控制电路设计毕业论文中英文对照资料外文翻译文献

毕业设计论文外文文献翻译基于PLC双电源开关设计外文翻译中英文对照英文题目 Based on PLC dual power switch design 中文题目基于PLC双电源开关设计系 (院) 自动化系专业电气自动化技术滨州学院专科毕业设计(外文翻译)Intelligent double power1 Intelligent dual power supply switching technologyIn this paper, the double load - dual power automatic switching of PLC control, PLC control program to replace relay logic control circuits, it has the three-phase power supply phase detection and protection switching function, power returned to normal after the automatic reverse switch, when a fault and restore normal respectively sends out two difference clear alarm and prompt sound. Double load - dual power automatic switching control of PLC, the open-phase protection mainly adopts the technical proposal that : setting the three-phase open-phase detection signal circuit, the three-phase open-phase detection signal circuit directly from the main circuit of three-phase power supply, namely the intermediate relay KA1-KA3 and KA4-KA6, respectively connected to power supply main loop U1 and U2 A, B and C single phase circuit, KA1-KA3 and KA4-KA6 normally open contacts respectively as PLCinput signal, namely as the preparation of PLC U1 and U2 three-phase open-phase detection logic control program input conditions. With short phase protection double load - dual power automatic switching control, not only has the open-phase protection, but also has a short circuit and overload protection, under-voltage protection function; automatic phase lack detection, three-phase current display, a road power supply circuit can automatically switch to another power source to load power supply, light and sound alarm; in the power supply return to normal after automatic reverse switch; in the event of a failure and return to normal when respectively sends out two difference obvious alarm and prompt sound effects. It overcomes the shortcomings of low double power supply switching control system without phase protection, can automatically reverse switch, as well as fault and return to normal when using asingle audio prompts defects. The control system has perfect function, reliable performance, simple circuit structure, low manufacturing cost etc...2 Intelligent dual power supplies switching main circuit controlWith short phase protection double load - dual power automatic switching control circuit. It includes a main circuit and three-phase short signal detecting sampling circuit. The main circuit of the input power supply power supply U1 and U2, its output has two2滨州学院专科毕业设计(外文翻译)loads W1 and W2. Power main circuit of AC contactor U1 through KM1 main contacts and a load of W1 connected; power supply U2 main circuit through the AC contactor KM2 main contacts and a load of W2 connected; under the control of a control circuit, a power failure occurs, the AC contactor lost the first electrically disconnected, so that the load of detachment faults power supply circuit, the AC contactor KM3 main contact closing conduction contact loop, will be connected to the fault loop load switch automatically to another normal power supply continues to supply. Power supply U1 and U2 main circuit input end of the automatic switch in QF1 and QF2 is the primary role of overload protection and short-circuit protection; two phase power supply main loop in each phase are current meter to indicate the phase current status, with the control circuit of phase lack detection. The three-phase open-phase detection signal sampling circuit, the phase detection signal directly from the main circuit of three-phase power supply, namely the intermediate relay KA1 ~ KA3KA4 ~ KA6 are respectively connected to the power supply main loop U1 and U2 A, B phase and C phase of the single-phase circuit, KA1 ~ KA3 and KA4 ~ KA6 normally open contact as U1 and U2 three-phase open-phase detection switch sampling signal, to the PLC input terminal. Considering the PLC relay output point load capacity, through the contactor KM01 ~ KM03 to drive high current contactor KM1 ~ KM3.For three-phase power U1 A, B phase and C phase lack detection, the use of an intermediate relay KA1, KA2 and KA3, respectively connected topower the U1 main circuit A, B phase and C phase and zero line N constitute a single-phase circuit, the formation of A1, B1 and C1 phase detection circuit. The normally open contact of KA1 ~ KA3 as U1 three-phase.Phase lack detection switch sampling signal, to the PLC input terminal, used in the preparation of PLC U1 three-phase open-phase detection logic control program input conditions; similarly, the three-phase power supply U2 A, B phase and C phase lack detection, but also the use of an intermediate relay KA4, KA5 and KA6, respectively connected to power the U2 main circuit A2, B2 phase and C2 phase and zero line N constitute a single-phase circuit, the formation of A2, B2 and C2 three-phase open-phase detection circuit. KA4 ~ KA6 normally open contacts respectively as U2 three-phase open-phase detection switch sampling signal, to the PLC input terminal, used in the3滨州学院专科毕业设计(外文翻译)preparation of PLC U2 three-phase open-phase detection logic control program input conditions.3 With PLC intelligent dual power controlThe three-phase open-phase detection signal sampling circuit, as U1 and U2 three-phase open-phase detection switch sampling signals of KA1-KA3 and KA4-KA6, the normally open contacts respectively for the input of the PLC X0-X2, X3-X5. In the PLC ladder diagram program, auxiliary relay R1 as the three-phase power supply of U1 three-phase open-phasedetection, which is normally open input conditions for X0, X1 and X2" and" logic; similarly, internal intermediate relay R2 as the three-phase power supply of U2 three-phase open-phase detection, it’s on conditions for the normally open input X3, X4 and X5" and" logic.In automatic switching control process, PLC ladder diagram procedure of auxiliary relay R1 and R2 respectively controlled AC contactor KM1 ( Y0 ) and KM2 ( Y1 ) coil and electric state, directly reflects two three-phase power supply U1 and U2 respectively the total phase condition, namely, either U1 or U2 three-phase power supply phase, KM1 ( Y0 ) or KM2 ( Y1 ) will immediately loses electricity, the normally closed contact of the alternating current contactor closed KM3 ( Y2 ) control coil gets electricity to attract, through the KM3 main contacts closed conduction contact loop, will be connected to the fault circuit load W1 or W2 automatically switches to a normal power supply U2 or U1 to power supply, so as to realize open-phase protection automatic switching. In automatic switching control process, auxiliary relay R1 and R2 main function is: when troubleshooting, three-phase power U1 orU2 recover the normal power supply, R1 (or R2) have electricity, the normally closed contact action, R3 reset, cut KM3 (Y2), then KM1 (Y0) or KM1 (Y1) complex have electricity, thereby automatically reverse switching back to the power supply to load W1 U1, U2 W2 power supply to load the normal power supply state.The control circuit adopts electric whistle (or buzzer) as an alarm sound (at) the same time with the red signal (at the same time with thered signal lamp), and returned to normal when the bell HA as prompt sound. Can produce two distinct alarms and prompt sound effects.4滨州学院专科毕业设计(外文翻译)智能双电源1 智能双电源切换的技术方案本文所述的双负载—双电源自动切换的PLC控制,用PLC控制程序取代继电器逻辑控制电路,其具有对三相供电电源的缺相检测及保护切换功能,在电源恢复正常后能自动进行反切换,当发生故障和恢复正常时能分别发出两种区别明显的报警和提双负载—双电源自动切换的PLC控制,其缺相保护主要采取的技术方案是:示音响。

控制系统基础论文中英文资料外文翻译文献文献翻译原文：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 par 4s , 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 the 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 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 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 floorenvironment 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 mportant 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 evelopment 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 ignal Processors.There are numerous situations where analog signals to be processed in manyways, 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 SP‟s that can erform broad ranges of processing tasks. 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 two 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 DSP‟s: 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 (DSP‟s) , 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 techniques such as adaptive control , Kalman filtering , and state control. The C24xDSP 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-purpose 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 e mbedded control marketplace.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 climate control---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, supportthe 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.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 theerror. A system with one or more feedback pats 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 human being 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 is As anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system of The 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.译文：控制系统基础数字控制机床常常重达上百吨，但却常常要求切削工具的定位精度达到0.002毫米。

中英文对照资料外文翻译文献外文文献：Designing Stable Control LoopsThe objective of this topic is to provide the designer with a practical review of loop compensation techniques applied to switching power supply feedback control. A top-down system approach is taken starting with basic feedback control concepts and leading to step-by-step design procedures, initially applied to a simple buck regulator and then expanded to other topologies and control algorithms. Sample designs are demonstrated with Math cad simulations to illustrate gain and phase margins and their impact on performance analysis.I. I NTRODUCTIONInsuring stability of a proposed power supply solution is often one of the more challenging aspects of the design process. Nothing is more disconcerting than to have your lovingly crafted breadboard break into wild oscillations just as its being demonstrated to the boss or customer, but insuring against this unfortunate event takes some analysis which many designers view as formidable. Paths taken by design engineers often emphasize either cut-and-try empirical testing in the laboratory or computer simulations looking for numerical solutions based on complex mathematical models. While both of these approach a basic understanding of feedback theory will usually allow the definition of an acceptable compensation network with a minimum of computational effort.II. S TABILITY D EFINEDFig. 1. Definition of stabilityFig. 1 gives a quick illustration of at least one definition of stability. In its simplest terms, a system is stable if, when subjected to a perturbation from some source, its response to that perturbation eventually dies out. Note that in any practical system, instability cannot result in a completely unbounded response as the system will either reach a saturation level –or fail. Oscillation in a switching regulator can, at most, vary the duty cycle between zero and 100% and while that may not prevent failure, it wills ultimate limit the response of an unstable system. Another way of visualizing stability is shown in Fig. 2. While this graphically illustrates the concept of system stability, it also points out that we must make a further distinction between large-signal and small-signal stability. While small-signal stability is an important and necessary criterion, a system could satisfy thisrt quirement and yet still become unstable with a large-signal perturbation. It is important that designers remember that all the gain and phase calculations we might perform are only to insure small-signal stability. These calculations are based upon – and only applicable to – linear systems, and a switching regulator is – by definition –a non-linear system. We solve this conundrum by performing our analysis using small-signal perturbations around a large-signal operating point, a distinction which will be further clarified in our design procedure discussion。

Single-chip1.The definition of a single-chipSingle-chip is an integrated on a single chip a complete computer system .Even though most of his features in a small chip，but it has a need to complete the majority of computer components：CPU，memory，internal and external bus system，most will have the Core.At the same time，such as integrated communication interfaces，timers，real-time clock and other peripheral equipment.And now the most powerful single-chip microcomputer system can even voice ，image，networking，input and output complex system integration on a single chip.Also known as single-chip MCU（Microcontroller），because it was first used in the field of industrial control.Only by the single-chip CPU chip developed from the dedicated processor. The design concept is the first by a large numberof peripherals and CPU in a single chip，the computer system so that smaller，more easily integrated into the complex and demanding on the volume control devices.INTEL the Z80 is one of the first design in accordance with the idea of the processor，From then on，the MCU and the development of a dedicated processor parted ways.Early single-chip 8-bit or all the four.One of the most successful is INTELs 8031，because the performance of a simple and reliable access to a lot of good praise.Since then in 8031to develop a single-chip microcomputer system MCS51 series.based on single-chip microcomputer system of the system is still widely used until now.As the field of industrial control requirements increase in the beginning of a 16-bit single-chip，but not ideal because the price has not been very widely used.After the90s with the big consumer electronics product development，single-chip technology is a huge improvement.INTEL i960 series with subsequent ARM in particular ，a broad range of application，quickly replaced by 32-bit single-chip 16-bit single-chip performance has been the rapid increase in processing power compared to the 80s to raise a few hundred times.At present，the high-end 32-bit single-chip frequency over 300MHz，the performance of the mid-90s close on the heels of a special processor，while the ordinary price of the model dropped to one U.S dollars，the most high-end models，only 10 U.S dollars.Contemporary single-chip microcomputer system is no longer only the bare-metal environment in the development and use of a large number of dedicated embedded operating system is widely used in the full range of single-chip microcomputer.In PDAs and cellphones as the coreprocessing of high-end single-chip or even a dedicated direct access to Windows and Linux operating systems.More than a dedicated single-chip processor suitable for embedded systems，so it was up to the application.In fact the number of single-chip is the worlds largest computer.Modern human life used in almost every piece of electronic and mechanical products will have a single-chip integration.Phone，telephone，calculator，home applicances，electronic toys，handheld computers and computer accessories such as a mouse in the Department are equipped with 1-2 single chip.And personal computers also have a large number of single-chip microcomputer in the workplace.Vehicles equipped with more than 40 Department of the general single-chip ，complex industrial control systems and even single-chip may have hundreds of work at the same time!SCM is not only far exceeds the number of PC and other integrated computing,even more than the number of human beings.2.single-chip introducedSingle-chip,also known as single-chip microcontroller,it is not the completion of a logic function of the chip,but a computer system integrated into a chip.Speaking in general terms: a single chip has become a computer .Its small size,light weight,cheap,for the learning,application and development of facilities provided .At the same time,learning to use the principle of single-chip computer to understand and structure the best choice.Single-chip and computer use is also similar to the module,such as CPU,memory,parallel bus, as well as the role and the same hard memory,is it different from the performance of these components are relatively weak in our home computer a lot,but the price is low ,there is generally no more than 10yuan,,can use it to make some control for a class of electrical work is not very complex is sufficient.We are using automatic drum washing machines, smoke hood,VCD and so on inside the home appliances can see its shadow! It is mainly as part of the core components of the control.It is an online real-time control computer,control-line is at the scene,we need to have a stronger anti-interference ability,low cost,and this is off-line computer(such as home PC)The main difference.By single-chip process,and can be amended.Through different procedures to achieve different functions,in particular the special unique features,this is the need to charge other devices can do a great effort,some of it is also difficult to make great efforts to do so .A function is not very complicated fi the United States the development of the 50s series of 74 or 60 during the CD4000series to get these pure hardware,the circuit must be a big PCB board !However,if the United States if the successful 70s seriesof single-chip market ,the result will be different!Simply because the adoption of single-chip preparation process you can achieve high intelligence,high efficiency and high reliability!Because of cost of single-chip is sensitive,so the dominant software or the lowest level assembly language,which is in addition to the lowest level for more than binary machine code of the language ,since such a low-level so why should we use ?Many of the seniors language has reached a level of visual programming why is it not in use ?The reason is simple ,that is,single-chip computer as there is no home of CPU,also not as hard as the mass storage device.A visualization of small high-level language program,even if there is only one button which will reach the size of dozens of K! For the home PCs hard drive is nothing,but in terms of the single-chip microcomputer is unacceptable.Single-chip in the utilization of hardware resources have to do very high ,so the compilation of the original while still in heavy use .The same token ,if the computer giants operating system and appplications run up to get the home PC,homePCcan not afford to sustain the same.It can be said that the twentieth century across the three “power”of the times,that is ,the electrical era,the electronic age and has now entered the computer age. However ,such a computer,usually refers to a personal computer,or PC.It consisits of the host ,keyboards,displays .And other components.There is also a type of computer,not how most people are familiar with . This computer is smart to give a variety of mechanical single-chip(also known as micro-controller).As the name suggests,these computer systems use only the minimum of an integrated circuit to make a simple calculation and control. Because of its small size,are usually charged with possession of machine in the “belly”in. It in the device,like the human mind plays a role, it is wrong,the entire device was paralyzed .Now,this single chip has a very wide field of use,such as smart meters,real-time industrial control,communications equipment,navigation systems,and household appliances. Once a variety of products with the use of the single-chip ,will be able to play so that the effectiveness of product upgrading,product names often adjective before the word “intelligent”,such as was hing machines and so intelligent.At present,some technical personnel of factories or other amateur electrtonics developers from engaging in certain products ,not the circuit is too complex ,that is functional and easy to be too simple imitation.The reason may be the product not on the cards or the use of single-chip programmable logic device on the other.3.single-chip historysingle-chip 70 was born in the late 20th century,experienced a SCM,MCU,SOC three stages.Single-chip micro-computer 1.SCM that(Single Chip Microcomputer)stage,is mainly a single from to find the best of the best embedded systems architecture.”Innovation model”to be successful,lay the SCM with the general-purpose computers,a completely different path of development . In embedded systems to create an independent development path,Intel Corporation credit.That is 2.MCU microcontroller(Micro Controller Unit)stage,the main direction of technology development: expanding to meet the embedded applications,the target system requirements for the various peripheral circuits and interface circuits,to highlingt the target of intelligent control.It covers all areas related with the objectSystem,therefore,the development of MCU inevitably fall on the heavy electrical,electronics manufacturers. From this point of view ,Intels development gradually MCU has its objective factors.MCU in the development ,the most famous manufacturers when the number of Philips Corporation.Philips in embedded applications for its enormous advantages,the MCS-51 from the rapid deveploment of single-chip micro-computer to the microcontroller.Therefore,when we look back at the path of development of embedded systems,Intel and Philips do not forget the historical merits.3.Single-chip is an independent embedded systems development,to the MCU an important factor in the development stage,is seeking applications to maximize the natural trend .With the mico-electronics technology,IC design,EDA tools development,based on the single-chip SOC design application systems will have greater development. Therefore,the understanding of single-chip micro-computer from a single ,monolithic single-chip microcontroller extends to applications.4.Single-chip applicationsAt present,single-chip microcomputer to infiltrate all areas of our lives,which is very difficult to find the area of almost no traces of single-chip microcomputer.Missile navigation equipment,aircraft control on a variety of instruments,compuer network communications and data transmission,industrial automation,real-time process control and data processing ,are widely used in a variety of smart IC card,limousine civilian security systems,video recorders,cameras,the control of automatic washing machines,as well as program-controllde toys,electronic pet,etc,which are inseparable from the single-chip microcomputer.Not to mention the field of robot automation ,intelligent instrumentation,medical equipment has been. Therefore,the single- chip learning ,development and application to a large number of computer applications and intelligent control of scientists,engineers.Single-chip widely used in instruments and meters,household appliances，medical equipment ,acrospace,specialized equipment and the intellingent management in areas such as process control,generally can be divided into the following areas:1.In the smart application of instrumentationSingle-chip with small size,low power consumption,control,and expansion flexibility , miniaturization and ease of sensors,can be realized,suchvoltage,power,frequency,humidity,temperature,flow,speed,thickness,angle,length,hardness,elemen t,measurement of physical pressure. SCM makes use of digital instrumentation,intelligence,miniaturization and functional than the use of electronic or digital circuitry even stronger.For example,precision measurement equipment(power meter,oscilloscope,and analyzer).2.In the industrial controlMCU can constitute a variety of control systems,data acquisition system.Such as factory assembly line of intelligent management ,intelligent control of the lift ,all kinds of alarm systems ,and computer networks constitute a secondary control system.3.In the applicationof household appliancesIt can be said that almost all home appliances are using the single-chip control,electric rice from favorable,washing machines,refrigerators,air conditioners,color TV and other audio video equipment,and then to the electronic weighing equipment,all kinds ,everywhere.4.On computer networks and communication applications in the field ofGenerally with the modern single-chip communication interface,can be easily carried out with computer carried out with computer data communications,computer networks and in inter-application communications equipment to provide an excellent material conditions,the communications equipment to provide an excellent material condition,from the mobile phone ,telephone , mini-program-controlled switchboards,buiding automated communications system call,the train wireless communications,and then you can see day-to-day work of mobile phones,Mobile communications,such as radios.5.Single-chip in the field of medical equipment applicationsSingle-chip microcomputer in medical devices have a wide range of purpose,such as medical ventilator,various analyzers,monitors,ultrasonic diagnostic equipment and hospital call systems.6.In a variety of large-scale electrical applications of modularSome special single-chip design to achieve a specific function to carry out a variety of modular circuitapplications,without requiring users to understand its internal structure.Integrated single-chip microcomputer such as music ,which seems to be simpleFunctions,a miniature electronic chip in a pure(as distinct from the principle of tape machine),would require a complex similar to the principle of the computer. Such as :music signal to digital form stored in memory(similar to ROM),read out by the microcontroller into analog music signal(similar to the sound card).In large circuits,modular applications that greatly reduces the size ,simplifying the circuit and reduce the damage,error rate ,but also to facilitate the replacement.In addition,single-chip microcomputer in the industrial,commercial,financial,scientific research ,education,defense aerospace and other fields have a wide range of uses.单片机1.单片机定义单片机是一种集成在电路芯片上的完整计算机系统。

标准文档外文翻译院（系）专业班级姓名学号指导教师年月日Programmable designed for electro-pneumatic systemscontrollerJohn F.WakerlyThis project deals with the study of electro-pneumatic systems and the programmable controller that provides an effective and easy way to control the sequence of the pneumatic actuators movement and the states of pneumatic system. The project of a specific controller for pneumatic applications join the study of automation design and the control processing of pneumatic systems with the electronic design based on microcontrollers to implement the resources of the controller.1. IntroductionThe automation systems that use electro-pneumatic technology are formed mainly by three kinds of elements: actuators or motors, sensors or buttons and control elements like valves. Nowadays, most of the control elements used to execute the logic of the system were substituted by the Programmable Logic Controller (PLC). Sensors and switches are plugged as inputs and the direct control valves for the actuators are plugged as outputs. An internal program executes all the logic necessary to the sequence of the movements, simulates other components like counter, timer and control the status of the system.With the use of the PLC, the project wins agility, because it is possible to create and simulate the system as many times as needed. Therefore, time can be saved, risk of mistakes reduced and complexity can be increased using the same elements.A conventional PLC, that is possible to find on the market from many companies, offers many resources to control not only pneumatic systems, but all kinds of system that uses electrical components. The PLC can be very versatile and robust to be applied in many kinds of application in the industry or even security system and automation of buildings.Because of those characteristics, in some applications the PLC offers to much resources that are not even used to control the system, electro-pneumatic system is one of this kind of application. The use of PLC, especially for small size systems, can be very expensive for the automation project.An alternative in this case is to create a specific controller that can offer the exactly size and resources that the project needs [3, 4]. This can be made using microcontrollers as the base of this controller.The controller, based on microcontroller, can be very specific and adapted to only one kind of machine or it can work as a generic controller that can be programmed as a usual PLC and work with logic that can be changed. All these characteristics depend on what is needed and how much experience the designer has with developing an electronic circuit and firmware for microcontroller. But the main advantage of design the controller with the microcontroller is that the designer has the total knowledge of his controller, which makes it possible to control the size of the controller, change the complexity and the application of it. It means that the project gets more independence from other companies, but at the same time the responsibility of the control of the system stays at the designer hands2. Electro-pneumatic systemOn automation system one can find three basic components mentioned before, plus a logic circuit that controls the system. An adequate technique is needed to project the logic circuit and integrate all the necessary components to execute the sequence of movements properly.For a simple direct sequence of movement an intuitive method can be used [1, 5], but for indirect or more complex sequences the intuition can generate a very complicated circuit and signal mistakes. It is necessary to use another method that can save time of the project, makea clean circuit, can eliminate occasional signal overlapping and redundant circuits. The presented method is called step-by-step or algorithmic [1, 5], it is valid for pneumatic and electro-pneumatic systems and it was used as a base in this work.The method consists of designing the systems based on standard circuits made for each change on the state of the actuators, these changes are called steps.The first part is to design those kinds of standard circuits for each step, the next task is to link the standard circuits and the last part is to connect the control elements that receive signals from sensors, switches and the previous movements, and give the air or electricity to the supply lines of each step. In Figs. 1 and 2 the standard circuits are drawn for pneumatic and electro-pneumatic system [8]. It is possible to see the relations with the previous and the next steps.3. The method applied inside the controllerThe result of the method presented before is a sequence of movements of the actuator that is well defined by steps. It means that each change on the position of the actuators is a new state of the system and the transition between states is called step.The standard circuit described before helps the designer to define the states of the systems and to define the condition to each change betweenthe states. In the end of the design, the system is defined by a sequencethat never chances and states that have the inputs and the outputs well defined. The inputs are the condition for the transition and the outputs are the result of the transition.All the configuration of those steps stays inside of the microcontroller and is executed the same way it was designed. The sequences of strings are programmed inside the controller with 5 bytes; each string has the configuration of one step of the process. There are two bytes for the inputs, one byte for the outputs and two more for the other configurations and auxiliary functions of the step. After programming, this sequence of strings is saved inside of a non-volatile memory of the microcontroller, so they can be read and executed.The controller task is not to work in the same way as a conventional PLC, but the purpose of it is to be an example of a versatile controller that is design for an specific area. A conventional PLC process the control of the system using a cycle where it makes an image of the inputs, execute all the conditions defined by the configuration programmed inside, and then update the state of the outputs. This controller works in a different way, where it read the configuration of the step, wait the condition of inputs to be satisfied, then update the state or the outputs and after that jump to the next step and start the process again.It can generate some limitations, as the fact that this controller cannot execute, inside the program, movements that must be repeated for some time, but this problem can be solved with some external logic components. Another limitation is that the controller cannot be applied on systems that have no sequence. These limitations are a characteristic of the system that must be analyzed for each application.4. Characteristics of the controllerThe controller is based on the MICROCHIP microcontroller PIC16F877 [6,7] with 40 pins, and it has all the resources needed for thisproject .It has enough pins for all the components, serial communication implemented in circuit, EEPROM memory to save all the configuration of the system and the sequence of steps. For the execution of the main program, it offers complete resources as timers and interruptions.The list of resources of the controller was created to explore all the capacity of the microcontroller to make it as complete as possible. During the step, the program chooses how to use the resources reading the configuration string of the step. This string has two bytes for digital inputs, one used as a mask and the other one used as a value expected. One byte is used to configure the outputs value. One bytes more is used for the internal timer , the analog input or time-out. The EEPROM memory inside is 256 bytes length that is enough to save the string of the steps, with this characteristic it is possible to save between 48 steps （Table 1）.The controller (Fig.3) has also a display and some buttons that are used with an interactive menu to program the sequence of steps and other configurations.4.1. Interaction componentsFor the real application the controller must have some elements to interact with the final user and to offer a complete monitoring of the system resources that are available to the designer while creating the logic control of the pneumatic system (Fig.3):•Interactive mode of work; function available on the main program for didactic purposes, the user gives the signal to execute the step. •LCD display, which shows the status of the system, values of inputs, outputs, timer and statistics of the sequence execution.•Beep to give important alerts, stop, start and emergency.• Leds to show power on and others to show the state of inputs and outputs.4.2. SecurityTo make the final application works property, a correct configuration to execute the steps in the right way is needed, but more then that itmust offer solutions in case of bad functioning or problems in the execution of the sequence. The controller offers the possibility to configure two internal virtual circuits that work in parallel to the principal. These two circuits can be used as emergency or reset buttons and can return the system to a certain state at any time [2]. There are two inputs that work with interruption to get an immediate access to these functions. It is possible to configure the position, the buttons and the value of time-out of the system.4.3. User interfaceThe sequence of strings can be programmed using the interface elements of the controller. A Computer interface can also be used to generate the user program easily. With a good documentation the final user can use the interface to configure the strings of bytes that define the steps of the sequence. But it is possible to create a program with visual resources that works as a translator to the user, it changes his work to the values that the controller understands.To implement the communication between the computer interface and the controller a simple protocol with check sum and number of bytes is the minimum requirements to guarantee the integrity of the data.4.4. FirmwareThe main loop works by reading the strings of the steps from the EEPROM memory that has all the information about the steps.In each step, the status of the system is saved on the memory and it is shown on the display too. Depending of the user configuration, it can use the interruption to work with the emergency circuit or time-out to keep the system safety. In Fig.4,a block diagram of micro controller main program is presented.5. Example of electro-pneumatic systemThe system is not a representation of a specific machine, but it is made with some common movements and components found in a real one. The system is composed of four actuators. The actuators A, B and C are double acting and D-single acting. Actuator A advances and stays in specified position till the end of the cycle, it could work fixing an object to the next action for example (Fig. 5) , it is the first step. When A reaches the end position, actuator C starts his work together with B, making as many cycles as possible during the advancing of B. It depends on how fastactuator B is advancing; the speed is regulated by a flowing control valve. It was the second step. B and C are examples of actuators working together, while B pushes an object slowly, C repeats its work for some time.When B reaches the final position, C stops immediately its cycle and comes back to the initial position. The actuator D is a single acting one with spring return and works together with the back of C, it is the third step. D works making very fast forward and backward movement, just one time. Its backward movement is the fourth step. D could be a tool to make a hole on the object.When D reaches the initial position, A and B return too, it is the fifth step.Fig. 6 shows the first part of the designing process where all the movements of each step should be defined [2]. (A+) means that the actuator A moves to the advanced position and (A−) to the initial position. The movements that happen at the same time are joined together in the same step. The system has five steps.These two representations of the system (Figs. 5 and 6) together are enough to describe correctly all the sequence. With them is possible to design the whole control circuit with the necessary logic components. But till this time, it is not a complete system, because it is missing some auxiliary elements that are not included in this draws because they work in parallel with the main sequence.These auxiliary elements give more function to the circuit and are very important to the final application; the most important of them is the parallel circuit linked with all the others steps. That circuit should be able to stop the sequence at any time and change the state of the actuators to a specific position. This kind of circuit can be used as a reset or emergency buttons.The next Figs. 7 and 8 show the result of using the method without the controller. These pictures are the electric diagram of the control circuit of the example, including sensors, buttons and the coils of the electrical valves.The auxiliary elements are included, like the automatic/manual switcher that permit a continuous work and the two start buttons that make the operator of a machine use their two hands to start the process, reducing the risk of accidents.6. Changing the example to a user programIn the previous chapter, the electro-pneumatic circuits were presented, used to begin the study of the requires to control a system that work with steps and must offer all the functional elements to be used in a real application. But, as explained above, using a PLC or this specific controller, the control becomes easier and the complexity can be increasealso.Table 2 shows a resume of the elements that are necessary to control the presented example.With the time diagram, the step sequence and the elements of the system described in Table 2 and Figs. 5 and 6 it is possible to create the configuration of the steps that can be sent to the controller (Tables 3 and 4).While using a conventional PLC, the user should pay attention to the logic of the circuit when drawing the electric diagram on the interface (Figs. 7 and 8), using the programmable controller, described in this work, the user must know only the concept o f the method and program only the configuration of each step.It means that, with a conventional PLC, the user must draw the relationbetween the lines and the draw makes it hard to differentiate the steps of the sequence. Normally, one needs to execute a simulation on the interface to find mistakes on the logicThe new programming allows that the configuration of the steps be separated, like described by the method. The sequence is defined by itself and the steps are described only by the inputs and outputs for each step.The structure of the configuration follows the order:1-byte: features of the step;2-byte: mask for the inputs;3-byte: value expected on the inputs;4-byte: value for the outputs;5-byte: value for the extra function.Table 5 shows how the user program is saved inside the controller, this is the program that describes the control of the example shown before.The sequence can be defined by 25 bytes. These bytes can be dividedin five strings with 5 bytes each that define each step of the sequence (Figs. 9 and 10).7. ConclusionThe controller developed for this work (Fig. 11) shows that it is possible to create a very useful programmable controller based on microcontroller. External memories or external timers were not used in case to explore the resources that the microcontroller offers inside. Outside the microcontroller, there are only components to implement the outputs, inputs, analog input, display for the interface and the serial communication.Using only the internal memory, it is possible to control a pneumatic system that has a sequence with 48 steps if all the resources for all steps are used, but it is possible to reach sixty steps in the case of a simpler system.The programming of the controller does not use PLC languages, but a configuration that is simple and intuitive. With electro-pneumatic system, the programming follows the same technique that was used before to design the system, but here the designer work s directly with the states or steps of the system.With a very simple machine language the designer can define all the configuration of the step using four or five bytes. It depends only on his experience to use all the resources of the controller.The controller task is not to work in the same way as a commercial PLC but the purpose of it is to be an example of a versatile controller that is designed for a specific area. Because of that, it is not possible to say which one works better; the system made with microcontroller is an alternative that works in a simple way.应用于电气系统的可编程序控制器约翰 F.维克里此项目主要是研究电气系统以及简单有效的控制气流发动机的程序和气流系统的状态。

附件1：外文原文PID controllerZuo Xin and Sun Jinming(Research Institute ofAutomation, University of Petroleum,Belting 102249,China)Received April 2，2005Abstract:Performance assessment of a proportional-integral-derivative(PID)controller is condueted using the PID achievable minimum variance as abenchmark．When the process model is unknown，we carl estimate the P／D·achievable minimum variance and the corresponding parameters by routine closed-loop operation data．Simulation results show that the process output variance is reduced by retuning controller parameters．Key words：Performance assessment，PID control，minimum varianceA proportional–integral–derivative controller (PID controller) is a generic .control loop feedback mechanism widely used in industrial control systems.A PID controller attempts to correct the error between a measured process variable and a desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly.The PID controller calculation (algorithm) involves three separate parameters; the Proportional, the Integral and Derivative values. The Proportional value determines the reaction to the current error, the Integral determines the reaction based on the sum of recent errors and the Derivative determines the reaction to the rate at which the error has been changing. The weightedsum of these three actions is used to adjust the process via a control element such as the position of a control valve or the power supply of a heating element.By "tuning" the three constants in the PID controller algorithm the PID can provide control action designed for specific process requirements. The response of the controller can be described in terms of the responsiveness of the controller to an error, the degree to which the controller overshoots the setpoint and the degree of system oscillation. Note that the use of the PID algorithm for control does not guarantee optimal control of the system or systemstability.Some applications may require using only one or two modes to provide the appropriate system control. This is achieved by setting the gain of undesired control outputs to zero. A PID controller will be called a PI, PD, P or I controller in the absence of the respective control actions. PI controllers are particularly common, since derivative action is very sensitive to measurement noise, and the absence of an integral value may prevent the system from reaching its target value due to the control action.Note: Due to the diversity of the field of control theory and application, many naming conventions for the relevant variables are in common use.1.Control loop basicsA familiar example of a control loop is the action taken to keep one's shower water at the ideal temperature, which typically involves the mixing of two process streams, cold and hot water. The person feels the water to estimate its temperature. Based on this measurement they perform a control action: use the cold water tap to adjust the process. The person would repeat this input-output control loop, adjusting the hot water flow until the process temperature stabilized at the desired value.Feeling the water temperature is taking a measurement of the process value or process variable (PV). The desired temperature is called the setpoint (SP). The output from the controller and input to the process (the tap position) is called the manipulated variable (MV). The difference between the measurement and the setpoint is the error (e), too hot or too cold and by how much.As a controller, one decides roughly how much to change the tap position (MV) after one determines the temperature (PV), and therefore the error. This first estimate is the equivalent of the proportional action of a PID controller. The integral action of a PID controller can be thought of as gradually adjusting the temperature when it is almost right. Derivative action can be thought of as noticing the water temperature is getting hotter or colder, and how fast, and taking that into account when deciding how to adjust the tap.Making a change that is too large when the error is small is equivalent to a high gain controller and will lead toovershoot. If the controller were to repeatedly make changes that were too large and repeatedly overshoot the target, this control loop would be termed unstable and the output would oscillate around the setpoint in either a constant, growing, or decaying sinusoid. A human would not do this because we are adaptive controllers, learning from the process history, but PID controllers do not have the ability to learn and must be set up correctly. Selecting the correct gains for effective control is known as tuning the controller.If a controller starts from a stable state at zero error (PV = SP), then further changes by the controller will be in response to changes in other measured or unmeasured inputs to the process that impact on the process, and hence on the PV. Variables that impact on the process other than the MV are known as disturbances and generally controllers are used to reject disturbances and/or implement setpoint changes. Changes in feed water temperature constitute a disturbance to the shower process.In theory, a controller can be used to control any process which has a measurable output (PV), a known ideal value for that output (SP) and an input to the process (MV) that will affect the relevant PV. Controllers are used in industry to regulate temperature, pressure, flow rate, chemical composition, speed and practically every other variable for which a measurement exists. Automobile cruise control is an example of a process which utilizes automated control.Due to their long history, simplicity, well grounded theory and simple setup and maintenance requirements, PID controllers are the controllers of choice for many of these applications.2.PID controller theoryNote: This section describes the ideal parallel or non-interacting form of the PID controller. For other forms please see the Section "Alternative notation and PID forms".The PID control scheme is named after its three correcting terms, whose sum constitutes the manipulated variable (MV). Hence:Where Pout, Iout, and Dout are the contributions to the output from the PID controller from each of the three terms, as defined below.2.1. Proportional termThe proportional term makes a change to the output that is proportional to the current error value. The proportional response can be adjusted by multiplying the error by a constant Kp, called the proportional gain.The proportional term is given by:WherePout: Proportional outputKp: Proportional Gain, a tuning parametere: Error = SP − PVt: Time or instantaneous time (the present)Change of response for varying KpA high proportional gain results in a large change in the output for a given change in the error. If the proportional gain is too high, the system can become unstable (See the section on Loop Tuning). In contrast, a small gain results in a small output response to a large input error, and a less responsive (or sensitive) controller. If the proportional gain is too low, the control action may be too small when responding to system disturbances.In the absence of disturbances, pure proportional control will not settle at its target value, but will retain a steady state error that is a function of the proportional gain and the process gain. Despite the steady-state offset, both tuning theory and industrial practice indicate that it is the proportional term that should contribute the bulk of the output change.2.2.Integral termThe contribution from the integral term is proportional to both the magnitude of the error and the duration of the error. Summing the instantaneous error over time (integrating the error) gives the accumulated offset that should have been correctedpreviously. The accumulated error is then multiplied by the integral gain and added to the controller output. The magnitude of the contribution of the integral term to the overall control action is determined by the integral gain, Ki.The integral term is given by:Iout: Integral outputKi: Integral Gain, a tuning parametere: Error = SP − PVτ: Time in the past contributing to the integral responseThe integral term (when added to the proportional term) accelerates the movement of the process towards setpoint and eliminates the residual steady-state error that occurs with a proportional only controller. However, since the integral term is responding to accumulated errors from the past, it can cause the present value to overshoot the setpoint value (cross over the setpoint and then create a deviation in the other direction). For further notes regarding integral gain tuning and controller stability, see the section on loop tuning.2.3 Derivative termThe rate of change of the process error is calculated by determining the slope of the error over time (i.e. its first derivative with respect to time) and multiplying this rate of change by the derivative gain Kd. The magnitude of the contribution of the derivative term to the overall control action is termed the derivative gain, Kd.The derivative term is given by:Dout: Derivative outputKd: Derivative Gain, a tuning parametere: Error = SP − PVt: Time or instantaneous time (the present)The derivative term slows the rate of change of the controller output and this effect is most noticeable close to the controller setpoint. Hence, derivative control is used to reduce the magnitude of the overshoot produced by the integral component and improve the combined controller-process stability. However, differentiation of a signal amplifies noise and thus this term in the controller is highly sensitive to noise in the error term, and can cause a process to become unstable if the noise and the derivative gain are sufficiently large.2.4 SummaryThe output from the three terms, the proportional, the integral and the derivative terms are summed to calculate the output of the PID controller. Defining u(t) as the controller output, the final form of the PID algorithm is:and the tuning parameters areKp: Proportional Gain - Larger Kp typically means faster response since thelarger the error, the larger the Proportional term compensation. An excessively large proportional gain will lead to process instability and oscillation.Ki: Integral Gain - Larger Ki implies steady state errors are eliminated quicker. The trade-off is larger overshoot: any negative error integrated during transient response must be integrated away by positive error before we reach steady state.Kd: Derivative Gain - Larger Kd decreases overshoot, but slows down transient response and may lead to instability due to signal noise amplification in the differentiation of the error.3. Loop tuningIf the PID controller parameters (the gains of the proportional, integral and derivative terms) are chosen incorrectly, the controlled process input can be unstable, i.e. its output diverges, with or without oscillation, and is limited only by saturation or mechanical breakage. Tuning a control loop is the adjustment of its control parameters (gain/proportional band, integral gain/reset, derivative gain/rate) to the optimumvalues for the desired control response.The optimum behavior on a process change or setpoint change varies depending on the application. Some processes must not allow an overshoot of the process variable beyond the setpoint if, for example, this would be unsafe. Other processes must minimize the energy expended in reaching a new setpoint. Generally, stability of response (the reverse of instability) is required and the process must not oscillate for any combination of process conditions and setpoints. Some processes have a degree of non-linearity and so parameters that work well at full-load conditions don't work when the process is starting up from no-load. This section describes some traditional manual methods for loop tuning.There are several methods for tuning a PID loop. The most effective methods generally involve the development of some form of process model, then choosing P, I, and D based on the dynamic model parameters. Manual tuning methods can be relatively inefficient.The choice of method will depend largely on whether or not the loop can be taken "offline" for tuning, and the response time of the system. If the system can be taken offline, the best tuning method often involves subjecting the system to a step change in input, measuring the output as a function of time, and using this response to determine the control parameters.Choosing a Tuning MethodMethodAdvantagesDisadvantagesManual TuningNo math required. Online method.Requires experiencedpersonnel.Ziegler–NicholsProven Method. Online method.Process upset, sometrial-and-error, very aggressive tuning.Software ToolsConsistent tuning. Online or offline method. May includevalve and sensor analysis. Allow simulation before downloading.Some cost and training involved.Cohen-CoonGood process models.Some math. Offline method. Onlygood for first-order processes.3.1 Manual tuningIf the system must remain online, one tuning method is to first set the I and D values to zero. Increase the P until the output of the loop oscillates, then the P should be left set to be approximately half of that value for a "quarter amplitude decay" type response. Then increase D until any offset is correct in sufficient time for the process. However, too much D will cause instability. Finally, increase I, if required, until the loop is acceptably quick to reach its reference after a load disturbance. However, too much I will cause excessive response and overshoot. A fast PID loop tuning usually overshoots slightly to reach the setpoint more quickly; however, some systems cannot accept overshoot, in which case an "over-damped" closed-loop system is required, which will require a P setting significantly less than half that of the P setting causing oscillation.3.2Ziegler–Nichols methodAnother tuning method is formally known as the Ziegler–Nichols method, introduced by John G. Ziegler and Nathaniel B. Nichols. As in the method above, the I and D gains are first set to zero. The "P" gain is increased until it reaches the "critical gain" Kc at which the output of the loop starts to oscillate. Kc and the oscillation period Pc are used to set the gains as shown:3.3 PID tuning softwareMost modern industrial facilities no longer tune loops using the manual calculation methods shown above. Instead, PID tuning and loop optimization software are used to ensure consistent results. These software packages will gather the data, develop process models, and suggest optimal tuning. Some software packages can even develop tuning by gathering data from reference changes.Mathematical PID loop tuning induces an impulse in the system, and then uses the controlled system's frequency response to design the PID loop values. In loops with response times of several minutes, mathematical loop tuning is recommended, because trial and error can literally take days just to find a stable set of loop values.Optimal values are harder to find. Some digital loop controllers offer a self-tuning feature in which very small setpoint changes are sent to the process, allowing the controller itself to calculate optimal tuning values.Other formulas are available to tune the loop according to different performance criteria.4 Modifications to the PID algorithmThe basic PID algorithm presents some challenges in control applications that have been addressed by minor modifications to the PID form.One common problem resulting from the ideal PID implementations is integralwindup. This can be addressed by:Initializing the controller integral to a desired valueDisabling the integral function until the PV has entered the controllable region Limiting the time period over which the integral error is calculatedPreventing the integral term from accumulating above or below pre-determined boundsMany PID loops control a mechanical device (for example, a valve). Mechanical maintenance can be a major cost and wear leads to control degradation in the form of either stiction or a deadband in the mechanical response to an input signal. The rate of mechanical wear is mainly a function of how often a device is activated to make a change. Where wear is a significant concern, the PID loop may have an output deadband to reduce the frequency of activation of the output (valve). This is accomplished by modifying the controller to hold its output steady if the change would be small (within the defined deadband range). The calculated output must leave the deadband before the actual output will change.The proportional and derivative terms can produce excessive movement in the output when a system is subjected to an instantaneous "step" increase in the error, such as a large setpoint change. In the case of the derivative term, this is due to taking the derivative of the error, which is very large in the case of an instantaneous step change.5. Limitations of PID controlWhile PID controllers are applicable to many control problems, they can perform poorly in some applications.PID controllers, when used alone, can give poor performance when the PID loop gains must be reduced so that the control system does not overshoot, oscillate or "hunt" about the control setpoint value. The control system performance can be improved by combining the feedback (or closed-loop) control of a PID controller with feed-forward (or open-loop) control. Knowledge about the system (such as the desired acceleration and inertia) can be "fed forward" and combined with the PID output to improve the overall system performance. The feed-forward value alone can often provide the major portion of the controller output. The PID controller can then be used primarily to respond to whatever difference or "error" remains between the setpoint (SP) and the actual value of the process variable (PV). Since the feed-forward output is not affected by the process feedback, it can never cause the control system to oscillate, thus improving the system response and stability.For example, in most motion control systems, in order to accelerate a mechanical load under control, more force or torque is required from the prime mover, motor, or actuator. If a velocity loop PID controller is being used to control the speed of the load and command the force or torque being applied by the prime mover, then it is beneficial to take the instantaneous acceleration desired for the load, scale that value appropriately and add it to the output of the PID velocity loop controller. This means that whenever the load is being accelerated or decelerated, a proportional amount of force is commanded from the prime mover regardless of the feedback value. The PID loop in this situation uses the feedback information to effect any increase or decrease of the combined output in order to reduce the remaining difference between the process setpoint and thefeedback value. Working together, the combined open-loop feed-forward controller and closed-loop PID controller can provide a more responsive, stable and reliable control system.Another problem faced with PID controllers is that they are linear. Thus, performance of PID controllers in non-linear systems (such as HV AC systems) isvariable. Often PID controllers are enhanced through methods such as PID gain scheduling or fuzzy logic. Further practical application issues can arise from instrumentation connected to the controller. A high enough sampling rate, measurement precision, and measurement accuracy are required to achieve adequate control performance.A problem with the Derivative term is that small amounts of measurement or process noise can cause large amounts of change in the output. It is often helpful to filter the measurements with a low-pass filter in order to remove higher-frequency noise components. However, low-pass filtering and derivative control can cancel each other out, so reducing noise by instrumentation means is a much better choice. Alternatively, the differential band can be turned off in many systems with little loss of control. This is equivalent to using the PID controller as a PI controller.6. Cascade controlOne distinctive advantage of PID controllers is that two PID controllers can be used together to yield better dynamic performance. This is called cascaded PID control. In cascade control there are two PIDs arranged with one PID controlling the set point of another. A PID controller acts as outer loop controller, which controls the primary physical parameter, such as fluid level or velocity. The other controller acts as inner loop controller, which reads the output of outer loop controller as set point, usually controlling a more rapid changing parameter, flowrate or accelleration. It can be mathematically proved that the working frequency of the controller is increased and the time constant of the object is reduced by using cascaded PID controller.[vague]7. Physical implementation of PID controlIn the early history of automatic process control the PID controller was implemented as a mechanical device. These mechanical controllers used a lever, spring and a mass and were often energized by compressed air. These pneumatic controllers were once the industry standard.Electronic analog controllers can be made from a solid-state or tube amplifier, a capacitor and a resistance. Electronic analogPID control loops were often found within more complex electronic systems, for example, the head positioning of a disk drive, the power conditioning of a power supply, or even the movement-detection circuit of a modern seismometer. Nowadays, electronic controllers have largely been replaced by digital controllers implemented with microcontrollers or FPGAs.Most modern PID controllers in industry are implemented in software in programmable logic controllers (PLCs) or as a panel-mounted digital controller. Software implementations have the advantages that they are relatively cheap and are flexible with respect to the implementation of the PID algorithm.References[1]Byung，S.K.(2000)On Performance Assessment of Feedback Control Loops．Austin：The University of Texas Austin[2]Desborough，L．and Harris，T.(1992)Performance Assessment Measures for Univariate Feedback Control. The Canadian Journal of Chemical Engineering,70(12)．1186-1197[3]Ender,D.B.(1993)Process Control Performance：Not as Good as You Think．Control Engineering，40(10)[4]Harris,T(1993)Pefformance Assessment Measllres for Univariate Feedforward/Feedback Control．The Canadian Journal of Chemical Engineering，71(8)，1186-1197[5]Qin，S．J．(1 998)Contr01 Performance Monitoring： A Review and Assessment．Com．Chem．Eng．，(23)，173．186[6]Sun,Jinming(2004)PID Performance Assessment and Parameters Tuning．Beijing：China University of Petroleum[7]Xu，Xi；Li，Tao and Bo，Xiaochen(2000)Matlab Toolbox Application--Control Engineering．Bering：Electron Industry Press附件2：外文资料翻译译文PID控制器左信孙金明（石油大学自动化研究所，北京，102249，中国）发表于2005.4.2摘要：一个比例积分微分（PID）控制器的性能评价进行使用PID实现的最小方差作为参照。

电动机控制中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：Control of Electric winchFor motor control, we know the best way is to use the style buttons to move the many simple manual console. And this console, in some applications may still be a good choice, as some complex control headache can also be used. This article describes in your design, build or purchase winch controller, you have the motor's basic electrical equipment and you will need to address the user interface command addressed.First, the manual should be a manual control console type, so if you remove your finger buttons, hoist will stop. In addition, each control station equipped with an emergency need to brake, hoist the emergency brake to cut off all power, not just the control circuit. Think about it, if the hoist at the stop, it did not stop, you do need a way to cut off the fault line protection power. Set the table in the control of a key operated switch, is also a very good idea, especially in the line leading to theworkstation can not control, you can use the switch.(in the design of the console, even the simplest manual console, but also consider setting by specialized personnel to operate the safe operation of the keys.) Constant speed motor controlFor a fixed speed winch actual control device is a three-phase starter. Turn the motor is reversed, by a simple switch controlled phase transformation sequence from ABC to CBA. These actions are completed by two three-pole contactor-style, and they are interlocked, so that they can not be simultaneously closed. NEC, required in addition to overload and short circuit protection devices. To protect the motor against overload due to mechanical effects caused by overheating in the heat to be installed inside the starter overload delay device. When the heat overload delay device overheating, it has a long double off the metal motor power. In addition In addition, you can also select a thermistor can be installed in the motor winding way, it can be used to monitor motor temperature changes. For the short-circuit protection, we generally used by motor fuses to achieve.A linear current independent contactors, the contactors are configured should be more than the current main circuit contactor, so as to achieve the purpose of redundancy. This sets the current contactor is controlled by the security circuit, such as: emergency brake and the more-way limits.We can use the limit switches to achieve the above operation. When you reach the end of the normal travel limit position, the hoist will stop, and you can only move the winch in the opposite direction (ie, the direction away from the limit position.) There is also need for a more limited way just in case, due to electrical or mechanical problems, leaving the operation of hoist limit bit more than normal. If you run into more limiter, linear contactor will open, therefore, can not be driven winch will exceed this limit position. If this happens, you need to ask a professional technician to check the lead to meet the more specific reasons limiter. Then, you can use thestarter toggle switch inside the elastic recovery process to deal with more problems, rather than tripping device or a hand-off the current contacts.A necessary condition for speedOf course, the simple fixed speed starter is replaced by variable speed drives. This makes things start to get interesting again! At a minimum, you need to add a speed control dial operation platform. Joystick is a better user interface, because it makes you move parts of a more intuitive control.Unfortunately, you can not just from your local console to send commands to control the old variable speed drives, in addition, you can not want it in the initial stages, will be able to enhance the safe and reliable and decentralized facilities. Most of the variable speed drive can not achieve these requirements, because they are not designed to do upgrading work. Drivers need to be set to release the brake before the motor can generate torque, and when parking, that is, before the revocation of torque, the brake will be the first action.For many years, DC motors and drives provide a number of common solutions, such as when they are in a variety of speeds with good torque characteristics. For most of the hoist of the large demand for DC motor is very expensive, and that the same type of AC motor than the much more expensive. Although the early AC drives are not very useful, as they have a very limited scope of application of the speed, but produced only a small low-speed torque. Now, with the DC drives the development of low cost and a large number of available AC motors has led to a communication-driven revolution.Variable speed AC drives in two series. Frequency converter has been widely known and, indeed, easy to use. These drives convert AC into DC, and then, and then convert it back to exchange, the exchange after the conversion is a different frequency. If the drive produced the exchange of 30Hz, 60Hz a normal motor will run at half speed. Theoretically, this is very good, but in practice, this will have a lot of problems. First of all, a typical linear motor 60Hz frequencies below 2Hz 3Hz area or there will be errors, and start cog (that urgent push, yank), or parking. This will limit your speed range lower than 20:1, almost not adapted to the operational phase of the fine adjustment. Second, many low-cost converter is not able to provide the rated torque at low speeds. Use of these drives, will result in the rapid move to upgrade the components or complete failure, precisely, when you try to upgrade a stable scientific instruments, you do not want to see this situation. Some new inverter is a closed-loop system (to get feedback from the motor to provide a more accurate speed control), and the motor will work quite well.Another series of AC drives is the flow vector type drive. These components require installation of the spindle motor encoder, encoder makes use of these drivescan accurately monitor the rotation of the motor armature. Processor accurately measured magnetic flux vector values that are required to make the armature at a given speed rotation. These drives allow infinite speed, so you actually can produce at zero speed to rated torque. These drives provide precise speed and position control, so these drives in high performance applications to be welcomed.(Based on PLC controllers provide system status and control options. This screen shows the operator full access to the nine-story elevator enhance the control panel.) PLC-based systemsIs the full name of a PLC programmable logic controller. First of all, PLC controller developed to replace the fifties and sixties-based industrial control system relay, they work in harsh industrial indoor environments. These are modular systems that have a large variety of I / O modules. The modular system can easily achieve the semi-custom hardware configuration assembled, and the resulting configuration is also very reasonable price. These modules include: position control module, the counter, A / D and D / A converter, and a variety of physical state or physical contact with closed output module. Large number of different types of I / O components and PLC module property makes it an effective way to assemble custom and semi custom control system.The biggest shortcoming of PLC systems is the lack of the real number of display to tell you what is being done and the PLC on the PLC program to help you.T he first is professional entertainment for the large-scale PLC system is one of the original in Las Vegas, MGM (now Bailey Company) of the riding and carriage system. Many manufacturers offer a standard PLC-based semi-automated acoustic systems and a host of signs, set the location of the command line interpreter, and the upgrading of the control system is also available. Using standard modules to set user-defined system configuration capability is based on the PLC controller of the greatest advantage.High-end controllerFor complex transmission, the controller became complex, more than speed, time and location control. They include complex instructions to write and record the movement contour, and the processing can immediately run the ability to multi-point instructions.Many large opera house is toward the direction of point lift system, where each one is equipped with a rope to enhance independent winches, rope equivalent to those of each dimmer circuit. When more than one hoist is used to enhance the individual part, the hoist must be fully synchronous, or the load to shift, so will lead to a separate winch becomes the risk of overload. Control system must be able to be selected to keep pace winch, or a hoist winch is not able to maintain synchronization with the other, can provide the same high-speed parking capacity. For a typical speed of 240 ft / min and a winch to maintain the rate of error of between 1 / 8 points of equipment, you only have less than three microseconds of time to identify problems and try to correct the error The hoist speed, make sure you fail, you start all the winch stop the group. This will require a large amount of computation, fast I / O interface, and easy to use to write software.For large rope control system has two very different solutions. The first is to use a separate console, the problem in general terms, this console should be installed in the appropriate location of the operator perspective. However, this not only from one angle to another angle, but still can not get an instruction to another instruction from the control. These difficulties have been partially resolved. Installed in different locations through the use of video cameras, and these cameras connected to the three-dimensional display graphics, these graphics enables the operator to observe from the perspective of any of the three coordinates in the expected direction of rope movement. These operators can make from a console for him at the actual angle, or closed circuit camera practical perspective, to observe the movement of the rope on the screen. For the complex interrelated moving parts, makes the implementation of the above observation Failure to control and find out easier.Another solution to the problem is a distributed system that uses multiple light console. This will allow the different operators in the same way the different aspects of control gear, we have improved the manual control device. A vivid example is the flower in a vegetable market in central London, the Royal Opera House, the program uses the above, where the control console 240 with ten motors. Each console has five playback device, and has been open, so that each motor has been assigned to a single console. An operator and a console can control all the devices, however, often may be running a console platform screen upgrade, another console is a console on the transmission device, and the third console is used to the necessary backgroundin the background image down.(edge-type portable console allows the operator many advantages from the start to control the movement of the machine, and provide three-dimensional image display.)ConclusionA huge change in the rope control system, a workstation has been developed from a push-button to complex multi-user computerized control system. When the control system to buy rope, you can always find to meet your needs. Control system performance is the most important security and reliability. These are the true value of the property, and you can expect the price to buy a suitable way of security. With a certain product manufacturers to work, he will make you know how to install it. And he will make contact with you and the users, those users have with similar requests.译文：电动卷扬机的控制对于电动机的控制，我们所知道的最好的方式就是使用由许多点动式按钮组成的简单的手工操作台。

Single-chip1.The definition of a single-chipSingle-chip is an integrated on a single chip a complete computer system .Even though most of his features in a small chip，but it has a need to complete the majority of computer components：CPU，memory，internal and external bus system，most will have the Core.At the same time，such as integrated communication interfaces，timers，real-time clock and other peripheral equipment.And now the most powerful single-chip microcomputer system can even voice ，image，networking，input and output complex system integration on a single chip.Also known as single-chip MCU（Microcontroller），because it was first used in the field of industrial control.Only by the single-chip CPU chip developed from the dedicated processor. The design concept is the first by a large numberof peripherals and CPU in a single chip，the computer system so that smaller，more easily integrated into the complex and demanding on the volume control devices.INTEL the Z80 is one of the first design in accordance with the idea of the processor，From then on，the MCU and the development of a dedicated processor parted ways.Early single-chip 8-bit or all the four.One of the most successful is INTELs 8031，because the performance of a simple and reliable access to a lot of good praise.Since then in 8031to develop a single-chip microcomputer system MCS51 series.based on single-chip microcomputer system of the system is still widely used until now.As the field of industrial control requirements increase in the beginning of a 16-bit single-chip，but not ideal because the price has not been very widely used.After the90s with the big consumer electronics product development，single-chip technology is a huge improvement.INTEL i960 series with subsequent ARM in particular ，a broad range of application，quickly replaced by 32-bit single-chip 16-bit single-chip performance has been the rapid increase in processing power compared to the 80s to raise a few hundred times.At present，the high-end 32-bit single-chip frequency over 300MHz，the performance of the mid-90s close on the heels of a special processor，while the ordinary price of the model dropped to one U.S dollars，the most high-end models，only 10 U.S dollars.Contemporary single-chip microcomputer system is no longer only the bare-metal environment in the development and use of a large number of dedicated embedded operating system is widely used in the full range of single-chip microcomputer.In PDAs and cellphones as the coreprocessing of high-end single-chip or even a dedicated direct access to Windows and Linux operating systems.More than a dedicated single-chip processor suitable for embedded systems，so it was up to the application.In fact the number of single-chip is the worlds largest computer.Modern human life used in almost every piece of electronic and mechanical products will have a single-chip integration.Phone，telephone，calculator，home applicances，electronic toys，handheld computers and computer accessories such as a mouse in the Department are equipped with 1-2 single chip.And personal computers also have a large number of single-chip microcomputer in the workplace.Vehicles equipped with more than 40 Department of the general single-chip ，complex industrial control systems and even single-chip may have hundreds of work at the same time!SCM is not only far exceeds the number of PC and other integrated computing,even more than the number of human beings.2.single-chip introducedSingle-chip,also known as single-chip microcontroller,it is not the completion of a logic function of the chip,but a computer system integrated into a chip.Speaking in general terms: a single chip has become a computer .Its small size,light weight,cheap,for the learning,application and development of facilities provided .At the same time,learning to use the principle of single-chip computer to understand and structure the best choice.Single-chip and computer use is also similar to the module,such as CPU,memory,parallel bus, as well as the role and the same hard memory,is it different from the performance of these components are relatively weak in our home computer a lot,but the price is low ,there is generally no more than 10yuan,,can use it to make some control for a class of electrical work is not very complex is sufficient.We are using automatic drum washing machines, smoke hood,VCD and so on inside the home appliances can see its shadow! It is mainly as part of the core components of the control.It is an online real-time control computer,control-line is at the scene,we need to have a stronger anti-interference ability,low cost,and this is off-line computer(such as home PC)The main difference.By single-chip process,and can be amended.Through different procedures to achieve different functions,in particular the special unique features,this is the need to charge other devices can do a great effort,some of it is also difficult to make great efforts to do so .A function is not very complicated fi the United States the development of the 50s series of 74 or 60 during the CD4000series to get these pure hardware,the circuit must be a big PCB board !However,if the United States if the successful 70s seriesof single-chip market ,the result will be different!Simply because the adoption of single-chip preparation process you can achieve high intelligence,high efficiency and high reliability!Because of cost of single-chip is sensitive,so the dominant software or the lowest level assembly language,which is in addition to the lowest level for more than binary machine code of the language ,since such a low-level so why should we use ?Many of the seniors language has reached a level of visual programming why is it not in use ?The reason is simple ,that is,single-chip computer as there is no home of CPU,also not as hard as the mass storage device.A visualization of small high-level language program,even if there is only one button which will reach the size of dozens of K! For the home PCs hard drive is nothing,but in terms of the single-chip microcomputer is unacceptable.Single-chip in the utilization of hardware resources have to do very high ,so the compilation of the original while still in heavy use .The same token ,if the computer giants operating system and appplications run up to get the home PC,homePCcan not afford to sustain the same.It can be said that the twentieth century across the three “power”of the times,that is ,the electrical era,the electronic age and has now entered the computer age. However ,such a computer,usually refers to a personal computer,or PC.It consisits of the host ,keyboards,displays .And other components.There is also a type of computer,not how most people are familiar with . This computer is smart to give a variety of mechanical single-chip(also known as micro-controller).As the name suggests,these computer systems use only the minimum of an integrated circuit to make a simple calculation and control. Because of its small size,are usually charged with possession of machine in the “belly”in. It in the device,like the human mind plays a role, it is wrong,the entire device was paralyzed .Now,this single chip has a very wide field of use,such as smart meters,real-time industrial control,communications equipment,navigation systems,and household appliances. Once a variety of products with the use of the single-chip ,will be able to play so that the effectiveness of product upgrading,product names often adjective before the word “intelligent”,such as was hing machines and so intelligent.At present,some technical personnel of factories or other amateur electrtonics developers from engaging in certain products ,not the circuit is too complex ,that is functional and easy to be too simple imitation.The reason may be the product not on the cards or the use of single-chip programmable logic device on the other.3.single-chip historysingle-chip 70 was born in the late 20th century,experienced a SCM,MCU,SOC three stages.Single-chip micro-computer 1.SCM that(Single Chip Microcomputer)stage,is mainly a single from to find the best of the best embedded systems architecture.”Innovation model”to be successful,lay the SCM with the general-purpose computers,a completely different path of development . In embedded systems to create an independent development path,Intel Corporation credit.That is 2.MCU microcontroller(Micro Controller Unit)stage,the main direction of technology development: expanding to meet the embedded applications,the target system requirements for the various peripheral circuits and interface circuits,to highlingt the target of intelligent control.It covers all areas related with the objectSystem,therefore,the development of MCU inevitably fall on the heavy electrical,electronics manufacturers. From this point of view ,Intels development gradually MCU has its objective factors.MCU in the development ,the most famous manufacturers when the number of Philips Corporation.Philips in embedded applications for its enormous advantages,the MCS-51 from the rapid deveploment of single-chip micro-computer to the microcontroller.Therefore,when we look back at the path of development of embedded systems,Intel and Philips do not forget the historical merits.3.Single-chip is an independent embedded systems development,to the MCU an important factor in the development stage,is seeking applications to maximize the natural trend .With the mico-electronics technology,IC design,EDA tools development,based on the single-chip SOC design application systems will have greater development. Therefore,the understanding of single-chip micro-computer from a single ,monolithic single-chip microcontroller extends to applications.4.Single-chip applicationsAt present,single-chip microcomputer to infiltrate all areas of our lives,which is very difficult to find the area of almost no traces of single-chip microcomputer.Missile navigation equipment,aircraft control on a variety of instruments,compuer network communications and data transmission,industrial automation,real-time process control and data processing ,are widely used in a variety of smart IC card,limousine civilian security systems,video recorders,cameras,the control of automatic washing machines,as well as program-controllde toys,electronic pet,etc,which are inseparable from the single-chip microcomputer.Not to mention the field of robot automation ,intelligent instrumentation,medical equipment has been. Therefore,the single- chip learning ,development and application to a large number of computer applications and intelligent control of scientists,engineers.Single-chip widely used in instruments and meters,household appliances，medical equipment ,acrospace,specialized equipment and the intellingent management in areas such as process control,generally can be divided into the following areas:1.In the smart application of instrumentationSingle-chip with small size,low power consumption,control,and expansion flexibility , miniaturization and ease of sensors,can be realized,suchvoltage,power,frequency,humidity,temperature,flow,speed,thickness,angle,length,hardness,elemen t,measurement of physical pressure. SCM makes use of digital instrumentation,intelligence,miniaturization and functional than the use of electronic or digital circuitry even stronger.For example,precision measurement equipment(power meter,oscilloscope,and analyzer).2.In the industrial controlMCU can constitute a variety of control systems,data acquisition system.Such as factory assembly line of intelligent management ,intelligent control of the lift ,all kinds of alarm systems ,and computer networks constitute a secondary control system.3.In the applicationof household appliancesIt can be said that almost all home appliances are using the single-chip control,electric rice from favorable,washing machines,refrigerators,air conditioners,color TV and other audio video equipment,and then to the electronic weighing equipment,all kinds ,everywhere.4.On computer networks and communication applications in the field ofGenerally with the modern single-chip communication interface,can be easily carried out with computer carried out with computer data communications,computer networks and in inter-application communications equipment to provide an excellent material conditions,the communications equipment to provide an excellent material condition,from the mobile phone ,telephone , mini-program-controlled switchboards,buiding automated communications system call,the train wireless communications,and then you can see day-to-day work of mobile phones,Mobile communications,such as radios.5.Single-chip in the field of medical equipment applicationsSingle-chip microcomputer in medical devices have a wide range of purpose,such as medical ventilator,various analyzers,monitors,ultrasonic diagnostic equipment and hospital call systems.6.In a variety of large-scale electrical applications of modularSome special single-chip design to achieve a specific function to carry out a variety of modular circuitapplications,without requiring users to understand its internal structure.Integrated single-chip microcomputer such as music ,which seems to be simpleFunctions,a miniature electronic chip in a pure(as distinct from the principle of tape machine),would require a complex similar to the principle of the computer. Such as :music signal to digital form stored in memory(similar to ROM),read out by the microcontroller into analog music signal(similar to the sound card).In large circuits,modular applications that greatly reduces the size ,simplifying the circuit and reduce the damage,error rate ,but also to facilitate the replacement.In addition,single-chip microcomputer in the industrial,commercial,financial,scientific research ,education,defense aerospace and other fields have a wide range of uses.单片机1.单片机定义单片机是一种集成在电路芯片上的完整计算机系统。

英文资料及中文翻译Radio ReceiverA block diagram for a modern radio receiver is shown in Fig..2-4.The input signals to this radio are amplitude-modulated radio waves. The basic electronic circuits include: antenna ,tuner, mixer, local oscillator ,IF amplifier, audio detector, AF amplifier, loudspeaker, and power supply.Fig.2-4 A Block Diagram For Modern Radio ReceiverAny antenna system capable of radiating electrical energy is also able to abstract energy from a passing radio wave. Since every wave passing the receiving antenna. Induces its own voltage in the antenna conductor, it is necessary that the receiving equipment be capable of separating the desired signal from the unwanted signals that are also inducing voltages in the antenna. This separation is made on the basis of the difference in frequency between transmitting stations and is carried out by the use of resonant circuits, which can be made to discriminate very strongly in favor of a particular frequency. It has already been pointed that, by making antenna circuit resonant to a particular frequency, the energy abstracted from radio waves of that frequency will be much greater than the energy from waves of other frequencies; this alone gives a certain amount of separation between signals. Still greater selective action can be obtained by the use of additional suitably adjusted resonant circuits located somewhere in the receiver in such a way as to reject all but the desired signal. The ability to discriminate between radio waves of different frequencies is called selectivity and the process of adjusting circuits to resonance with the frequency of a desired signal is spoken of as tuning.Although intelligible radio signals have been received from the stations thousands of miles distant, using only the energy abstracted from the radio wave by the receiving antenna much more satisfactory reception can be obtained if the received energy isamplified. This amplification may be applied to the radio-frequency currents before detection, in which case it is called radio-frequency amplification or it may be applied to the rectified currents after detection, in which case it is called audio-frequency amplification. The use of amplification makes possible the satisfactory reception of signals from waves that would otherwise be too weak to give an audible response.The process by which the signal being transmitted is reproduced from the radio-frequency currents present at the receiver is called detection, or sometimes demodulation. Where the intelligence is transmitted by varying the amplitude of the radiated wave, detection is accomplished by rectifying the radio frequency current. The rectified current thus produced varies in accordance with the signal originally modulated on the wave irradiated at the transmitter and so reproduces the desired signal. Thus, when the modulated wave is rectified, the resulting current is seen to have an average value that varies in accordance with the amplitude of the original signal.Receiver circuit are made up a of a number of stages. A stage is a single transistor connected to components which provide operating voltages and currents and also signal voltages and currents. Each stage has its input circuit from which the signal comes in and its output circuit from which the signal, usually amplified, goes out. When one stage follows another, the output circuit of the first feeds the signal to the second. And so the signal is amplified, stage by stage, until it strong enough to operate the loudspeaker.Radio WavesRadio Waves are a member of the electromagnetic of waves. They are energy-carriers which trave l at the speed of light (ν), their frequency(ƒ) and wavelength(λ) being related , as for any wave motion, by the equationν=ƒ* λwhere ν=c=3.0*108 m/s in a vacuum (or air). If λ=300m, then ƒ=ν/λ=3.0*108 /(3.0*10 2)=106Hz=1MHz. The smaller λis, the larger ƒ.Radio Waves can be described either by their frequency or their wavelength. But the former is more fundamental since, unlike λ (and ν ), f does not change when the waves travel form one medium to another.Radio Waves can travel form a transmitting aerial in one or more of three different ways.Surface or ground wave.. This travels along a ground, the curvature of the earth’s surface. Its range is limited mainly by the extent to which energy is absorbed form it by the ground. Poor conductors such as sand absorb more strongly that water, and the higher thefrequency the greater the absorption. The range may be about 1500km at low frequencies (long wave, but much less for v. h. f.).Sky wave. This travels skywards and, if it is below a certain critical frequency (typically 30MHz), is returned to earth by the ionosphere. This consists of layers of air molecules (the D,E and F layer), stretching form about 80km above the earth to 50km, which have become positively charged through the remova l of electrons by the sun’s ultraviolet radiation. On striking the earth the sky wave bounces back to the ionosphere where it is again gradually refracted and returned earthwards as if by 'reflection '. This continues until it is completely attenuated.Space wave. For v. h . f., u. h. f. and microwave signals, only the space wave, giving line-of sight transmission, is effective. A range of up to 150km is possible on earth if the transmitting aerial is on high ground and there are no intervening obstacles such as hills, buildings or trees.OscillatorsElectrical oscillators are widely used in radio and television transmitters and receivers, in signal generators, oscilloscopes and computers, to produce A.C. with waveforms which may be sinusoidal, square, sawtooth etc. and with frequencies from a few hertz up to millions of hertz.Oscillatory circuitWhen a capacitor discharges through an inductor in a circuit of low resistance, an A.C. flows. The circuit is said to oscillate at its natural frequency which, as we will show shortly, equals LC 21, i.e. its resonant frequency f0. Electrical resonance thus occurs when the applied frequency equals the natural frequency as it does in a mechanical system..In Fig,2-2(a) , a charged capacitor C is shown connected across a coil L.C immediately starts to discharge, current flows and a magnetic field is created which induces an e. m. f. in L. This e. m. f. opposes the current . When C is completely discharged the electrical energy originally stored in the electric field between its plates has been transferred to the magnetic field around L.By the time the magnetic field has collapsed, the energy is again stored in C. Once more C starts to discharge but current now flows in the opposite direction, creating a magnetic field of opposite polarity. When this field has decayed, C is again charged with its upper plate positive and the same cycle is repeated.In the absence of resistance in any part of the circuit , an undamped sinusoidal A.C. would be obtained. In practice , energy is gradually dissipated by resistance as heat and a damped oscillation is produced.OscillatorAs the resistance of an LC circuit increases, the oscillation decay more quickly. To obtain undamped oscillations, energy has to be fed into the LC circuit in phase with its natural oscillations to compensate for the energy dissipated in the resistance of the circuit. This can be done with the help of a transistor in actual oscillators.A simple tuned oscillator is shown in Fig.2-2(b). The LC circuit is connected in the collector circuit (as the load) and oscillations start in it when the supply is switched on . The frequency of the oscillations is given by, i.e. then natural frequency of the LC circuit. The transistor merely ensures that energy is fed back at the correct instant from the battery. The current bias for the base of the transistor is obtained through R .AMPLIFIERIntroductionThe term amplifier is very generic. In general, the purpose of an amplifier is to take an input signal and make it stronger (or in more technically correct terms, increase its amplitude). Amplifiers find application in all kinds of electronic devices designed to perform any number of functions. There are many different types of amplifiers, each with a specific purpose in mind. For example, a radio transmitter uses an RF Amplifier (RF stands for Radio Frequency); such an amplifier is designed to amplify a signal so that it may drive an antenna. This article will focus on audio power amplifiers. Audio power amplifiers are those amplifiers which are designed to drive loudspeakers. Specifically, this discussion will focus on audio power amplifiers intended for DJ and sound reinforcement use. Much of the material presented also applies to amplifiers intended for home stereo system use.The purpose of a power amplifier, in very simple terms, is to take a signal from a source device (in a DJ system the signal typically comes from a preamplifier or signal processor) and make it suitable for driving a loudspeaker. Ideally, the ONLY thing different between the input signal and the output signal is the strength of the signal. In mathematical terms, if the input signal is denoted as S, the output of a perfect amplifier is X*S, where Xis a constant (a fixed number). The "*" symbol means? Multiplied by".This being the real world, no amplifier does exactly the ideal, but many do a very good job if they are operated within their advertised power ratings. The output of all amplifiers contain additional signal components that are not present in the input signal; these additional (and unwanted)characteristics may be lumped together and are generally known as distortion. There are many types of distortion; however the two most common types are known as harmonic distortion and inter modulation distortion. In addition to the "garbage" traditionally known as distortion, all amplifiers generate a certain amount of noise (this can be heard as a background "hiss" when no music is playing). More on these later.All power amplifiers have a power rating, the units of power are called watts. The power rating of an amplifier may be stated for various load impedances; the units for load impedance are ohms. The most common load impedances are 8 ohms, 4 ohms, and 2 ohms (if you have an old vacuum tube amplifier the load impedances are more likely to be32 ohms, 16 ohms, 8 ohms, and maybe 4 ohms). The power output of a modern amplifier is usually higher when lower impedance loads (speakers) are used (but as we shall see later this is not necessarily better).In the early days, power amplifiers used devices called vacuum tubes (referred to simply as "tubes" from here on). Tubes are seldom used in amplifiers intended for DJ use (however tube amplifiers have a loyal following with musicians and hi-fi enthusiasts). Modern amplifiers almost always use transistors (instead of tubes); in the late 60's and early 70's, the term "solid state" was used (and often engraved on the front panel as a "buzz word"). The signal path in a tube amplifier undergoes similar processing as the signal in a transistor amp, however the devices and voltages are quite different. Tubes are generally "high voltage low current" devices, where transistors are the opposite ("low voltage high current"). Tube amplifiers are generally not very efficient and tend to generate a lot of heat. One of the biggest differences between a tube amplifier and a transistor amplifier is that an audio output transformer is almost always required in a tube amplifier (this is because the output impedance of a tube circuit is far too high to properly interface directly to a loudspeaker). High quality audio output transformers are difficult to design, and tend to be large, heavy, and expensive. Transistor amplifiers have numerous practical advantages as compared with tube amplifiers: they tend to be more efficient, smaller, more rugged (physically), no audio output transformer is required, and transistors do not require periodic replacement (unless you continually abuse them). Contrary to what many people。

电动机控制中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：Control of Electric winchFor motor control, we know the best way is to use the style buttons to move the many simple manual console. And this console, in some applications may still be a good choice, as some complex control headache can also be used. This article describes in your design, build or purchase winch controller, you have the motor's basic electrical equipment and you will need to address the user interface command addressed.First, the manual should be a manual control console type, so if you remove your finger buttons, hoist will stop. In addition, each control station equipped with an emergency need to brake, hoist the emergency brake to cut off all power, not just the control circuit. Think about it, if the hoist at the stop, it did not stop, you do need a way to cut off the fault line protection power. Set the table in the control of a key operated switch, is also a very good idea, especially in the line leading to theworkstation can not control, you can use the switch.(in the design of the console, even the simplest manual console, but also consider setting by specialized personnel to operate the safe operation of the keys.) Constant speed motor controlFor a fixed speed winch actual control device is a three-phase starter. Turn the motor is reversed, by a simple switch controlled phase transformation sequence from ABC to CBA. These actions are completed by two three-pole contactor-style, and they are interlocked, so that they can not be simultaneously closed. NEC, required in addition to overload and short circuit protection devices. To protect the motor against overload due to mechanical effects caused by overheating in the heat to be installed inside the starter overload delay device. When the heat overload delay device overheating, it has a long double off the metal motor power. In addition In addition, you can also select a thermistor can be installed in the motor winding way, it can be used to monitor motor temperature changes. For the short-circuit protection, we generally used by motor fuses to achieve.A linear current independent contactors, the contactors are configured should be more than the current main circuit contactor, so as to achieve the purpose of redundancy. This sets the current contactor is controlled by the security circuit, such as: emergency brake and the more-way limits.We can use the limit switches to achieve the above operation. When you reach the end of the normal travel limit position, the hoist will stop, and you can only move the winch in the opposite direction (ie, the direction away from the limit position.) There is also need for a more limited way just in case, due to electrical or mechanical problems, leaving the operation of hoist limit bit more than normal. If you run into more limiter, linear contactor will open, therefore, can not be driven winch will exceed this limit position. If this happens, you need to ask a professional technician to check the lead to meet the more specific reasons limiter. Then, you can use thestarter toggle switch inside the elastic recovery process to deal with more problems, rather than tripping device or a hand-off the current contacts.A necessary condition for speedOf course, the simple fixed speed starter is replaced by variable speed drives. This makes things start to get interesting again! At a minimum, you need to add a speed control dial operation platform. Joystick is a better user interface, because it makes you move parts of a more intuitive control.Unfortunately, you can not just from your local console to send commands to control the old variable speed drives, in addition, you can not want it in the initial stages, will be able to enhance the safe and reliable and decentralized facilities. Most of the variable speed drive can not achieve these requirements, because they are not designed to do upgrading work. Drivers need to be set to release the brake before the motor can generate torque, and when parking, that is, before the revocation of torque, the brake will be the first action.For many years, DC motors and drives provide a number of common solutions, such as when they are in a variety of speeds with good torque characteristics. For most of the hoist of the large demand for DC motor is very expensive, and that the same type of AC motor than the much more expensive. Although the early AC drives are not very useful, as they have a very limited scope of application of the speed, but produced only a small low-speed torque. Now, with the DC drives the development of low cost and a large number of available AC motors has led to a communication-driven revolution.Variable speed AC drives in two series. Frequency converter has been widely known and, indeed, easy to use. These drives convert AC into DC, and then, and then convert it back to exchange, the exchange after the conversion is a different frequency. If the drive produced the exchange of 30Hz, 60Hz a normal motor will run at half speed. Theoretically, this is very good, but in practice, this will have a lot of problems. First of all, a typical linear motor 60Hz frequencies below 2Hz 3Hz area or there will be errors, and start cog (that urgent push, yank), or parking. This will limit your speed range lower than 20:1, almost not adapted to the operational phase of the fine adjustment. Second, many low-cost converter is not able to provide the rated torque at low speeds. Use of these drives, will result in the rapid move to upgrade the components or complete failure, precisely, when you try to upgrade a stable scientific instruments, you do not want to see this situation. Some new inverter is a closed-loop system (to get feedback from the motor to provide a more accurate speed control), and the motor will work quite well.Another series of AC drives is the flow vector type drive. These components require installation of the spindle motor encoder, encoder makes use of these drivescan accurately monitor the rotation of the motor armature. Processor accurately measured magnetic flux vector values that are required to make the armature at a given speed rotation. These drives allow infinite speed, so you actually can produce at zero speed to rated torque. These drives provide precise speed and position control, so these drives in high performance applications to be welcomed.(Based on PLC controllers provide system status and control options. This screen shows the operator full access to the nine-story elevator enhance the control panel.) PLC-based systemsIs the full name of a PLC programmable logic controller. First of all, PLC controller developed to replace the fifties and sixties-based industrial control system relay, they work in harsh industrial indoor environments. These are modular systems that have a large variety of I / O modules. The modular system can easily achieve the semi-custom hardware configuration assembled, and the resulting configuration is also very reasonable price. These modules include: position control module, the counter, A / D and D / A converter, and a variety of physical state or physical contact with closed output module. Large number of different types of I / O components and PLC module property makes it an effective way to assemble custom and semi custom control system.The biggest shortcoming of PLC systems is the lack of the real number of display to tell you what is being done and the PLC on the PLC program to help you.T he first is professional entertainment for the large-scale PLC system is one of the original in Las Vegas, MGM (now Bailey Company) of the riding and carriage system. Many manufacturers offer a standard PLC-based semi-automated acoustic systems and a host of signs, set the location of the command line interpreter, and the upgrading of the control system is also available. Using standard modules to set user-defined system configuration capability is based on the PLC controller of the greatest advantage.High-end controllerFor complex transmission, the controller became complex, more than speed, time and location control. They include complex instructions to write and record the movement contour, and the processing can immediately run the ability to multi-point instructions.Many large opera house is toward the direction of point lift system, where each one is equipped with a rope to enhance independent winches, rope equivalent to those of each dimmer circuit. When more than one hoist is used to enhance the individual part, the hoist must be fully synchronous, or the load to shift, so will lead to a separate winch becomes the risk of overload. Control system must be able to be selected to keep pace winch, or a hoist winch is not able to maintain synchronization with the other, can provide the same high-speed parking capacity. For a typical speed of 240 ft / min and a winch to maintain the rate of error of between 1 / 8 points of equipment, you only have less than three microseconds of time to identify problems and try to correct the error The hoist speed, make sure you fail, you start all the winch stop the group. This will require a large amount of computation, fast I / O interface, and easy to use to write software.For large rope control system has two very different solutions. The first is to use a separate console, the problem in general terms, this console should be installed in the appropriate location of the operator perspective. However, this not only from one angle to another angle, but still can not get an instruction to another instruction from the control. These difficulties have been partially resolved. Installed in different locations through the use of video cameras, and these cameras connected to the three-dimensional display graphics, these graphics enables the operator to observe from the perspective of any of the three coordinates in the expected direction of rope movement. These operators can make from a console for him at the actual angle, or closed circuit camera practical perspective, to observe the movement of the rope on the screen. For the complex interrelated moving parts, makes the implementation of the above observation Failure to control and find out easier.Another solution to the problem is a distributed system that uses multiple light console. This will allow the different operators in the same way the different aspects of control gear, we have improved the manual control device. A vivid example is the flower in a vegetable market in central London, the Royal Opera House, the program uses the above, where the control console 240 with ten motors. Each console has five playback device, and has been open, so that each motor has been assigned to a single console. An operator and a console can control all the devices, however, often may be running a console platform screen upgrade, another console is a console on the transmission device, and the third console is used to the necessary backgroundin the background image down.(edge-type portable console allows the operator many advantages from the start to control the movement of the machine, and provide three-dimensional image display.)ConclusionA huge change in the rope control system, a workstation has been developed from a push-button to complex multi-user computerized control system. When the control system to buy rope, you can always find to meet your needs. Control system performance is the most important security and reliability. These are the true value of the property, and you can expect the price to buy a suitable way of security. With a certain product manufacturers to work, he will make you know how to install it. And he will make contact with you and the users, those users have with similar requests.译文：电动卷扬机的控制对于电动机的控制，我们所知道的最好的方式就是使用由许多点动式按钮组成的简单的手工操作台。

电气系统可编程序控制器中英文资料外文翻译文献英文原文Programmable controller designed for electro-pneumatic systems This project deals with the study of electro-pneumatic systems and the programmable controller that provides an effective and easy way to control the sequence of the pneumatic actuators movement and the states of pneumatic system. The project of a specific controller for pneumatic applications join the study of automation design and the control processing of pneumatic systems with the electronic design based on microcontrollers to implement the resources of the controller.1.IntroductionThe automation systems that use electro-pneumatic technology are formed mainly by three kinds of elements: actuators or motors, sensors or buttons and control elements like valves. Nowadays, most of the control elements used to execute the logic of the system were substituted by the Programmable Logic Controller(PLC).Sensors and switches are plugged as inputs and the direct control valves for the actuators are plugged as outputs. An internal program executes all the logic necessary to the sequence of the movements, simulates other components like counter, timer and control the status of the system.With the use of the PLC the project wins agility, because it is possible to create and simulate the system as many times as needed. Therefore, time can be saved, risk of mistakes reduced and complexity can be increased using the same elements.A conventional PLC, that is possible to find on the market from many companies, offers many resources to control not only pneumatic systems, but all kinds of system that uses electrical components. The PLC can be very versatile and robust to be applied in many kinds of application in the industry or even security system and automation of buildings.Because of those characteristics, in some applications the PLC offers to much resources that are not even used to control the system, electro-pneumatic system is one of this kind of application. The use of PLC, especially for small size systems, can be very expensive for the automation project.An alternative in this case is to create a specific controller that can offer the exactly size and resources that the project needs[3,4].This can be made using microcontrollers as the base of thiscontroller.The controller, based on microcontroller, can be very specific and adapted to only one kind of machine or it can work as a generic controller that can be programmed as a usual PLC and work with logic that can be changed. All these characteristics depend on what is needed and how much experience the designer has with developing an electronic circuit and firmware for microcontroller. But the main advantage of design the controller with the microcontroller is that the designer has the total knowledge of his controller, which makes it possible to control the size of the controller, change the complexity and the application of it. It means that the project gets more independence from other companies, but at the same time the responsibility of the control of the system stays at the designer hands2.Electro-pneumatic systemOn automation system one can find three basic components mentioned before ,plus a logic circuit that controls the system. An adequate technique is needed to project the logic circuit and integrate all the necessary components to execute the sequence of movements properly.For a simple direct sequence of movement an intuitive method can be used[1,5],but for indirect or more complex sequences the intuition can generate a very complicated circuit and signal mistakes. It is necessary to use another method that can save time of the project, make a clean circuit, can eliminate occasional signal overlapping and redundant circuits.The presented method is called step-by-step or algorithmic [1,5], it is valid for pneumatic and electro-pneumatic systems and it was used as a base in this work. The method consists of designing the systems based on standard circuits made for each change on the state of the actuators, these changes are called steps.Fig.1.Standard circuit for the pneumatic system.Fig.2.Standard circuit for the electro-pneumatic system.The first part is to design those kinds of standard circuits for each step, the next task is to link the standard circuits and the last part to connect the control element that receive signals from sensors, switches and the previous movement and give the air or electricity to the supply lines of each step. In Figs.1 and 2 the standard circuits are drawn for pneumatic and electro-pneumatic system [8].It is possible to see the relations with the previous and the next steps.3. The method applied inside the controllerThe result of the method presented before is a sequence of movements of the actuator that is well defined by steps. It means that each change on the position of the actuators is a new state of the system and the transition between states is called step.The standard circuit described before helps the designer to define the states of the systems and to define the condition to each change between the states. In the end of the design, the system is defined by a sequence that never chances and states that have the inputs and the outputs well defined. The inputs are the condition for the transition and the outputs are the result of the transition.All the configuration of those steps stays inside of the microcontroller and is executed the same way it was designed. The sequences of strings are programmed inside the controller with 5 bytes; each string has the configuration of one step of the process. There are two bytes for the inputs, one byte for the outputs and two more for the other configurations and auxiliary functions of the step. After programming, this sequence of strings is saved inside of a non-volatile memory of the microcontroller, so they can be read and executed.The controller task is not to work in the same way as a conventional PLC, but the purpose of it is to be an example of a versatile controller that is design for an specific area. A conventional PLC process the control of the system using a cycle where it makes an image of the inputs, execute all the conditions defined by the configuration programmed inside, and thenupdate the state of the outputs. This controller works in a different way, where it read the configuration of the step, wait the condition of inputs to be satisfied, then update the state or the outputs and after that jump to the next step and start the process again.It can generate some limitations, as the fact that this controller cannot execute, inside the program, movements that must be repeated for some time, but this problem can be solved with some external logic components. Another limitation is that the controller cannot be applied on systems that have no sequence. These limitations are a characteristic of the system that must be analyzed for each application.4. Characteristics of the controllerThe controller is based on the MICROCHIP microcontroller PIC16F877 [6,7] with 40 pins, and it has all the resources needed for this project. It ha enough pins for all the components, serial communication implemented in circuit, EEPROM memory to save all the configuration of the system and the sequence of steps. For the execution of the main program, it offers complete resources as timers and interruptions.The list of resources of the controller was created to explore all the capacity of the microcontroller to make it as complete as possible. During the step, the program chooses how to use the resources reading the configuration string of the step. This string has two bytes for digital inputs, one used as a mask and the other one used as a value expected. One byte is used to configure the outputs value. One bytes more is used for the internal timer, the analog input or time-out. The EEPROM memory inside is 256 bytes length that is enough to save the string of the steps, with this characteristic it is possible to save between 48 steps.The controller has also a display and some buttons that are used with an interactive menu to program the sequence of steps and other configurations.4.1.Interaction componentsFor the real application the controller must have some elements to interact with the final user and to offer a complete monitoring of the system resources that are available to the designer while creating the logic control of the pneumatic system:.Interactive mode of work; function available on the main program for didactic purposes, the user gives the signal to execute the step..LCD display, which shows the status of the system, values of inputs, outputs, timer and statistics of the sequence execution..Beep to give important alerts, stop, start and emergency..Leds to show power on and others to show the state of inputs and outputs.4.2. SecurityTo make the final application works property, a correct configuration to execute the steps in the right way is needed, but more then that it must offer solutions in case of bad functioning or problems in the execution of the sequence. The controller offers the possibility to configure two internal virtual circuits that work in parallel to the principal. These two circuits can be used as emergency or reset buttons and can return the system to a certain state at any time[2]. There are two inputs that work with interruption to get an immediate access to these functions. It is possible to configure the position, the buttons and the value of time-out of the system.er interfaceThe sequence of strings can be programmed using the interface elements of the controller. A computer interface can also be used to generate the user program easily. With a good documentation the final user can use the interface to configure the strings of bytes that define the steps of the sequence. But it is possible to create a program with visual resources that works as a translator to the user,it changes his work to the values that the controller understands.To implement the communication between the computer interface and the controller a simple protocol with check sum and number of bytes is the minimum requirements to guarantee the integrity of the data.4.4. FirmwareThe main loop works by reading the strings of the steps from the EEPROM memory that has all the information about the steps.In each step, the status of the system is saved on the memory and it is shown on the display too. Depending of the user configuration, it can use the interruption to work with the emergency circuit or time-out to keep the system safety. A block diagram of micro controller main program is presented.5.Example of electro-pneumatic systemThe system is not a representation of a specific machine, but it is made with some common movements and components found in a real one. The system is composed of four actuators. The actuators A,B and C are double acting and D-single acting. Actuator A advances and stays in specified position till the end of the cycle, it could work fixing an object to the next action for example(Fig.3), it is the first step. When A reaches the end position, actuator C starts his work together with B, making as many cycles as possible during the advancing of B. It depends on how fast actuator B is advancing; the speed is regulated by a flowing control valve. It was the second step. B and C are examples of actuators working together, while B pushes an objectslowly, C repeats. its work for some time.Fig.3.Time diagram of A,B,C and D actuators.When B reaches the final position, C stops immediately its cycle and comes back to the initial position. The actuator D is a single acting one with spring return and works together with the back of C, it is the third step. D works making very fast forward and backward movement, just one time. Its backward movement is the fourth step. D could be a tool to make a hole on the object.When D reaches the initial position, A and B return too, it is the fifth step.Fig.4 shows the first part of the designing process where all the movements of each step should be defined [2]. (A+)means that the actuator A moves to the advanced position and (A . )to the initial position. The movements that happen at the same time are joined together in the same step. The system has five steps.Fig.4.Step sequence of A,B,C and D actuators.These two representations of the system(Figs.3 and 4) together are enough to describe correctly all the sequence. With them is possible to design the whole control circuit with the necessary logic components. But till this time, it is not a complete system, because it is missing some auxiliary elements that are not included in this draws because they work in parallel with the main sequence.These auxiliary elements give more function to the circuit and are very important to the final application; the most important of them is the parallel circuit linked with all the others steps. That circuit should be able to stop the sequence at any time and change the state of the actuators to a specific position. This kind of circuit can be used as a reset or emergency buttons.The next Figs.5 and 6 show the result of using the method without the controller. Thesepictures are the electric diagram of the control circuit of the example, including sensors, buttons and the coils of the electrical valves.Fig.5.Electric diagram of the example.Fig.6.Electric diagram of the example.The auxiliary elements are included, like the automatic/manual switcher that permit a continuous work and the two start buttons that make the operator of a machine use their two hands to start the process, reducing the risk of accidents.6. Changing the example to a user programIn the previous chapter, the electro-pneumatic circuits were presented, used to begin thestudy of the requires to control a system that work with steps and must offer all the functional elements to be used in a real application. But, as explained above, using a PLC or this specific controller, the control becomes easier and the complexity can be increase also.It shows a resume of the elements that are necessary to control the presented example.With the time diagram, the step sequence and the elements of the system described in Figs.3 and 4 it is possible to create the configuration of the steps that can be sent to the controller.While using a conventional PLC, the user should pay attention to the logic of the circuit when drawing the electric diagram on the interface (Figs.5and 6), using the programmable controller, describe in this work, the user must know only the concept of the method and program only the configuration of each step.It means that, with a conventional PLC, the user must draw the relation between the lines and the draw makes it hard to differentiate the steps of the sequence. Normally, one needs to execute a simulation on the interface to find mistakes on the logic.The new programming allows that the configuration of the steps be separated, like described by the method. The sequence is defined by itself and the steps are described only by the inputs and outputs for each step.The structure of the configuration follows the order:1-byte: features of the step;2-byte: for the inputs;3-byte: value expected on the inputs;4-byte: value for the outputs;5-byte: value for the extra function.Fig.7.Actuators A and B, and sensors.Fig.8.Actuators C and D, and sensors.Table 5 shows how the user program is saved inside the controller, this is the program that describes the control of the example shown before.The sequence can be defined by 25 bytes. These bytes can be divided in five strings with 5 bytes each that define each step of the sequence (Figs.7 and 8).7. ConclusionThe controller developed for this work shows that it is possible to create a very useful programmable controller based on microcontroller. External memories or external timers were not used in case to explore the resources that the microcontroller offers inside. Outside the microcontroller, there are only components to implement the outputs, inputs, analog input, display for the interface and the serial communication.Using only the internal memory, it is possible to control a pneumatic system that has a sequence with 48 steps if all the resources for all steps are used, but it is possible to reach sixty steps in the case of a simpler system.The programming of the controller does not use PLC languages, but a configuration that is simple and intuitive. With electro-pneumatic system, the programming follows the same technique that was used before to design the system, but here the designer works directly with the states or steps of the system.With a very simple machine language the designer can define all the configuration of the step using four or five bytes. It depends only on his experience to use all the resources of the controller.The controller task is not to work in the same way as a commercial PLC but the purpose of it is to be an example of a versatile controller that is designed for a specific area. Because of that, it is not possible to say which one works better; the system made with microcontroller is an alternative that works in a simple way.References[1]E.Nelli Silva,Fluid-mechanics systems Manual, Escola Politecnica USP,2002(in Portuguese).[2]J.Swider,Control and Automation of Technological Process and Mechatronic systems,Silesian University Publishing Company,Gli-wice,2002(redaction in Polish).[3]J.Swider, G.Wszolek, W.Carvalho. Example of the system prepared to be controlled by the controller based on microcontroller,in:12 International Scientific Conference—Achievements in Mechanical and MaterialsEngineering,Gliwice-Zakopane,Poland,2003,pp.965-970.[4]J.Swider,G.Wszolek,W.Carvalho, Controller based on microcontroller designed to execute the logic control of pneumatic systems, in:12International Scientific Conference—Achievements in Mechanical and Materials Engineering,Gliwice-Zakopane,Poland,2003,pp. 959–964.[5]J.Swider,G.Wszoek, The methodical collection of laboratory and project tasks of technological process control in Pneumatic and Electro-pneumatic Systems with Logical PLC Control, Silesian University Publishing Company,Gliwice,2003.[6]PIC 16f87xDatasheet.MICROCHIP,2001.[7]Application notes AN587 and AN546.MICROCHIP,1997.[8]Fundamental of electro-pneumatic—FESTODidactic,2000.中文翻译应用于电气系统的可编程序控制器摘要此项目主要是研究电气系统以及简单有效的控制气流发动机的程序和气流系统的状态。

毕业论文外文译文学院自动化与电气工程学院专业自动控制Component-based Safety Computer of Railway SignalInterlocking System1 IntroductionSignal Interlocking System is the critical equipment which can guarantee traffic safety and enhance operational efficiency in railway transportation. For a long time, the core control computer adopts in interlocking system is the special customized Signal, and so on. Along with the rapid development of electronic technology, the customized safety computer is facing severe challenges, for instance, the the meantime, there are several explorations and practices about adopting open system architecture in avionics. The United Stated and Europe aerospace and other safety-critical fields. In recent years, it is gradually becoming a new trend that the utilization of standardized components in aerospace, industry, transportation and other safety-critical fields.2 Railways signal interlocking system2.1 Functions of signal interlocking systemThe basic function of signal interlocking system is to protect train safety by controlling signal equipments, such as switch points, signals and track units in a station, and it interlocking regulation.Since the birth of the railway transportation, signal interlocking system computer-based Interlocking System.2.2 Architecture of signal interlocking systemGenerally, the Interlocking System of equipments, the system can be divided to the function of equipments; the system can be divided into three layers as shown in figure1.Man-Machine Interface layerInterlocking safety layerImplementation layerOutdoorequiptmentsFigure 1 Architecture of Signal Interlocking System3 Component-based safety computer design3.1 Design strategyThe design concept of component-based safety critical computer is different from that of special customized computer. Our design strategy of SIC is on a base of fault-tolerance and system integration. We separate the SIC into three layers, the standardized component unit layer, safety software layer and the system layer. Different safety functions are allocated for each layer, and the final integration of the three layers ensures the predefined safety integrity level of the whole SIC. The three layers can be described as follows:(1) Component unit layer includes four independent standardized CPU modules. A this year.(2) Safety software layer mainly utilizes fail-safe strategy and fault-tolerant management. The interlocking safety computing of the whole system adopts two outputs from different CPU, it can mostly ensure the diversity of software to errors of signal version and remove risks.(3) System layer aims to improve reliability, availability and maintainability by means of redundancy.3.2 Design of in figure 2, the SIC of four independent component units (C11, C12, C21, C22). The fault-tolerant architecture adopts dual 2 vote 2 (2v2×2) structure, and a kind of selected as computing unit which adopts Intel X Scale kernel, 533 MHZ.The operation of SIC is based on a dual two-layer data buses. The protocol, and the low bus is Controller Area Network (CAN). C11、C12 and C21、C22 respectively make up of two safety computing components IC1 and IC2, which are of 2v2 structure. And each component external dynamic circuit watchdog that is set for computing supervision and switching.Diagnosis terminalC12C21C22&&Watchdog driver Fail-safe switchInput modle Output ModleInterfaceConsole C11High bus (Ether NET)Low bus (CAN)Figure 2 Hardware structure of SIC3.3 Standardized component unitAfter component module is made certain, according to the safety-critical requirements of railway signal interlocking system, we the module. The design includes power supply, interfaces and other embedded circuits.The fault-tolerant processing, synchronized computing, and fault diagnosis of SIC mostly depend on the safety software. Here the safety software design method is differing from that of the special computer too. For dedicated computer, the software is often specially designed based on the bare object, a special scheduling program is commonly designed as safety software for the computer, and not a universal operating system. The fault-tolerant processing and fault diagnosis of the dedicated computer are tightly a standard Linux OS.The safety software is vital element of secondary development. It includes Linux OS adjustment, fail-safe process, fault-tolerance management, and safety interlocking logic. The them are shown in Figure 4.Safety Interlock LogicFail-safe process Fault-tolerance management Linux OS adjustmentFigure 4 Safety software3.4.1 Fault-tolerant modelThe Fault-tolerant computation of SIC is of a multilevel model:SIC=F1002D(F2002(S c11,S c12),F2002(S c21,S c22))Firstly, basic computing unit Ci1 adopts one algorithm to complete the S Ci1, and Ci2 finishes the S Ci2 via a different algorithm, secondly 2 out of 2 (2oo2) safety computing component of SIC executes 2oo2 calculation and gets F SICi from the calculation results of S Ci1 S Ci2, and thirdly, according the states of watchdog and switch unit block, the result of SIC is gotten via a 1 out of 2 with diagnostics (1oo2D) calculation, which is based on F SIC1 and F SIC2.The flow of calculations is as follows:(1) S ci1=F ci1 (D net1,D net2,D di,D fss)(2) S ci2=F ci2 (D net1,D net2,D di,D fss)(3) F SICi=F2oo2 (S ci1, S ci2 ),(i=1,2)(4) SIC_OutPut=F1oo2D (F SIC1, F SIC2)3.4.2 Safety computationAs interlocking system consists of a fixed set of task, the computational model of SIC is task-based. In general, applications may conform to a time-triggered, event-triggered or mixed computational model. Here the time-triggered mode is selected, tasks are executed cyclically. The consistency of computing states between the two units is the foundation of SIC for ensuring safety and credibility. As SIC works under a loosely coupled mode, it is different from that of dedicated algorithm is necessary for SIC.SIC can be considered as a multiprocessor distributed system, and its computational model is essentially based on data comparing via . First, an analytical approach is used to confirm the worst-case response time of each task. To guarantee the deadline of tasks that communicate across the network, the access time and delay of communication medium is set to a fixed possible value. Moreover, the computational model must meets the real time requirements of railway interlocking system, within the system computing cycle, we set many check points P i(i=1,2,... n) , which are small enough for synchronization, and computation result voting is executed at each point. The safety computation flow of SIC is shown in Figure 5.S t a r tS t a r t０τ１τ２τ１Ｐ２Ｐ０τ１τ２τ１Ｐ２Ｐ０Ｔ０ＴＣ1i Ｃi 21Ｔ2Ｔ1Ｔ2Ｔ…………………n+1τn+1τn Ｐn Ｐn τn τclockclockS a f e t y f u n c t i o n sT a s k s o f i n t e r l o c k i n gl o g i ci :p:c h e c k p o i n tI n i t i a l i z e S y n c h r o n i z a t i o nG u a r a n t e e S y n c h r o n o u s T i m e t r i g g e rFigure 5 Safety computational model of SIC4. Hardware safety integrity level evaluation4.1 Safety IntegrityAs an authoritative international standard for safety-related system, IEC 61508 presents a definition of safety integrity: probability of a safety-related system satisfactorily performing the required safety functions under all the stated conditions within a stated period of time. In IEC 61508, there are four levels of safety integrity are prescribe, SIL1～SIL4. The SIL1 is the lowest, and SIL4 . The SIL of SIC can be evaluated via the probability of dangerous per of SIL about such system in IEC 61508, see table 1.Table 1-Safety Integrity levels: target failure measures for a safety function operating in Safety Integrity levelHigh demand or continuous mode of Operation (Probability of a dangerous Failure per hour)4 ≥10-9 to ＜10-8 3 ≥10-8 to ＜10-7 2 ≥10-7 to ＜10-6 1 ≥10-6 to ＜10-54.2 Reliability block diagram of SICAfter analyzing the structure and working principle of the SIC, we get the bockdiagram of reliability, as figure 6.2002200220022002NET1NET2NET1NET2λ=1×10-7DC=99%Voting=1002Dλ=1×10-7DC=99%Voting=1002Dλ=1×10Β=2%βD =1%DC=99% Voting=1002DHigh bus Logic subsystemLow busFigure 6 Block diagram of SIC reliability5. ConclusionsIn this paper, we proposed an available standardized component-based computer SIC. Railway signal interlocking is a fail-safe system with a required probability of less than 10-9 safety critical failures per order to meet the critical constraints, fault-tolerant architecture and safety tactics are used in SIC. Although the computational model and implementation techniques are rather complex, the philosophy of SIC provides a cheerful prospect to safety critical applications, it renders in a simpler style of shorten development cycle and reduce cost. SIC put into practical application, and proven.………………………………………………………………………………………………………From: ),取值很小，能实现同步，并且在每个检查点得出计算结果。

Oscillation, Instability and Control of Stepper Motors LIYU CAO and HOWARD M. SCHWARTZDepartment of Systems and Computer Engineering, Carleton University, 1125 Colonel By Drive,Ottawa, ON K1S 5B6, Canada(Received: 18 February 1998; accepted: 1 December 1998)AbstractA novel approach to analyzing instability in permanent-magnet stepper motors is presented. It is shown that there are two kinds of unstable phenomena in this kind of motor: mid-frequency oscillation and high-frequency instability. Nonlinear bifurcation theory is used to illustrate the relationship between local instability and mid frequency oscillatory motion. A novel analysis is presented to analyze the loss of synchronism phenomenon, which is identified as high-frequency instability. The concepts of separators and attractors in phase-space are used to derive a quantity to evaluate the high-frequency instability. By using this quantity one can easily estimate the stability for high supply frequencies. Furthermore, a stabilization method is presented. A generalized approach to analyze the stabilization problem based on feedback theory is given. It is shown that the mid-frequency stability and the high-frequency stability can be improved by state feedback.Keywords: Stepper motors, instability, nonlinearity, state feedback.1. IntroductionStepper motors are electromagnetic incremental-motion devices which convert digital pulse inputs to analog angle outputs. Their inherent stepping ability allows for accurate position control without feedback. That is, they can track any step position in open-loop mode, consequently no feedback is needed to implement position control. Stepper motors deliver higher peak torque per unit weight than DC motors; in addition, they are brushless machines and therefore require less maintenance. All of these properties have made stepper motors a very attractive selection in many position and speed control systems, such as in computer hard disk drivers and printers, XY-tables, robot manipulators, etc.Although stepper motors have many salient properties, they suffer from an oscillation or unstable phenomenon. This phenomenon severely restricts their open-loop dynamic performance and applicable area where high speed operation is needed. The oscillation usually occurs at stepping rates lower than 1000 pulse/s, and has been recognized as a mid-frequency instability or local instability , or a dynamic instability . In addition, there is another kind of unstable phenomenon in stepper motors, that is, the motors usually lose synchronism at higher stepping rates, even though load torque is less than their pull-out torque. This phenomenon is identified as high-frequency instability in this paper, because it appears at much higher frequencies than the frequencies at which the mid-frequency oscillation occurs. The high-frequency instability has not been recognized as widely as mid-frequency instability, and there is not yet a method to evaluate it.Mid-frequency oscillation has been recognized widely for a very long time, however, acomplete understanding of it has not been well established. This can be attributed to the nonlinearity that dominates the oscillation phenomenon and is quite difficult to deal with.Most researchers have analyzed it based on a linearized model . Although in many cases, this kind of treatments is valid or useful, a treatment based on nonlinear theory is needed in order to give a better description on this complex phenomenon. For example, based on a linearized model one can only see that the motors turn to be locally unstable at some supply frequencies, which does not give much insight into the observed oscillatory phenomenon. In fact, the oscillation cannot be assessed unless one uses nonlinear theory.Therefore, it is significant to use developed mathematical theory on nonlinear dynamics to handle the oscillation or instability. It is worth noting that Taft and Gauthier , and Taft and Harned used mathematical concepts such as limit cycles and separatrices in the analysis of oscillatory and unstable phenomena, and obtained some very instructive insights into the so-called loss of synchronous phenomenon. Nevertheless, there is still a lack of a comprehensive mathematical analysis in this kind of studies. In this paper a novel mathematical analysis is developed to analyze the oscillations and instability in stepper motors.The first part of this paper discusses the stability analysis of stepper motors. It is shown that the mid-frequency oscillation can be characterized as a bifurcation phenomenon (Hopf bifurcation) of nonlinear systems. One of contributions of this paper is to relate the mid-frequency oscillation to Hopf bifurcation, thereby, the existence of the oscillation is proved theoretically by Hopf theory. High-frequency instability is also discussed in detail, and a novel quantity is introduced to evaluate high-frequency stability. This quantity is very easy to calculate, and can be used as a criteria to predict the onset of the high-frequency instability. Experimental results on a real motor show the efficiency of this analytical tool.The second part of this paper discusses stabilizing control of stepper motors through feedback. Several authors have shown that by modulating the supply frequency , the mid-frequency instability can be improved. In particular, Pickup and Russell have presented a detailed analysis on the frequency modulation method. In their analysis, Jacobi series was used to solve a ordinary differential equation, and a set of nonlinear algebraic equations had to be solved numerically. In addition, their analysis is undertaken for a two-phase motor, and therefore, their conclusions cannot applied directly to our situation, where a three-phase motor will be considered. Here, we give a more elegant analysis for stabilizing stepper motors, where no complex mathematical manipulation is needed. In this analysis, a d–q model of stepper motors is used. Because two-phase motors and three-phase motors have the same q–d model and therefore, the analysis is valid for both two-phase and three-phase motors. Up to date, it is only recognized that the modulation method is needed to suppress the mid-frequency oscillation. In this paper, it is shown that this method is not only valid to improve mid-frequency stability, but also effective to improve high-frequency stability.2. Dynamic Model of Stepper MotorsThe stepper motor considered in this paper consists of a salient stator with two-phase or three-phase windings, and a permanent-magnet rotor. A simplified schematic of athree-phase motor with one pole-pair is shown in Figure 1. The stepper motor is usually fed by a voltage-source inverter, which is controlled by a sequence of pulses and produces square-wave voltages. This motor operates essentially on the same principle as that of synchronous motors. One of major operating manner for stepper motors is that supplying voltage is kept constant and frequency of pulses is changed at a very wide range. Under this operating condition, oscillation and instability problems usually arise.Figure 1. Schematic model of a three-phase stepper motor.A mathematical model for a three-phase stepper motor is established using q–d frame-reference transformation. The voltage equations for three-phase windings are given byva = Ria + L*dia /dt − M*dib/dt − M*dic/dt + dλpma/dt ,vb = Rib + L*dib/dt − M*dia/dt − M*dic/dt + dλpmb/dt ,vc = Ric + L*dic/dt − M*dia/dt − M*dib/dt + dλpmc/dt ,where R and L are the resistance and inductance of the phase windings, and M is the mutual inductance between the phase windings. _pma, _pmb and _pmc are the flux-linkages of the phases due to the permanent magnet, and can be assumed to be sinusoid functions of rotor position _ as followλpma = λ1 sin(Nθ),λpmb = λ1 sin(Nθ − 2 /3),λpmc = λ1 sin(Nθ - 2 /3),where N is number of rotor teeth. The nonlinearity emphasized in this paper is represented by the above equations, that is, the flux-linkages are nonlinear functions of the rotor position.By using the q; d transformation, the frame of reference is changed from the fixed phase axes to the axes moving with the rotor (refer to Figure 2). Transformation matrix from the a; b; c frame to the q; d frame is given byFor example, voltages in the q; d reference are given byIn the a; b; c reference, only two variables are independent (ia C ib C ic D 0); therefore, the above transformation from three variables to two variables is allowable. Applying the above transformation to the voltage equations (1), the transferred voltage equation in the q;d frame can be obtained asvq = Riq + L1*diq/dt + NL1idω + Nλ1ω,vd=Rid + L1*did/dt − NL1iqω,Figure 2. a, b, c and d, q reference frame.where L1 D L CM, and ! is the speed of the rotor.It can be shown that the motor’s t orque has the following formT = 3/2Nλ1iqThe equation of motion of the rotor is written asJ*dω/dt = 3/2*Nλ1iq − Bfω – Tl ,where Bf is the coefficient of viscous friction, and Tl represents load torque, which is assumed to be a constant in this paper.In order to constitute the complete state equation of the motor, we need another state variable that represents the position of the rotor. For this purpose the so called load angle _ [8] is usually used, which satisfies the following equationDδ/dt = ω−ω0 ,where !0 is steady-state speed of the motor. Equations (5), (7), and (8) constitute the statespace model of the motor, for which the input variables are the voltages vq and vd. As mentioned before, stepper motors are fed by an inverter, whose output voltages are not sinusoidal but instead are square waves. However, because the non-sinusoidal voltages do not change the oscillation feature and instability very much if compared to the sinusoidal case (as will be shown in Section 3, the oscillation is due to the nonlinearity of the motor), for the purposes of this paper we can assume the supply voltages are sinusoidal. Under this assumption, we can get vq and vd as followsvq = Vmcos(Nδ) ,vd = Vmsin(Nδ) ,where Vm is the maximum of the sine wave. With the above equation, we have changed the input voltages from a function of time to a function of state, and in this way we can represent the dynamics of the motor by a autonomous system, as shown below. This will simplify the mathematical analysis.From Equations (5), (7), and (8), the state-space model of the motor can be written in a matrix form as followsẊ = F(X,u) = AX + Fn(X) + Bu , (10) where X D Tiq id ! _UT , u D T!1 TlUT is defined as the input, and !1 D N!0 is the supply frequency. The input matrix B is defined byThe matrix A is the linear part of F._/, and is given byFn.X/ represents the nonlinear part of F._/, and is given byThe input term u is independent of time, and therefore Equation (10) is autonomous.There are three parameters in F.X;u/, they are the supply frequency !1, the supply voltage magnitude Vm and the load torque Tl . These parameters govern the behaviour of the stepper motor. In practice, stepper motors are usually driven in such a way that the supply frequency !1 is changed by the command pulse to control the motor’s spee d, while the supply voltage is kept constant. Therefore, we shall investigate the effect of parameter !1.3. Bifurcation and Mid-Frequency OscillationBy setting ! D !0, the equilibria of Equation (10) are given asand ' is its phase angle defined byφ= arctan(ω1L1/R) . (16) Equations (12) and (13) indicate that multiple equilibria exist, which means that these equilibria can never be globally stable. One can see that there are two groups of equilibria as shown in Equations (12) and (13). The first group represented by Equation (12) corresponds to the real operating conditions of the motor. The second group represented by Equation (13) is always unstable and does not relate to the real operating conditions. In the following, we will concentrate on the equilibria represented by Equation (12).翻译译文步进电机的振荡、不稳定以及控制摘要本文介绍了一种分析永磁步进电机不稳定性的新颖方法。