文献翻译-汽车电动助力转向系统发展综述
汽车助力转向文献综述
文献综述汽车转向是通过驾驶者转动方向盘，经过转向系统提供的操纵力以改变车轮角度来实现。
助力转向是一种为了减轻驾驶员的操纵力而设有主力机构的转向装置。
为方便驾驶员易于操纵转向系，动力转向已经成为汽车的标准装备。
黄蓉清认为：汽车汽车转向系统大致经历了无助力的纯机械转向(MS)、有液压助力的液压助力转向(HPS)、随车速改变助力大小的电控液压助力转向(ECHPS)、由电动机直接驱动转向油泵的电动液压助力转向(EHPS)、纯粹靠电动机提供助力的电动助力转向(EPS)、可变传动比转向系统(VGRS)等发展历程。
专家们预测,未来汽车转向系统的发展趋势是线控转向(SBW),即取消方向盘与转向车轮之间原有的机械连接,而改用控制信号代替的一种电动转向系统。
（电动助力转向的原理和发展，华南理工大学汽车工程学院，广东广州510640，黄蓉清，向铁明，许迎东）。
电子助力转向系统的发展是朝着EPS的方向发展的，未来汽车配置中将必不可少的拥有电子助力转向系统，对司机的安全驾驶起到协助作用。
李国洪（电动助力系统控制单元的设计，天津理工大学，天津市复杂系统控制理论及应用重点实验室，天津300384）做出论断：在电动助力转向系统中，电子控制单元是整个系统的控制核心，也是驾驶系统的主要工作，电子控制单元设计要实现的主要功能如下：（1）采集方向盘扭矩信号和车速信号，并将其转化为DSP可以接收、处理的信号。
（2）根据控制要求，确定助力特性，将扭矩值换算成为电机提供的目标电流值。
（3）设计合适的驱动电路，将DSP的输出信号提供给直流助力电机。
（4）跟踪目标电流形成闭环控制，保证实际电流和目标电流的误差不超过允许范围.（5）对系统进行监控和保护，保证系统正常工作。
电动助力系统控制单元的设计是重中之重，对于控制单元的设计，我会尽力于老师沟通，毕竟控制单元一步错步步错，对于控制单元我细心加谨慎，来认真完成。
郝金魁认为（电动助力转向系统驱动电路的设计，石家庄铁道学院机械工程分院，2006-09-11，郝金魁，张超风）：电动助力转向系统的硬件电路主要包括以下模块：MC9S12DP256 微控制器、电源电路、信号处理电路、直流电机功率驱动模块、故障诊断模块与显示模块、车速传感器、扭矩传感器、发动机点火信号、电流及电流传感器等接人处理电路, 另外还有电磁离合器等。
汽车转向系统综述
汽车转向系统概述摘要本文简述了汽车转向系统在国内外的发展，经历了机械转向、液压助力转向、电控液压助力转向、电动助力转向系统四个阶段的发展的汽车转向系统已经相对成熟，探讨了汽车转向系统的发展趋势。
提出了通过控制信号解决方向盘与转向轴之间的联系问题，省略去方向盘与转向轴的机械连接装置，使汽车转向有更好的灵活性，更好的稳定性，轻便省力，并发现了系统中不够成熟和有待解决的问题。
关键词：助力转向；液压助力转向；电动助力转向AbstractThis article describes the steering system's development at home and abroad. The steering system experienced a mechanical steering, hydraulic power steering, electric hydraulic power steering and electric power steering four stages. Automotive steering system has been relatively mature. And the article explores the steering system trends. It proposed by the steering wheel and shift control signals to resolve the linkage between the axes, omitted to steering wheel and steering shaft of the mechanical connection device. It can make the car turn better flexibility, better stability. And I found that the system is not mature enough and the problems to be solved.Key Words: power steering; hydraulic power steering；electric power steering引言汽车转向系统的发展经历了传统的机械转向、液压助力转向、电控液压助力转向、电动助力转向系统四个阶段。
汽车电动助力转向系统的发展
汽车电动助力转向系统的发展汽车电动助力转向系统（Electric Power Steering，EPS）是一种利用电动机驱动的辅助转向系统，通过电子控制单元（ECU）对电动机进行控制，以提供相应的转向力。
相比传统液压助力转向系统，EPS系统具有更快的反应速度、更高的能效和更好的可调性。
本文将从EPS系统的发展历程、工作原理和优势等方面来探讨汽车电动助力转向系统的发展。
汽车电动助力转向系统最早可以追溯到20世纪70年代，当时主要是为了提高驾驶舒适性而引入的。
而随着电子技术和电动机技术的不断发展，EPS系统逐渐成为了汽车领域的研究热点。
特别是在21世纪初，EPS系统开始逐渐取代液压助力转向系统，成为了新一代汽车助力转向系统的主流。
汽车电动助力转向系统主要由电动助力转向机构、电子控制单元（ECU）、转向传感器和转向力传感器等组成。
在转向过程中，车辆的转向操作通过转向传感器转化为电信号，经过ECU处理后，输出给电动助力转向机构，电动助力转向机构则产生相应的转向力。
整个过程实现了驾驶员的转向意图和车辆的实际转向行为之间的转换。
与传统液压助力转向系统相比，汽车电动助力转向系统具有以下优势。
EPS系统可以根据驾驶员的需求提供不同的转向力，提高了转向的稳定性和可调性。
EPS系统通过电子控制单元对电机进行精确控制，使得转向更加精准和灵活。
EPS系统没有液压助力转向系统的泄漏和污染问题，更加环保和可靠。
EPS系统由于采用了电动机，能够根据车速的不同自动调整转向力的大小，提高了能效。
EPS系统的响应速度更快，可以在瞬间提供所需的转向力。
随着汽车技术和电子技术的发展，EPS系统也在不断演进和更新。
目前，EPS系统已经可以实现自适应转向力调节、主动防侧移、纠偏保持和自动泊车等功能。
还有一些新的技术在不断应用于EPS系统中，例如电磁轮边转向系统、无杆电动助力转向系统和双电机电动助力转向系统等。
汽车电动助力转向系统是汽车发展的一个重要方向，具有更好的转向稳定性、可靠性和能效。
中英文文献翻译-电动助力转向系统
附录A 外文文献Electric Power Steering system1.HistoryIn automobile development course, Steering system experienced four stages of development: from the initial mechanical Steering system (for your DNS setting Steering, abbreviation ) development for Hydraulic Steering system (Hydraulic Power Steering, abbreviation HPS), then again appeared electronically controlled Hydraulic Steering system (Electro Hydraulic Power Steering, abbreviation EHPS) and Electric Power Steering system (Steering, room Power as EPS). Assemble mechanical steering system of car parking and low-speed driving, when the driver's steering control burden too heavy, in order to solve this problem, the American GM in the 1950s took the lead in the car hydraulic steering system. But, hydraulic steering system can't juggle vehicles to speed portability and high speed, so the steering stability Koyo in Japan in 1983, with the company introduced the application of speed sensing function of hydraulic steering system. This new type of steering system can provide speed increased with the decreasing steering, but complicated structure, cost is higher, and cannot overcome hydraulic system itself has many shortcomings, is a cross between a hydraulic steering and electric power steering the transition between the products. In 1988, Japan Suzuki company first in small cars equipped with Cervo Koyo company development on the steering column, power type electric power steering system; In 1990, Japan Honda NSX in sports car company adopted self-developed rack power type electric power steering system, henceforth unveils the electric power steering in cars applications history2.Working principleElectric power steering system are as follows: first, the working principle, torque sensor measured on steering wheel drivers on the manipulation of the moment, the wheel speed sensors detect the vehicle driving speed, then present the two signals to ECU; According to the built-in control strategy: ECU, calculates the ideal target booster torque, into current instructions to motor; Then, the power generated by the torque motor slowdown institutions amplification on steering system in mechanical manipulation of the moment, and the driver together to overcome resistance torque, realize to the vehicle steering.3. Working processElectric power steering system as traditional hydraulic system alternative products has entered into the auto manufacturing. And had predicted instead, EPS not only applicable to small cars, and some for 12V medium vehicle installed electric system.EPS system includes the following components:The torque sensor: detection steering wheel motion and vehicle motion situation;Electronic control units: according to provide the torque sensor the size of the signal computing power;Motor: according to the electronic control units; turn power output value generation Reduction gear: improve motor power, and produce turn it sends to steering mechanism.Other vehicle system control algorithm input information is provided by the car CAN bus (for example steering Angle and bus speed, etc.). Motor drive also need other information, such as motor rotor position and the three-phase motor sensor (current sensor provided). Motor control by four MOSFET, due to micro controller cannot direct drive of large gate capacitance, MOSFET using drive IC form needed the interface, for safety, complete motor control system must implement monitoring, motor control system integration in PCB, usually contains a relay, the relay use, as the main switch under the condition of the fault detection, disconnect motor and electronic control units.Micro control device must control EPS system and have brushless motor. Micro control device according to the torque sensor provide needed the steering wheel torque information, forming a current control loop. In order to improve the security of the system level, the micro control device should have an on-board oscillator, so even in external oscillator malfunction case, also ensure micro control device performance, also should have chip watchdog. Infineon XC886 integration of the company all the important micro control device component, other safety features for through the software to realize, if must implement safety standards IEC61508 industries, you have to finish all kinds of diagnosis and self-inspection task and increase micro control device work load. At present different customers use of torque sensor and rotor position sensor difference is very big. They use different measuring principle, such as decomposing machine, magnetic resonance device, based on the integration of giant magnet or stance sensor.The role of power levels is switch electric current. The power level has two main functions: drive IC control and protection MOSFET, MOSFET itself and to be responsible for switch currents. MOSFET and partition.Micro control device PWM output port provides driver current and voltage is too low, can't directly connected with MOSFET screen realization. Drive IC role is to provide enough current, the grid to charge for MOSFET, so that in the and discharge 20kHz conditions, and ensure the normal realization switch for discretion side provides the high bar source voltage MOSFET, ensure that you get the low conduction resistance. If the high side MOSFET in open state, to source potential close battery level. Want to make MOSFET arrived at nominal conduction resistance, gate to higher than 8V source voltage. MOSFET completely conduction needed the most ideal voltage is required, therefore 10V or above a grid of potential than battery voltage 10V is higher. Charge pump is to ensure that the function to the largest extent reduce MOSFET power (even if low battery voltage conditions) circuit.The other key charge pump design according to different characteristics that can be PWM pattern request, achieve extremely low (low to 1%) and high rate of 390v (high to 100%). Drive IC another important function is testing, avoid damage to short-circuit mosfets, affected MOSFET will be closed, diagnosis submitted to micro control device.附录B 外文文献的中文翻译电动助力转向系统1.发展历史在汽车的发展历程中，转向系统经历了四个发展阶段：从最初的机械式转向系统（Manual Steering，简称MS）发展为液压助力转向系统（Hydraulic Power Steering，简称HPS），然后又出现了电控液压助力转向系统（Electro Hydraulic Power Steering，简称EHPS）和电动助力转向系统（Electric Power Steering，简称EPS）。
汽车电动助力转向系统的研究大学毕业论文外文文献翻译及原文
毕业设计（论文）外文文献翻译文献、资料中文题目：汽车电动助力转向系统的研究文献、资料英文题目：The auto electric power steering system research 文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期：2017.02.14英文原文The auto electric power steering system researchAlong with automobile electronic technology swift and violent development, the people also day by day enhance to the motor turning handling quality request. The motor turning system hanged, the hydraulic pressure boost from the traditional machinery changes (Hydraulic Power Steering, is called HPS), the electrically controlled hydraulic pressure boost changes (Electronic Hydraulic Power Steering, is called EHPS), develops the electrically operated boost steering system (Electronic Power Steering, is called EPS), finally also will transit to the line controls the steering system (Steer By Wire, will be called SBW).The machinery steering system is refers by pilot's physical strength achievement changes the energy, in which all power transmission all is mechanical, the automobile changes the movement is operates the steering wheel by the pilot, transmits through the diverter and a series of members changes the wheel to realize. The mechanical steering system by changes the control mechanism, the diverter and major part changes the gearing 3 to be composed.Usually may divide into according to the mechanical diverter form: The gear rack type, follows round the world -like, the worm bearing adjuster hoop type, the worm bearing adjuster refers sells the type. Is the gear rack type and follows using the broadest two kinds round the world -like (uses in needing time big steering force).In follows round the world -like in the diverter, the input changes the circle and the output steering arm pivot angle is proportional; In the gear rack type diverter, the input changes the turn and the output rack displacement is proportional. Follows round the world -like the diverter because is the rolling friction form, thus the transmission efficiency is very high, the ease of operation also the service life are long, moreover bearing capacity, therefore widely applies on the truck. The gear rack type diverter with follows round the world -like compares, the most major characteristic is the rigidity is big, the structure compact weight is light, also the cost is low. Because this way passes on easily by the wheel the reacting force to the steering wheel, therefore has to the pavement behavior response keen merit, but simultaneously also easy to have phenomena and so on goon and oscillation, also its load bearing efficiency relative weak, therefore mainly applies on the compact car and the pickup truck, at present the majority of low end passenger vehicle uses is the gear rack type machinery steering system.Along with the vehicles carrying capacity increase as well as the people to the vehicles handling quality request enhancement, the simple mechanical type steering system were already unable to meet the needs, the power steering system arise at the historic moment, it could rotate the steering wheel while the pilot to provide the boost, the power steering system divides into thehydraulic pressure steering system and the electrically operated steering system 2kinds.Hydraulic pressure steering system is at present uses the most widespread steering system.The hydraulic pressure steering system increased the hydraulic system in the mechanical system foundation, including hydraulic pump, V shape band pulley, drill tubing, feed installment, boost installment and control valve. It with the aid of in the motor car engine power actuation hydraulic pump, the air compressor and the generator and so on, by the fluid strength, the physical strength or the electric power increases the pilot to operate the strength which the front wheel changes, enables the pilot to be possible nimbly to operate motor turning facilely, reduced the labor intensity, enhanced the travel security.The hydraulic pressure boost steering system from invented already had about half century history to the present, might say was one kind of more perfect system, because its work reliable, the technology mature still widely is applied until now. It takes the power supply by the hydraulic pump, after oil pipe-line control valves to power hydraulic cylinder feed, through the connecting rod impetus rotation gear movement, may changes the boost through the change cylinder bore and the flowing tubing head pressure size the size, from this achieved changes the boost the function. The traditional hydraulic pressure type power steering system may divide into generally according to the liquid flow form: Ordinary flow type and atmospheric pressure type 2 kind of types, also may divide into according to the control valve form transfers the valve type and the slide-valve type.Along with hydraulic pressure power steering system on automobile daily popularization, the people to operates when the portability and the road feeling request also day by day enhance, however the hydraulic pressure power steering system has many shortcomings actually: ①Because its itself structure had decided it is unable to guarantee vehicles rotates the steering wheel when any operating mode, all has the ideal operation stability, namely is unable simultaneously to guarantee time the low speed changes the portability and the high speed time operation stability;②The automobile changes the characteristic to drive the pilot technical the influence to be serious;③The steering ratio is fixed, causes the motor turning response characteristic along with changes and so on vehicle speed, transverse acceleration to change, the pilot must aim at the motor turning characteristic peak-to-peak value and the phase change ahead of time carries on certain operation compensation, thus controls the automobile according to its wish travel. Like this increased pilot's operation burden, also causes in the motor turning travel not to have the security hidden danger; But hereafter appeared the electrically controlled hydraulic booster system, it increases the velocity generator in the traditional hydraulic pressure power steering system foundation, enables the automobile along with the vehicle speed change automatic control force size, has to a certain extent relaxed the traditional hydraulic pressure steering system existence question.At present our country produces on the commercial vehicle and the passenger vehicle uses mostly is the electrically controlled hydraulic pressure boost steering system, it is quite mature andthe application widespread steering system. Although the electrically controlled hydraulic servo alleviated the traditional hydraulic pressure from certain degree to change between the portability and the road feeling contradiction, however it did not have fundamentally to solve the HPS system existence insufficiency, along with automobile microelectronic technology development, automobile fuel oil energy conservation request as well as global initiative environmental protection, it in aspect and so on arrangement, installment, leak-proof quality, control sensitivity, energy consumption, attrition and noise insufficiencies already more and more obvious, the steering system turned towards the electrically operated boost steering system development.The electrically operated boost steering system is the present motor turning system development direction, its principle of work is: EPS system ECU after comes from the steering wheel torque sensor and the vehicle speed sensor signal carries on analysis processing, controls the electrical machinery to have the suitable boost torque, assists the pilot to complete changes the operation. In the last few years, along with the electronic technology development, reduces EPS the cost to become large scale possibly, Japan sends the car company, Mitsubishi Car company, this field car company, US's Delphi automobile system company, TRW Corporation and Germany's ZF Corporation greatly all one after another develops EPS.Mercedes2Benz Siemens Automotive Two big companies invested 65,000,000 pounds to use in developing EPS, the goal are together load a car to 2002, yearly produce 300 ten thousand sets, became the global EPS manufacturer. So far, the EPS system in the slight passenger vehicle, on the theater box type vehicle obtains the widespread application, and every year by 300 ten thousand speed development.Steering is the term applied to the collection of components, linkages, etc. which allow for a vessel (ship, boat) or vehicle (car) to follow the desired course. An exception is the case of rail transport by which rail tracks combined together with railroad switches provide the steering function.The most conventional steering arrangement is to turn the front wheels using ahand–operated steering wheel which is positioned in front of the driver, via the steering column, which may contain universal joints to allow it to deviate somewhat from a straight line. Other arrangements are sometimes found on different types of vehicles, for example, a tiller orrear–wheel steering. Tracked vehicles such as tanks usually employ differential steering — that is, the tracks are made to move at different speeds or even in opposite directions to bring about a change of course.Many modern cars use rack and pinion steering mechanisms, where the steering wheel turns the pinion gear; the pinion moves the rack, which is a sort of linear gear which meshes with the pinion, from side to side. This motion applies steering torque to the kingpins of the steered wheels via tie rods and a short lever arm called the steering arm.Older designs often use the recirculating ball mechanism, which is still found on trucks and utility vehicles. This is a variation on the older worm and sector design; the steering column turns a large screw (the "worm gear") which meshes with a sector of a gear, causing it to rotate about its axis as the worm gear is turned; an arm attached to the axis of the sector moves the pitman arm, which is connected to the steering linkage and thus steers the wheels. The recirculating ball version of this apparatus reduces the considerable friction by placing large ball bearings between the teeth of the worm and those of the screw; at either end of the apparatus the balls exit from between the two pieces into a channel internal to the box which connects them with the other end of the apparatus, thus they are "recirculated".The rack and pinion design has the advantages of a large degree of feedback and direct steering "feel"; it also does not normally have any backlash, or slack. A disadvantage is that it is not adjustable, so that when it does wear and develop lash, the only cure is replacement.The recirculating ball mechanism has the advantage of a much greater mechanical advantage, so that it was found on larger, heavier vehicles while the rack and pinion was originally limited to smaller and lighter ones; due to the almost universal adoption of power steering, however, this is no longer an important advantage, leading to the increasing use of rack and pinion on newer cars. The recirculating ball design also has a perceptible lash, or "dead spot" on center, where a minute turn of the steering wheel in either direction does not move the steering apparatus; this is easily adjustable via a screw on the end of the steering box to account for wear, but it cannot be entirely eliminated or the mechanism begins to wear very rapidly. This design is still in use in trucks and other large vehicles, where rapidity of steering and direct feel are less important than robustness, maintainability, and mechanical advantage. The much smaller degree of feedback with this design can also sometimes be an advantage; drivers of vehicles with rack and pinion steering can have their thumbs broken when a front wheel hits a bump, causing the steering wheel to kick to one side suddenly (leading to driving instructors telling students to keep their thumbs on the front of the steering wheel, rather than wrapping around the inside of the rim). This effect is even stronger with a heavy vehicle like a truck; recirculating ball steering prevents this degree of feedback, just as it prevents desirable feedback under normal circumstances.The steering linkage connecting the steering box and the wheels usually conforms to a variation of Ackermann steering geometry, to account for the fact that in a turn, the inner wheel is actually traveling a path of smaller radius than the outer wheel, so that the degree of toe suitable for driving in a straight path is not suitable for turns.As vehicles have become heavier and switched to front wheel drive, the effort to turn the steering wheel manually has increased - often to the point where major physical exertion is required. To alleviate this, auto makers have developed power steering systems. There are two types of power steering systems—hydraulic and electric/electronic. There is also ahydraulic-electric hybrid system possible.A hydraulic power steering (HPS) uses hydraulic pressure supplied by an engine-driven pump to assist the motion of turning the steering wheel. Electric power steering (EPS) is more efficient than the hydraulic power steering, since the electric power steering motor only needs to provide assist when the steering wheel is turned, whereas the hydraulic pump must run constantly. In EPS the assist level is easily tunable to the vehicle type, road speed, and even driver preference. An added benefit is the elimination of environmental hazard posed by leakage and disposal of hydraulic power steering fluid.An outgrowth of power steering is speed adjustable steering, where the steering is heavily assisted at low speed and lightly assisted at high speed. The auto makers perceive that motorists might need to make large steering inputs while manoeuvering for parking, but not while traveling at high speed. The first vehicle with this feature was the Citroën SM with its Diravi layout, although rather than altering the amount of assistance as in modern power steering systems, it altered the pressure on a centring cam which made the steering wheel try to "spring" back to the straight-ahead position. Modern speed-adjustable power steering systems reduce the pressure fed to the ram as the speed increases, giving a more direct feel. This feature is gradually becoming commonplace across all new vehicles.Four-wheel steering (or all wheel steering) is a system employed by some vehicles to increase vehicle stability while maneuvering at high speed, or to decrease turning radius at low speed.In most four-wheel steering systems, the rear wheels are steered by a computer and actuators. The rear wheels generally cannot turn as far as the Alternatively, several systems, including Delphi's Quadrasteer and the system in Honda's Prelude line, allow for the rear wheels to be steered in the opposite direction as the front wheels during low speeds. This allows the vehicle to turn in a significantly smaller radius — sometimes critical for large trucks or vehicles with trailers.Electronic power steering systemWhat it isElectrically powered steering uses an electric motor to drive either the power steering hydraulic pump or the steering linkage directly. The power steering function is therefore independent of engine speed, resulting in significant energy savings.How it works :Conventional power steering systems use an engine accessory belt to drive the pump, providing pressurized fluid that operates a piston in the power steering gear or actuator to assist the driver.In electro-hydraulic steering, one electrically powered steering concept uses a high efficiency pump driven by an electric motor. Pump speed is regulated by an electric controller to vary pump pressure and flow, providing steering efforts tailored for different driving situations. The pump can be run at low speed or shut off to provide energy savings during straight ahead driving (which is most of the time in most world markets).Direct electric steering uses an electric motor attached to the steering rack via a gear mechanism (no pump or fluid). A variety of motor types and gear drives is possible. A microprocessor controls steering dynamics and driver effort. Inputs include vehicle speed and steering, wheel torque, angular position and turning rate.Working In Detail:A "steering sensor" is located on the input shaft where it enters the gearbox housing.The steering sensor is actually two sensors in one: a "torque sensor" that converts steering torque input and its direction into voltage signals, and a "rotation sensor" that converts the rotation speed and direction into voltage signals. An "interface" circuit that shares the same housing converts the signals from the torque sensor and rotation sensor into signals the control electronics can process.Inputs from the steering sensor are digested by a microprocessor control unit that also monitors input from the vehicle's speed sensor. The sensor inputs are then compared to determine how much power assist is required according to a preprogrammed "force map" in the control unit's memory. The control unit then sends out the appropriate command to the "power unit" which then supplies the electric motor with current. The motor pushes the rack to the right or left depending on which way the voltage flows (reversing the current reverses the direction the motor spins). Increasing the current to the motor increases the amount of power assist.The system has three operating modes: a "normal" control mode in which left or right power assist is provided in response to input from the steering torque and rotation sensor's inputs; a "return" control mode which is used to assist steering return after completing a turn; and a "damper" control mode that changes with vehicle speed to improve road feel and dampen kickback.If the steering wheel is turned and held in the full-lock position and steering assist reaches a maximum, the control unit reduces current to the electric motor to prevent an overload situation that might damage the motor. The control unit is also designed to protect the motor against voltage surges from a faulty alternator or charging problem.The electronic steering control unit is capable of self-diagnosing faults by monitoring the system's inputs and outputs, and the driving current of the electric motor. If a problem occurs, the control unit turns the system off by actuating a fail-safe relay in the power unit. This eliminates all power assist, causing the system to revert back to manual steering. A dash EPS warning light is also illuminated to alert the driver. To diagnose the problem, a technician jumps the terminals on the service check connector and reads out the trouble codes.Electric power steering systems promise weight reduction, fuel savings and package flexibility, at no cost penalty.Europe's high fuel prices and smaller vehicles make a fertile testbed for electric steering, a technology that promises automakers weight savings and fuel economy gains. And in a short time, electric steering will make it to the U.S., too. "It's just just a matter of time," says Aly Badawy, director of research and development for Delphi Saginaw Steering Systems in Saginaw, Mich. "The issue was cost and that's behind us now. By 2002 here in the U.S. the cost of electric power steering will absolutely be a wash over hydraulic."Today, electric and hybrid-powered vehicles (EV), including Toyota's Prius and GM's EV-1, are the perfect domain for electric steering. But by 2010, a TRW Inc. internal study estimates that one out of every three cars produced in the world will be equipped with some form of electrically-assisted steering. The Cleveland-based supplier claims its new steering systems could improve fuel economy by up to 2 mpg, while enhancing handling. There are true bottom-line benefits as well for automakers by reducing overall costs and decreasing assembly time, since there's no need for pumps, hoses and fluids.Another claimed advantage is shortened development time. For instance, a Delphi group developed E-TUNE, a ride-and-handling software package that can be run off a laptop computer. "They can take that computer and plug it in, attach it to the controller and change all the handling parameters -- effort level, returnability, damping -- on the fly," Badawy says. "It used to take months." Delphi has one OEM customer that should start low-volume production in '99.Electric steering units are normally placed in one of three positions: column-drive, pinion-drive and rack-drive. Which system will become the norm is still unclear. Short term, OEMs will choose the steering system that is easiest to integrate into an existing platform. Obviously, greater potential comes from designing the system into an all-new platform."We have all three designs under consideration," says Dr. Herman Strecker, group vice president of steering systems division at ZF in Schwaebisch Gmuend, Germany. "It's up to the market and OEMs which version finally will be used and manufactured.""The large manufacturers have all grabbed hold of what they consider a core technology," explains James Handysides, TRW vice president, electrically assisted steering in Sterling Heights, Mich. His company offers a portfolio of electric steering systems (hybrid electric, rack-, pinion-, and column-drive). TRW originally concentrated on what it still believes is the purest engineering solution for electric steering--the rack-drive system. The system is sometimes refered to as direct drive or ball/nut drive.Still, this winter TRW hedged its bet, forming a joint venture with LucasVarity. The British supplier received $50 million in exchange for its electric column-drive steering technology and as sets. Initial production of the column and pinion drive electric steering systems is expected to begin in Birmingham, England, in 2000."What we lack is the credibility in the steering market," says Brendan Conner, managing director, TRW/LucasVarity Electric Steering Ltd. "The combination with TRW provides us with a good opportunity for us to bridge that gap." LucasVarity currently has experimental systems on 11 different vehicle types, mostly European. TRW is currently supplying its EAS systems for Ford and Chrysler EVs in North America and for GM's new Opel Astra.In 1995, according to Delphi, traditional hydraulic power steering systems were on 7596 of all vehicles sold globally. That 37-million vehicle pool consumes about 10 million gallons in hydraulic fluid that could be superfluous, if electric steering really takes off.The present invention relates to an electrically powered drive mechamsm for providing powered assistance to a vehicle steering mechanism. According to one aspect of the presentinvention, there is provided an electrically powered driven mechanism for providing powered assistance to a vehicle steering mechanism having a manually rotatable member for operating the steering mechanism, the drive mechanism including a torque sensor operable to sense torque being manually applied to the rotatable member, an electrically powered drive motor drivingly connected to the rotatable member and a controller which is arranged to control the speed and direction of rotation of the drive motor in response to signals received from the torque sensor, the torque sensor including a sensor shaft adapted for connection to the rotatable member to form an extension thereof so that torque is transmitted through said sensor shaft when the rotatable member is manually rotated and a strain gauge mounted on the sensor shaft for producing a signal indicative of the amount of torque being transmitted through said shaft.Preferably the sensor shaft is non-rotatably mounted at one axial end in a first coupling member and is non-rotatably mounted at its opposite axial end in a second coupling member, the first and second coupling members being inter-engaged to permit limited rotation therebetween so that torque under a predetermined limit is transmitted by the sensor shaft only and so that torque above said predetermined limit is transmitted through the first and second coupling members.The first and second coupling members are preferably arranged to act as a bridge for drivingly connecting first and second portions of the rotating member to one another.Preferably the sensor shaft is of generally rectangular cross-section throughout the majority of its length.Preferably the strain gauge includes one or more SAW resonators secured to the sensor shaft.Preferably the motor is drivingly connected to the rotatable member via a clutch.Preferably the motor includes a gear box and is concentrically arranged relative to the rotatable member.Various aspects of the present invention will hereafter be described, with reference to the accompanying drawings, in which :Figure 1 is a diagrammatic view of a vehicle steering mechanism including an electrically powered drive mechanism according to the present invention,Figure 2 is a flow diagram illustrating interaction between various components of the drive mechanism shown in Figure 1 ,Figure 3 is an axial section through the drive mechanism shown in Figure 1, Figure 4 is a sectional view taken along lines IV-IV in Figure 3,Figure 5 is a more detailed exploded view of the input drives coupling shown in Figure 3, andFigure 6 is a more detailed exploded view of the clutch showing in Figure 3. Referring initially to Figure 1 , there is shown a vehicle steering mechanism 10 drivingly connected to a pair of steerable road wheels The steering mechanism 10 shown includes a rack and pinion assembly 14 connected to the road wheels 12 via joints 15. The pinion(not shown) of assembly 14 is rotatably driven by a manually rotatable member in the form of a steering column 18 which is manually rotated by a steering wheel 19.The steering column 18 includes an electric powered drive mechanism 30 which includes an electric drive motor (not shown in Figure 1) for driving the pinion in response to torque loadings in the steering column 18 in order to provide power assistance for the operative when rotating the steering wheel 19.As schematically illustrated in Figure 2, the electric powered drive mechanism includes a torque sensor20 whichmeasures the torque applied by the steering column 18 when driving the pinion and supplies a signal to a controller 40. The controller 40 is connected to a drive motor 50 and controls the electric current supplied to the motor 50 to control the amount of torque generated by the motor 50 and the direction of its rotation.The motor 50 is drivingly connected to the steering column 18 preferably via a gear box 60, preferably an epicyclic gear box, and a clutch 70. The clutch 70 is preferably permanently engaged during normal operation and is operative under certain conditions to isolate drive from the motor 50 to enable the pinion to be driven manually through the drive mechanism 30. This is a safety feature to enable the mechanism to function in the event of the motor 50 attempting to drive the steering column too fast and/or in the wrong direction or in the case where the motor and/or gear box have seized.The torque sensor 20 is preferably an assembly including a short sensor shaft on which is mounted a strain gauge capable of accurately measuring strain in the sensor shaft brought about by the application of torque within a predetermined range.Preferably the predetermined range of torque which is measured is 0-lONm; more preferably is about l-5Nm.Preferably the range of measured torque corresponds to about 0-1000 microstrain and the construction of the sensor shaft is chosen such that a torque of 5Nm will result in a twist of less than 2°in the shaft, more preferably less than 1 ° .Preferably the strain gauge is a SAW resonator, a suitable SAW resonator being described in WO91/13832. Preferably a configuration similar to that shown in Figure 3 of WO91/13832 is utilised wherein twoSAW resonators are arranged at 45° to the shaft axis and at 90°to one another.Preferably the resonators operate with a resonance frequency of between 200-400 MHz and are arranged to produce a signal to the controller 40 of 1 MHz ±500 KHz depending upon the direction of rotation of the sensor shaft. Thus, when the sensor shaft is not being twisted due to the absence of torque, it produces a 1 MHz signal.When the sensor shaft is twisted in one direction it produces a signal between 1.0 to 1.5 MHz. When the sensor shaft is twisted in the opposite direction it produces a signal between 1.0 to 0.5 MHz. Thus the same sensor is able to produce a signal indicative of the degree of torque and also the direction of rotation of the sensor shaft.Preferably the amount of torque generated by the motor in response to a measured torque of between 0-10Nm is 0-40Nm and for a measured torque of between l-5Nm is 0-25Nm.Preferably a feed back circuit is provided whereby the electric current being used by the motor is measured and compared by the controller 40 to ensure that the motor is running in the correct direction and providing the desired amount of power assistance. Preferably the controller acts to reduce the measured torque to zero and so controls the motor to increase its torque output to reduce the measured torque.A vehicle speed sensor (not shown) is preferably provided which sends a signal indicative of vehicle speed to the controller. The controller uses this signal to modify the degree of power assistance provided in response to the measured torque.Thus at low vehicle speeds maximum power assistance will be provided and a high vehicle speeds minimum power assistance will be provided.The controller is preferably a logic sequencer having a field。
汽车电动助力转向系统的发展
汽车电动助力转向系统的发展汽车电动助力转向系统是汽车科技领域的一项重要技术发展，它的出现极大地提高了汽车的操控性和驾驶舒适度。
在汽车行驶过程中，转向系统是非常重要的部件，它直接影响着车辆的操控性和安全性。
而传统的液压助力转向系统存在着高能耗、响应速度慢等问题，电动助力转向系统的出现被视为该领域的一次重大革新。
本文将从电动助力转向系统的发展历程、技术特点和未来发展方向三个方面对该技术进行全面剖析。
一、发展历程汽车行驶过程中，驾驶员需要通过方向盘的转动来控制车辆的行驶方向。
在车辆制动、转向、起步等操作中，液压助力转向系统为驾驶员提供了很大的便利。
随着汽车工业的发展和对汽车性能要求的不断提高，传统的液压助力转向系统逐渐暴露出了一些问题，如能耗高、响应速度慢、维护保养困难等。
人们开始寻求一种替代方案来提高转向系统的性能。
1990年代初，电动助力转向系统开始逐渐出现在市场上。
电动助力转向系统的出现颠覆了传统的液压助力转向系统，它通过电动机和传感器的配合，利用电力来提供辅助转向力，从而更加高效地满足车辆操控的需求。
由于电动助力转向系统的响应速度更快、能效更高、维护更方便、集成度更高等优点，逐渐被众多汽车制造商所采用，成为当今汽车转向系统的主流技术。
二、技术特点1. 高效能电动助力转向系统利用电动机的动力来提供辅助转向力，相较于传统的液压助力转向系统，其能耗更低，效率更高。
在电动助力转向系统中，电动机作为动力源，能够根据车速、方向盘转角等参数动态调整转向力的大小，使得转向更加轻松自如。
2. 响应速度快电动助力转向系统中的传感器能够实时监测车辆的状态，并将数据传输给控制系统，通过对电动机的精准控制，使得转向系统的响应速度得到了极大的提升。
在紧急情况下，能够更快地为驾驶员提供转向支持，提高了行驶的安全性。
3. 配置灵活相较于传统的液压助力转向系统，电动助力转向系统的传感器和电动机能够更加灵活地配置在车辆的不同部位，便于实现对转向力的精准控制。
汽车电动助力转向系统的发展
汽车电动助力转向系统的发展汽车电动助力转向系统是一种通过电力系统控制汽车转向的技术，可以减少驾驶员的劳动强度，提高驾驶的安全性和舒适性。
随着汽车电动化技术的发展，电动助力转向系统在汽车行业中的应用得到了广泛的关注和应用。
本文将从发展历程、技术原理和应用前景等方面详细讨论汽车电动助力转向系统的发展。
一、发展历程在1990年代初期，汽车制造商开始尝试使用故障检测测试仪来检测电动助力转向系统的故障。
此外，汽车电动助力转向系统还开始拥有了更多的功能，例如在高速行驶中对方向盘操作的调节和自动起步和加速的控制功能，这些功能通过电子控制单元实现。
在2000年之后，汽车电动助力转向系统经历了大量的升级和改进。
目前，许多汽车制造商已经开始采用了更高级的技术来改善汽车电动助力转向系统的性能和稳定性。
二、技术原理汽车电动助力转向系统是通过电机带动转向泵实现助力转向的。
电机由车辆的电瓶供电，在驾驶员转动方向盘时，电控单元接收到转向方向和大小的信号后，对电机进行控制，使转向泵输出适当的油压来帮助转向。
汽车电动助力转向系统的核心部件是电子控制单元，它能够根据车速和驾驶员的转向操作，自主控制助动力的大小和响应速度。
此外，电子控制单元还可以对转向力矩进行检测和调节，实现更加平稳和精确的转向感受。
三、应用前景汽车电动助力转向系统的应用前景非常广阔。
随着汽车电气化和智能化的快速发展，汽车电动助力转向系统已经成为汽车制造商竞相研发和应用的重要技术之一。
同时，汽车电动助力转向系统的创新应用也是不断涌现的。
例如，一些制造商开始应用机器学习技术来自适应驾驶员的驾驶习惯，进一步提高转向系统的性能和驾驶体验。
汽车电动助力转向系统的发展
汽车电动助力转向系统的发展随着科技的不断进步，汽车行业也在不断地进行改革和创新。
汽车电动助力转向系统的发展在近年来得到了广泛关注。
电动助力转向系统通过电动机或者液压泵等方式，为驾驶员提供操控方向盘的帮助，使得操控更为轻松和舒适。
这一系统的发展不仅带来了更好的驾驶体验，也在一定程度上提高了行车的安全性和稳定性。
本文将从电动助力转向系统的发展历程、技术特点和未来发展趋势等方面展开分析。
一、发展历程汽车电动助力转向系统的发展可以追溯到上个世纪70年代，当时一些高端车型开始使用电动助力转向系统，而在20世纪80年代，这种技术逐渐普及并应用于更多的车型中。
随着电子技术的快速发展，越来越多的汽车制造商开始将电动助力转向系统作为标配，甚至将其与先进的主动安全系统相结合，为驾驶员提供更全面的驾驶辅助。
在过去，汽车的转向系统主要采用液压助力转向方式，通过液压泵和液压缸的工作来帮助驾驶员转动方向盘。
而随着电子技术的应用，电动助力转向系统逐渐替代了传统的液压助力转向系统，使得转向系统更为智能化和高效化。
随着混合动力和纯电动汽车的出现，电动助力转向系统也得到了进一步的发展和完善，以适应不同类型汽车的需求。
二、技术特点电动助力转向系统相比传统的液压助力转向系统具有许多技术特点。
电动助力转向系统的配备更加智能化的控制单元，通过精准的电子控制来感知车辆的行驶状态和驾驶员的操控需求，从而实现更为精准和及时的转向助力。
电动助力转向系统采用了先进的电动机或者电动液压泵等设备，通过电能转换为机械能，提供源源不断的助力，使得操控更为轻松和灵活。
电动助力转向系统的节能环保性能也得到了显著提升，用电能取代液压油，降低了车辆能耗和排放。
一些电动助力转向系统还具有自适应和主动安全的功能，能够根据前方道路情况和车辆速度自动调整转向助力，提高行车安全性和稳定性。
而且，通过与车辆的其它系统和传感器相互联动，电动助力转向系统还可以实现车道保持辅助、碰撞预警等先进的辅助功能，为驾驶员提供更为全面的驾驶辅助。
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附录A 外文文献Overview ofDevelopment on Vehicle EPS SystemAbstractThe currentdevelopment of an electric power steering(EPS) system in an automobile is explicated. The structure, types and characteristics of electric power steering system are introduced. The modeling technologies for electric power steering system and control strategies are analyzed and compared. The development trend of electric power steering system in an automobile is also discussed. It is pointed that the electric power steering technology is one orientation ofpower steering technologies in the future, and whichwill occupy a predominantposition in power steering field.Key words:Automobile; Electric power steering system; Development trend1EPS system types and characteristics1.1EPS system classificationThe early development of EPS system is low in steering type car。
Present 4 types of EPS system are based on rack-and pinion steering system,The installation position according to power motors can be divided into different:Type booster steering、Small gear power type、Double small gear power type and Rack power type。
The steering the instrumentality of motor power type EPS installed in the steering,Motor power torque through increased after worm worm gear deceleration in the steering directly added twist。
Its advantage is motor can be installed in any position hacking,Relative to other several types minimum cost;The drawback to motor torque ripple effects of driver feel bigger。
The drawback to motor torque ripple effects of driver feel bigger,The instrumentality of torque motor added in small gear axle directly。
Advantage: rigid, steering road to feel strong。
Double pinion steering rack boosts type EPS are installed on two small gear, A small gear and steering plate connected, power motors through another pinion and rack meshing, provide power for rack. Advantage: can provide relatively large pow.1.2EPS system meritEPS system and the traditional hydraulic power steering system has the following advantages compared（1)EPS in various riding condition can provides the best efforts。
In the car or parking at Treasury and low-speed steering provide enough power for the driver，In high-speed steering made drivers have good road feeling，And reduce caused by pavement of rough disturbance of steering system，Improving auto steering characteristics。
（2）Improve the car fuel economy，Urban conditions can improve fuel economy.(3) the average 5%, saving fuel 3. EPS system only when the vehicle steering only provide power, U nlike traditional hydraulic power steering system even in don't turn,Pumps have been running.（3）EPS system structure is compact, parts, convenient in installation and smaller number to assemble, enhanced the labor productivity due to tell the packed in engine pulleys and oil pump, set aside of the space can be used to install other parts of FIAT Punto production company adopted DELPHI company developed the electric power steering system, loading time reduced around 80 percent.（4）EPS system cancelled hydraulic loop, there is no oil leakage and oil leakage problem, reduce the pollution to the environment, and save a lot of steering oil.（5）EPS system has the function of self diagnosis, convenient in maintenance and maintenance.（6）EPS system has good low temperature performance, even in 40 environment, EPS system also can work very well, has higher reliability and safety.（7）EPS system's biggest advantage is the performance of the whole system can not changing the system structure of the cases, by changing the system control strategy of programming realize, in order to meet different models and different driving feel the need, greatly reduced the development cost and improve the efficiency of development.2 EPS System Key ComponentsEPS system key components Angle sensor are mainly torque sensor speed preach 2.1 Corner Sorque SensorSensors for real-time detection of steering Angle rotation direction and steering disk disk position，The torque sensor for real-time detection steering dish torque size，And will signal transmission to EPS system of electronic control unit (ECU)。
Corner the torque sensor precision problem decided the electric power steering system performance and reliability，Accelerate development research performance reliable, low-cost corner torque sensor is very important，T he cost of the sensor is restricted by the electric power steering system one of the main factors market.2.2 Speed SensorThe wheel speed sensors used to measure the size of the average speed speed sensor using electromagnetic induction sensor installation on the sensor in gearbox according to the change, the main speed pulse vice two system signals to ECU, because this was two system, therefore the signal reliability improved2.3 Power MotorsPower motors is EPS system actuators, and help motor characteristics directly affect the EPS system to control the ease or drivers handle EPS system for power motors are basic requirements of the high reliability should be, big power, low noise and vibration, low friction torque, small volume and weight; Can turn in blocking next output torque; good m echanical properties, in the process of operation, as far as possible to small torque ripple; The small inertia should as far as possible; Should be able to fast reverse current EPS system the instrumentality of permanent magnet dc motor are usually motive brushless dc motor and switched reluctance motor dc have brush motor mature technology, controller, low cost, but simple existing wear easily power dense brush Spark, need not often maintenance and high efficiency and power density under。