CNC machine controller. Process variables based on experience in the form of pre-fixed parameters, processing procedures before the actual processing by hand or throughCAD / CAM and automatic programming system prepared. CAD / CAM and CNC have no feedback control link, the entire manufacturing process CNC is a closed ring-opening implementing agencies. In a complex and changing environment under the conditions of processing tool in the process of composition, workpiece material, spindle speed, feed rate, tool path, cutting depth, step, allowance and other processing parameters, not at the scene circumstances under external interference and real-time dynamic random factors, not by random amendment feedback control link CAD / CAM settings volume, in turn, affect the work of CNC machining efficiency and product quality. Clearly, the traditional fixed CNC system that controlled mode and closed architecture, limiting the CNC to the development of more intelligent control variables, can no longer meet the increasingly complex manufacturing process, therefore, the CNC technology in the potential for change inevitable.2 NC technology development trends2.1 Performance development direction(1) high-speed high-precision efficient speed, accuracy and efficiency of machinery manufacturing technology is the key performance indicators. As a result of the high-speedCPU chips, RISC chip, as well as multi-CPU control system with high-resolution detector of the absolute exchange digital servo system, taken at the same time improve the machine dynamic and static characteristics of effective measures, the high-speed high-precision machine has been efficient greatly enhanced.(2) Flexible includes two aspects: CNC system itself flexibility, NC system is modular in design, functional coverage, can be cut and strong, and easy to meet the needs of different users; group control system flexibility, with a control system pursuant to the requirements of different production processes, materials flow and information flow automatically dynamically adjusted to maximize their group control system performance.(3) Process of composite and multi-axis to reduce the process time for the main purpose of supporting the composite processing, and are moving towards multi-axis, multi-function control of the direction of series development. NC Machine Tool Technology composite refers to the workpiece in a single machine on a fixture, through an automatic tool change, rotating spindle head or turntable, and other measures to accomplish multiple processes, multi-surface machining compound. Axis CNC technology, Siemens 880-axis control system for up to 24 axes.(4) Real-time Intelligent early for the real-time system is usually relatively simple ideal environment, and its role is to scheduling tasks, to ensure that the task be completed within a specified time limit. And artificial intelligence is used to model the realization of mankind''s various intelligent behaviors. To the development of science and technology today, real-time systems and artificial intelligence combined with each other towards artificial intelligence is a real-time response, a more realistic field of development, and also in the real-time system with intelligent behavior, the more complex application development, resulting in the Intelligent real-time control of this new area. NC technology in the field, real-time intelligent control of the research and application of development along several main branches: adaptive control, fuzzy control, neural network control, experts control, learning control, feed-forward control.For example, in CNC programming system with expert systems, fault diagnosis expert system parameters automatically set and tool management and automatic compensation, such as adaptive conditioning systems, in high-speed processing of the integrated motion control ahead of the introduction of budget projections and functional, dynamic Feedforward functions in pressure, temperature, position, velocity, control, fuzzy control, the control of the NC system performance greatly improved, so as to achieve optimal control purposes.2.2 functional development direction(1) The user interface is graphical user interface with the CNC system of dialogue between the user interface. Since different users interface requirements are different, thus the development of the workload of great user interface, user interface software developed into the most difficult part of. At present INTERNET, virtual reality, visualization in scientific computing and multimedia technologies, such as the user interface has put a higher demand. Graphical user interface greatly facilitates the use of non-professional users, it can be carried out through the window and menu operation, ease of programming and blueprint for rapid programming, three-dimensional dynamic three-dimensional color graphics, graphics, simulation, graphics, dynamic tracking and simulation, and the different directions view and partial display ratio scaling function can be achieved.(2) visualization in scientific computing visualization in scientific computing can be used for efficient data processing and interpretation of data, so that the exchange of information is no longer limited to using the written word and language, and can direct the use of graphics, image, animation, video and other information. Visualization technology and virtual environmenttechnology, to further broaden the application areas, such as a drawing design, virtual prototyping technology, which shorten product design cycles, improving product quality, reduce production cost is of great significance. NC technology in the areas of visualization technology can be used for CAD / CAM, such as automatic programming design parameters automatically set, tool compensation and tool management of dynamic data processing and display, as well as the processing of visual simulation, and other presentations.(3) interpolation, and a variety of methods of compensation interpolation methods such as multiple linear interpolation, circular interpolation, cylindrical interpolation, space elliptical surface interpolation, thread interpolation, polar coordinates interpolation, 2 D +2 helical interpolation , NANO interpolation, interpolation NURBS (non-uniform rational B-spline interpolation), spline interpolation (A, B, C kind), such as polynomial interpolation. A variety of functions such as compensation gap compensation vertical compensation quadrant error compensation, and measurement systems pitch error compensation, and speed-related feedforward compensation and temperature compensation, with nearly smooth and exit, as well as the opposite point of the cutter radius compensation.(4) high-performance PLC contents contents performance CNC system PLC control module can be directly used ladder diagram or high-level language programming, with intuitive online debugging and online help function. Programming tools include the standard used lathe and milling machine PLC user program an example, users may PLC user program standards on the basis of editorial changes, thus easily build their own applications.(5) application of multimedia technology of multimedia technology-computers, audio-visual andcommunication technology, and it has the computer integrated voice, text, images and video information. In NC technology, multimedia technology can be applied to information processing integrated, intelligent, real-time monitoring system in the field and production equipment fault diagnosis, monitoring of process parameters such as production has a significant value.2.3 Development of the Architecture(1) integration of a highly integrated CPU, programmable RISC chips and large-scale integrated circuits FPGA, EPLD, CPLD and ASIC ASIC chips that can improve the CNC system integration and hardware and software operating speed. Application FPD flat panel display technology can improve display performance. Flat-panel displays with high science and technology content, light weight, small size, low power consumption and portability advantages can be realized Supersized, a counterweight to the emerging and CRT display technology, display technology in the 21st century the mainstream. Application of advanced packaging and interconnect technologies, semiconductors and surface mount technology integration. By increasing the density of integrated circuits, reducing the length and number of interconnection products to reduce prices, improve performance, reduce component size, improve the reliability of the system.(2) easy to implement modular hardware modular NC systems integration and standardization. According to various functional requirements, the basic modules, such as CPU, memory, position servo, PLC, the input and output interfaces, and communications modules, making the standard Series products, through functional building-block approach to cutting the number of steps and modules, a NC system at different grades.(3) machine interconnection network for remote control of unmanned operation. Machine through networking, can be in any one machine on the other machine programming, configuration, operation, operating, different machine can be displayed on the screen each machine on the screen.(4) general-open the closed-loop control mode to adopt a common computer component Bus, modular, open, embedded architecture, ease of cutting, expansion and upgrading, can be composed of different grades, different types, different degree of integration CNC system. Closed-loop control mode is the traditional CNC system only for single closed-open-loop control mode proposed. The manufacturing process is a multi-variable control and the role of integrated processing complex process, including processing, such as size, shape, vibration, noise, temperature and thermal deformation, and other factors, therefore, to achieve the process of multi-objective optimization, Multivariable must adopt the closed-loop control, real-time processing in the dynamic adjustment process variables. Processing the adoption of open universal real-time closed-loop control mode the whole dynamic, easy real-time intelligent computer technology, network technology, multimedia technology, CAD / CAM, servo control, adaptive control, dynamic data management and dynamic tool compensation, dynamic simulation and other high technology into one, a tight closed-loop manufacturing process control system to achieve integrated, intelligent, network-based.3 PCNC new generation of intelligent CNC systemResearch and Development adapted to the current complexity of the manufacturing process, with the structure of the closed-loop control system, a new generation of intelligent PCNCCNC system has become possible. PCNC NC intelligent system will be a new generation of intelligent computer technology, network technology, CAD / CAM, servo control, adaptive control, dynamic data management and dynamic tool compensation, dynamic simulation and other high technology into one, a tight closure of the manufacturing process Central control system.。

附录1The developmenttrend of the numerical control technology Summary : Have introduced numerical control technology and the development trend of the equipment and the current situations of the technical development of numerical control equipment and industrialization of our country of our times briefly , have discussed under the new environment further deepened in our country's accession to the WTO and opening to the outside world on this basis, develop technology of numerical control of our country and the importance of the information-based level of manufacturing industry of our country and international competitiveness equips , improves, and has put forward technology of numerical control of our country and some views equipped of developing from two aspects of strategy and tactics.The engineering level of equipment industry and modernized intensity are determining the level of the whole national economy and modernized intensity , numerical control technology and equip , develop new developing new high-tech industry and most advanced industry To can make technology and basic equipment most (national defense industry industries , such as information technology and their industry , biotechnology , industry , aviation , spaceflight ,etc. ). Marx has ever said " the differences of different economic times, do not lie in what is produced , lie in how produce , with what means of labor produce ". Manufacturing technology and equipping the most basic means of production that are that the mankind produced the activity, and numerical control technology to equip most central technology. Nowadays the manufacturing industry all around the world adopts the technology of numerical control extensively, in order to improve manufacturing capacity and level, improve the adaptive capacity and competitive power to the changeable market of the trends . In addition every industrially developed country in the world also classifies the technology and numerical control equipment of numerical control as the strategic materials of the country, not merely take the great measure to develop one's own numerical control technology and industry, and implement blockading and restrictive policy to our country in " high-grade , precision and advanced " key technology and equipment of numerical control. In a word, develop taking technology of numerical control as thecore advanced manufacturing technology become world all developed country , accelerate economic development already in a more cost-effective manner, important route to improve the comprehensive national strength and national position.Numerical control technology to go on technology that control with digital information to mechanical movement and working course, numerical control equipment whether represented by technology of numerical control new technology make industry and new developing infiltration electromechanics integrated product that form of manufacturing industry to tradition, i.e. what is called digitization equip, its technological range covers a lot of fields: (1)Mechanical manufacturing technology; (2)Information processing , processing , transmission technology; (3)Automatic control technology; (4)Servo drive technology; (5)Transducer technology; (6)Software engineering ,etc..1Development trend of a numerical control technologyThe application of the technology of numerical control has not only brought the revolutionary change to traditional manufacturing industry, make the manufacturing industry become the industrialized symbol , and with the constant development of the technology of numerical control and enlargement of application, the development of he some important trades (IT , car , light industry , medical treatment ,etc. ) to the national economy and the people's livelihood plays a more and more important role, because these trade necessary digitization that equipped has already been the main trend of modern development. According to the technology of numerical control and equipment development trend in the world at present, its main research focus has the following several respect [1~4].A high-speed , high finish machining technology and new trendequippedEfficiency , quality are subjects of the advanced manufacturing technology. At a high speed, high finish machining technology can raise the efficiency greatly, quality and grade to raise product, shorten production cycle and improve the competitive power of market. Japan carry technological research association classify their as one of the 5 loud modern manufacturing technologies first for this reason, learn (CIRP ) to confirm it as the centre in the 21st century to study one of the directions in international production engineering. In the field of car industry, produce 40 second when beat such as production of 300,000 / vehicle peryear, and many variety process it is car that equip one of the key problems that must be solved; In the fields of aviation and aerospace industry, its processing's spare parts are mostly the thin wall and thin muscle, rigidity very bad, material aluminium or aluminium alloy, in high to cut pace and cut strength very under the little situation only, could process these muscles , walls . Adopt large-scale whole aluminium alloy blank method of " pay empty " make the wing recently, large-scale parts such as the fuselage ,etc. come to substitute a lot of parts to assemble through numerous rivet , screw and other connection ways, make the intensity , rigidity and dependability of the component improved. All these requirement for processing and equipping and proposing high-speed , high and precise and high flexibility.According to EMO2001 exhibition situation, the high-speed machining center enters for the pace to can reach 80m/min , even high, air transport competent pace can reach 100m/min about. A lot of car factories in the world at present, including Shanghai General Motors Corporation of our country, adopt , substitute and make the lathe up with high-speed machining center production line part that make up already. HyperMach lathe of Company , CINCINNATI of U.S.A. , enter , give pace to be most loud to reach 60m/min, it is 100m/min to be fast, acceleration reach 2g, the rotational speed of the main shaft has already reached 60 000r/min. Processing a thin wall of plane parts, spend 30min only, and same part general at a high speed milling machine process and take 3h, process and need 8h with ordinary milling machine; The paces and acceleration of main shaft of dual main shaft lathes of Germany DMG Company reach 12* separately! 000r/mm and 1g. In machining accuracy, in the past 10 years, ordinary progression has accused of the machining accuracy of the lathe to already improve from 10μm to 5μm, accurate grades of machining center from 3- 5μm, raise to 1- 1.5μm, and ultraprecision machining accuracy begin , enter getting nanometer already.In machining accuracy, the past 10 years, ordinary progression accuse of machining accuracy of lathe raise to 5μm , from 3- 5μm accurate grades of machining center from 10μm already, improve to 1- 1.5μm, and the ultraprecision machining accuracy has already begun to enter nanometer (0.01μm )ly. In dependability, MTBF value of the foreign numerical control device has already reached above 6 000h, MTBF value of the servo system reaches above 30000h, demonstrate very high dependability . For realize at a high speed , high finish machining, relatedto it function part if electric main shaft , straight line electrical machinery get fast development, the application is further expanded .5 axles link and process and compound and process the lathe to develop fastAdopt 5 axle link , to three-dimensional curved surface processing of part , can cut with the best geometirc form of the cutter, not only highly polished, but also efficiency is improved by a large margin . It is generally acknowledged , a 5 axle gear beds of efficiency can equal 2 3 axle gear beds , use cubic nitrogen boron wait ultra hard material milling cutter go on at a high speed milling , sharpening , quenching hard steel at the part, 5 axle link , process constant 3 axle link , process , give play to high benefit. But go over because 5 axles link the numerical control system , complicated reason of host computer structure, price its link numerical control to be lathe several times higher than 3 axle, in addition programming technological difficulty relatively heavy , have restricted 5 axle gear beds of development. At present because of electric appearance of main shaft, make , realize 5 axle compound main shaft hair structure processed to link greatly simplify, it make difficulty and cost reduce by a large margin , numerical control price disparity of systems shrink. So promote compound main shaft head type 5 axle gear bed and compound development to process lathe (process the lathe including 5 ).At EMO2001 exhibition, new Japanese 5 of worker machine process lathe adopt compound main shaft hair, can realize 4 processing and arbitrary processing of angle of vertical plane, make 5 process and 5 axles are processed and can be realized at the same lathe, can also realize the inclined plane and pour the processing of the hole of awls . Company , DMG of Germany , exhibit DMUV oution series machining center , can put , insert , down 5 process and 5 axes link and process in one, can be controlled by CNC system or CAD/CAM controls directly or indirectly.intellectualizations, open style, the network turns into for the contemporary numerical control system development mainly hastensThe 21st century numerical control equipments will be has certain intellectualized the system, the intellectualized content including in numerical control system each aspect: In order to pursue the processing efficiency and the processing quality aspect intellectualization, like processing process adaptive control, craft parameter automatic production; In order to enhance the actuation performance and the use connection convenient intellectualization, like the feed-forward control, the electricalmachinery parameter auto-adapted operation, the automatic diagnosis load automatic designation model, is automatic entire grades; Simplification programming, simplification operation aspect intellectualization, like intellectualized automatic programming, intellectualized man-machine contact surface and so on; Also has the intelligence to diagnose, the intelligent monitoring aspect content, the convenience system diagnosis and the service and so onIn order to solve the traditional numerical control system seal and the numerical control application software industry production existence question. At present many countries conduct the research to the open style numerical control system, like US'S NGC (The Next Generation Work-Station/Machine Control), European Economic Community's OSACA (Open System Architecture for Control within Automation Systems), Japan's OSEC (Open System Environment for Controller), China's ONC (Open Numerical Control System) and so on. The numerical control system will open already becomes the numerical control system road of the future. The so-called open style numerical control system is the numerical control system development may in the unified movement platform, face the engine bed factory and the end-user, through the change, the increase or the tailor structure object (numerical control function), forms the seriation, and may conveniently integrates user's special application and the technical knack in the control system, the fast realization different variety, the different scale open style numerical control system, forms has the bright individuality famous brand goods. At present the open style numerical control system system structure standard, the correspondence standard, the disposition standard, the movement platform, the numerical control system function storehouse as well as the numerical control system function software development kit and so on is the current research coreThe network numerical control equipment is a nearly two year international famous engine beds expositions new luminescent spot. The numerical control equipment network enormously will satisfy the production line, the manufacture system, the manufacture enterprise to the information integration demand, also will be realizes new manufacture pattern like agile manufacture, hypothesized enterprise, the global manufacture foundation unit. The domestic and foreign some famous numerical controls engine bed and the numerical control system manufacture company has all promoted the related new concept and theprototype in the nearly two years, if unfolds in EMO2001, Japanese Shan Qima Mazak the company displays "CyberProduction Center" (intelligence production control center, is called CPC); Japan is Okuma the engine bed company to display "IT plaza" (information technology square, is called the IT square); German Simens (Siemens) the company displays Open Manufacturing Environment (opening manufacture environment, is called OME) and so on, had reflected the numerical control engine bed processing the tendency which develops to the network direction1.4 takes the new technical standard, the standard establishment1.4.1 about numerical control system design development gaugeAs noted previously, there are better commonability , flexibility , adaptability , expanding in the open numerical control system, countries such as U.S.A. , European Community and Japan ,etc. implement the strategic development plan one after another , carry on research and formulation of the systematic norm of structural numerical control of the open system (OMAC , OSACA , OSEC ), 3 of world heavy economy carry on the same science plan and standardize formulation nearly in a short time most, have indicated a new arrival of period of change of the technology of numerical control. Our country started research and formulation which standardized the frame of ONC numerical control system of China too in 2000.1.4.2 About the numerical control standardThe numerical control standard is a kind of trend of information-based development of manufacturing industry. Numerical control technology information exchange of 50 year born , to based on ISO6983 standard, adopt G , M code describes how processes, its essential characteristic faces the processing course, obviously, he can't meet demands of high-speed development of the technology of modern numerical control more and more already. For this reason, studying and making a kind of new CNC system standard ISO14649 (STEP-NC ) in the world, its purpose is offering a kind of neutral mechanism not depending on the concrete system , can describe the unified data model in whole lifespan of the products , thus realize the whole manufacture process, and even the standardization of each industrial field product information.The appearance of STEP-NC may be a revolution of the technical field of the numerical control, on development and even the whole manufacturing industry of the technology of numerical control , will exerta far-reaching influence. First of all, STEP-NC puts forward a kind of brand-new manufacture idea , in the traditional manufacture idea, NC processes the procedures to all concentrate on single computer. Under the new standard, NC procedure can be dispersed on Internet, this is exactly a direction of open , networked development of technology of numerical control. Secondly, STEP-NC numerical control system also can reduce , process (about 75% ) drawing , process procedure work out (about 35% ) time and process (about 50% ) time greatly.At present, American-European countries pay much attention to the research of STEP-NC, Europe initiates IMS plan (1999.1.1- 2001.12.3 ) of STEP-NC. 20 CAD/CAM/CAPP/CNC users , manufacturers and academic organizations from Europe and Japan participated in this plan. STEP Tools Company of U.S.A. is a developer of the data interchange software of manufacturing industry in the global range, he has already developed and accused of the super model (Super Model ) of information exchange of machine tooling by counting, its goal is to describe all processing courses with the unified norm. Such new data interchange form has already been verified in allocating the SIEMENS , FIDIA and European OSACA-NC numerical control at present.2pairs of basic estimations of technology and industry development of numerical control of our countryThe technology of numerical control of our country started in 1958, the development course in the past 50 years can roughly be divided into 3 stages: The first stage is from 1958 to 1979, i.e. closed developing stage. In this stages, technology of foreign countries blockade and basic restriction of terms of our country, the development of the technology of numerical control is comparatively slow. During " Sixth Five-Year Plan Period " , " the Seventh Five-Year Plan Period " of the country in second stage and earlier stage in " the Eighth Five-Year Plan Period ", introduce technology , digest and assimilate, the stage of establishing the system of production domesticization arisesing tentatively. At this stage , because of reform and opening-up and national attention , and study the improvement of the development environment and international environment, research , development and all making considerable progress in production domesticization of the products of the technology of numerical control of our country. The third stage is that on the later stage in " the Eighth Five-Year Plan Period " of the country and during the " Ninth Five-Year Plan Period ", implement the research ofindustrialization , enter market competition stage. At this stage, made substantive progress in industrialization of the domestic numerical control equipment of our country. In " the Ninth Five-Year Plan " latter stage, domestic numerical control domestic market share of lathe reach 50% , mix domestic numerical control system (popular ) to up to 10%.Review the development course in the past 50 years of technology of numerical control of our country, especially pass the brainstorm of 4 Five-Year Plans, all in all has made following achievements.a. Have establish the foundation of the technical development of numerical control, has basically mastered the technology of modern numerical control. Our country know from numerical control system , servo urge , numerical control host computer , special plane and their basic of fittings basically already now, among them most technology have already possessed the foundation that is commercialized and developed , some technology has already, industrialization commercialized.a.Have formed the industrial base of numerical control tentatively. In tackling key problems the foundation that the achievement and some technology commercialize , set up the systematic factories of numerical control with production capacity of batch such as numerical control of Central China , spaceflight numerical control etc.. Electrical machinery plant of Lanzhou, a batch of servo systems and first machine tool plant , first machine tool plant of Jinan of servo electrical machinery factory and Beijing ,etc. several numerical control host computer factories such as the numerical control in Central China. These factories have basically formed the numerical control industrial base of our country.b.Have set up research of a numerical control, development , managerial talent's basic team . Though has made considerable progress in research and development and industrialization of the technology of numerical control, but we will realize soberly, the research and development of the technology of advanced numerical control of our country, there is greater disparity between current situation and current demand of our country of engineering level especially in industrialization. Though very fast from longitudinal development to watch our country, horizontal until (contrast with foreign countries ) , the engineering level has disparity, there is disparity too in development speed in some aspects, i.e. the disparity of engineering level between some high-grade , precision and advanced numerical control equipment has the tendency to expand . Watch from world , estimate roughly as follows about the numericalcontrol engineering level of our country and industrialization level.a.On the engineering level, in probably backward 10- 1 years with the advanced level in foreign countries, it is bigger in high-quality precision and sophisticated technology.b.At the industrialization level, the market share is low, the variety coverage rate is low, have not formed the large-scale production yet; Function part specialized level of production and form a complete set ability to be lower; Appearance quality is relatively poor; Dependability is not high, the commercialized intensity is insufficient; Not setting up one's own brand effect yet in domestic numerical control system, users have insufficient confidence.c.At the ability of sustainable development, to competition numerical control research and development of technology, engineered ability weaker; Numerical control technological application expand efforts to be better; The research , formulation that relevant standards are normal lags behind.It is analyzed that the main reason for having disparity described above has the following several respect.a.Realize the respect. Know to domestic numerical control industry process arduousness , complexity and long-term characteristic insufficiently; One that is to market unstandard, foreign blockade add strangle , system ,etc. underestimate while being difficult; It is not enough to analyze to technological application level and ability of numerical control of our country.b.System. Pay close attention to numerical control industrialization many in the issue , consider numerical control industrialization little in the issue synthetically in terms of the systematic one , industry chain in terms of technology; Set up intact related system , complete training , service network ,etc. of high quality support the system.c.Mechanism. The bad mechanism causes the brain drain , restraining technology and technological route from innovating again , products innovation, and has restricted the effective implementation of planning , has often planned the ideal , implement the difficulty.d.Technology. Enterprises are indifferent in autonomous innovation in technology, key technology is engineered and indifferent. Lathe standard lag behind, level relatively low, numerical control system new standard study enoughly.3 strategic thinking until technology and industrialization of numerical control of our country develop3.1 Strategic considerationOur country of strategic consideration makes the big country , should try hard to accept the front instead of the back transformation in the world industry shifts , should master and make key technology advancedly , otherwise in a new round of international industrial structure adjustment, of our country manufacturing industry step forward " the empty core ". We regard resource , environment , market as cost, possibility got to exchange " assemble the centre ", but not master the status of the manufacturing center of key technology , will so influence the development process of the modern manufacturing industry of our country seriously.We should stand in the height of national security strategy paying attention to the technology of numerical control and industry's question , at first seen from social safety, because manufacturing industry whether our country obtain employment most populous trade, the development of manufacturing industry not only can improve the people's living standard but also can relieve the pressure of employment of our country , ensure the stability of the society; Secondly seen from security of national defence, the western developed country has classified all the high-grade , precision and advanced numerical control products as the strategic materials of the country, realize embargo and restriction to our country, " Toshiba incident " and " Cox Report " is the best illustration.3.2 Development tacticsProceed from the angles of the fundamental realities of the country of our country, regard the strategic demand of the country and market demand of the national economy as the direction, regard improving our country and making the comprehensive competitive power of equipping industry and industrialization level as the goal, use the systematic method , be able to choose the support technology that the initial our country makes the key technology upgraded in development of equipping industry and supports the development of industrialization in 21st century of leading factor, the ability to supply the necessary technology realizes making the jump type development of the equipping industry as the content of research and development.Emphasize market demand is a direction, take terminal products of numerical control as the core , with the complete machine (Such as the numerical control lathe having a large capacity and a wide range, milling machine , high speed high precise high-performance numerical controllathe , model digitized machinery , key industry key equipment ,etc. ) drive numerical control development of industry. Solve the numerical control system and relevant functions part especially The dependability in (digitized servo system and electrical machinery , electric main shaft system of high speed and new attachment that equip ,etc. ) and production scale question. There are no products without high dependability of scale ; Will not have cheap and products rich in the competitiveness without scale ; Certainly, it is difficult finally to have the day to hold up head that there is no Chinese numerical control equipment of scale .In equipping researching and developing high-grade , precision and advancedly , should emphasize the production, learning and research and close combination of end user, regard " obtaining, using, selling " as the goal, tackle key problems according to the national will, in order to solve the needing badly of the country. The technology of numerical control, emphasized innovation, put emphasis on researching and developing technology and products with independent intellectual property right before the competition, establish the foundation for the numerical control industry of our country , sustainable development of the equipment manufacture and even the whole manufacturing industry.附录2数控技术发展趋势1 国内外数控系统发展概况随着计算机技术的高速发展，传统的制造业开始了根本性变革，各工业发达国家投入巨资，对现代制造技术进行研究开发，提出了全新的制造模式。

英文资料翻译题目：NC Technology系别中德机电学院专业机电一体化技术班级机电0902姓名学号指导教师2012年4月The developments of NC technologyOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC). Prior to the advent of NC, all machine tools were manually operated and controlled. Among the many limitations associated withmanual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator. Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems through the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool. For a machine tool to be numerically controlled, it must be interfaced with a device for accepting and decoding the programmed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operators, and it has done so. Numerical control machines are more accurate than manually operated machines, they can produce parts more uniformly, they are faster, and the long-run tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3.Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide variety of parts, each involving an assortment of widely varied and complex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies, NC was born in the laboratories of the Massachusetts Institute of Technology. The concept of NC was developed in the early 1950s with funding provided by the U. S. Air Force. In its earliest stages, NC machines were able to make straight cuts efficiently and effectively.However, curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve.The shorter is the straight lines making up the steps, the smoother is the curve. Each line segment in steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language. This is a special programming language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC systems were vastly different from those used today. T he machines had hardwired logic circuit. The instructional programs were written on punched paper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium. It was common for the paper tape containing the programmed instructions to break or tear during a machining process. This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to be rerun through the reader. If it was necessary to produce 100 copies of a given part, it was also necessary to run the paper tape through the reader 100 separate times. Fragile paper tapes simply could not withstand the rigors of a shop floor environment and this kind of repeated use.This led to the development of a special magnetic plastic tape. Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape, the plastic tape carried the instructions, as a series of magnetic dots. The plastic tape was much stronger than the paper tape, which solved the problem of frequent tearing and breakage. However, it still left two other problems.The most important of these was that it was difficult or impossible to change the instructions entered on the tape. To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape through the reader as many timesas there were parts to be produced. Fortunately, computer technology became a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as direct numerical control (DNC) solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control, machine tools are tied, via a data transmission link, to a host computer, Program for operating the machine tool are stored in the host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitation as all technologies that depend on a host computer. When the host computer goes down, the machine tools also experience down time. This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLCs) and microcomputers. These two technologies allowed for the development of computer numerical control (CNC). With CNC, each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. It also allows programs to be developed off-line and downloaded at each individual machine tool. CNC solved the problems associated downtime of the host computer, but it introduced another problem known as data management. The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connect microcomputers for better data management.In the past, machine tools were kept as simple as possible in order to keep their costs down. Because of the ever-rising cost of labor, better machine tools, complete with electronic controls, were developed so that industry could produce more and better products at prices that were competitive with those offshore industries.NC is being used on all types of machine tools from the simplest to the most complex. The most common machine tools are the single-spindle drilling machine, lathe, milling machine, turning center, and machining center.1. Single-Spindle Drilling MachineOne of the simplest numerically controlled machine tools is the single-spindle drilling machine. Most drilling machines are programmed on three axes:a. The X-axis controls the table movement to the right or left.b. The Y-axis controls the table movement toward or away from the column.c. The Z-axis controls the up or down movement of the spindle to drill holes to depth.2. LatheThe engine lathe, one of the most productive machine tools, has been a very efficient means of producing round parts. Most lathes are programmed on two axes:a. The X-axis controls the cross motion (in or out) of the cutting tool.b. The Z-axis controls the carriage travel toward or away from the headstock.3. Milling MachineThe milling machine has always been one of the most versatile machine tools used in industry. Operations such as milling, contouring, gear cutting, drilling, boring and reaming are only a few of the many operations that can be performed on a milling machine.The milling machine can be programmed on three axes:a. The X-axis controls the table movement to the right or left.b. The Y-axis controls the table movement toward or away from the column.c. The Z-axis controls the vertical (up and down) movement of the knee or spindle.4. Turning CenterTurning Centers were developed in the mid-1960s after studies showed that about 40 percent of all metal cutting operations were performed on lathes. These numerically controlled machines are capable of greater accuracy and higher production rates than the engine lathe. The basic turning centre operates on only two axes:a. The X-axis controls the cross motion of the turret head.b. The Z-axis controls the lengthwise travel (toward or away from the headstock) of the turret head.5. Machining CenterMachining centers were developed in the 1960s so that a part did not have to be moved from machine to machine in order to perform various operations. These machines greatly increased production rates because more operations could be performed on a work-piece in one setupThere are two main types of machining centers, the horizontal and the vertical spindle types.a. The horizontal spindle-machining center operates on three axes:(a) The X-axis controls the table movement to the right or left.(b) The Y-axis controls the vertical movement (up and down) of the spindle.(c) The Z-axis controls the horizontal movement (in or out) of the spindle.b. The vertical spindle-machining center operates on three axes:(a) The X-axis controls the table movement to the right or left.(b) The Y-axis controls the table movement toward or away from the column.(c) The Z-axis controls the vertical movement (up and down) of the spindle.A program for numerical control consists of a sequence of directions that caused a NC machine to carry out a certain operation, machining being the most commonly used process. Programming for NC may be done by an internal programming department, on the shop floor, or purchased from an outside source. Also, programming may be done manually or with computer assistance.The program contains instructions and commands. Geometric instructions pertain to relative movements between the tool and the work-piece. Processing instructions pertain to spindle speeds, feeds, tools, and so on. Travel instructions pertain to the type of interpolation and slow or rapid movements of the tools or worktables. Switching commands pertain to on/off position for coolant supplies, spindle rotation, direction of spindle rotation, tool changes, work-piece feeding, clamping and so on.(1). Manual programming.Manual part programming consists of first calculating dimensional relationships of the tool, work-piece and worktable based on the engineering drawings of the part, and manufacturing operations to be performedand their sequence. A program sheet is then prepared, which consists of the necessary information to carry out the operation, such as cutting tools, spindle tools, feeds, depth of cut, cutting fluids, power, and tool or work-piece relative positions and movements. Based on this information, the part program is prepared.Usually a paper tape is first prepared for typing out and debugging the program. Depending on how often it is to be used, the tape may be made of more durable mylar.Someone knowledgeable about the particular process and able to understand, read, and change part programs can do manual programming.Because they are familiar with machine tools and process capabilities, skilled machinists can do manual programming with some training in programming, however, the work is tedious, time consuming, and uneconomical and is used mostly in simple point-to-point applications.(2). Computer-aided puter-aided part programming involves special symbolic programming languages that determine the coordinate points of corners, edges, and surfaces of the part.Because numerical control involves the insertion of data concerning work-piece materials and processing parameters, programming must be done by operators or programmers who are knowledgeable about the relevant aspects of the manufacturing processes being used. Before production begins, programs should be verified, either by viewing a simulation of the procession on a CRT screen or by making the part from an inexpensive material, such as aluminum, wood, or plastic, rather than the material specified for the finished parts.Principles of NC MachinesAn NC machine can be controlled through two types of circuits: open-loop and closed-loop. In the open-loop system (Figure 1 (a)), the singles are sent to the servomotor by the controller, but the movements and final positions of the worktable are not checked for accuracy.The closed-loop system (Figure 1(b)) is equipped with various transducers, sensors, and counters that measure accurately the position of the worktable. Through feedback control, the position of the worktable is compared against the signal. Tablemovements terminate when the proper coordinates are reached. The closed-loop system is more complicated and more expensive than the open-loop system.Figure 1 Schematic illustration of (a) an open-loop and (b) a closed-loop control system for an NC machine Types of Control SystemsThere are two basic types of control systems in numerical control, point-to-point and contouring.(1) In a point-to-point system, also called positioning, each axis of the machine is driven separately by lead screws and, depending on the type of operation, at different velocities. The machine moves initially at maximum velocity in order to reduce nonproductive time, but decelerates as the tool approaches its numerically defined position. Thus, in an operation such as drilling (or punching a hole), the positioning and cutting take place sequentially.After the hole is drilled or punched, the tool retracts upward and moves rapidly to another position, and the operation is repeated. The path followed from one position to another is important in only one respect. It must be chosen to minimize the time of travel, for better efficiency. Point-to-point systems are used mainly in drilling, punching, and straight milling operations.(2) In a contouring system (also known as a continuous path system), the positioning and the operations are both performed along controlled paths but at different velocities. Because the tool acts as it travels along a prescribed path, accuratecontrol and synchronization of velocities and movements are important. The contouring system is typically used on lathes, milling machines, grinders, welding machinery, and machining centers.Master the forms of compensationWhat are offsets?All forms of compensation work with offsets. You can think of CNC offsets as like memories on an electronic calculator. If your calculator has memories, you know you can store a constant value into each memory for use during a calculation. This keeps you from having to enter the number over and over again with redundant calculations.Like the memories of an electronic calculator, offsets in the CNC control are storage locations into which numerical values can be placed. Just as the value within the memory of a calculator has no meaning until referenced by its user within a calculation, neither does the value within an offset of the CNC control have any meaning until it is referenced by a CNC program.To specify each tool’s lengthFor machining center applications, it would be very difficult for the programmer to predict the precise length of each tool used in the program. For this reason, the feature tool length compensation allows the programmer to ignore each tool’s length as the program is written. At the time of setup, the setup person measures the length of each tool and inputs the tool length value into the corresponding offset.To specify the radius of the cutting toolWhen milling on the periphery of the cutter (contour milling), it can be cumbersome and difficult for the programmer to program the cutter’s path based on the size of the milling cutter being used. Also, if the cutter size must change (possibly due to re-sharpening), it would be infeasible to change the program based on the new cutter size. For this reason, the feature cutter radius compensation allows the programmer to ignore the cutter size as the program is written. The setup person inputs the size of each milling cutter into its corresponding tool offset. In similar fashion, turning centers have a feature called tool nose radius compensation. With thisfeature, an offset is used to specify the radius of the very tip of the turning or boring tool.To assign program zeroMachining centers that have fixture offsets (also called coordinate system shifting) allow the user to specify the position of the program zero point within offsets, keeping the assignment of program zero separate from the program. In similar fashion many turning centers allow the assignment of program zero with offsets (this feature is commonly called geometry offsets).Types of compensationNow let’s discuss the compensation types for the two most popular forms of CNC machine tools, machining centers and turning centers. Keep in mind that while the actual use of these functions vary dramatically from one machine to the next, the basic reasoning behind each type is required, and with an elementary understanding of how it is applied to one specific control, you should be able to adapt to any variations that you come across.Tool length compensationThis machining center compensation type allows the programmer to forget about each tool’s length as the program is written. Instead of having to know the exact length of each tool and tediously calculating Z axis positions based on the tool’s length, the programmer simply instates tool length compensation on each tool’s first Z axis approach movement to the work piece.At the machine during setup, the operator will input the tool length compensation value for each tool in the corresponding offset. This, of course, means the tool length compensation value must first be measured.If tool length compensation is used wisely, the tool length compensation value can be measured off line (in a tool length measurement gage) to minimize setup time. With this method, the tool length compensation value is simply the length of the tool.Many CNC controls allow the length of the tool to be used as the offset value. One popular command to instate tool length compensation is G43. Within the G43 command, the programmer includes an H word that specifies the number of the offsetcontaining the tool’s length value. Here is an example program that utilizes tool length compensation with two tools. The program simply drills two holes (one with each tool). Notice that tool length compensation is being instated in lines N015 and N055. Program:O0001 ; Program numberN005 T01 M06 ; Place tool number one in the spindleN010 G54 G90 S400 M03 T02 ; Select coordinate system, absolute mode, startspindle CW at 400 RPM, get tool number tworeadyN013 G00 X1.0 Y1.0 ; Rapid to first XY positionN015 G43 H01 Z.1 M08 ; Instate tool length compensation on first Z move,turn on coolantN020 G01 Z-1.5 F4. ; Drill holeN025 G00 Z.1 M09 ; Rapid out of hole, turn off coolantN030 G91 G28 Z0 M19 ; Return to tool change position, orient spindleN035 M01 ; Optional stopN040 T02 M06 ; Place tool number two in spindleN045 G54 G90 S400 M03 T01 ; Select coordinate system, absolute mode, startspindle at 400 RPM, get tool number onereadyN050 G00 X2. Y1. ; Rapid to first XY positionN055 G43 H02 Z.1 M08 ; Instate tool length compensation on tool’s first Zmove, turn on coolantN060 G01 Z-1.2 F5.5 ; Drill holeN065 G00 Z.1 M09 ; Rapid out of hole, turn off coolantN070 G91 G28 Z0 M19 ; Return to tool change position, orient spindleN075 M30 ; End of program数控的发展先进制造技术中的一个最基本的概念是数字控制（NC）。

Not only the Chinese numerical control lathe present situation andthe trend of developmentanalysis numerical control technology application has brought the revolutionary change for the traditional manufacturing industry, causes the manufacturing industry to become the industrialization the symbol, moreover along with numerical control technology unceasing development and application domain expansion, it to national economy and the people's livelihood some important professions (IT, automobile, light industry, medical service and so on) development more and more vital role, because these professions must equip the digitization already was the modern development major tendency. The current numerical control lathe presents following trend of development. 1. high speed, high precisionHigh speed, precise is the engine bed development eternal goal.Development progresses by leaps and bounds which along with the science and technology, the mechanical and electrical products renewal speed speeds up, increasingly is also high to the components processing precision and the surface quality request.In order to satisfy this complex changeable market the demand, the current engine bed to the high-speed cutting, is doing the cutting and does the direction of cut to develop, the processing precision also in unceasingly enhances. On the other hand, the electricity main axle and the straight line electrical machinery success application, the ceramics ball bearing, the high accuracy lead greatly hollow in cold and the ball bearing nut strong cold low temperature high speed ball bearing guide screw vice-and the belt ball bearing retainer straight line guide rail vice-and so on engine bed function part appearing on the market, also for the engine bed to high speed, the precise development has created the condition. The numerical control lathe picks uses electricity the main axle, has cancelled links and so on leather belt, band pulley and gear, reduced the master drive rotation inertia greatly, enhanced the main axle dynamic speed of response and the work precision, when thorough settlement main axle high-speed operation transmission and so on leather belt and band pulley vibrations and noise question.Picks uses electricity the main axle structure to be possible to enable the main axle rotational speed to achieve above 10000r/min.The straight line motor-driven speed is high, adds the moderating properties to be good, has the superior response characteristic and the followed precision. Made the servo with the straight line electrical machinery to actuate, to omit the ball bearing guide screw this intermediate drive link, eliminated the transmission gap (including reverse gap), themovement inertia was small, the system rigidity was good, could locate precisely under high speed, thus increased the servo precision enormously.Straight line trundle guide rail, because it has respectively to the gap for the zero and the extremely small rolling friction, wears slightly, gives off heat may ignore, has the extremely good thermostability, increased the entire journey pointing accuracy and the repetition pointing accuracy. Through the straight line electrical machinery and the straight line trundle guide rail vice-application, may make the engine bed the rapid traverse speed to enhance 60~80m/min from present 10~20m/mim, even reaches as high as 120m/min.2. redundant reliablenumerical control engine bed reliability is a numerical control engine bed product quality crucial target.Whether does the numerical control engine bed display its high performance, the high accuracy and the high efficiency, and obtains the good benefit, the key is decided by its reliable height.3. function recombinefunction recombine goal is further enhances the engine bed the production efficiency, uses reduces to few in the non-processing non-cutting time.Through the function recombine, may expand the engine bed the use scope, enhances the efficiency, realizes multipurpose one machine, one machine many energy, namely a numerical control lathe already may realize the turning function, also may realize the milling processing; Or in also may realize the abrasive machining by the mill primarily engine bed on.4. intellectualizations, the network, the flexibility and the integrated21st century numerical control equipments has certain intellectualized system. In order to pursue the processing efficiency and the processing quality aspect intellectualization, like processing process adaptive control, craft parameter automatic production; In order to enhance the actuation performance and the use connection aspect intellectualization, like feed-forward control, electrical machinery parameter auto-adapted operation, automatic diagnosis load automatic designation model, self regulating grade; Simplification programming, simplification operation aspect intellectualization, like intellectualized automatic programming, intellectualized man-machine contact surface and so on; Also has the intelligence to diagnose, aspect and so on intelligent monitoring contents, by facilitates the system the diagnosis and the service and so on. The numerical control engine bed the tendency which develops to the flexibility automated system is: From (numerical control single plane, processing center and numerical control compound processing engine bed), line (FMC, FMS, FTL, FML) to surface (construction sectionworkshop independent manufacture island, FA), body (CIMS, distribution network integration manufacture system) the direction develops, on the other hand develops to the attention utility and the efficient direction. The flexible automation technology is the manufacturing industry adapts the dynamic market demand and the product rapid renewal main method, is the various countries' manufacturing industry development mainstream tendency, is the advanced manufacture domain foundation technology.Its key point is by enhances the system the reliability, changes into the premise practical, take the easy networking and the integration as the goal, the attention enhancement unit technology development and the consummation.The CNC single plane to the high accuracy, the high velocity and the high flexible direction develops. The numerical control engine bed and the constitution flexibility manufacture system can conveniently and joints and so on CAD, CAM, CAPP and MTS, develops to the information integration direction.The network system to the opening, the integration and the intellectualized direction develops.中国数控车床的现状和发展趋势分析数控技术的应用不但给传统制造业带来了革命性的变化，使制造业成为工业化的象征，而且随着数控技术的不断发展和应用领域的扩大，它对国计民生的一些重要行业(IT、汽车、轻工、医疗等)的发展起着越来越重要的作用，因为这些行业所需装备的数字化已是现代发展的大趋势。

Development and maintenance of CNC technology Numerical control technology and equipment is the development of new high-tech industry and cutting-edge enabling technology, industry and the most basic equipment. The world information industry, biological industry, aviation, aerospace and other defense industry widely used numerical techniques to improve manufacturing capacity and level, to improve the adaptability of the market and competitiveness. Industrial countries and CNC numerical control technology and equipment will also be listed as countries of strategic materials, not only to develop their own numerical control technology and industry, and in "sophisticated" technology and equipment, numerical control key aspects of the policy of closures and restrictions. Therefore, efforts to develop advanced numerical control technology as the core manufacturing technology has become the world's developed countries to accelerate economic development, enhance the comprehensive national strength and an important way to statehood.Part I: the development of CNC machine tools trends in individual1. High speed, high accuracy, high reliabilityHigh speed: To improve the speed and increase feed spindle speed.High precision: the precision from micron to sub-micron level, and even the nano-level (high reliability: the reliability of numerical control system generally higher than the reliability of numerical control equipment more than an order of magnitude, but not the higher the better reliability because the goods by the cost performance constraints.2. CompositeComposite function CNC machine tool development, its core is in a single machine to complete the turning, milling, drilling, tapping, reaming and reaming and other operating procedures, thereby increasing the efficiency and precision machine tools to improve production flexibility.3. IntelligentIntelligent content included in all aspects of the numerical control system: the pursuit of processing efficiency and processing quality of intelligence; to improve the performance and the use of convenient connections and other aspects of intelligence; simplify programming, simplifying operational intelligence; also like the intelligent automatic programming, intelligent man-machine interface, as well as intelligent diagnostics, intelligent monitoring and other aspects, to facilitate system diagnostics and maintenance.4. Flexible, integratedThe world of CNC machine tools to the development trend of flexible automation systems are: from the point (CNC single, composite machining centers and CNC machine tools), line (FMC, FMS, FTL, FML) to the surface (Section workshop independent manufacturing island FA) , body (CIMS, distributed network integrated manufacturing system) direction, the other to focus on applied and economic direction. Flexible automation technology is the industry to adapt to dynamic market demands and quickly update the primary means of product is the main trend of national manufacturing industry is the basis for the field of advanced manufacturing technology.Second, personalization is the adaptability of the market trendsToday's market, gradually formed the pattern of international cooperation, the products becoming more competitive, efficient and accurate processing of the escalating demand means, the user's individual requirements become increasingly strong, professional, specialization, more and more high-tech machine tools by the users of all ages.Third, the open architecture trend isThe core of a new generation of CNC system development is open. Open software platform and hardware platforms are open systems, modular, hierarchical structure, and through out the form to provide a unified application interface.CNC system to address the closure of the traditional CNC applications and industrial production problems. At present, many countries of open CNC system, CNC system has become an open numerical control system of the future of the road. The open numerical control system architecture specification, communication specifications, configuration specifications, operating platform, function libraries and CNC numerical control system software development tools, system function is the core of the current study. Network numerical control equipment is nearly two years of a new focus. NC network equipment will greatly satisfy the production lines, manufacturing systems, manufacturing information integration needs of enterprises, but also achieve new manufacturing model, such as agile manufacturing, virtual enterprises, global manufacturing the base unit. Some well-known at home and abroad, and CNC CNC machine tools manufacturing company inPart II: Machine MaintenanceCNC machine tools is electronic technology, measurement technology, automation technology, semiconductor technology, computer technology and electrical technology, and integrated set of automation equipment, high precision, high efficiency and high flexibility. CNC machine tools is a process control equipment and asked him in real-time control of the accuracy of every moment of work, any part of the fault and failure, so that the machine will shut down, resulting in production stoppages, which seriously affected and restricted the production efficiency . CNC machine tools in many industries to work the device is critical, if not after a failure in its maintenance and troubleshooting time, it will cause greater economic losses. Therefore, the principle that complex numerical control system, structure, maintenance of sophisticated equipment is necessary. CNC machine tools to enhance fault diagnosis and maintenance of power, can improve the reliability of CNC machine tools, CNC machine tools is conducive to the promotion and use.CNC machine tools is a mechanical, electrical, hydraulic, gas combination of complex equipment, though the reasons for failure vary, but the failure occurred, the general idea of the steps are the same. Fails,Spindle start below to stop immediately after the fault diagnosis of CNC machine tools as an example the general process.First, the fault-site investigation. The survey content includes 1, 2 types of failure, the failure frequency of 3, 4, external conditions, the operating conditions 5, 6, machine conditions, the functioning of 7, wiring between machine tools and systems 8, CNC equipment visual inspection. After an investigation, such failure is spindle class failure, only once, outside of all normal, the operator of a boot to reflect this situation.Second, the fault information collation, analysis. For some simple fault, because not alot of time, the method can be used form of logical reasoning, analysis, identification and troubleshooting. After a failed on-site investigation for several reasons we suspect that the system output pulse ①②drive is not enough time to move the state line to control the spindle components ③④damage to the spindle motor short-circuit, causing the spindle thermal relay protection ⑤ not with self-control loop lock circuits, and the parameter is set to pulse signal output, so that the spindle can not operate normally. Identify possible reasons to rule out one by one.Third, conduct fault diagnosis and troubleshooting.Diagnosis usually follows the following principles: 1, after the first outside inside. Reliable line of modern CNC system increasingly high failure rate of CNC system itself less and less, and most are non-occurrence of failure causes the system itself. The CNC machine is a mechanical, hydraulic, electrical as one of the tools, the occurrence of the fault will be reflected by these three comprehensive, maintenance personnel should be from outside to inside one by one investigation to avoid arbitrary unsealed, demolition, otherwise expand the malfunction, so that the loss of precision machine tools, slow performance, outside the system detected the fault is due to open one by one, hydraulic components, pneumatic components, electrical actuators, mechanical devices caused problems. 2, the first after the electrical machinery. In general, the mechanical failure easier to find, and numerical control system and electrical fault diagnosis more difficult, before the troubleshooting to rule out mechanical failure of the first 3, after the first static dynamic. Power off the machine first, quiescent state, through understanding, observation, testing, analysis, confirm the power failure will not result in expansion of the incident only after the power to the machine, run the state, the dynamic of observation, inspection and testing, to find fault. While after the devastating power failure, you must first rule out the danger, before electricity. 4, after the first simple and complex. When multiple failures are intertwined, and sometimes impossible to start with, we should first solve the problem easily, then solve the difficult problem, often a simple problem to solve, the difficulty of the problem may also become easier.CNC machine tools in the fault detection process, should make full use of numerical control system self-diagnostic features to be judged, but also flexibility in the use of some common troubleshooting methods. Troubleshooting common methods are:1. Routine examination methodRoutine examination method is mainly of hands, eyes, ears, nose and other organs of the fault occurrence of various light, sound, smell and abnormal observations and careful look at every system, follow the "first post outside of" the principle of fault diagnosis by looking, listening, smelling, asking, mold and so on, from outside to inside one by one check, the fault can often be narrowed down to a module or a printed circuit board. This requires maintenance personnel have a wealth of practical experience, to the wider multidisciplinary and comprehensive knowledge of the ability to judge.2. Self-diagnostic function methodModern CNC system has yet to achieve a high degree of intelligence. But already has a strong self-diagnostic function. CNC ready to monitor the hardware and software is working. Once the abnormal, immediately displayed on the CRT alarm or fault LEDs indicate the approximate cause. Using self-diagnosis function, but also shows the interface signals between the system and the host state, in order to determine the fault occurred in themechanical part or parts of NC system, and indicate the approximate fault location. This method is currently the most effective maintenance methods.3. Functional program testing methodSo-called functional program testing method is commonly used in the numerical control system functions and special features, such as linear positioning, circular interpolation, helical cut, fixed cycle, such as the user macro programming by hand or automatic programming methods, the preparation of test procedures into a functional program , into the numerical control system, and then start the CNC system to make it run, to check the im time the first boot of CNC whether a programming error or operational error or machine4. Spare parts substitutionSpare parts replacement method is a simple method to determine the scene is one of the most commonly used. The so-called spare substitution is generally the cause of failure in the analysis of the case, maintenance personnel can use the alternate PCB, templates, integrated circuit chip or replace the questionable parts of components, which narrowed the fault to a printed circuit board or chip level. It is actually in the verification analysis is correct. However, before switching the standby board should carefully check the spare board is intact, and should check the status of reserve board should be fully consistent with the original board the state. This includes checking with the board selection switch, set the location and the short rod potentiometer position. In short, we must strictly in accordance with the system's operation, maintenance requirements manual operation.In determining the replacement of a part to, should carefully check the relevant connected to electrical lines and other related, confirming that no failure up to the new replacement to prevent failures caused by external damage to replace the parts up.5. Transfer ActThe so-called transfer method is to have the same numerical control system features two printed circuit boards, templates, integrated circuit chips or components to exchange, observed failure phenomena be transferred. In this way, the system can quickly determine the fault position. This method is actually a kind of spare parts substitution. Therefore, the considerations described in the same spare parts substitution.6. Parameter check methodKnown parameters can directly affect the numerical performance of CNC machine tools. Parameters are usually stored in the magnetic bubble memory, or stored in batteries to be maintained by the CMOS RAM, once the battery is low or because of outside interference and other factors, some parameters will be lost or change in chaos, so that the machine does not work. At this point, through the proofreading, correction parameters, will be able to troubleshoot. When the machine idle for a long time to work again for no reason that there is no normal or failure without warning, it should be based on fault characteristics, inspection and proof-reading the relevant parameters.After a long run of CNC machine tools, wear and tear due to its mechanical drive components, electrical component performance changes and other reasons, also need to adjust the parameters of its. Some machine tool failure is often not timely because the parameters change due to some not meet. Of course, these failures are the fault of the areas are soft.7. Measurement of Comparative LawCNC system in the design of printed circuit board manufacturing plant, in order to adjust, repair facilities, in the printed circuit board designed a number of test terminals. Users can also use normal printed circuit board terminals comparing the measured and the difference between the printed circuit board failure. These terminals can detect the voltage and waveform measurements, analyze the causes of failure and failure location. Even on a normal printed circuit board can sometimes artificially create "fault", such as broken connection or short circuit, unplug the components, in order to determine the real cause of failure. Therefore, maintenance personnel should be in the usual accumulation of key parts of the printed circuit board or failure-prone parts of the right in the normal waveform and voltage values. Because the CNC system manufacturer often does not provide the information in this regard.8. Percussion methodWhen the CNC system failures showed Ruoyouruowu, often used method for detecting the fault struck the site lies. This is because the numerical control system is composed by the multi-block printed circuit boards, each board has a lot of solder joints, plates or between modules and is connected through the connectors and cables. Therefore, any cold solder joint or bad, may cause a malfunction. When the tap with the insulation and poor contact with Weld doubt at fault must be repeated reproduction.9. Local heating methodAfter a long running CNC system components are to be aging, performance will deteriorate. When they are not fully damaged, failures will become from time to time. Then heat can be used such as a hair dryer or electric iron is suspected to local heating components, accelerating the aging so thoroughly exposed fault components. Of course, using this method, be sure to pay attention to components of the temperature parameters, do not roast the original device is a good or bad.10. Principle of analysisThe composition according to principles of numerical control system can be analyzed from various points of logical levels and logical parameters (such as voltage or waveform) and then with a multimeter, logic pen, only the oscilloscope or logic analyzer to measure, analyze and compare, and thus failure positioning. Using this method, which requires maintenance personnel to be on the whole system or the principle of each circuit have a clear, deep understanding.Based on the above principles and methods, we may be itemized on the check it and eliminate the causes.The first possible failure for the system output pulse time is not enough, we adjust the M-code system, start the spindle output time, found the problem still exists, and then find the next possible cause may be in the drive to move the state, refer to the manual drive , set parameters start the spindle, the problem still exists we suspected spindle motor short-circuit, resulting in thermal relay protection. Then find the cause of the short, so that the spindle thermal relay reset the start and found that the normal operation of the spindle, the problem solved.Fourth, do a lessons learned and recorded. After troubleshooting, repair work can not be considered complete, still need technical and management aspects of the underlying causes of failure have to take appropriate measures to prevent failures from happening again. Underfield conditions when necessary use of mature technologies to transform and improve the equipment. Finally, the failure of the maintenance of the phenomenon, cause analysis, resolution process, the replacement of components, legacy, etc. to make a record.数控技术的发展与维修数控技术及装备是发展新兴高新技术产业和尖端工业的使能技术和最基本的装备。

1 原文一CNC machine tools Outdate, J. and Joe, J. Configuration Synthesis of Machining Centers with Tool ，John Wiley & sons, 2001 While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment. The The first first first benefit benefit benefit offered offered offered by by by all all all forms forms forms of of of CNC CNC CNC machine machine machine tools tools tools is is is improved improved automation. automation. The The The operator operator operator intervention intervention intervention related related related to to to producing producing producing work work work pieces pieces pieces can can can be be reduced reduced or or or eliminated. eliminated. eliminated. Many Many Many CNC CNC CNC machines machines machines can can can run run run unattended unattended unattended during during during their their their entire entire machining machining cycle, cycle, cycle, freeing freeing freeing the the the operator operator operator to to to do do do other other other tasks. tasks. tasks. This This This gives gives gives the the the CNC CNC CNC user user several several side side side benefits benefits benefits including including including reduced reduced reduced operator operator operator fatigue, fatigue, fatigue, fewer fewer fewer mistakes mistakes mistakes caused caused caused by by human human error, error, error, and and and consistent consistent consistent and and and predictable predictable predictable machining machining machining time time time for for for each each each work work work piece. piece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing work pieces with conventional machine tools. The second major benefit of CNC technology is consistent a nd accurate work and accurate work pieces. Today's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical work pieces can be easily produced with precision and consistency. A third benefit offered by most forms of CNC machine tools is flexibility. Since these these machines machines machines are are are run run run from from from programs, programs, programs, running running running a a a different different different workpiece workpiece workpiece is is is almost almost almost as as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements. Motion control - the heart of CNC The The most most most basic basic basic function function function of of of any any any CNC CNC CNC machine machine machine is is is automatic, automatic, automatic, precise, precise, precise, and and consistent consistent motion motion motion control. control. control. Rather Rather Rather than than than applying applying applying completely completely completely mechanical mechanical mechanical devices devices devices to to cause cause motion motion motion as as as is is is required required required on on on most most most conventional conventional conventional machine machine machine tools, tools, tools, CNC CNC CNC machines machines allow motion control in a revolutionary manner2. All forms of CNC equipment have two two or or or more more more directions directions directions of of of motion, motion, motion, called called called axes. axes. axes. These These These axes axes axes can can can be be be precisely precisely precisely and and automatically automatically positioned positioned positioned along along along their their their lengths lengths lengths of of of travel. travel. travel. The The The two two two most most most common common common axis axis types are linear (driven along a straight path) and rotary (driven along a circular path). Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed programmed commands. commands. commands. Generally Generally Generally speaking, speaking, speaking, the the the motion motion motion type type type (rapid, (rapid, (rapid, linear, linear, linear, and and circular), the axes to move, the amount of motion and the motion rate (federate) are programmable with almost all CNC machine tools. A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw drives the linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3. Refer to fig.1. fig.1 typical drive system of a CNC machine tool Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis. How axis motion is commanded - understanding coordinate systems It would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion motion amount4. amount4. amount4. (This (This (This would would would be be be like like like having having having to to to figure figure figure out out out how how how many many many turns turns turns of of of the the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more a much simpler and more logical logical way way way by by by utilizing utilizing utilizing some some some form form form of of of coordinate coordinate coordinate system. system. system. The The The two two two most most most popular popular coordinate coordinate systems systems systems used used used with with with CNC CNC CNC machines machines machines are are are the the the rectangular rectangular rectangular coordinate coordinate coordinate system system and and the the the polar polar polar coordinate coordinate coordinate system. system. system. By By By far, far, far, the the the more more more popular popular popular of of of these these these two two two is is is the the rectangular coordinate system. The program zero point establishes the point of reference for motion commands in in a a a CNC CNC CNC program. program. program. This This This allows allows allows the the the programmer programmer programmer to to to specify specify specify movements movements movements from from from a a common common location. location. location. If If If program program program zero zero zero is is is chosen chosen chosen wisely, wisely, wisely, usually usually usually coordinates coordinates coordinates needed needed needed for for the program can be taken directly from the print. With this technique, if the programmer wishes the tool to be sent to a position one one inch inch inch to to to the the the right right of of the the the program program program zero zero zero point, point, point, X1.0 X1.0 X1.0 is is is commanded. commanded. If If the the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer to fig.2, 3. fig.2, 3. Understanding absolute versus incremental motion All discussions to this point assume that the absolute mode of programming is used6. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion. In the incremental mode (commonly specified by G91), end points for motions are are specified specified specified from from from the the the tool's tool's tool's current current current position, position, position, not not not from from from program program program zero. zero. zero. With With With this this method method of of of commanding commanding commanding motion, motion, motion, the the the programmer programmer programmer must must must always always always be be be asking asking asking "How "How "How far far should should I I I move move move the the the tool?" tool?" tool?" While While While there there there are are are times times times when when when the the the incremental incremental incremental mode mode mode can can can be be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode. Be Be careful careful careful when when when making making making motion motion motion commands. commands. commands. Beginners Beginners Beginners have have have the the the tendency tendency tendency to to think think incrementally. incrementally. incrementally. If If If working working working in in in the the the absolute absolute absolute mode mode mode (as (as (as beginners beginners beginners should), should), should), the the programmer should always be asking "To what position should the tool be moved?" This position is relative to program zero, NOT from the tools current position. Aside Aside from from from making making making it it it very very very easy easy easy to to to determine determine determine the the the current current current position position position for for for any any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands. In the absolute mode, if a motion mistake is made in one one command command command of of of the the the program, program, program, only only only one one one movement movement movement will will will be be be incorrect. incorrect. incorrect. On On On the the the other other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect. Assigning program zero Keep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. program. With this With this method, the programmer tells the control how far it is from from the the program program zero point to zero point to t he starting position of the machine. This the starting position of the machine. This is is commonly done commonly done with a G92 (or G50) command at least at the beginning of the program and possibly at the beginning of each tool. Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets. fig.4 assign program zero through G54 Flexible manufacturing cells A flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS: 1. An FMC is not under the direct control of the central computer. Instead, instructions from the central computer are passed to the cell controller. 2. The cell is limited in the number of part families it can manufacture. The following elements are normally found in an FMC: • Cell controller • Programmable logic controller (PLC) • More than one machine tool • A materials handling device (robot or pallet) The The FMC FMC FMC executes executes executes fixed fixed fixed machining machining machining operations operations operations with with with parts parts parts flowing flowing flowing sequentially sequentially between operations. High speed machining The term High Speed Machining (HSM) commonly refers to end milling at high rotational rotational speeds speeds speeds and and and high high high surface surface surface feeds. feeds. feeds. For For For instance, instance, instance, the the the routing routing routing of of of pockets pockets pockets in in aluminum airframe sections with a very high material removal rate1. Refer to fig.5 for the cutting data designations and for mulas. Over the past 60 60 years, HSM years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the the production production production of of of components components components with with with specific specific specific surface surface surface topography topography topography requirements requirements requirements and and machining machining of of of materials materials materials with with with hardness hardness hardness of of of 50 50 50 HRC HRC HRC and and and above. above. above. With With most most steel steel components components hardened hardened hardened to to to approximately approximately approximately 32-42 32-42 32-42 HRC, HRC, HRC, machining machining machining options options options currently currently include: Fig.5 cutting data rough rough machining machining machining and and and semi-finishing semi-finishing semi-finishing of of of the the the material material material in in in its its its soft soft soft (annealed) (annealed) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrodes and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting cutting tools) tools) tools) finishing finishing finishing and and and super-finishing super-finishing super-finishing of of of cylindrical/flat/cavity cylindrical/flat/cavity cylindrical/flat/cavity surfaces surfaces surfaces with with appropriate cemented carbide, cermets, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN) For many components, the production process involves a combination of these options options and and and in in in the the the case case case of of of dies dies dies and and and moulds moulds moulds it it it also also also includes includes includes time time time consuming consuming consuming hand hand finishing. Consequently, production costs can be high and lead times excessive. It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering. The main criteria are the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy. One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times. Main economical and technical factors for the development of HSM Survival The The ever ever ever increasing increasing increasing competition competition competition in in in the the the marketplace marketplace marketplace is is is continually continually continually setting setting setting new new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions... Materials The development of new, more difficult to machine materials has underlined the necessity necessity to to to find find find new new new machining machining machining solutions. solutions. solutions. The The The aerospace aerospace aerospace industry industry industry has has has its its its heat heat resistant resistant and and and stainless stainless stainless steel steel steel alloys. alloys. alloys. The The The automotive automotive automotive industry industry industry has has has different different different bimetal bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The The die die die and and and mould mould mould industry industry industry mainly mainly mainly has has has to to to face face face the the the problem problem problem of of of machining machining machining high high hardened tool steels, from roughing to finishing. Quality The The demand demand demand for for for higher higher higher component component component or or or product product product quality quality quality is is is the the the result result result of of of ever ever increasing competition. HSM, if applied correctly, offers a number of solutions in this area. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry. Processes The demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes processes can can can also also also be reduced or eliminated with be reduced or eliminated with HSM. Design & development One of the main tools in today's competition is to sell products on the value of novelty. novelty. The The The average average average product product product life life life cycle cycle cycle on on on cars cars cars today today today is is is 4 4 4 years, years, years, computers computers computers and and accessories accessories 1.5 1.5 1.5 years, years, years, hand hand hand phones phones phones 3 3 3 months... months... months... One One One of of of the the the prerequisites prerequisites prerequisites of of of this this development of fast design changes and rapid product development time is the HSM technique. Complex products There is an increase of m ulti-functional multi-functional multi-functional surfaces surfaces surfaces on components, such on components, such a s new as new design design of of of turbine turbine turbine blades blades blades giving giving giving new new new and and and optimized optimized optimized functions functions functions and and and features. features. features. Earlier Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpiece that have to be machined (medical equipment, electronics, defense products, computer parts). Production equipment The The strong strong strong development development development of of of cutting cutting cutting materials, materials, materials, holding holding holding tools, tools, tools, machine machine machine tools, tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5. Definition of HSM Salomon's Salomon's theory, theory, theory, "Machining "Machining "Machining with with with high high high cutting cutting cutting speeds..." speeds..." speeds..." on on on which, which, which, in in in 1931, 1931, took out a German patent, assumes that "at a certain cutting speed (5-10 times higher than than in in in conventional conventional conventional machining), machining), machining), the the the chip chip chip removal removal removal temperature temperature temperature at at at the the the cutting cutting cutting edge edge will start to decrease...".See fig.6. Fig.6 chip removal temperature as a result of the cutting speed Given Given the the the conclusion:" ... conclusion:" ... seems seems to to to give give give a a a chance chance chance to to to improve improve improve productivity productivity productivity in in machining with conventional tools at high cutting speeds..." Modern research, unfortunately, has not been able to verify this theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials. The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors. Given Given today's today's today's technology, technology, technology, "high "high "high speed" speed" speed" is is is generally generally generally accepted accepted accepted to to to mean mean mean surface surface speeds between 1 and 10 kilometers perminute, or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being being used. used. used. One One One trend trend trend which which which is is is very very very evident evident evident today today today is is is the the the use use use of of of very very very large large large cutter cutter diameters for these applications - and this has important implications for tool design. There are many opinions, many myths and many different ways to define HSM. Maintenance and troubleshooting Maintenance for a horizontal MC The The following following following is is a a list list list of of of required required required regular regular regular maintenance maintenance for for a a a Horizontal Horizontal Machining Center as shown in fig.7. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty. Fig. 7 horizontal machining center Daily Top Top off off off coolant coolant coolant level level level every every every eight eight eight hour hour hour shift shift shift (especially (especially (especially during during during heavy heavy heavy TSC TSC usage). Check way lube lubrication tank level. Clean chips from way covers and bottom pan. Clean chips from tool changer. Wipe spindle taper with a clean cloth rag and apply light oil. Weekly • Check for proper operation of auto drain on filter regulator. See fig. 8 Fig. 8 way lube and pneumatics On machines with the TSC option, clean the chip basket on the coolant tank. Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the controller and POWER OFF the control before working on the coolant tank. Do this monthly for machines without the TSC option. Check air gauge/regulator for 85 psi. For For machines machines machines with with with the the the TSC TSC TSC option, option, option, place place place a a a dab dab dab of of of grease grease grease on on on the the the V-flange V-flange V-flange of of tools. Do this monthly for machines without the TSC option. Clean exterior surfaces with mild cleaner. DO NOT use solvents. Check the hydraulic counterbalance pressure according to the machine's specifications. Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools". Monthly Check oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank. Clean pads on bottom of pallets. Clean Clean the the the locating locating locating pads pads pads on on on the the the A-axis A-axis A-axis and and and the the the load load load station. station. station. This This This requires requires removing the pallet. • Inspect Inspect way way way covers covers covers for for for proper proper proper operation operation operation and and and lubricate lubricate lubricate with with with light light light oil, oil, oil, if if necessary. Six months Replace coolant and thoroughly clean the coolant tank. Check all hoses and lubrication lines for cracking. Annually • Replace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil. • Check oil filter and clean out residue at bottom for the lubrication chart. Replace air filter on control box every 2 years. Mineral Mineral cutting cutting cutting oils oils oils will will will damage damage damage rubber rubber rubber based based based components components components throughout throughout throughout the the machine. Troubleshooting This section is intended for use in determining the solution to a known problem. Solutions Solutions given given given are are are intended intended intended to to to give give give the the the individual individual individual servicing servicing servicing the the the CNC CNC CNC a a a pattern pattern pattern to to follow in, first, determining the problem's source and, second, solving the problem. Use common sense Many Many problems problems problems are are are easily easily easily overcome overcome overcome by by by correctly correctly correctly evaluating evaluating evaluating the the the situation. situation. situation. All All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, don't expect the machine to correct the fault. Don't Don't suspect suspect suspect machine machine machine accuracy accuracy accuracy if if if the the the vise vise vise bends bends bends the the the part. part. part. Don't Don't Don't claim claim claim hole hole miss-positioning if you don't first center-drill the hole. Find the problem first Many Many mechanics mechanics mechanics tear tear tear into into into things things things before before before they they they understand understand understand the the the problem, problem, problem, hoping hoping that it will appear as they go. We know this from the fact that more than half of all warranty warranty returned returned returned parts parts parts are are are in in in good good good working working working order. order. If If the the the spindle spindle spindle doesn't doesn't doesn't turn, turn, remember remember that that that the the the spindle spindle spindle is is is connected connected connected to to to the the the gear gear gear box, box, box, which which which is is is connected connected connected to to to the the spindle spindle motor, motor, motor, which which which is is is driven driven driven by by by the the the spindle spindle spindle drive, drive, drive, which which which is is is connected connected connected to to to the the the I/O I/O BOARD, BOARD, which which which is is is driven driven driven by by by the the the MOCON, MOCON, MOCON, which which which is is is driven driven driven by by by the the the processor. processor. processor. The The moral here is doing replace the spindle drives if the belt is broken. Find the problem first; don't just replace the easiest part to get to. Don tinker with the machine There are hundreds of parameters, wires, switches, etc., that you can change in this machine. Don't start randomly changing parts and parameters. Remember, there is a good chance that if you change something, y ou will incorrectly install it or break you will incorrectly install it or break something else in the process6. Consider for a moment changing the processor's board. First, you have to download all parameters, remove a dozen connectors, replace the board, board, reconnect reconnect reconnect and and and reload, reload, reload, and and and if if if you you you make make make one one one mistake mistake mistake or or or bend bend bend one one one tiny tiny tiny pin pin pin it it WON'T WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better. 。

NC technology application and development prospects The numerical control technology is the development emerging high-techindustry and the state-of-art industry enables the technology. Variouscountries defense industry and so on information industries,biological industry, aviation, astronautics widely uses the numericalcontrol technology, sharpens the manufacturing capacity and the level,enhances to the market adaptiveness and the competitive ability.1.NC technology development trendsNC technology applications not only to the traditional manufacturing industry has brought revolutionary changes to the manufacturing sector to become a symbol of industrialization, and with the continuous development of NC technology and the expansion of application fields, he Guojiminsheng some of the important sectors (it , Automobiles, light industrial, medical, etc.) development plays an increasingly important role, because these industries for the digital equipment is the major trend of modern development. NC from the world's technology and its equipment development trends, its main research focus in the following areas [1-4].1.1 High-speed, high-finishing technology and equipment to the new trend Efficiency, and quality is the main body of advanced manufacturing technology.High-speed, high-finishing technologies can greatly increase efficiency, improve product quality and grades, and shorten the production cycle and enhance market competitiveness. To that end Japan will tip technology research as its five major modern manufacturing technology of international production Engineering Society (cirp) be identified as the 21st century one of the studies.In the car industry, with an annual output of 300,000 rhythms of production is 40 seconds / vehicles, but cars are more varieties processing equipment needed to be solved in one of the key problems in the field of aviation and aerospace industry, processing more for the thin-walled parts And the thin line, stiffness poor material for aluminum or aluminum alloy, only high cutting speed and cutting force in small cases, can these tendons, wall processing. Recently a large overall aluminum billet "hollowed out" approach to manufacture wings, fuselage and other parts to replace large parts by a large number of rivets, screws and other means assembled links to members of the strength, stiffness and reliability Is improved. These are the proposed high-speed processing equipment, high-precision and high flexibility requirements.Emo2001 show from the situation, high-speed processing center feed rate up to 80 m / min, or even higher, and air speed up to 100 m / min around. At present many of the world's automobile plants, including China's Shanghai General Motors Corp., have adopted a high-speed processing center of the production line somecombination of alternative machine. U.S. Cincinnati hyper mach machine tool company to the maximum speed of 60 m / min, quick to 100 m / min, acceleration of 2 g, spindle speed has reached 60 000r/min. A thin-walled processing aircraft parts, only 30 min, and the same high-speed milling machine parts in the general processing takes 3 h, in the general processing and milling machine to be 8 h; Germany dmg company's dual-spindle lathe spindle speed and acceleration respectively 12 *! 000 r / mm And 1 g.In the processing precision, the past 10 years, the general level of processing precision CNC machine tools by 10 μ m to 5 μ m, Precision Machining Center from 3 ~ 5 μ m, to 1 ~ 1.5 μ m, and ultra-precision machining accuracy has begun to enter the nano - - (0.01 μ m).The reliability of foreign NC devices mtbf value has reached more than 6 000h, servo system mtbf value reached more than 30000 h, showing a very high reliability.In order to achieve high-speed, high-finished, its accompanying features such as the spindle, linear motor has been the rapid development of applications to further expand.1.2 5-axis processing and rapid development of the processing machineUsing a 5-axis three-dimensional surface of the parts processing, the best available tool for cutting geometry, not only finish high, but also substantially improve efficiency. Is generally believed that, one 5-axis machine efficiency can be equivalent to 2 sets of 3-axis machine tools, in particular the use of super-hard materials such as cubic boron nitride for high-speed milling cutter hardened steel parts, 5-axis processing comparable three-axis Processing to play a higher efficiency. But in the past due to 5-axis NC system, host of complex reasons, its price than the three-axis CNC machine tools is several times higher, plus the programming more difficult, and restricted the 5-axis machine tool development.At present, due to the emergence of spindle, making 5-axis processing to achieve the main axis of the first structure greatly simplified and its manufacturing difficulties and costs significantly reduced, the NC system to narrow the price gap. Therefore promotion of the first type of spindle 5-axis machine tools and composite Machines (including 5-Machines) development.Emo2001 in the exhibition, the new Japanese machine-processing machine used five main axis of the first to achieve four vertical plane of any point of processing and processing, making 5 of 5-axis machining processing and the same machine can be achieved, Can achieve tilt-and inverted cone-processing. German exhibition companies dmg dmuvoution series processing center, a fixture in the 5-processing and 5-axis machining, cnc system can be controlled or cad / cam direct or indirect control.1.3 Intelligent, open-end, the network has become the contemporary development of numerical control system of the main trendsNC 21 will be equipped with certain intelligent systems, intelligent content, including numerical control systems in all aspects: the pursuit of processing efficiency and quality of the intelligence processing, such as the adaptive control process, process Parameters automatically generated; drive to improve performance and facilitate the use of intelligent connection, such as feed forward control, the electrical parameters of adaptive computing, automatic identification load automatically selected model, self-tuning, and so to simplify programming, simplifying the operation Intelligent, such as intelligent automatic programming, intelligent man-machine interface; are intelligent diagnosis, intelligent monitoring of the content, facilitate the diagnosis and repair.To address the traditional system of NC and NC closed the application software industry production of the existing problems. At present, many countries open NC system to study, such as the United States ngc (the next generationwork-station/machine control), the EC osaca (open system architecture for control within automation systems), Japan's osec (open system environment for controller), China's onc (open numerical control system) and so on. NC system and opening up has become a numerical control system for the future path. The so-called open system that is NC NC system in the development of a unified operating platform, and the machine tool manufacturers and end-users, through the change, increase or cut structural object (NC function), a series, and easily The user's application-specific integrated into the technical know-how and control system, and rapid realization of different species, different grades of open NC system, forming a distinct personality of the brand-name products. NC currently open system architecture standards, communications standards, standardized configuration, operating platforms, NC system and the NC system functions such as software development tools is the core of the current study.NC Network equipment is world-renowned machine tool the past two years, the Expo a new bright spot. NC equipment of the network will greatly meet the production lines, manufacturing systems, manufacturing enterprise information integration on the demand, but also create a new model such as agile manufacturing, virtual enterprises, the global manufacturing base unit. Some well-known at home and abroad CNC machine tools and CNC manufacturing company in the past two years introduced a new concept and related prototype, as in emo2001 exhibition, the Japanese Yamazaki Mazak (mazak) at the company's "cyber production center" (Smart Production Control Center, or cpc); Japan's Okuma (okuma) machine tool company at "it plaza" (Information Technology Square, referred to it Square);Germany's Siemens (Siemens) at the company's open manufacturing environment (open manufacturing environment, or omen ), Reflecting the NC machine tool to develop in the direction of the network trend.1.4 Takes the new technical standard, the standard establishment(1)About numerical control system design development gaugeAs noted previously, there are better common ability , flexibility , adaptability , expanding in the open numerical control system, countries such as U.S.A. , European Community and Japan ,etc. implement the strategic development plan one after another , carry on research and formulation of the systematic norm of structural numerical control of the open system (OMAC , OSACA , OSEC ), 3 of world heavy economy carry on the same science plan and standardize formulation nearly in a short time most, have indicated a new arrival of period of change of the technology of numerical control. Our country started research and formulation which standardized the frame of ONC numerical control system of China too in 2000.(2) About the numerical control standardThe numerical control standard is a kind of trend of information-based development of manufacturing industry. Numerical control technology information exchange of 50 year born , to based on ISO6983 standard, adopt G , M code describes how processes, its essential characteristic faces the processing course, obviously, he can't meet demands of high-speed development of the technology of modern numerical control more and more already. For this reason, studying and making a kind of new CNC system standard ISO14649 (STEP-NC ) in the world, its purpose is offering a kind of neutral mechanism not depending on the concrete system , can describe the unified data model in whole lifespan of the products , thus realize the whole manufacture process, and even the standardization of each industrial field product information. acne of STEP-NC may be a revolution of the technical field of the numerical control, on development and even the whole manufacturing industry of the technology of numerical control , will exert afar-reaching influence. First of all, STEP-NC puts forward a kind of brand-new manufacture idea , in the traditional manufacture idea, NC processes the procedures to all concentrate on single computer. Under the new standard, NC procedure canbe dispersed on Internet, this is exactly a direction of open , networked development of technology of numerical control. Secondly, STEP-NC numerical control system also can reduce , process (about 75% ) drawing , process procedure work out (about 35% ) time and process (about 50% ) time greatly.At present, American-European countries pay much attention to the research of STEP-NC, Europe initiates IMS plan (1999.1.1- 2001.12.3 ) of STEP-NC. 20CAD/CAM/CAPP/CNC users , manufacturers and academic organizations from Europe and Japan participated in this plan. STEP Tools Company of U.S.A. is a developer of the data interchange software of manufacturing industry in the global range, he has already developed and accused of the super model (Super Model ) of information exchange of machine tooling by counting, its goal is to describe all processing courses with the unified norm. Such new data interchange form hasalready been verified in allocating the SIEMENS , FIDIA and European OSACA-NC numerical control at present.2. World numerical control engine bed industry market and expense demand2.1 Market demand development and pattern changeThe world equipment manufacturing industry market is making great strides forward to the comprehensive information direction, the technological development main performance for the flexible manufacture system, the computer integration manufacture system development and the application, and develops to the manufacture intellectualization direction.The market pattern performance for the colony development tendency, namely homogeneous industrial or the correlation industry enterprise organically gathers in the same place, through unceasingly innovates wins the competitive advantage2.2 World engine bed industry productive consumption and trade（1）Engine bed productionIn 2006 the world engine bed output value is 59.25 billion US dollars, with compared to increases 10.4%, increases nearly 5.6billion US dollars compared to 2005, the concrete data see Table 1.Before the world engine bed production five are in turn: Japan 13.52billion US dollar, Germany 10.78 billion US dollar, China 7.06 billion US dollar, Italian 5.45 billion US dollars with South Korean 4.14billion US dollars. In first five has three in Asia, two in Europe.（2）The engine bed expendsStarts from 2003, China became the global biggest engine bed to expend the country, also was in the world the biggest numerical control engine bed imports the country. In 2006 China continued to maintain the engine bed to expend the world first, imports first, produces third and exports the eighth status.（3）Engine bed tradeIn 2006 the world engine bed total export is 33.73 billion US dollars, approximately composes the world engine bed output value 57%.This indicated the world engine bed produces one above the half is the exportation, keeps only four tenths which uses for oneself.3. The Chinese numerical control engine bed industry is risingOur country engine bed profession is being in the high speed development time, profession total output value and the sales income continuously 6 years maintains 20% above the growth, the numerical control engine bed expends continuously for 5 years to be situated the world first. The strong market demand has brought the development opportunity, " 十15 " Period will be the numerical control engine bed big development time, the country highly takes with the support development domestic product numerical control engine bed, has formulated the numerical control engine bed development plan, has appeared the corresponding supportpolicy, the domestically produced numerical control engine bed accounts for the domestic market proportion 2010 to reach 50%，mix domestic numerical control system (popular ) to up to 10%.3.1 Review the development course in the past 50 years of technology of numerical control of our country, especially pass the brainstorm of 4 Five-Year Plans, all in all has made following achievements：（1）Have establish the foundation of the technical development of numerical control, has basically mastered the technology of modern numerical control. Our country know from numerical control system , servo urge , numerical control host computer , special plane and their basic of fittings basically already now, among them most technology have already possessed the foundation that is commercialized and developed , some technology has already, industrialization commercialized.（2）Have formed the industrial base of numerical control tentatively. In tackling key problems the foundation that the achievement and some technology commercialize , set up the systematic factories of numerical control with production capacity of batch such as numerical control of Central China , spaceflight numerical control etc.. Electrical machinery plant of Lanzhou, a batch of servo systems and first machine tool plant , first machine tool plant of Jinan of servo electrical machinery factory and Beijing ,etc. several numerical control host computer factories such as the numerical control in Central China. These factories have basically formed the numerical control industrial base of our country.（3）Have set up research of a numerical control, development , managerial talent's basic team .Though has made considerable progress in research and development and industrialization of the technology of numerical control, but we will realize soberly, the research and development of the technology of advanced numerical control of our country, there is greater disparity between current situation and current demand of our country of engineering level especially in industrialization. Though very fast from longitudinal development to watch our country, horizontal until (contrast with foreign countries ) , the engineering level has disparity, there is disparity too in development speed in some aspects, i.e. the disparity of engineering level between some high-grade , precision and advanced numerical control equipment has the tendency to expand .3.2 Watch from world , estimate roughly as follows about the numerical control engineering level of our country and industrialization level：（1）On the engineering level, in probably backward 10- 1 years with the advanced level in foreign countries, it is bigger in high-quality precision and sophisticated technology.（2）At the industrialization level, the market share is low, the variety coverage rate is low, have not formed the large-scale production yet; Function part specialized level of production and form a complete set ability to be lower; Appearance quality is relatively poor; Dependability is not high, the commercialized intensity is insufficient; Not setting up one's own brand effect yet in domestic numerical control system, users have insufficient confidence.（3）At the ability of sustainable development, to competition numerical control research and development of technology, engineered ability weaker; Numerical control technological application expand efforts to be better; The research , formulation that relevant standards are normal lags behind.3.3 I t is analyzed that the main reason for having disparity described above has the following several respect.（1）Realize the respect. Know to domestic numerical control industry process arduousness , complexity and long-term characteristic insufficiently; One that is to market substandard, foreign blockade add strangle , system ,etc. underestimate while being difficult; It is not enough to analyze to technological application level and ability of numerical control of our country.（2）System. Pay close attention to numerical control industrialization many in the issue , consider numerical control industrialization little in the issue synthetically in terms of the systematic one , industry chain in terms of technology; Set up intact related system , complete training , service network ,etc. of high quality support the system.（3）Mechanism. The bad mechanism causes the brain drain , restraining technology and technological route from innovating again , products innovation, and has restricted the effective implementation of planning , has often planned the ideal , implement the difficulty. d.（4）Technology. Enterprises are indifferent in autonomous innovation in technology, key technology is engineered and indifferent. Lathe standard lag behind, level relatively low, numerical control system new standard study enough. 4．Strategic thinking until technology and industrialization of numerical control of our country develop4.1 Strategic considerationour country , ensure the stability of the society; Secondly seen from security of national defense, the western developed country has classified all the high-grade , precision and advanced numerical control products as the strategic materials of the country, realize embargo and restriction to our country, " Toshiba incident " and " Cox Report " is the best illustration.4.2 Development tacticsProceed from the angles of the fundamental realities of the country of our country, regard the strategic demand of the country and market demand of the national economy as the direction, regard improving our country and making the comprehensive competitive power of equipping industry and industrialization level as the goal, use the systematic method , be able to choose the support technology that the initial our country makes the key technology upgraded in development of equipping industry and supports the development of industrialization in 21st century of leading factor, the ability to supply the necessary technology realizes making the jump type development of the equipping industry as the content of research and development.Emphasize market demand is a direction, take terminal products of numerical control as the core , with the complete machine (Such as the numerical control lathe having a large capacity and a wide range, milling machine , high speed high precise high-performance numerical control lathe , model digitized machinery , key industry key equipment ,etc. ) drive numerical control development of industry. Solve the numerical control system and relevant functions part especially The dependability in (digitized servo system and electrical machinery , electric main shaft system of high speed and new attachment that equip ,etc. ) and production scale question. There are no products without high dependability of scale ; Will not have cheap and products rich in the competitiveness without scale ; Certainly, it is difficult finally to have the day to hold up head that there is no Chinese numerical control equipment of scale .In equipping researching and developing high-grade , precision and advanced , should emphasize the production, learning and research and close combination of end user, regard " obtaining, using, selling " as the goal, tackle key problems according to the national will, in order to solve the needing badly of the country. The technology of numerical control, emphasized innovation, put emphasis on researching and developing technology and products with independent intellectual property right before the competition, establish the foundation for the numerical control industry of our country , sustainable development of the equipment manufacture and even the whole manufacturing industry.数控技术的应用及发展前景数控技术是发展新兴高新技术产业和尖端工业的使能技术。

数控专业的英语作文带翻译Title: The Development of CNC Technology。

With the rapid development of technology, CNC (Computer Numerical Control) technology has become an indispensable part of modern manufacturing industry. It hasrevolutionized the traditional manufacturing processes by automating and improving efficiency, accuracy, andflexibility in various industries.CNC technology utilizes computer programs to control machine tools and equipment, allowing for precise and complex operations that were previously impossible with manual methods. This technology has greatly increased productivity and reduced production costs for manufacturers, making it a popular choice for producing a wide range of products, from automotive parts to aerospace components.One of the key advantages of CNC technology is itsability to produce high-quality and consistent productswith minimal human intervention. This not only improves the overall quality of the products but also reduces the riskof errors and defects, leading to higher customersatisfaction and loyalty.Furthermore, CNC technology has also enabled manufacturers to produce customized products quickly and efficiently. By simply inputting the desired specifications into the computer program, manufacturers can easily create unique products tailored to the specific needs and preferences of their customers.In addition to its manufacturing capabilities, CNC technology has also played a significant role in advancing other industries, such as healthcare, transportation, and construction. For example, CNC machines are used in the medical industry to produce custom implants and prosthetics, while in the transportation industry, CNC technology isused to manufacture precision components for aircraft and automobiles.Looking ahead, the future of CNC technology is bright,with continuous advancements in automation, artificial intelligence, and connectivity. These developments will further enhance the capabilities of CNC machines, making them even more efficient, accurate, and versatile in meeting the evolving demands of the manufacturing industry.In conclusion, CNC technology has significantly transformed the manufacturing industry and will continue to play a crucial role in shaping the future of manufacturing. Its ability to automate processes, improve efficiency, and produce high-quality products has made it an essential tool for manufacturers worldwide. As technology continues to evolve, CNC technology will undoubtedly remain at the forefront of innovation and progress in the manufacturing industry.随着技术的快速发展，数控（Computer Numerical Control）技术已经成为现代制造业不可或缺的一部分。

Intelligent Open CNC TechnologyI. Technical OverviewIndustrial countries around the world through the development of CNC technology, a CNC machine tool industry, prompting machinery industry entered a new "modern" stage of historical development, and thus the structure of the national economy has brought great changes. CNC machine tools is not only an important basis for mechanical and electrical industrial equipment, automotive, petrochemical, electronics and other pillar industries, the primary means of production modernization, NC is the third industrial revolution the world is an important content. Output of CNC machine tool industry itself far less automobile, chemical and other industries, but thehigh-performance CNC machine tools to the manufacturing industry has brought the benefits of the high rate of production growth and modernization is to promote national economic development of the huge source of power. In particular, numerical control technology in the manufacturing sector expansion and extension of the role and the resulting ripple effect of radiation on the mechanical manufacturing industry sufficient structure, product structure, specialized division of labor, machining methods and management models, the production of social division of labor, business operational mechanism of profound change.In CNC machine tools are widely used in the numerical control technology, is a machining process using computer control information in a variety of digital computing, processing, and high-performance drive units through the implementation of mechanical components for automatic control of high-tech. The current equipment has been used a lot of CNC machining technology, the most typical and most widespread is the application of CNC machine tools. The machining process of the diversity and complexity of machining parts, CNC machine tools to the specifications, types and properties very different from the complexity of the control parameters, debugging complicated operation, so in general will continue the rapid development of computer technology and its architecture , the modern automatic control theory and modern technology to a new generation of power electronics CNC machine tools, we should emphasize them with "open" and "intelligent" features.1. "Open"Requires a new generation of CNC machine tool control system is an open, modular architecture, its features are: Modular elements in the realization of the system at the same time, there should be standardized between these elements can be provided by the different elements of the buyer free to combine, which can easily constitute a complete system. As follows:--- Elements of the system should be modular, while the interface between the modules must be standardized;--- System software, hardware configuration should be "transparent", "portable";--- System should have the "continuous upgrade" capability.At the same time the mechanical structure of a new generation of CNC machine tools also should be open, should be characterized by:--- Function module components using the machine;--- A "technology plan", "processing database" to users;--- Use of "information technology" will be a reasonable allocation of social resources, manufacturing machinery manufacturing industry gradually establish a perfect virtualization and network-based advanced manufacturing systems, machinery manufacturing resources to be used efficiently, to reduce costs, improve quality, the purpose of reducing manufacturing cycle.2. IntelligentThe so-called intelligent control system, is smart with anthropomorphic features, the numerical control system with simulation, extension, expansion of the intelligent behavior of the knowledge processing activities, such asself-learning, adaptive, self-organization, self-optimizing, Zi calm,self-recognition from planning, self-healing, self-reproduction. Through the intelligent CNC machining accuracy and efficiency of physical testing, modeling, feature extraction, processing system automatically senses the internal state and external environment, to quickly make the best goal of the intelligent decision-making, feed rate, cutting depth , coordinate movement, spindle speed and other parameters in real-time control, so that the processing machine at its best.The current NC system functionality required not only high performance (high-speed, high precision and high reliability), but also includes many smart features, such as the processing of motion planning, reasoning,decision-making ability and perception processing environment, manufacturing, network communication capacity (including the interaction with others), intelligent programming, intelligent databases, intelligent surveillance.Practice has proved that these "intelligent" technology, also used in the 21st century, the adjustment of a new generation of CNC machine tools, use and maintenance of all aspects, so that human intervention greatly simplified, to apply "smart" technology, human machine interface for packaging, to make full use of natural language, artificial Windows interface and simple operation, so that adjustment of the machine, use and maintenance tends to be "fool."Second, the status quo and development trend of domestic and foreign1. Overseas DevelopmentThroughout the history of the development of numerical control technology, is easy to see the development of numerical control technology step through the development of computer technology continues to develop, from 1956 to the present, has gone through four stages as follows:In 1956 -1974, the era of proprietary hardware NC;1975 -1989, the special computer numerical control era, that era of the microprocessor NC (μ PC);In 1990 -1995, BASIC PC's CNC times;Since 1996, started the whole PC open a new stage of intelligent CNC.The first three stages of the NC devices there are the following limitations: --- Not free to select the information from the information network;--- Not open architecture, user interface imperfections, machinery manufacturers and users can not independently numerical control system according to crop needs, the user's own technical know-how is not easy to integrate into, and create their own brand names;--- Can not fully utilize the existing resources of common software;--- Can not be free access to the external condition information;--- Architecture many, is not conducive to mass production, improve reliability and reduce costs, reduce the market supply capacity and competitiveness, while limiting the development of numerical control technology.In recent years the United States, the European Community, Japan and other countries have taken measures, a lot of money, the joint of the plant, or even more countries to study a new generation of numerical control systems, from the foregoing information, the world is in the NC Technology All PC CNC open architecture platform, turning the era, the turn is adapted to computer technology, information technology, network technology, the inevitable result of technological development.As modern machinery industry gradually to flexible, integrated, intelligent direction, so must be stressed that a new generation of numerical control technology to have an open and intelligent features. Developed countries have taken measures in recent years, lots of manpower and financial resources to organize a new generation of superior forces and open architecture CNC with intelligent features technology development and research, including the United States of NGC and OMAC plan, the EC OSACA plan, OSEC plans.CNC machine tool mechanical structure is more inclined to "open", to meet the diverse needs of the modern machinery for processing, a new generation of CNC machine tools has the following characteristics:(1) according to the modular machine structure, the principles of design and manufacturing series in order to shorten lead times, best meet the needs of the user's process.(2) As many parts of NC machine tool quality indicators continue to improve, gradually increase the variety of specifications, a more substantial mechanical and electrical integration, functional parameters of the increasingly numerous and so dedicated to supporting a variety of CNC machine features are fully commercialized, to build a competitive machine tool plant created the conditions.(3) to the users, CNC Machine Tool Plant of the developed countries areactively building completely open product sales service system. Part to establish an open laboratory, establishment of self-service CNC machine operator and maintenance training center.(4) using information network technology to a variety of manufacturing resources in society were based on the rational combination of processing tasks and call the 21st century advanced manufacturing technology development trend, the world's countries are active in research in this area.(5) artificial intelligence technology in the promotion and application of CNC technology. With the continued penetration in the computer field of artificial intelligence and development of the intelligent CNC system development. In the new generation of CNC system and servo devices, the use of "evolutionary computation" (Evolutionary Computation), "Fuzzy Systems" (Fuzzy System) and "neural networks" (Neural Network) and other three new control mechanism, the performance greatly increased. This high-performance intelligent CNC system not only has the automatic programming, feedforward control, adaptive cutting, self-generating process parameters, motion parameters of dynamic compensation and other functions, more features are taken into account operational factors used in the very present friendly interface.The current principle of fuzzy control systems, and CNC EDM with aself-learning, self-established mathematical model, high-performanceself-tuning parameters of the servo drive CNC machine tools and existing products in the market with a strong competitive edge.2. Current Situation and Development of numerical control technology gap China's CNC technology, in the "Eighth Five-Year" key in order to seize the opportunity to own the copyright for the proposed target to platform-based development strategy, but also in the research process, aiming or adjustment to the development of PC-based route , and thus the formation of two platforms, developed four basic systems, central China and the ChineseI-I-NC-specific template is embedded into a single general-purpose PC NC system bodies, space and the blue sky I-I-is embedded in the PC, being composed of CNC multi-machine CNC system, the formation of the typical structure of front, the domestic unit also has developed other open architecture system.However, in general terms, but only at the initial stage, although different systems direction to the PC platform, but in the concrete implementation of the development there are still some problems. The biggest problem that is open enough, lack of development environment and support measures, as a user easily to the secondary development of the degree of openness is far from being reached, but has considerable technical force of the developer to use, and as able to spread to the general extent of users is not enough.Design by PC-NC system makes CNC's focus from hardware to software, to eliminate the development of the CNC hardware "bottlenecks", which could accelerate the production of useful products. And PC-NC, after all, so that theopen architecture CNC a big step.In the design and manufacture of CNC machine tools, China has started a modular technology, the CNC machining process parameters, tools, system optimization, intelligent adaptive control have been studied, the intelligent control of it lay the foundation for further study, But the work is only the beginning, still in the "fifth" during a series of research and development work, tracking the world's digital technology, to promote the development of numerical control industry.Third, the "fifth" major research objectives and1. TargetIn order to further improve China's CNC technology, CNC machine tools industry, the Chinese can get a place in the international competition, China's development strategy of numerical control technology, in conjunction with the characteristics of China's economic development, first with "open", "intelligent" features CNC technology for innovative research, to focus on CNC turning, milling, grinding and processing power on the basis of advanced manufacturing technologies and processes, and then develop a generation of "open", "intelligent" CNC lathes, CNC milling machine (including the processing center) and CNC EDM products.2. Main content①Development of a new generation of open CNC system. Construction of open CNC system, interface and protocol research, including research systems, subsystems and functional modules hierarchical control structure, open CNC system interface and the Protocol.②a new generation of intelligent CNC system. Developed and worked out for turning, milling, machining centers, electrical generation of intelligent processing, and other basic computer numerical control system and the corresponding intelligent programming system. Including research and development of intelligent CNC system hardware, software specification and implementation in the main production base of CNC; development of two common systems (turning, machining centers) three applications (turning centers, five-sided machining centers, intelligent power processing ); intelligent programming system.③spindle and servo-drive a new generation of innovative research and development work out the corresponding high-performance servo drives and motors, including self-learning, self-tuning parameters, all-digital, low-cost type of linear motor and drive.④Development of efficient numerical control equipment. According to the principles of modular design, developed a highly efficient processing unit, developed a highly efficient CNC milling machine, crankshaft grinder, laser forming, CNC machining centers and integrated high-speed engraving and milling machines and other highly efficient CNC machine tools, and furtherdeveloped the idea and design platform for intelligent and efficient processing unit robot flexible manufacturing cell.⑤common basis for a new generation of flexible manufacturing equipment, technology and research. Various types of CNC machine tools including the new module design, reliability, design, mechanical design optimization of structural characteristics, computer-aided industrial design, new materials and a sense of control compensation, integrated precision contour compensation technology, high-speed high-precision axis unit, tool and integrated tool system, handling and transmission, cooling and protective, functional integration, a sense of control of integrated manufacturing and processing technologies.⑥machining theory and method of flexible automation. Including the commercialization of flexible manufacturing cell, quasi-practical flexible manufacturing system, flexible multi-standard processing techniques,multi-format production unit of flexible manufacturing technology.mon basis for a new generation of flexible manufacturing equipment, technology and research. Various types of CNC machine tools including the new module design, reliability, design, mechanical design optimization of structural characteristics, computer-aided industrial design, new materials and a sense of control compensation, integrated precision contour compensation technology, high-speed high-precision axis unit, tool and integrated tool system, handling and transmission, cooling and protective, functional integration, a sense of control of integrated manufacturing and processing technologies.8.machining theory and method of flexible automation. Including the commercialization of flexible manufacturing cell, quasi-practical flexible manufacturing system, flexible multi-standard processing techniques,multi-format production unit of flexible manufacturing technology.开放式智能化数控技术一、技术概述世界各工业发达国家通过发展数控技术、建立数控机床产业，促使机械加工业跨入一个新的“现代化”的历史发展阶段，从而给国民经济的结构带来了巨大的变化。