毕业设计外文翻译---汽车的转向控制

附录Steering knuckle technology development present situationAuto steering knuckle is key automotive parts, the quality of the security of the fit and unfit quality directly support crew and cargo security. At the same time, the car turned to the festival is very complex, difficult shape forming high parts. Our traditional ways of manufacturing high energy consumption, low material utilization ratio, die life, high cost and low manufacturing production environment is bad, and can't meet the requirements of the development of China's automotive high speed. At present, China's automotive steering knuckle is in the stage of development, technical level is developed countries also has the disparity.With the high speed development of auto industry, China's automobile steering knuckle is gradually towards specialized, advanced. In 2007, China's weapon equipment group company self-developed aluminum alloy steering knuckle smooth through the national nonferrous metal and electronic material analysis and test center of the test, can meet the international similar product standard, become our country the firstsuccessfully developed the aluminum alloy of steering joint enterprise, fill the product of domestic blank.In 2008, China successfully built a has the Chinese the most advanced technology, minimum investment scale, the lowest manufacturing costs and highest input-output ratio, the shortest investment return cycle of production capacity of 180000 pieces of heavy trucks to section of the automatic production line, the production out external shape in good condition, internal quality, the products consistency of strong, organization performance standards steering knuckle products.Product process characteristics or processAuto steering knuckle processing is divided into blank manufacturing and finished product machine to add. At present, the blank mainly forging is given priority to, also have made by casting the blank, but is less. Blank forging process mainly for PiCha, pull rod, the forging, eventually working procedure such as forging components.Will tell from machining, automobile steering knuckle divided into stem, flange constructed and a fork department etc three parts processing. 1, stem processing to the centralhole positioning, car and ground is given priority to, processing key is grinding. 2, flange constructed is mainly brake installing hole processing of processing, to ensure that its position degree, and at the same time should take the processing efficiency. And, using one hole as processing fork department with positioning. 3, fork department is car steering knuckle processing the difficulties in processing, the two side, the machining positioning pin mainly is to guarantee the coaxial tolerance of the caster hole, and king pin hole and end of the vertical degree in, is the whole processing technology investment focus and equipment type selection of the key. Most of the cars in the region and to day the bars for assembly cone hole, which increased the fork of difficulty, cone hole machining processing is a lot of manufacturer is difficult to 100% qualified projects, shall be paid more and more attention, and otherwise, automobile steering knuckle early failure will start from here. 4, the stem strengthen treatment in order to improve the car turned to the section of the fatigue life, for most types of automotive steering knuckle all have the technical requirements, generally for rolling and intermediate frequency quenching, in order to form surface residual stress, improve product fatigue strength. Domestic processing ofrolling demand is not high, difficulties in intermediate frequency quenching, mainly is the sensor in the design and manufacture of, but, in this home has professional manufacturers to solve. 5, king pin hole press-printing bushing after processing, some after being not request processing, some after being request processing. From the assembly point, processing after being more advantageous to the assembly, or influence to flexibility. Above is the automobile steering knuckle processing main content, according to the specific vehicle steering section of the different, there will be different degree of change, at the same time, processing equipment choice for the whole the effect of process is bigger, therefore, specific processes shall be according to the production program and selection of equipment to develop.转向节技术发展现状汽车转向节是汽车关键的保安零件，其品质的优劣直接维系着乘员和货物的安全。

英文原文Introductions to Control SystemsAutomatic control has played a vital role in the advancement of engineering and science. In addition to its extreme importance in space-vehicle, missile-guidance, and aircraft-piloting systems, etc, automatic control has become an important and integral part of modern manufacturing and industrial processes. For example, automatic control is essential in such industrial operations as controlling pressure, temperature, humidity, viscosity, and flow in the process industries; tooling, handling, and assembling mechanical parts in the manufacturing industries, among many others.Since advances in the theory and practice of automatic control provide means for attaining optimal performance of dynamic systems, improve the quality and lower the cost of production, expand the production rate, relieve the drudgery of many routine, repetitive manual operations etc, most engineers and scientists must now have a good understanding of this field.The first significant work in automatic control was James Watt’s centrifugal governor for the speed control of a steam engine in the eighteenth century. Other significant works in the early stages of development of control theory were due to Minorsky, Hazen, and Nyquist, among many others. In 1922 Minorsky worked on automatic controllers for steering ships and showed how stability could be determined by the differential equations describing the system. In 1934 Hazen, who introduced the term “ervomechanisms”for position control systems, discussed design of relay servomechanisms capable of closely following a changing input.During the decade of the 1940’s, frequency-response methods made it possible for engineers to design linear feedback control systems that satisfied performance requirements. From the end of the 1940’s to early 1950’s, the root-locus method in control system design was fully developed.The frequency-response and the root-locus methods, which are thecore of classical theory, lead to systems that are stable and satisfy a set of more or less arbitrary performance requirements. Such systems are, in general, not optimal in any meaningful sense. Since the late 1950’s, the emphasis on control design problems has been shifted from the design of one of many systems that can work to the design of one optimal system in some meaningful sense.As modern plants with many inputs and outputs become more and more complex, the description of a modern control system requires a large number of equations. Classical control theory, which deals only with single-input-single-output systems, becomes entirely powerless for multiple-input-multiple-output systems. Since about 1960, modern control theory has been developed to cope with the increased complexity of modern plants and the stringent requirements on accuracy, weight, and industrial applications.Because of the readily available electronic analog, digital, and hybrid computers for use in complex computations, the use of computers in the design of control systems and the use of on-line computers in the operation of control systems are now becoming common practice.The most recent developments in modern control theory may be said to be in the direction of the optimal control of both deterministic and stochastic systems as well as the adaptive and learning control of complex systems. Applications of modern control theory to such nonengineering fields as biology, economics, medicine, and sociology are now under way, and interesting and significant results can be expected in the near future.Next we shall introduce the terminology necessary to describe control systems.Plants. A plant is a piece of equipment, perhaps just a set of machine parts functioning together, the purpose of which is to perform a particular operation. Here we shall call any physical object to be controlled (such as a heating furnace, a chemical reactor, or a spacecraft) a plant.Processes. The Merriam-Webster Dictionary defines a process to be a natural, progressively continuing operation or development marked by a series of gradual changes that succeed one another in a relatively fixedway and lead toward a particular result or end; or an artificial or voluntary, progressively continuing operation that consists of a series of controlled actions or movements systematically directed toward a particular result or end.Here we shall call any operation to be controlled a process. Examples are chemical, economic, and biological process.Systems. A system is a combination of components that act together and perform a certain objective. A system is not limited to abstract, dynamic phenomena such as those encountered in economics. The word “system” should, therefore, be interpreted to imply physical, biological, economic, etc., system.Disturbances. A disturbance is a signal which tends to adversely affect the value of the output of a system. If a disturbance is generated within the system, it is called internal, while an external disturbance is generated outside the system and is an input.Feedback control.Feedback control is an operation which, in the presence of disturbances, tends to reduce the difference between the output of a system and the reference input (or an arbitrarily varied, desired state) and which does so on the basis of this difference. Here, only unpredictable disturbance (i.e., those unknown beforehand) are designated for as such, since with predictable or known disturbances, it is always possible to include compensation with the system so that measurements are unnecessary.Feedback control systems. A feedback control system is one which tends to maintain a prescribed relationship between the output and the reference input by comparing these and using the difference as a means of control.Note that feedback control systems are not limited to the field of engineering but can be found in various nonengineering fields such as economics and biology. For example, the human organism, in one aspect, is analogous to an intricate chemical plant with an enormous variety of unit operations.The process control of this transport and chemical-reaction network involves a variety of control loops. In fact, human organism is an extremely complex feedback control system.Servomechanisms. A servomechanism is a feedback control systemin which the output is some mechanical position, velocity, or acceleration. Therefore, the terms servomechanism and position- (or velocity- or acceleration-) control system are synonymous. Servomechanisms are extensively used in modern industry. For example, the completely automatic operation of machine tools, together with programmed instruction, may be accomplished by use of servomechanisms.Automatic regulating systems. An automatic regulating system is a feedback control system in which the reference input or the desired output is either constant or slowly varying with time and in which the primary task is to maintain the actual output at the desired value in the presence of disturbances.A home heating system in which a thermostat is the controller is an example of an automatic regulating system. In this system, the thermostat setting (the desired temperature) is compared with the actual room temperature. A change in the desired room temperature is a disturbance in this system. The objective is to maintain the desired room temperature despite changes in outdoor temperature. There are many other examples of automatic regulating systems, some of which are the automatic control of pressure and of electric quantities such as voltage, current and frequency.Process control systems. An automatic regulating system in which the output is a variable such as temperature, pressure, flow, liquid level, or pH is called a process control system.Process control is widely applied in industry. Programmed controls such as the temperature control of heating furnaces in which the furnace temperature is controlled according to a preset program are often used in such systems. For example, a preset program may be such that the furnace temperature is raised to a given temperature in a given time interval and then lowered to another given temperature in some other given time interval. In such program control the set point is varied according to the preset time schedule. The controller then functions to maintain the furnace temperature close to the varying set point. It should be noted that most process control systems include servomechanisms as an integral part.译文：控制系统介绍自动控制在工程学和科学的推进扮演一个重要角色。

附录BHistoryThe earliest known patent related to power steering was that by Frederick W. Lanchester in the UK,in February 1902. His invention was to "cause the steering mechanism to be actuated by hydraulic power". The next design was filed as recorded by the US Patent Office on August 30, 1932, by Klara Gailis, from Belmont, Massachusetts. There is another inventor credited with the invention of power steering by the name of Charles F. Hammond an American, born in Detroit, who filed similar patents, the first of which was filed as recorded by the Canadian Intellectual Property Office.Chrysler Corporation introduced the first commercially available power steering system on the 1951 Chrysler Imperial under the name Hydraguide. Most new vehicles now have power steering, owing to the trends toward front wheel drive, greater vehicle mass, and wider tires, which all increase the required steering effort. Heavier vehicles as common in some countries would be extremely difficult to maneuver at low speeds, while vehicles of lighter weight may not need power assisted steering at allHydraulic systemsA power steering fluid reservoir and pulley driven pumpMost power steering systems work by using a hydraulic system to turn the vehicle's wheels. The hydraulic pressure is usually provided by a gerotor or rotary vane pump driven by the vehicle's engine. A double-acting hydraulic cylinder applies a force to the steering gear, which in turn applies a torque to the steering axis of the roadwheels. The flow to the cylinder is controlled by valves operated by the steering wheel; the more torque the driver applies to the steering wheel and the shaft it is attached to, the more fluid the valves allow through to the cylinder, and so the more force is applied to steer the wheels in the appropriate direction.One design for measuring the torque applied to the steering wheel is to fix a torsion bar to the end of the steering shaft. As the steering wheel rotates, so does the attached steering shaft, and so does the top end of the attached torsion bar. Since the torsion bar is relatively thin and flexible and the bottom end is not completely free to rotate, the bar will soak up some of the torque; the bottom end will not rotate as far as the top end. The difference in rotation between the top and bottom ends of the torsion bar can be used to control the valve that allows fluid to flow to the cylinder which providessteering assistance; the greater the "twist" of the torsion bar, the more steering assistance will be provided.Since the pumps employed are of the positive displacement type, the flow rate they deliver is directly proportional to the speed of the engine. This means that at high engine speeds the steering would naturally operate faster than at low engine speeds. Because this would be undesirable, a restricting orifice and flow control valve are used to direct some of the pump's output back to the hydraulic reservoir at high engine speeds. A pressure relief valve is also used to prevent a dangerous build-up of pressure when the hydraulic cylinder's piston reaches the end of the cylinder.Some modern implementations also include an electronic pressure relief valve which can reduce the hydraulic pressure in the power steering lines as the vehicle's speed increases (this is known as variable assist power steering).DIRAVIIn the DIRAVI system invented by Citroën, the force turning the wheels comes from the car's high pressure hydraulic system and is always the same no matter what the road speed is. As the steering wheel is turned, the wheels are turned simultaneously to acorresponding angle by a hydraulic piston. In order to give some artificial steering feel, there is a separate hydraulically operated system that tries to turn the steering wheel back to centre position. The amount of pressure applied is proportional to road speed, so that at low speeds the steering is very light, and at high speeds it is very difficult to move more than a small amount from the centre position.As long as there is pressure in the car's hydraulic system, there is no mechanical connection between the steering wheel and the roadwheels. This system was first introduced in the Citroën SM in 1970, and was known as 'VariPower' in the UK and 'SpeedFeel' in the U.S.While DIRAVI is not the mechanical template for all modern power steering arrangements, it did innovate the now common benefit of speed adjustable steering. The force of the centering device increases as the car's road speed increases.Electro-hydraulic systemsElectro-hydraulic power steering systems, sometimes abbreviated EHPS, and also sometimes called "hybrid" systems, use the same hydraulic assist technology as standard systems, but thehydraulic pressure is provided by a pump driven by an electric motor instead of being belt-driven by the engine.In 1965, Ford experimented with a fleet of "wrist-twist instant steering" equipped Mercury Park Lanes that replaced the conventional large steering wheel with two 5-inch (127 mm) rings, a fast 15:1 gear ratio, and an electric hydraulic pump in case the engine stalled.In 1994 Volkswagen produced the Mark 3 Golf Ecomatic, which utilized an electric pump so that the power steering could operate while the engine had been turned off by the computer to save fuel.Electro-hydraulic systems can be found in some cars by Ford, Volkswagen, Audi, Peugeot, Citroen, SEAT, Skoda, Suzuki, Opel, MINI, Toyota, Honda, and Mazda.ServotronicServotronic offers true speed-dependent power steering, in which the amount of servo assist depends on road speed, and thus provides even more comfort for the driver. The amount of power assist is greatest at low speeds, for example when parking the car. The greater assist makes it easier to maneuver the car. At higher speeds, an electronic sensing system gradually reduces the level ofpower assist. In this way, the driver can control the car even more precisely than with conventional power steering. Servotronic is used by a number of automakers, including Audi, BMW, Volkswagen, Volvo, and Porsche. Servotronic is a trademark of AM General Corp.附录C历史已知最早的专利有关的动力转向系统是由弗雷德里克兰彻斯特在英国，在1902年2月。

关于转向系统的外文翻译——中英文翻译、外文The Mazda Speed Sensing Computerised 4-Wheel Steering System. Three and a half decades ago, two young Mazda designers arrived at a far-sighted and well-calculated conclusion that was quite revolutionary for the time. In their technical presentation at the October 26, 1962 Japanese Automotive Engineers' Society Technical Conference, Dr Tadashi Okada and engineer Toshiaki summarised their arduous research concerning vehicle dynamics as follows. The basic difference in the characteristics of oversteer and understeer lies in the magnitude of time delay and response. a vehicle that is stable under high speed must possess understeer characteristics the rear wheel tyre reflects heavily on the stability and a major improvement on control and stability may be anticipated by means of the automatic rear wheel steering system. The conclusions and formulations presented by these two engineers established the foundation for Mazda's present-day reputed suspension technology. Over years of dedicated research and development expertise, their original discoveries and theories have contributed to some of the most significant achievements within the recent history of automotive chassis engineering, incorporated by Mazda within its series production products. These developments include the twin trapezoidal link rearsuspension, first employed in the original front-wheel drive Mazda 323 (1980) and the Mazda 626 (1982), and then perfected within the updated Mazda 626; the award winning Dynamic Tracking Suspension System of the second generation Mazda RX-7 (1985); and the elaborate E-link rear suspension of the new Mazda 929 (1987). While various external forces and loads are exerted to the rear wheels of a vehicle as it combats the elements of the law of motion as defined by Sir Isaac Newton, these new suspension systems convert those forces into "4WS effects" which positively aid in vehicle stability and agility. The Mazda designers' and engineers' ultimate goal was still a positive measure to generate forces for positive controls; a Four-Wheel Steering system. In 1983, Mazda astonished the automotive world with the introduction of an engineering concept car, the MX-02, exhibited at the Tokyo Motor Show. This four-door Sedan, with generous passenger accommodation on an unusually long wheelbase, incorporated among its numerous advanced features a true 4WS system that aided high-speed stability as well as its low-speed manoeuvring. The degree of rear wheel steering was determined by the measurement of both front wheel steering angle and vehicle speed, by means of a central computer unit. The MX-02 was followed by another exciting concept car; the MX-03, first exhibited at the Frankfurt Motor Show in September 1985. This sleek four seat futuristic coupe of the 1990s combined a refined electronically-controlled 4WS system with a continually varyingtorque-split, four-wheel drive system and a powerful three-rotary engine. Mazda Electronically -Controlled Four-Wheel Steering System: A Beneficial Technology Mazda's electronically-controlled, vehicle-speed-sensing Four-Wheel Steering System (4WS) steers the rear wheels in a direction and to a degree most suited to a corresponding vehicle speed range. The system is mechanically and hydraulically actuated, producing greatly enhanced stability, and within certain parameters, agility. The driver of a Mazda 4WS-equipped car derives five strategic benefits, over and above the conventional vehicle chassis. Superior cornering stability Improved steering responsiveness and precision High-speed straightline stability Notable improvement in rapid lane-changing manoeuvres Smaller turning radius and tight-space manoeuvrability at low vehicle speed range The most outstanding advantage of the Mazda 4WS is that it contributes to a notable reduction in driver fatigue over high-speed and extended travelling. This is achieved by optimally: reducing the response delay to steering input and action and eliminating the vehicle's excessive reaction to steering input In essence, by providing the optimum solution to the phenomena researched by the two young Mazda engineers in the early sixties - by the method advocated by them - the 4WS system has emerged as a fully beneficial technology. Strategic Construction The Mazda 4WS consists of a rack-and-pinion front steering system that is hydraulically assisted by a twin-tandem pump mainpower source, with an overall steering ratio of 14.2:1. The rear wheel steering mechanism is also hydraulically assisted by the main pump and electronically controlled - according to the front steering angle and vehicle speed. The rear steering shaft extends from the rack bar of the front steering gear assembly to the rear steering-phase control unit. The rear steering system is comprised of the input end of the rear steering shaft, vehicle speed sensors, a steering-phase control unit (determining direction and degree), a power cylinder and an output rod. A centering lock spring is incorporated, which locks the rear system in a neutral (straightforwa。

毕业论文中英文资料外文翻译文献Design of an Intelligent Car ControllerBased on Embedded PlatformAbstract: The paper presents a design of an intelligent car controller using embedded ARM7 chips as core component. Modular method has been applied in the design of the hardware; the paper focuses on layout of tracking circuit for the car and design ideas for the software. The experiment result proves that the designed intelligent car is stable in operation and good in tracking performance.Keywords: ARM Intelligent Tracking1 、IntroductionIn the 21st century, with development of science and technology, researches on intelligent car and its correlative techniques have become the focus in this field. Aiming to enhance practical ability，innovation, and teamwork performance of college students across the country, theEducation Department sponsored National Undergraduate Intelligent Car Contest. Based on the background, the paper introduces the design of multifunctional intelligent car controller on embedded platform, including design of hardware circuit and software implementation for key functional modules.2、Design of hardwareBy function and application, the controlling platform for the intelligent car is divided into several modules as shown below.2.1 Design of core moduleAT91SAM7S256 microprocessor produced by ATMEL has been adopted for the controller of the car, which a 32-bit low-power RISC microprocessor chip based on ARM7 TDMI-S core, and embedded with 64KB SARM, 256KB high-speed Flash and JTAG port for downloading or debugging of the program. As the core component of the car, the microprocessor plays a key role in controlling all running statuses of the car. PWM generating module inside it can be change duty cycle of outputted square wave by programming, and thus change the voltage loaded on the DC motor, which is amplified to control the revolution speed of the motor. The ports PA0, PA1, PA2 and PA3 of the PWM module respectively control the DC motor and the steering motor to perform functions such as go forward, retreat and turn etc.2.2 Design of power moduleThe car is powered by four AA dry batteries. The voltage is outputted through low-Noise LDO regulator MIC5209-3.3 to supply power for ARM7 chips and peripheral circuits. The working current of MIC5209-3.3 is as high as 500mA. When input voltage is above 3.5V, the module of MIC5209-3.3 can output stable voltage of 3.3V and achieve low power consumption. 2.3 Temperature detection ModuleMono-line digital temperature sensor DS18B20 is used to detect temperature in the car. The measure range is from -55℃ to +125℃, with increment of 0.5℃. It is low in power consumption and small in size, occupying only one I/O port.2.4 Auto tracking module2.4.1 Principles for tracking of intelligent carTracking means that the car goes along the two-centimeter-wide black guide line on the white floor. Infrared acquisition and camera shooting acquisition are commonly used for it.Infrared acquisition: Taking advantage of the feature that infrared light can change its reflective quality according to object surface of various colors. During running the car continuously sends infrared light to the ground, which will, either be reflected back by the white floor and received by the receiving tube in the car, or be absorbed by the black guide line and thus missed by the receiving tube. By this means the black guide line is positioned to identify the path for the car.Camera shooting acquisition: In certain resolution sample the image by interlaced scanning. When scanning a point, image sensor transfers the gray threshold into corresponding voltage which will be outputted via video signal port. As the car achieves auto tracking by recognizing the black guide line on the track, the image processing is a process of extracting the destination guide line. The task of image processing program is to identify the dots in the black-and-white image and filter noise, record dot positions relative to the image, and finally, by algorithm of control strategy, realize tracking and turning of the car along the guide line.2.4.2 Installation of tracking infrared probeChoosing proper detection method and sensor is the important factor to achieve tracking. Here we choose infrared acquisition. Correct installation of device is also a decisive factor for accomplishment of tracking circuit. In terms of simplicity, easiness, practicality and reliability, four infrared probes need be installed on the front chassis of the car to fulfill two-staged directional correction control to enhance the reliability of tracking. Four tracking sensors have been fixed, all in one line, among which L1 and R1 are primary sensors for direction control; L2 and R2 are secondary sensors. The distance between the two ipsilateral sensors should nor be more than width of the black direction control. When the car is running, the black guide line is always kept right between the two primary sensors L1 and L2. When the car goes off the black line, the primary sensors detect it, and thus the ARM7 chip detect level jump and execute the pre-prepared correction program to navigate the car back onto the track. The secondary sensors are actually a back-up for the primary. Once the car offsets the track for inertia, beyond the reach of detection of the primary probes, the secondary perform to correct the motion of the car, so as to ensure the reliability of tracking.3 Design of softwareThe software is developed in C language in Keil Uvision3 IDE, debugged and downloaded in J-Link ARM emulator. J-Link is a JTAG emulator which was brought out by SEGGER in USA to support emulation chips with ARM core. It works with IDEs such as IAREWARM, ADS, Keil, WINARM, and RealView, supports all ARM7/ARM9 core chips simulation, and seamlessly connects with various IDE by RDI interface. Easy to operate and to connect to, it is the most practical tool for study and development of ARM.The key for the design of software lies in the control process of tracking. The sensors are equipped with E3F-DS10C4 integrated infrared probes with photoelectric switch. There are only three wires（power wire, ground wire, and signal wire）at the output pin of the module. Connect the signal wire to I/O port of ARM7 chip, and execute enquiry check. Low level will be detected for the black guide line, while high level for the white floor. According to the principles stated above, flows of the algorithm for control tracking of the car. Two-stage control method is adopted to ensure the car’s adherence to the black guide line, and the effect is satisdied.4 Debugging of the finished carBased on the design scheme presented above, finish making of PCB board for hardware circuit of the car, welding of components, and debugging and downloading of the software. Test the car for several times on the track made of white KT board in the middle of which a two-centimeter-wide black guide line is pasted. The results have showed that, the car runs steadily even at a high speed along straight black guide line. When around the curve, if control the speed properly, the car goes smoothly as well. Two pieces of experience as shown below: (1)E3F-DS10C4 photoelectric sensor should be fixed as close tothe ground as possible to minimize the interference of environmental light to it. Vertical height of the sensor had better be 5~8mm. Too far distance from the ground causes weak reflective signal and unstable output of up level signal;too close distance may damage the sensor and intensify the effect of diffuse reflection.(2)Due to common DC motor adopted for it, the control of thecar is not accurate and stable enough to perform a break turn unless several same photoelectric sensors are added to the bottom of the car.5 ConclusionIntelligent car is a front subject which has synthesized many other subjects and has a widely-applied prospect. It particularly helps to develop the present Chinese undergraduates’ imagination, practical abilities, team awareness, and hi-tech innovation capacity.References[1] Wu Binghua, Huang Weihua, Cheng Lei among others, Systematic Design of Intelligent Car Based on Route Identification [J]. Application of Electronic Technique, 2007(3): 80-83.[2] Wang Chaoyi, Wang Yihuai. Design of Control System of Auto Tracking Car Based on Infrared Sensor [J]; Computer and Automation Techniques, 2008, 34(11):60-62[3] Li Yi, Lu Ren Yi, & Wu Tian. Intelligence Tracking Car [J]. Electronic Techniques, 2008, 45(1): 39-41[4] Wen Quangang, Principles and Application of Embedded System Interface [M]. Beijing: Aeronautics and Astronautics University Press, 2009[5] G.C.Hua, F.C.Lee. Soft-switching technique in PWM converter[J]. IEEE Trans. on Industrial Electronics 995.42(6):595-603.Author BiographyLiu Gang: (1963-) male, senior engineer, received his Bachelor’s degree from Beijing University of Aeronautics & astronautics in 1991, main research direction: computer measurement and control technology ete基于嵌入式平台的智能小车控制器的设计摘要：本论文介绍了智能小车控制器的设计方案。

汽车转向系统ES设计论文汽车转向系统（ES）是汽车的重要安全控制系统之一，它具有控制车辆转向动作的功能。

随着汽车技术的发展和智能化水平的提高，汽车转向系统的设计也变得越来越重要。

本文将探讨汽车转向系统的设计，并介绍一些目前比较常见的设计方案。

首先，汽车转向系统的设计应考虑到车辆的稳定性和安全性。

在转向过程中，车辆必须保持平稳，并且转向动作应该准确可靠。

因此，汽车转向系统应该具备快速而精准的响应能力。

一种常见的设计方案是采用电动助力转向系统（EPAS），它通过电动马达提供动力，并且可以根据车速和驾驶员的输入进行精确控制。

EPAS可以实现转向力的实时调节，提高转向精度和驾驶稳定性。

另外，汽车转向系统的设计还需要考虑到能耗和环保性。

传统的液压助力转向系统存在液压流体泄漏和能量浪费的问题。

为了解决这些问题，一种可行的设计方案是采用电子助力转向系统（EPS）。

EPS利用电动机替代了传统的液压泵，从而减少了能源的消耗。

而且，EPS还可以根据驾驶条件和需求调整转向力的大小，提供更好的驾驶体验。

此外，在汽车转向系统的设计中，还需要考虑到自动驾驶技术的应用。

随着自动驾驶技术的发展，汽车转向系统需要能够与其他智能化技术进行联动，实现更高级别的自动驾驶功能。

例如，通过与车辆定位系统和传感器的协同工作，汽车转向系统可以自动感知道路情况，并根据需要进行自动转向。

这样可以大大提高驾驶的安全性和舒适性。

最后，汽车转向系统的设计还应该兼顾可靠性和故障监测与诊断（FDD）功能。

由于汽车在使用过程中可能会遇到各种故障和异常情况，因此必须具备故障检测和诊断功能。

一种常用的设计方法是采用红外传感器和电子控制单元进行实时监测和故障诊断。

当转向系统发生故障时，FDD系统可以及时发出警报并采取相应措施，确保驾驶员和车辆的安全。

综上所述，汽车转向系统的设计应注重提高驾驶稳定性、降低能耗、适应自动驾驶技术和增强故障监测与诊断功能。

未来，随着汽车技术的不断发展，我们可以期待更先进和智能化的汽车转向系统的设计和应用。

附录A：英文参考文献及其翻译Direct torque controlDirect torque control(DTC) is one method used in variable frequency drives to control the torque (and thus finally the speed) of three-phaseAC electric motors. This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor. MethodStatorflux linkage is estimated by integrating the stator voltages. Torque is estimated as a cross product of estimated stator flux linkagevector and measured motor currentvector. The estimated flux magnitude and torque are then compared with their reference values. If either the estimated flux or torque deviates from the reference more than allowed tolerance, the transistors of the variable frequency drive are turned off and on in such a way that the flux and torque will return in their tolerance bands as fast as possible. Thus direct torque control is one form of the hysteresis or bang-bang control.This control method implies the following properties of the control:∙Torque and flux can be changed very fast by changing the references∙High efficiency & low losses - switching losses are minimized because the transistors are switched only when it is needed to keep torque and flux within their hysteresisbands∙The step response has no overshoot∙No coordinate transforms are needed, all calculations are done in stationary coordinate system∙No separate modulator is needed, the hysteresis control defines the switch control signals directly∙There are no PI current controllers. Thus no tuning of the control is required∙The switching frequency of the transistors is not constant. However, by controlling the width of the tolerance bands the average switching frequency can be kept roughly atits reference value. This also keeps the current and torque ripple small. Thus thetorque and current ripple are of the same magnitude than with vector controlled drives with the same switching frequency.∙Due to the hysteresis control the switching process is random by nature. Thus there are no peaks in the current spectrum. This further means that the audible noise of themachine is low∙The intermediate DC circuit's voltage variation is automatically taken into account in the algorithm (in voltage integration). Thus no problems exist due to dc voltage ripple (aliasing) or dc voltage transients∙Synchronization to rotating machine is straightforward due to the fast control; Just make the torque reference zero and start the inverter. The flux will be identified by the first current pulse∙Digital control equipment has to be very fast in order to be able to prevent the flux and torque from deviating far from the tolerance bands. Typically the control algorithmhas to be performed with 10 - 30 microseconds or shorter intervals. However, theamount of calculations required is small due to the simplicity of the algorithm ∙The current and voltage measuring devices have to be high quality ones without noise and low-pass filtering, because noise and slow response ruins the hysteresis control ∙In higher speeds the method is not sensitive to any motor parameters. However, at low speeds the error in stator resistance used in stator flux estimation becomes criticalThe direct torque method performs very well even without speed sensors. However, the flux estimation is usually based on the integration of the motor phase voltages. Due to the inevitable errors in the voltage measurement and stator resistance estimate the integrals tendto become erroneous at low speed. Thus it is not possible to control the motor if the output frequency of the variable frequency drive is zero. However, by careful design of the control system it is possible to have the minimum frequency in the range 0.5 Hz to 1 Hz that is enough to make possible to start an induction motor with full torque from a standstill situation.A reversal of the rotation direction is possible too if the speed is passing through the zero range rapidly enough to prevent excessive flux estimate deviation.If continuous operation at low speeds including zero frequency operation is required, a speed or position sensor can be added to the DTC system. With the sensor, high accuracy of the torque and speed control can be maintained in the whole speed range.HistoryDirect torque control was patented by Manfred Depenbrock in U.S. Patent 4,678,248 filed originally on October 20, 1984 in Germany. He called it "Direct Self-Control" (DSC). However, Isao Takahashi and Toshihiko Noguchi presented a similar idea only few months later in a Japanese journal. Thus direct torque control is usually credited to all three gentlemen.The only difference between DTC and DSC is the shape of the path along which the flux vector is controlled to follow. In DTC the path is a circle and in DSC it was a hexagon. Today DTC uses hexagon flux path only when full voltage is required at high speeds.Since Depenbrock, Takahashi and Noguchi had proposed direct torque control (DTC) for induction machines in the mid 1980s, this new torque control scheme has gained much momentum. From its introduction, the Direct Torque control or Direct Self Control (DSC) principle has been used for Induction Motor (IM) drives with fast dynamics. Despite its simplicity, DTC is able to produce very fast torque and flux control, if the torque and flux are correctly estimated.Among the others, DTC/DSC was further studied in Ruhr-University in Bochum, Germany at the end of 80's. A very good treatment of the subject 。

英文资料SuspensionSuspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose –contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations,etc. These goals are generally at odds, so the tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.Leaf springs have been around since the early Egyptians.Ancient military engineers used leaf springs in the form of bows to power their siege engines, with little success at first. The use of leaf springs in catapults was later refined and made to work years later. Springs were not only made of metal, a sturdy tree branch could be used as a spring, such as with a bow.Horse drawn vehiclesBy the early 19th century most British horse carriages were equipped with springs; wooden springs in the case of light one-horse vehicles to avoid taxation, and steel springs in larger vehicles. These were made of low-carbon steel and usually took the form of multiple layer leaf springs.[1]The British steel springs were not well suited for use on America's rough roads of the time, and could even cause coaches to collapse if cornered too fast. In the 1820s, the Abbot Downing Company of Concord, New Hampshire developed a system whereby the bodies of stagecoaches were supported on leather straps called "thoroughbraces", which gave a swinging motion instead of the jolting up and down of a spring suspension (the stagecoach itself was sometimes called a "thoroughbrace")AutomobilesAutomobiles were initially developed as self-propelled versions of horse drawn vehicles. However, horse drawn vehicles had been designed for relatively slow speeds and their suspension was not well suited to the higher speeds permitted by the internal combustion engine.In 1903 Mors of Germany first fitted an automobile with shock absorbers. In 1920 Leyland used torsion bars in a suspension system. In 1922 independent front suspension was pioneered on the Lancia Lambda and became more common in mass market cars from 1932.[2]Important propertiesSpring rateThe spring rate (or suspension rate) is a component in setting the vehicle's ride height or its location in the suspension stroke. Vehicles which carry heavy loads will often have heavier springs to compensate for the additional weight that would otherwise collapse a vehicle to the bottom of its travel (stroke). Heavier springs are also used in performance applications where the loading conditions experienced are more extreme. Springs that are too hard or too soft cause the suspension to become ineffective because they fail to properly isolate the vehicle from the road. Vehicles that commonly experience suspension loads heavier than normal have heavy or hard springs with a spring rate close to the upper limit for that vehicle's weight. This allows the vehicle to perform properly under a heavy load when control is limited by the inertia of the load. Riding in an empty truck used for carrying loads can be uncomfortable for passengers because of its high spring rate relative to the weight of the vehicle. A race car would also be described as having heavy springs and would also be uncomfortably bumpy. However, even though we say they both have heavy springs, the actual spring rates for a 2000 lb race car and a 10,000 lb truck are very different. A luxury car, taxi, or passenger bus would be described as having soft springs. Vehicles with worn out or damaged springs ride lower to the ground which reduces the overall amount of compression available to the suspension and increases the amount of body lean. Performance vehicles can sometimes have spring rate requirements other than vehicle weight and load.Mathematics of the spring rateSpring rate is a ratio used to measure how resistant a spring is to being compressed or expanded during the spring's deflection. The magnitude of the spring force increases as deflection increases according to Hooke's Law. Briefly, this can be stated aswhereF is the force the spring exertsk is the spring rate of the spring.x is the displacement from equilibrium length i.e. the length at which the spring is neither compressed or stretched.Spring rate is confined to a narrow interval by the weight of the vehicle,load the vehicle will carry, and to a lesser extent by suspension geometry and performance desires.Spring rates typically have units of N/mm (or lbf/in). An example of a linear spring rate is 500 lbf/in. For every inch the spring is compressed, it exerts 500 lbf. Anon-linear spring rate is one for which the relation between the spring's compression and the force exerted cannot be fitted adequately to a linear model. For example, the first inch exerts 500 lbf force, the second inch exerts an additional 550 lbf (for a total of 1050 lbf), the third inch exerts another 600 lbf (for a total of 1650 lbf). In contrast a 500 lbf/in linear spring compressed to 3 inches will only exert 1500 lbf.The spring rate of a coil spring may be calculated by a simple algebraic equation or it may be measured in a spring testing machine. The spring constant k can be calculated as follows:where d is the wire diameter, G is the spring's shear modulus (e.g., about 12,000,000 lbf/in² or 80 GPa for steel), and N is the number of wraps and D is the diameter of the coil.Wheel rateWheel rate is the effective spring rate when measured at the wheel. This is as opposed to simply measuring the spring rate alone.Wheel rate is usually equal to or considerably less than the spring rate. Commonly, springs are mounted on control arms, swing arms or some other pivoting suspension member. Consider the example above where the spring rate was calculated to be500 lbs/inch, if you were to move the wheel 1 inch (without moving the car), the spring more than likely compresses a smaller amount. Lets assume the spring moved 0.75 inches, the lever arm ratio would be 0.75 to 1. The wheel rate is calculated by taking the square of the ratio (0.5625) times the spring rate. Squaring the ratio is because the ratio has two effects on the wheel rate. The ratio applies to both the force and distance traveled.Wheel rate on independent suspension is fairly straight-forward. However, special consideration must be taken with some non-independent suspension designs. Take the case of the straight axle. When viewed from the front or rear, the wheel rate can be measured by the means above. Yet because the wheels are not independent, when viewed from the side under acceleration or braking the pivot point is at infinity (because both wheels have moved) and the spring is directly inline with the wheel contact patch. The result is often that the effective wheel rate under cornering is different from what it is under acceleration and braking. This variation in wheel rate may be minimized by locating the spring as close to the wheel as possible.Roll couple percentageRoll couple percentage is the effective wheel rates, in roll, of each axle of the vehicle just as a ratio of the vehicle's total roll rate. Roll Couple Percentage is critical in accurately balancing the handling of a vehicle. It is commonly adjusted through the use of anti-roll bars, but can also be changed through the use of different springs.A vehicle with a roll couple percentage of 70% will transfer 70% of its sprung weight transfer at the front of the vehicle during cornering. This is also commonly known as "Total Lateral Load Transfer Distribution" or "TLLTD".Weight transferWeight transfer during cornering, acceleration or braking is usually calculated per individual wheel and compared with the static weights for the same wheels.The total amount of weight transfer is only affected by 4 factors: the distance between wheel centers (wheelbase in the case of braking, or track width in the case of cornering) the height of the center of gravity, the mass of the vehicle, and the amount of acceleration experienced.The speed at which weight transfer occurs as well as through which components it transfers is complex and is determined by many factors including but not limited to roll center height, spring and damper rates, anti-roll bar stiffness and the kinematic design of the suspension links.Unsprung weight transferUnsprung weight transfer is calculated based on the weight of the vehicle's components that are not supported by the springs. This includes tires, wheels, brakes, spindles, half the control arm's weight and other components. These components are then (for calculation purposes) assumed to be connected to a vehicle with zero sprung weight. They are then put through the same dynamic loads. The weight transfer for cornering in the front would be equal to the total unsprung front weight times theG-Force times the front unsprung center of gravity height divided by the front track width. The same is true for the rear.Suspension typeDependent suspensions include:∙Satchell link∙Panhard rod∙Watt's linkage∙WOBLink∙Mumford linkage∙Live axle∙Twist beam∙Beam axle∙leaf springs used for location (transverse or longitudinal)The variety of independent systems is greater and includes:∙Swing axle∙Sliding pillar∙MacPherson strut/Chapman strut∙Upper and lower A-arm (double wishbone)∙multi-link suspension∙semi-trailing arm suspension∙swinging arm∙leaf springsArmoured fighting vehicle suspensionMilitary AFVs, including tanks, have specialized suspension requirements. They can weigh more than seventy tons and are required to move at high speed over very rough ground. Their suspension components must be protected from land mines and antitank weapons. Tracked AFVs can have as many as nine road wheels on each side. Many wheeled AFVs have six or eight wheels, to help them ride over rough and soft ground. The earliest tanks of the Great War had fixed suspensions—with no movement whatsoever. This unsatisfactory situation was improved with leaf spring suspensions adopted from agricultural machinery, but even these had very limited travel. Speeds increased due to more powerful engines, and the quality of ride had to be improved. In the 1930s, the Christie suspension was developed, which allowed the use of coil springs inside a vehicle's armoured hull, by redirecting the direction of travel using a bell crank. Horstmann suspension was a variation which used a combination of bell crank and exterior coil springs, in use from the 1930s to the 1990s.By the Second World War the other common type was torsion-bar suspension, getting spring force from twisting bars inside the hull—this had less travel than the Christie type, but was significantly more compact, allowing the installation of larger turret rings and heavier main armament. The torsion-bar suspension, sometimes including shock absorbers, has been the dominant heavy armored vehicle suspension since the Second World War.中文翻译悬吊系统(亦称悬挂系统或悬载系统)是描述一种由弹簧、减震筒和连杆所构成的车用系统，用于连接车辆与其车轮。