中英文文献翻译-电动助力转向系统

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EPS电动助力转向文献综述

电动转向助力的原理、分类及发展综述摘要：转向系统作为汽车的一个重要组成部分，其性能的好坏将直接影响到汽车的转向特性、稳定性和行驶安全性。

在国外，各大汽车公司对汽车电动助力转向系统（Electric power steering-EPS,或称Elec-tric Assisted Steering-EAS）的研究有20多年的历史。

为了解决转向系统“轻”与“灵”的矛盾[1]，采用现代控制技术和电子技术的电动助力转向系统(EPS)应运而生。

随着近年来电子控制技术的成熟和成本的降低，EPS越来越受到人们的重视，并以其具有传统动力转向系统不可比拟的优点，迅速迈向了应用领域，部分取代了传统液压动力转向系统（Hydraulic powersteering,简称HPS）。

关键词：工作原理、分类、发展1.EPS的工作原理及特点电动助力转向系统是在传统机械转向系统的基础上发展起来的。

它利用电动机产生的动力来帮助驾驶员进行转向操作，系统主要由三大部分构成，信号传感装置(包括扭矩传感器、转角传感器和车速传感器)，转向助力机构(电机、离合器、减速传动机构)及电子控制装置[2]。

电动机仅在需要助力时工作，驾驶员在操纵转向盘时，扭矩转角传感器根据输入扭矩和转向角的大小产生相应的电压信号，车速传感器检测到车速信号，控制单元根据电压和车速的信号，给出指令控制电动机运转，从而产生所需要的转向助力。

其结构示意图如图1所示。

图1 带双小齿轮的电动机机械转向助力器总体视图1.1EPS的优点1.1.1节约了能源消耗。

没有转向油泵，且电动机只是在需要转向时才接通电源，所以动力消耗和燃油消耗均可降到最低。

1.1.2对环境无污染。

该系统应用电力作为能源，消除了由于转向油泵带来的噪声污染。

也不存在液压助力转向系统中液压油的泄漏与更换而造成的污染。

同时该系统由于没有使用不可回收的聚合物组成的油管、油泵和密封件等配件，从而避免了污染。

1.1.3增强了转向跟随性。

汽车转向系统中文文献

DSP-based电力辅助转向使用无刷直流电机MURUGAN NANDAKUMAR R,S和M S MOHIYADEENBharat Electronics Limited, Nandambakkam, Chennai 600 089e-mail: muruganr@bel.co.in; nandakumars@bel.co.in;mohiyadeenms@bel.co.in本文介绍了电的设计方法和步骤辅助动力转向系统(简称EAS)用无刷直流电机为一辆汽车。

控制建筑由两层控制,即车辆速度相关的控制以及扭矩协助控制。

在更高的层次上控制系统的体系结构、功能的车辆作为援助速度控制器、液位控制器的控制力。

在较低的水平,给出了转矩控制器的努力水平的控制。

这已经是实现了由扭矩传感器和车辆在DSP这种传感器。

为实现在系统中,DSP-based三相逆变器直流无刷电动机控制器模块是特意使用采用霍尔传感器反馈和一个单一的dc-link电流传感器。

这项工作是实现光商用车拥有一个循环球式齿轮。

这是第一次(简称EAS)的实施为这种类型的车辆在任何地方在世界上。

一般来说,有离合器递归断开电动机在高速度或非正常条件下从齿轮箱。

在该实现电动机直接耦合到变速箱没有离合器和所有的人异常处理的处理器。

这是执行,不修改车辆供应系统,比如改变现有的交流发电机或额定值电池,利用现有的传感器。

设计是这样一种方式的那种感觉司机援助可以变换轻易地在任何时间。

控制的性能实验结果表明,系统是它被测试在其中的轻型商用车辆(LCV)。

关键词。

无刷直流电机；EAS；转向系统。

1.介绍动力转向系统的转向努力降低车辆的使用外部的源,来协助将轮子。

现在大多数新一代车辆动力转向,由于车辆的趋势,走向更大质量和更宽的轮胎,所有增加的控制力所需要的。

现代交通工具很难动作,速度较低(例如当停车场)如果没有人帮助。

大多数助力转向系统工作,用皮带驱动泵提供的液压系统。

该液压压力泵,是所产生的车辆的引擎驱动。

中英文文献翻译—转向器的简单介绍

中英文文献翻译—转向器的简单介绍附录Hyundai Motor on the stcering control of the request is lightweight,safe,reliable,and should have sufficient life. In order to meet these requirements,the design of the steering gear should have a reasonable transmission ratio characteristics,the correct gap cating together,a higher transmission efficiency,sufficient rigidiy and strength.If the steering gear in the design is reasonable,then the product is good and bad parts of the key issucs of manufacturing and assembly.How to control the quality of the product?The key problem is that a reasonable detection methods,the key to strictly control the passing rate of time,such products will be able to guarantee the quality of parts and components.First of all,the quality of shifting ASSY,should control the assenmbly and to ensure that turning the steering shaft torque and rotational axis and the transmission gap between components.Followed by testing the performance of steering gear,steering gear must also be adopted by all types of test-bed to verify the established angle transmission ratio,transmission efficiency,rotational torque,rigid.In addition to examination other than the above-mentioned steering performance,but also in the pilot stage of its life nuclear reliability and life expectancy that is static torsion test:a thin red hammer,hit test,fatigue life test.To determine whether the quality of the product in hand national standards.Noise from the steering angle repair cream,which is also a test method to detect and can learn from the J class machincry manufacturing industry in China “in the past only means to recognize the importance of detection,and the lack of”lack of testing and testing of the poorlaw awareness.So have some of the parts is a qualified products I materials,and assembly of products from the pilot test proved to be defective,or:The test can verify the quality of products and design for the steering gear (1) the accuracy of parts of the foot only, finish second,two-phase the location of the elite“Measuring the content of L steering shaf t loaded journal bearings.Department feet inch accuracy and smoothness,anti-worm or worm-inch accuracy.smoothness and surface hardness and magnetic---for testing;steering vertical axis arm journal dimensional accuracy and smoothness, the worm wheel roller bearing of the journal center hole distance,wheel bearing and the journal” hole angle from the Chinese side,the block size,finish and degree of asymmetry；circulating ball tooth-type radial fan,big-law length,journal hardness,the magnetic;browser to Min Xuan cochlear aperture wheel size precision,smoothness,tooth surface roughness,intermediate thick teech,tooth,tooth degree ofasymmetry; ball rolling circle diameter,smooth,cylindrical roller Road”degree of accuracy and bias,raccway adjacent pitch error,cumulative error section of grass lines and sub-racj section from Rolling Road Center,rack section Road center line and the roll of injustice;carburizing layer thickness,hardn ess’magnetic flaw detection;ahift steering shaft shell aperture,roughness,different degree of heart;shift towards vertical axis aperture arm flying finish,different degree of heart;chaos and stecring shaft steering arm hole down the center distance,steering shaft-hole axes and steering arm hole down the center line of the non-verticality.(2) parts of cleanliness.Detection of the site is turning-browser shell surface and the surface parts.Detection method is to use cleaning fluid to clean parts,and then the cleaning fluid with impurities,and vacuum membranc leaching;further 120 weeks of petrol industrial solvents the menbranc will be washed with inpurities.To be volatile after the membranc cleaning fluid,together with the impurities from weighing with the magne cellophane packets are sorted in the iron impurities said the weight of a scrap-iro, The iron filings and then 40 times on the microscope with a disability in most dogs measured particle size.(3)assembly of the leakage.. Does not allow any leakage of the phenomenon of steering.Because of internal lubricants in the steering gear is used to turn parts lubricated friction pair,and if as a result of damage caused by leakng seals,lubrication will be affected; resulting in increased friction and wear parts and reduce the life span of steering gera;transminssion efficiency at the same time will lower.The use of conventional vibration and temperature 40 under the conditions of inspection,the shell and shell cap shaft oil scal joints as well as whether the spill.,and water to observe whether there are leakages.(4) after a good tune stecring assembly should check the technical requirements flexible and comfortable when turning the steering wheel,there is no axial gap I turn the steering wheel of the total value of the number required to turn around a few cars in line with the original request.Steering gear shife, also known as machine,machine,machine direction.which is steering the most important parts. Its role ie to increase the spread to turn steering wheel and transmission mechanism to change the direction of power transfer.Hydraulic Steering Hydraulic steering vehicles are windelyused in marine hydraulicsteering and rudder.Drivers can be used through its ability to manipulate smaller shift power to achieve greater control and performance of safe,reliable,flexible manipulation,light.The manipulation of steering is hydraulic,that is in the steering column and steering wheel there is no mechanical connection between the steering gear is between the fuel tank and steering hydraulic pipes or hoses link.When turning the steering wheel,steering wheel rotation in accordance with the relative proportion of transport fuel,the fuel tank directly into the corresponding control side,while the other side of the oil back to tank.BZZ steering is a switch-type full-hydraulic steering valve with the following characteristics:the elimination of mechanical linkage device,the host can reduce costs,provide a reliable,lightweight structures,manipulation of a flexible lightweight,safe,reliable,and can be very small continuous torque stepless control of rotation, provided to the control loop,as well as a wide range of host size choice,able to shift and a variety of pumps and hydraulic supply system.Steering by the structure can be divided into many types.History,there have been many forms of steering,there is currently more commonly used rack and pinion,worm means crank pins,recycling the ball-rack fan gear type,recycling the ball crank pins means,such as worm-type wheel.The second,fourth,respectively, is the first,the third form of the deformation,and the worm wheel is even more rare type.If the form in accordance with assistance,but also can be divided into mechanical(no help),and power-style(with help) two types of power steering which can be divided into pressure andmotivation,hydraulic-power, Electric power-type,electro-hydraulic power types of blocks.It is a rack and pinion of steering one of the most common.The basic structure is a pair of mutually meshing rack and pinon.Pinon steering drive shaft rotates, rack linear motion would be done. In some cases,directly driven by the rack cross-bar,you can make of steering wheel shift. So,this is one of the most simple steering. Its advantage is simple structure,low-cost,steering sensitivity,small size,can be directly cross-link.In widely used vehicle.It is a worm for the active parts,crank pin for the steering gear follower.Worm has a trapezoidal thread,referring to a finger-shaped pin with tapered bearings in the crank bearings,the crank shaft and the shift into one arm.Shifted through steering wheel rotating worm,helical worm embedded in the cone-shaped slot means the marketing side of the rotation,the crank shaft and the shift into one arm.Shifted through steering wheel rotating worm,helical worm embedded in the cone-shaped slot means the marketing side of the rotation,the side rocker shaft to do around the shifted are movement,thereby stimulating and steering crank arm swing down and then turning to make shift transmission wheel deflection.This steering is usually used to turn power on a larger truck.Circulating ball-type:This device is turned by the gear mechanism from the steering wheel to slow down the rotation of power,so that the rotation of steering wheel movement into rotary movement of the turbine worm,ball screw and nut holding the ball engagement,which Ball screw linear motion into rotary movement,with the fan-shaoed nut meshing gears,linear motion into rotary movement,with the fan-shaped nut meshing gears,linear motion into rotary movement,with the fan-shapednut meshing gears,linear motion into rotary movement again to shake the rod arm,link arm moving again so that even the bar and cross bar to do a straight-line movement to change the wheels direction.This is a classical institutions,most modern cars no longer have to use,but the way was the latest by the application of power steering device.It is equivalent to the principle use of nuts and bolts in the rotation process of relative movement,and in between the thread and thrend the ball into the folder to reduce the resistance,all the ball,both connected in a closed loop of the spiral curve rolling ball club is named after the cycle.Hydraulic rack and pinion steering gear is relative to the case of rack and pinion steering gear machinery, mainly to increase the steering pump,steering oiler,steering pineline, steering valve,steering components,suan as fuel tanks,with a view to improve the pilot hand,the purpose of increasing power steering of the steering device.After 10 years of internal development,has become a mature R&D and manufacturing technology manufacturers have Yubei Koyo Steering Gear Co.Ltd.and other enterprises.With the rapid development of automobile industry,as well as for comfort,safety and continuous improvement in performance,steering systems are also changing with the advance of technology.For the time being,electric power steering systems is turning the forefront of the industry rescarch projects,in accordance with its distribution of the form of string can be divided into power,gear Power,power rack,power bar,the form of electro-hydraulic power. Ago in some sci-fi movies of the unmanned aircraft can occur,such as unmanned acrial vehicle is now a reality,steering systems are moving in the direction of the development of more advanced,such as rescarch anddevelopment from Japan JTEKT advanced by the steer-by-wire systems.In this paper,choice-bassed recycling the ball GX1608A gear-steering rack as a research topic,its main contents are: knowledge of automotive steering gear,ball-type steering gear cycle of the main paramenters and design choices.Design also includes the shift rocker shaft,involute spline,fan gear shaft and screw shaft design and verification.According to its own independent study completed by the steering shaft and screw shaft rocker design and verification,in other parts of the network,as well as through the school library to collect relevant information and fax to the future,in the papers have used information the mark.The design has been through a total of about 16 Chinese and foreign-related literature,and learn from the relevant parts of which the essence of the final design of the times.Because of its limited ability to learn and,I urge teachers and experts have pointed out that less than one.中文现代汽车对转向器的要求是操纵轻便，安全、可靠、，并应具有足够的使用寿命。

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）。

Electric power steering(EPS)电动助力转向机

Electric power steeringThanks to its numerous advantages, electrically operated power steering systems (Electric Power Steering or EPS) are becoming increasingly widespread in today’s cars. Different variants are used in various vehicle classes and are tailored specifically to individual requirements (see chapter “Types of electric power steering systems,” page 52 ff.). In addition to their compact design and the fact that they are independent of internal combustion engine power, EPS systems also have a low level of energy consumption. In a 2000cc mid-range vehicle, fuel savings of up to 0.8 liters per 100 kilometers can be achieved solely by the use of an EPS system. This is due to the fact that EPS only requires energy when the steering wheel is being turned - a “power-on-demand system.”Structure and functional operationElectrically operated power steering (EPS) generates the power required for steering assistance through an electric motor. That power is transmitted to the steering rack or steering column via a power steering gear. The electric motor takes its energy out of the onboard supply system and is controlled by an electronic control unit (ECU). The steering command is registered by a torque sensor, which measures the displacement of the torsion bar connected to the steering system and transmits this data to the ECU. The electric motor, power steering gear and ECU are usually installed as a combined component, the “Powerpack,” while the torque sensor is installed separately.The electric motorThe electric motor is responsible for converting the electrical energy taken from the onboard supply system into mechanical energy which is then used for steering assistance. Due to the simple structure, high power density and easy controllability, no linear motors but only rotating machines with a fixed stator and relative to the stator a concentrically arranged, revolving rotor are used for EPS systems.Usually direct-current motors with mechanical commutator and permanent magnets are used in compact cars, since they can be operated with the vehicle’s DC power using a simple control unit. However, the maximum power output of DC motors depends on their size and is therefore limited by the available installation space.In heavier vehicles with higher electric motor power requirements, three-phase motors (asynchronous and synchronous) are used. However, these must be equipped with an inverter (and usually a field-oriented motor control) to convert the direct current from the onboard supply system into the required three-phase current. Asynchronous motors are available for mid-range vehicles, and thanks to their design provide enough power combined with a high degree of sturdiness and operational reliability. Synchronous motors with permanent magnets are used for mid-range vehicles as well as for heavier luxury vehicles and SUVs, and have the highest level of efficiency and power density to allow highly dynamic operation.Another advantage of three-phase motors compared to DC motors is the similarity between the power requirements of the EPS and the characteristic curve of the three-phase motor. The curve of the EPS performance requirements and the characteristic curve of the three-phase motor are almost identical, whereas upwards of the nominal speed, the characteristic curve of the DC motor falls significantly and rapidly.The power steering gearThe assist torque provided by the electric motor is transmitted to the steering rack via the power steering gear, with the rotating movement of the electric motor being converted into a linear movement of the steering rack. The speed and torque levels of the electric motor must be combined with a corresponding ratio of the power steering gear to match theperformance requirements of the steering system. Worm gears, ball and nut gears and toothed belt gears are used in EPS systems.In the case of a worm gear, the worm, which is shaped like a threaded bolt, engages in the worm wheel, which has teeth on its surface for that purpose. Worms used for EPS applications are made of hardened steel, but the teeth of the worm wheel are produced from high-performance plastic to reduce operating noise. Worm gears permit a large ratio with only one stage, but their efficiency level is not optimal.With an efficiency level of well over 90%, the ball and nut gear is considerably more efficient and also has a large ratio and a high level of mechanical stability. Ball and nut gears consist of a ball screw, an endless ball chain as a rolling element and a ball screw nut, including the return system for the ball chain and sealing elements. In EPS systems, the ball screw is designed as part of the steering rack, and the ball screw nut - referred to in these applications as a steering nut - is mounted around the ball screw via a ball bearing. The ball and nut gear is driven by the electric motor either directly or via a belt and pulley, where the steering nut rotates around the steering rack and the interposed ball chain converts the rotating motion into a linear motion of the steering rack.The additional interposition of a toothed belt gear into the ball and nut gear permits a second transmission stage, the ratio of which results from the size ratio of the two toothed disks.The electronic control unit (ECU)To control the electric motor, the EPS system has an ECU which calculates the necessary level of power assist through signal processing electronics and then supplies the requisite motor current via power electronics. A distinction is made between interior-mounted and engine compartment control units, mainly because of their temperature resistance, impermeability and resistance to various media such as oil, salt, etc., to which they are more (engine compartment units) or less (interior-mounted units) exposed.Preferably direct-mounted control units are being used, if possible in close proximity to the electric motor. In this way only short connection cables and fewer connectors are required, which reduces line losses and requires considerably less wiring. A stand-alone control unit is only installed in vehicles which do not have sufficient installation space available near the electric motor.To calculate the required level of power assist, the signal processing depends mainly on the information from the torque sensor. But the system is also connected to other ECUs in the vehicle via BUS interfaces, for example to the electronic stability program (ESP).This allows the detailed information about the current driving condition of the vehicle to be evaluated and processed by means of intelligent control and regulation algorithms. In this way a more refined control of the power assist level becomes possible.This can be used to adjust the required steering wheel torque (applied by the driver) to the current driving state, for example with a comfortable driving style, a lower steering wheel torque is required, while for a faster and sporty style, a higher torque will be necessary.The torque sensorA key parameter for calculation of the necessary power assist level in EPS systems is the steering wheel torque which the driver applies to the steering system by turning the steering wheel. This torque must be very precisely determined to give the driver a good steering feel and reassure him that his steering command is being directly implemented.Currently, only torque sensors with a mechanical torsion bar are used in EPS systems. They differ mainly in the method of measurement with which the torsion bar’s angle of rotation is determined during a steering operation. Torque sensors are available with potentiometric, inductive, magnetic and optical measurement, whereby because potentiometric sensors are not contactless and are thus subject to wear, they are only used nowadays for very low-cost EPS systems in com-pact cars.Inductive and magnetic measurement methods are based on measurement of magnetic field changes. In the case ofinductive measurement, the measurement takes place in an alternating magnetic field, while magnetic measurement is carried out in a static magnetic field. The advantages of both of these systems are that they use non-contact and therefore wear-free components, that they have a high degree of accuracy, and that they are impervious to dirt, water and oil.Optical measurement is performed using a light-emitting transmitter, for example an LED, and a light-sensitive receiver, for example a photodiode. A structured code disk, for example a stamped grid plate, is located between the transmitter and the receiver. The rotation of the torsion bar affects the light intensity between the transmitter and the receiver, and this change can be measured and evaluated in order to calculate the steering wheel torque. The advantage of optical sen-sors lies in their imperviousness to electro- magnetic interference. They are however very sensitive to contamination and to mechanical stress, so they can only be used within a limited temperature range.Types of electric power steering systemsThe types of electric power steering (EPS) systems differ in the location in which the servo unit is installed in the steering system. This is why they are called EPSc, EPSp, EPSdp, EPSapa and EPSrc - the lower-case suffixes describe the installation locations.EPSc - servo unit on the steering column (column)The first electric power steering system, the EPSc, was launched in the late 1980s and remains the most widely used EPS system in compact and mid-range vehicles. The servo unit including the torque sensor is located on the steering column and thus in the vehicle interior. This protects it from the environment; for example, it does not have to be waterproof and it is exposed to significantly lower temperature effects than those which exist in the engine compartment. One disadvantage here is, however, its proximity to the driver and the excessive distance to the steering gear.Its proximity to the driver can have an impact on safety if an accident occurs, because the distance to the steering gear results in a long transmission path for the forces via steering column, intermediate shaft and steering pinion. This limits the maximum achievable steering output. The assist torque from the electric motor to the steering column is generally transmitted via a worm gear.EPSp - servo unit on the steering pinion (pinion)In the EPSp, the assist torque of the electric motor is also transmitted by means of a worm gear, which in this case is directly connected to the steering pinion and the steering rack. This design eliminates the long transmission path, permitting higher steering forces compared to the EPSc. This design also enables the torque sensor to be directly combined with the servo unit.The installation options of the EPSp are subject to certain limitations, since the servo unit can only be rotated around the axis of the steering pinion. Furthermore, it is located in the driver’s footwell, so it needs to be ensured that the EPSp cannot penetrate into this area if an accident occurs, since this could lead to injury.Its position on the steering pinion means of course that the EPSp is located in the engine compartment, so it must meet higher demands regarding water tightness as well as resistance to temperature and vibration in this location. This also applies to all the types described below.EPSdp - servo unit on a second steering pinion (dual pinion)The limited installation options and the problematic accident safety issues of the EPSp led to development of the EPSdp design. Incorporating a second pinion into the steering system made it possible to place the sensor and the drive unit apart from one another. The torque sensor of the EPSdp is mounted on the actual steering pinion, from where it measuresthe steering wheel torque. The servo unit itself transmits the assist torque, but to the second pinion. Thanks to an appropriate worm gear design, the position of the servo unit relative to the rack-and-pinion and drive pinion axes can be adapted as required to fit the available installation space and to meet accident safety requirements.Another positive side-effect of this solution is a further increase in steering performance. The fact that the drive pinion ratio is independent of the steering ratio permitted the design of a performance-optimized drive ratio.EPSapa - servo unit with axis-parallel drive of the steering rack (axis parallel)A low level of system friction and a high degree of efficiency characterize the EPSapa design. This is why it is mainly used in vehicles with high steering assist requirements, such as sports cars, SUVs, upper mid-range cars and vans. As the name implies, the electric motor is mounted axially parallel to the steering rack, and the steering assistance is transmitted di-rectly to the steering rack by means of a ball screw drive equipped with a belt drive. This combination of ball screw drive and belt drive permits an additional transmission stage, and this is what creates the high level of efficiency (see chapter “The power steering gear”, page 46 ff.). As in the EPSdp, the torque sensor is located on the steering pinion and separated from the assist mechanism.Besides its high level of efficiency, the EPSapa offers optimum use of the available installation space. The motor parallel to the steering rack nestles up close to the rack and can be arranged around it depending on the space available.EPSrc - servo unit with concentric drive of the steering rack (rack concentric)The EPSrc is a particularly compact design in which the servo unit is arranged around the steering rack. However, this design requires a special electric motor with hollow shaft, since the rack passes through it. The motor power is transmitted directly to the steering rack via a ball screw drive. Since the additional transmission stage is not present, unlike in the EPSapa with its ball screw gear and belt drive, the electric motor requires a much higher torque to achieve a similar level of steering assistance.System safetyEach EPS system must be designed in such a way that safety-critical states can be ruled Ruling out of out during operation according to the state safety-critical of the art. A safety-critical state is considered any instance where the vehicle’s characteristics diverge so far from the normal state that the driver is unable to control the vehicle, creating a risk of danger to life, limb and property.ISO 26262 safety requirementsEPS systems, as safety-relevant electrical or electronic systems, are subject to the ISO 26262 standard, which governs the functional safety of motor vehicles. ISO 26262 states that the safety of an electrical or electronic system in the vehicle cannot be ensured by external safety measures, but must be an integral part of the system itself.For compliance with these requirements, the ISO 26262 standard defines a procedural model including its required activities, plus the methods to be used for the development and production of electrical and electronic systems in motor vehicles. Also defined in this standard are safety requirement levels, which are used to classify electrical and electronic systems. From these requirement levels, safety objectives are derived. The levels range from “QM” (quality measure) fornon-safety-relevant requirements to “ASIL D,” the highest possible safety requirement level (ASIL stands for Automotive Safety Integrity Level).Without taking into account safety measures, the associated risk for the overall system is first determined in line with ISO 26262 using a hazard and risk analysis. Based on the analysis results, classification of the system into one of the safety requirement levels, “QM” to “ASIL D,” follows. The next step is the development of a safety concept that minimizes the existing risk for the overall system to a calculable level by means of integrated safety-related measures. The effectiveness of this safety concept must be documented by a safety check, the scope of which is in turn specified by the previously determined safety requirement level.Risk classification of EPS systemsThe assessment of the overall system risk posed by EPS systems (as per ISO 26262) results in a classification into the highest safety requirement level, “ASIL D.” Individual potential fault scenarios are considered and, for example, evaluated as follows:• Unwanted activation of the electric motor leads to an “ASIL D” classification.• Sluggishness of the steering system caused by faulty activation of the electric motor also results in an “ASIL D”classification.• A sudden start of the steering assistance system receives an “ASIL A”, classification.• A failure of the steering power assist system is ultimately a qu ality measure, “QM.”These classifications only address risks related to malfunctions of the electrical or electronic system. Mechanical failures are not in-' eluded in the risk analysis and are excluded by appropriate standards for the mechanical design and structural measures defined therein. One important result of the risk analysis is the establishment of protection goals along with the assignment of the appropriate safety requirement level:• ASIL: All safety measures that contribute to ensuring the protection goal “inherit” the appropriate safety requirement level, which affects the required development process, quality, and residual fault probability of the safety measure. The higher the ASIL classification, the higher the requirements.• QM: These objectives are not addressed by ISO 26262, but must be rectified by quality assurance measures.In EPS systems, purely mechanical steering without steering power assist is available as a fail-back option. As such, the safety concept of EPS systems is considered to be a fail-safe principle, i.e. the steering power assist is switched off during a critical fault scenario. The driver then still has a fully functioning steering system at his disposal, albeit a more sluggish and purely mechanical one. A complete shutdown is rarely required. The switching off sub-functions, for example, will very often counteract a malfunction and restore the system to a safe operating state.As a result, an elaborate monitoring concept is used to carry out a fault diagnostic program aimed at determining the cause of the fault. Faults can be caused by both the EPS system and by external signals, which are evaluated and processed by the control unit. The system is then either partially or completely disabled via shutdown paths, with the type of shutdown depending on the results of the fault diagnosis and the safety measures associated with each. Defined fault tolerance times ensure that fault detection and operation of the shutdown paths take place within an acceptably short time frame, ensuring that no danger can arise for the driver.Steering functions and their controlAs in hydraulic power steering systems, EPS systems should assist the driver while steering the car, giving the maximum possible feeling of safety for the current driving situation. EPS has, however, more options than the required “basic steering functions.” These options are subdivided into “advanced steering functions” and “vehicle level functions.”The basic steering functions will not be discussed in detail at this juncture because they have already been covered in detail in the chapters entitled, “Principles of driving physics,”“Factors influencing driving feel”and “The hydraulic power steering system.”Advanced steering functionsThe advanced features of an EPS system include, in particular, measures to relieve the driver of the burden of making steering corrections during normal driving. The main features here are “Active Return”and “Straight-line Stability Correction.”A vehicle will usually return to straight-ahead driving by itself when the steering wheel is released after a steering command, even if the driver does not carry out the appropriate steering movements. The suspension design of modem vehicles, however, often yields an unsatisfactory response while returning to straight-ahead driving, particularly at low speeds. Depending on the suspension design, this can even lead to the steered wheels remaining in the turned position once the driver exceeds a certain steering angle. As a result, EPS systems have an active return function: If the control unit determines that this driving situation applies, the EPS system automatically assists the return of the steered wheels to the straight-ahead direction. It is crucial that the active return function gently returns the steering wheel, whether released or still held by the driver, to the straight-ahead position. This means, for example, that if the steering wheel is being held, all steering wheel movements and inputs, ranging from slight torques applied by the driver to a heavy grip holding the wheel firmly, are properly considered, so that the function does not overpower the driver.All roads have some lateral slope (camber) for proper rainwater runoff. A vehicle will follow this slope in straight-ahead driving, forcing the driver in this case to slightly countersteer against the inclination (never actually straight ahead). As such, the driver must constantly apply a torque, however slight, to the steering wheel to maintain a straight driving direction. The straight-line stability correction function in the EPS system relieves the driver of this task, enabling him to hold the steering wheel in a torque- free and effortless manner during straight-ahead driving. However, if straight-line stability correction is to function correctly, detection of the roadway gradient in question is essential, as this determines the necessary correction in the steering system.Vehicle level functionsIntegration of the EPS system as an intelligent element into the overall vehicle system permits not only steering assist functions, but also other driver aid functions, such as those which warn the driver of critical situations and help cope with them, or which even relieve the driver of complete driving operations.Lane departure warning is one example: On long freeway journeys, fatigue and lack of concentration can lead to a driver unintentionally leaving the intended traffic lane, which is a common cause of accidents. A warning system uses a camera to permanently monitor the position of the vehicle relative to the lane boundaries and detects when the vehicle is threatening to leave the lane. An appropriate warning is sent to the control device of the EPS, which then applies an addi-tional torque to the steering in the direction of the lane center. A vibration alarm can also be superimposed as an additional warning. This function is much more effective than just a vibration alarm, since the driver is given a recommendation in addition to the warning. Lane guidance functions take this concept one step further. They not only warn the driver of unintentional departure from the lane, but also use active steering assistance to keep the vehicle in the lane. Due to the current regulatory situation, however, autonomous lane guidance by the system is not yet permitted; assistance is only provided for the driver when the driver’s hands are on the steering wheel.Another EPS function at the vehicle level is the dynamic steering recommendation, where the EPS system gives the driver a ‘tip’ for the correct steering movement by means of a short torque pulse at the steering wheel. If, for example, the electronic control system of the vehicle determines that countersteering is required in a driving scenario, a short torque pulse prompts the driver to countersteer in the appropriate direction.It goes without saying that with all of these vehicle-level functions, the initiated pulses must not be triggered during any critical driving situations. The pulses must be perceived by the driver but should not startle in any way that could trigger incorrect responses. Even with active assistance, the driver must still remain in command of the driving situation and be able to nullify the steering torques at all times.The operation of the parking assist function contradicts these requirements. It actually takes over the vehicle’s steeringsystem, in particular while backing into a parking space at the curb. The driver can focus fully on operating the accelerator, brakes, and clutch. A position sensor system first determines the size of the parking space using ultrasonic sensors. It also determines whether or not any obstacles are present and the position of the vehicle in relation to the parking space. From this data, the control unit then calculates the required steering motion and controls the EPS system accordingly. During parking, this data must be continually evaluated and adapted to the current driving state, for example to take into account the driver’s accelerator and braking commands. In addition, safety must be ensured at all times. The turning of the steering wheel during the parking maneuver must not be able to injure the driver if a hand is accidentally reached into the wheel.Control conceptsAs with the basic steering functions, the “classic”control concept for EPS is also derived from the principles of hydraulic power steering. Depending on the steering wheel torque applied by the driver, a corresponding assist force is applied by the EPS system. The ratio between the steering wheel torque applied by the driver and the assist force is not linear but progressive, meaning that as steering wheel torque increases the assist force increases at a proportionately higher rate.In this concept, steering control is very closely linked to steering feel. Any modification to the steering feel always requires an intervention in the control system itself. This fact is the reason why any modification of the steering feel (i.e. vibrations in the steering wheel or torque pulses), which is requested by any of the vehicle-level steering functions, can only be carried out indirectly with the classic control concept.If the control concept is split into two independent components, steering feel and steering control, the requested torque interventions can be carried out directly without interaction with the control system.电动助力转向系统由于其众多的优点，电动的助力转向系统EPS 电动助力转向系统）正在变得越来越普遍在今天的汽车。

电动助力转向简介

电动助力简介■何谓EPS电动转向系统EPS就是英文Electric Power Steering System的缩写,即电动助力转向系统。

电动助力转向系统是汽车转向系统的发展方向。

该系统由电动助力机直接提供转向助力，省去了液压动力转向系统所必需的动力转向油泵、软管、液压油、传送带和装于发动机上的皮带轮，既节省能量，又保护了环境。

另外，还具有调整简单、装配灵活以及在多种状况下都能提供转向助力的特点。

正是有了这些优点，电动助力转向系统作为一种新的转向技术，将挑战大家都非常熟知的、已具有50多年历史的液压转向系统。

驾驶员在操纵方向盘进行转向时，转矩传感器检测到转向盘的转向以及转矩的大小，将电压信号输送到电子控制单元，电子控制单元根据转矩传感器检测到的转距电压信号、转动方向和车速信号等，向电动机控制器发出指令，使电动机输出相应大小和方向的转向助力转矩，从而产生辅助动力。

汽车不转向时，电子控制单元不向电动机控制器发出指令，电动机不工作。

■技术优势1、节能环保由于发动机运转时，液压泵始终处于工作状态，液压转向系统使整个发动机燃油消耗量增加了3％～5％，而EPS以蓄电池为能源，以电机为动力元件，可独立于发动机工作，EPS几乎不直接消耗发动机燃油。

EPS不存在液压动力转向系统的燃油泄漏问题，EPS通过电子控制，对环境几乎没有污染，更降低了油耗。

2、安装方便EPS的主要部件可以配集成在一起，易于布置，与液压动力转向系统相比减少了许多元件，没有液压系统所需要的油泵、油管、压力流量控制阀、储油罐等，元件数目少，装配方便，节约时间。

3、效率高液压动力转向系统效率一般在60%～70%，而EPS的效率较高，可高达90％以上。

4、路感好传统纯液压动力转向系大多采用固定放大倍数，工作驱动力大，但却不能实现汽车在各种车速下驾驶时的轻便性和路感。

而EPS系统的滞后特性可以通过EPS控制器的软件加以补偿，使汽车在各种速度下都能得到满意的转向助力。

中英文文献翻译-汽车电动助力转向系统发展综述

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。

转向系统的发展外文文献翻译、中英文翻译、外文翻译

的动态特征时,以低段参数效果不是很好,如果没有,目标车辆液压系统也必须在发动机驱动。

因此,能源消耗,增加燃料发动机,现有的液压油泄漏问题应该不仅污染环境,而且容易影响其他组件。

针对低温,液压系统性能很差。

近年来,随着电子技术的广泛应用,转向系统也越来越多的使用电子设备。

因此,变成使用电子控制系统出现相应的电动液压助力转向系统。

电动液压动力转向系统可以分为两类:电动液压操舵系统(电液压动力(EHPS)和电动液压转向电子控制转向(液压动力转向)。

电动液压操舵系统在液压动力系统的基础上开发的液压增压系统,不同的是,电动液压系统液压系统的电源,但不是由汽车发动机汽车驱动液压系统,节约能源,降低发动机油耗。

电动液压操舵装置是在传统的液压助力系统的基础上开发,所不同的是,电动液压操舵系统,电子控制设备增加。

电子控制单元可以根据转向速度,速度的汽车液压系统的操作参数,改变液压增压速度不同的大小,从而实现变化,动态特征。

但根据电机驱动液压系统,反过来,电机停止转动,从而减少能源消耗。

虽然电动液压动力转向液压操舵系统克服了缺点。

但由于液压系统的存在,它的存在液压油泄漏问题,和电动液压助力转向系统,介绍了电机驱动系统更复杂,成本和可靠性。

为了区别电动液压转向系统、电动助力转向系统电动助力转向(EPS)。

现在应该知道各种各样的转向系统,最大的区别在于电动助力转向系统没有液压系统。

最初由液压操舵系统的电动机。

电动助力转向系统一般由扭矩传感器和微处理器、电机、等的基本原理是:当司机将方向盘驱动轴旋转,安装在转动轴的扭矩传感器和扭矩信号到电信号微处理器,微处理器基于其他车辆运行速度和扭矩信号的参数,根据治疗的程序集电力汽车助推器方向和大小的助推器。

自1988年以来,第一次在日本铃木Cervo汽车装备转向系统、动力转向系统被广泛承认的人。

转向系统主要体现在以下方面:动力转向系统可以提供不同在不同速度下的动态特性。

低,方向盘,增加更多的光,在高速转向减少,甚至为了提高道路增加潮湿。

技术实习(车辆工程)外文翻译电动助力转向系统

浙江科技学院机械与汽车工程学院技术实习外文翻译题目电动助力转向系统专业车辆工程班级102 班姓名吴总荣学号110015036 指导教师程峰完成日期2013年 12月22日Electronic power-assisted 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 thatalso 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 systemsdivision 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 present invention, 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 bedescribed, 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 which measures 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 inresponse 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 programmable gate array for example a XC 4005 as supplied by Xilinx. Such a controller does not rely upon software and so is able to function more reliably in a car vehicle environment. It is envisaged that a logic sequence not having a field programmable array may be used.Electronic power steering system (English as EPS), and hydraulic power steering system (HPS) compared to, EPS has many advantages.The advantage is that the EPS:1) high efficiency. HPS efficiency is very low, generally 60% to 70%, while EPS and electrical connections, high efficiency, and some can be as high as 90 percent.2) less energy consumption. Automobile traffic in the actual process, at the time to about 5 percent of the time travelling, the HPS system, engine running, the pumps will always be in working condition, the oil pipeline has been in circulation, so that vehicle fuel consumption rate by 4 % To 6%, while EPS only when needed for energy, vehicle fuel consumption rates only increased by 0.5 percent.3) "Road sense of" good. Because EPS internal use of rigid, system of the lag can be controlled by software, and can be used in accordance with the operation of the driver to adjust.4) back to being good. EPS simple structure of small internal resistance, is a good back, get back to being the best characteristics, improve vehicle handling and stability.5) little environmental pollution. HPS hydraulic circuit in the hydraulic hoses and connectors, the existence of oil leaking, but hydraulic hoses can not be recovered, the environmental pollution are to a certain extent, while EPS almost no pollution to the environment.6) can be independent of the engines work. EPS for battery powered devices, as long as sufficient battery power, no matter what the condition for the engine, can produce power role.7) should have a wide range.8) easy to assemble and good layout.Now, power steering systems of some cars have become the standard-setting, the whole world about half of the cars used to power steering. With the development of automotive electronics technology, some cars have been using electric power steering gear, the car of the economy, power and mobility has improved. Electric power steering device on the car is a new power steering system device, developed rapidly in recent years both at home and abroad, because of its use of programmable electronic control devices, the flexibility in the same time there are also potential safety problems. In the analysis This unique product on the basis of the author of the characteristics of electronic control devices, security clearance just that the factors that deal with securitymeasures, and discussed a number of concerns the safety of specific issues. The results show that : Existing standards can not meet the electric power steering device security needs and made the electric power steering device safety evaluation of the idea. Research work on the electric power steering device development and evaluation of reference value.电动助力转向系统图1电动助力转向系统的工作原理：电动助力转向系统是通过一个电动机来驱动动力方向盘液压泵或直接驱动转向联动装置。

汽车转向系统英文文献

S¯a dhan¯a V ol.33,Part5,October2008,pp.581–590.©Printed in IndiaDSP-based electric power assisted steering using BLDC motorR MURUGAN,S NANDAKUMAR and M S MOHIYADEENBharat Electronics Limited,Nandambakkam,Chennai600089e-mail:muruganr@bel.co.in;nandakumars@bel.co.in;mohiyadeenms@bel.co.inAbstract.This paper introduces a design and implementation of electricallyassisted power steering(EAS)using BLDC motor for a vehicle.The control archi-tecture consists of two layers of control,namely the vehicle speed associated controland the torque assist control.In the higher level of control architecture,the vehiclespeed controller works as an assistance level controller for the steering effort.Inthe lower level,the torque controller gives the effort level control.This has beenrealized by torque sensor and vehicle sensor interfaced in the DSP.For implement-ing in the system,a DSP-based BLDC motor controller with three-phase invertermodule is specially designed using Hall-effect sensor feedback and a single dc-linkcurrent sensor.This work is implemented in a Light Commercial Vehicle havinga recirculating ball type gear.This is for theﬁrst time(EAS)being implementedfor this type of vehicle any where in the world.Generally,EAS having clutch todisconnect the motor in high speed or abnormal conditions from the gear box.Inthis implementation the motor is directly coupled to gearbox without clutch and allabnormalities are handled by the processor.This is implemented without modify-ing the vehicle supply system like changing the existing alternator or rating of thebattery and using the existing sensors.The design is such a way that the feel of thedriver assistance can be varied easily at any time.The performance of the controlsystem is experimentally veriﬁed and it is tested in one of the Light CommercialVehicle(LCV).Keywords.BLDC motor;EAS;steering.1.IntroductionPower steering is a system for reducing the steering effort on vehicles by using external source to assist in turning the wheels.Most new generation vehicles now have power steering, owing to the trends toward greater vehicle mass and wider tires,all increase the steering effort needed.Modern vehicles would be difﬁcult to maneuver at low speeds(e.g.when parking) without assistance.Most power steering systems work by using a belt-driven pump to provide hydraulic pressure to the system.This hydraulic pressure is generated by a pump which is driven by the vehicle’s engine.While the power steering is not used,i.e.driving in a straight line,twin hydraulic lines provide equal pressure to both sides of the steering wheel gear.581582R Murugan,S Nandakumar and M S MohiyadeenWhen torque is applied to the steering wheel,the hydraulic lines provide unequal pressures and hence assist in turning the wheels in the intended direction.Electric Power Steering systems use electric components with no hydraulic systems at all.Sensors detect the motion and torque of the steering column and a computer module applies assistive power via an electric motor coupled directly to either the steering gear or steering column.This allows varying amounts of assistance to be applied depending on driving conditions.In the event of component failure,a mechanical linkage such as a rack and pinion serves as a back-up in a manner similar to that of hydraulic systems.Electric systems have an advantage in fuel efﬁciency because there is no hydraulic pump constantly running. Their other big advantage is the elimination of a belt-driven engine accessory,and several high-pressure hydraulic hoses between the hydraulic pump,mounted on the engine,and the steering gear,mounted on the chassis.This greatly simpliﬁes manufacturing.The demand of electrically assisted power steering(EAS)has rapidly increased in past few years because of energy savings compared to Hydraulic Power Steering(HPS).Alternating current(ac)motors are designed to be highly efﬁcient and easily controlled with modern power circuitry.Because of the developments in switching techniques,it is quite feasible to use ac motors with a battery supply as source.The traditional worm gear driven dc motor system is constrained by the limitations of the dc motor brushes and size of the motor for the same torque of BLDC.In this case BLDC motor has been used as an actuator in the application for electric power steering.The BLDC motor provides high torque and easy control(Chan &Fang2002;Chu et al2001;Desai&Emadi2005;Jun-Uk Chu et al2004;Kevin Brown et al1990;NamhunKim et al2007).The basic mechanical properties of the vehicle are essentially invariant among all of the available brands.The electrically assisted power steering system consists of BLDC motor mounted to the frame of the steering column and coupled to the wheels through a worm speed reducer.Electrically assisted power steering is shown in ﬁgure1.An electrically assisted power steering is composed of several parts such as torque sensor, engine speed sensor,vehicle speed sensor,steering column,torsion bar and electronic control unit.Figure1.Electrically assisted power steering.DSP-based electric power assisted steering using BLDC motor583 Torque sensor output gives the torque difference to be developed by the motor to reduce the effort required by the driver while he is steering.Engine speed signal is required to start the assistance only when the engine is ON in order to save the battery life.Vehicle speed signal is required to control the assistance developed by the motor(for the same level of torque signal)at various vehicle speed,as assistance requirement comes down as speed of the vehicle increases.The control architecture consists of two layers of control,namely the assistance level control and the torque control.In the higher level of control architecture,vehicle speed signal works as a reference for controlling the assistance to be developed by the motor.In the inner layer torque sensor signal performs generation of torque.The torque output from motor is a function of torque sensor signal and it depends on the torque difference between the steering wheel and the wheel.The vehicle speed signal and engine speed signals are pulses with variable frequency.For system implementation,a DSP-based BLDC motor controller with three-phase inverter module is specially designed using Hall-effect sensor feedback and a single dc-link current sensor.The torque and Back EMF equations of BLDC motor are similar to that of dc motor.The current sensing is ensured by a low cost shunt resistor and used for over-current protection and current feedback.The current control is achieved by PID controller and pulse width modulation(PWM) signals with varying duty rates.Hall-effect sensors are available to detect rotor shaft position, used for electronic commutation,motor speed and direction of rotation.2.Hardware architectureA block diagram of the power assisted steering is illustrated inﬁgure2.The electrically assisted power steering system in a vehicle consists of the following parts.a.Digital signal processorb.Driver and protection cardc.Three phase inverterd.BLDC motor with Hall sensore.Reduction gear and sensors.Figure2.Block diagram of EAS.584R Murugan,S Nandakumar and M S MohiyadeenFigure3.DSP and protection card.2.1ProcessorThe DSP used for control and computation is TMS320F24XX.The processor is a single chip solution based on40MIPS,16bitﬁxed point DSP core with several associated peripherals such as Pulse Width Modulation generator(PWM)and Analog to Digital Converter(ADC) BPRA0551997;SPRU160C1999;SPRU161C1999.2.2Driver and protection circuitThe selected MOSFET Driver is from IR family.The PWM signals coming from the DSP are combined with protection logics and connected to MOSFET driver.The output of the driver is directly connected to the MOSFET switches through series gate resistor.The current sensing is done by the low cost shunt resistor.The voltage drop is processed with analog ampliﬁer and connected to ADC module and used for current feedback and over-current protection.The protection card used here is shown in theﬁgure3.2.3Three phase inverter moduleThe three phase inverter module is developed by using MOSFETs with low ON state drop and high switching frequency.The three-phase inverter card used is shown inﬁgure4.Figure4.MOSFET card.DSP-based electric power assisted steering using BLDC motor585Figure5.BLDC motor equivalent circuit.2.4BLDC motor with Hall sensorThe equivalent circuit of a BLDC motor is shown inﬁgure5.The BLDC motor used here has8magnetic pole pairs on the rotor and a three-phase star connected windings on stator. The voltage equation of BLDC motor can be represented as⎡⎣V aV bV c⎤⎦=⎡⎣R000R000R⎤⎦⎡⎣i ai bi c⎤⎦+⎡⎣L000L000L⎤⎦ddt⎡⎣i ai bi c⎤⎦+⎡⎣e ae be c⎤⎦(1)R=Phase resistanceL=Phase inductanceV a,V b,V c=Phase voltagesI a,i b,i c=Phase currentse a,e b,e c=Back EMFs.The generated motor torque is given byT=e a i a+e b i b+e c i cω,(2)whereωis motor angular velocity.The motor is equipped with three Hall effect sensors.The Hall sensors produce three180◦(electrical)overlapping signals as shown in theﬁgure6.Thus it is providing six mandatory commutation points.The Hall sensor outputs are directly connected to processor and it generate the necessary switching sequence as per commutation.2.5Gear box and sensing circuitsThe BLDC motor is connected to a reduction gear system as shown inﬁgure7.It drives the wheel.The torque difference between the steering wheel and wheel is sensed by a torsion bar.The output of the torsion bar is sensed by the torque sensor.The output of the torque sensor is directly connected to ADC for processing.586R Murugan,S Nandakumar and M S MohiyadeenFigure6.Hall sensor wave form.3.Controller design3.1Effort level controlThe electrically assisted power steering(EAS)incorporates a brushless electric motor located on the steering column,on the pinion that assists the driver when rmation like engine speed,and torque required are transmitted in real time to a DSP which deter-mines the optimal degree of assistance the electric motor should apply.Figure8shows the effort required by the driver without assistance and with assistance for a vehicle at static.Electrically assisted power steering eliminates the need for hydraulicﬂuids and complicated mechanical components(such as servo pumps),hydraulic lines,belts and pulleys,which add weight and volume.By eliminating the hydraulic pump,the EAS can operate without the help of the engine.Unlike a conventional hydraulic system,the EAS consumes energy only when providing assistance.The control algorithm for the electrically assisted steering system is shown inﬁgure9.The effective torque and velocity control of a BLDC motor is based on relatively simple torque and Back EMF equations,which are similar to those of the DC motor.Figure7.Gear box with motor.DSP-based electric power assisted steering using BLDC motor587Figure8.Effort curve. During any120degree interval of phase current,I the instantaneous power(P)being converted from electrical to mechanical isP=ωT e=2EI(3)T e=Electromagnetic torqueE=Induced EMF per phase.The‘2’in this equation arises from the fact that two-phase are conducting.E=2NphB g Lrω,per phase induced emf.(4)Nph=Number of winding turns per phaseB g=Rotor magneticﬁeld densityL=Length of the rotorr=Internal radius of rotor.Figure9.Control algorithms.588R Murugan,S Nandakumar and M S MohiyadeenUsing the above expression the electromagnetic torque is given by,T e=4NphBgLrI=KφI(5)K=Torque constantφ=Flux per pole pair.The system takes torque reference(I−ref)and feedback line current(Ifb)as input,produces duty-cycle reference as output.This is actually a PI controller.The following equation is implementedD−cycle=K p(I−ref−If b)+K pT i(I−ref−If b)dt,(6)Kp=Proportional constantT i=Time constant.Limiters are there atﬁnal controller output.Duty cycle reference is clamped to the peak of the saw tooth carrier wave.Current control is achieved by Pulse Width Modulation(ﬁxed frequency20kHz)signals with varying duty cycles.PWM width is determined by comparing the measured actual current with the desired reference current.To sum up,the Back EMF is directly proportional to the motor velocity and the torque production is almost directly proportional to the phase current.In this control scheme,torque production follows the principle that current shouldﬂow in only two of the three phases at a time.Only one current at a time needs to be controlled so that only one current sensor is necessary.The positioning of the current sensor allows the use of a low cost resistor as a shunt.3.2Assistance level controlFigure10shows the effort required to be produced by the motor for various vehicle speeds.Variable steering assistance(higher at low vehicle speed and lower at high vehiclespeed),Figure10.Boost curve for various speeds.DSP-based electric power assisted steering using BLDC motor589Figure11.Driving effort outputfrom EAS.which improves drivability and active safety.This has been implemented by sensing the vehicle speed and accordingly modiﬁes the effort to be produced by the electric motor by controlling reference to the controller.4.Experimental resultsIn this section,the result is presented(ﬁgure11)to ensure the validity of the proposed method at static driving.From the aboveﬁgure,we can see that the effort required by the driver is almost constant entire steering wheel rotation.The effort reduction comes around75%.The motor is selected such that the cogging torque is very less.The maximum peak cogging torque of the motor used at10rpm is0·0056Nm compared to peak torque of2·45Nm.The acceleration and deceleration of the motor is done in such a way that the driver does not feel the torque ripple in his hand.The torque ripple generally felt at low speed,here the system in a loop such that the system is always in acceleration/deceleration phase,so feel of torque ripple is less.Further to above,the mechanical system itself is in variable gear ratio and it has inherent torque variation more than the motor torque ripple produced by the motor.Hence the driver is not able to feel the torque ripple compared with EAS ON mode and EAS OFF mode.From this result,it is seen that the proposed EAS has performed as expected.Maximum torque required(manual):32NmTorque required during power assistance:8NmPercentage assistance provided:75%Average current consumption:8A5.ConclusionFor equivalent power steering efﬁciency,electrically assisted power steering improves fuel consumption by4percent or more compared to conventional hydraulic systems.The elimina-tion of hydraulicﬂuids is also more environmentally friendly for End of Life Vehicle(ELV) consideration.Electronic data management(wheel angle,vehicle speed,etc.)can be used to ﬁne-tune the power steering parameters,enhancing the car drivability.Variable steering assis-tance improves drivability and active safety.Steering force feedback incorporates controlled re-centre positioning of the steering wheel and active damping of highway vibration.590R Murugan,S Nandakumar and M S MohiyadeenReferencesBPRA055March1997DSP Solutions for BLDC motors.Literature number:Texas Instruments Europe Chan Lie-Tong Yan F,Shao-Yuan Fang2002In-Wheel permanent-magnet brushless dc motor drive for an electric bicycle.IEEE Trans.Energy Conversion17(2):229–232Chu C L,Tsai M C,Chen H Y2001Torque control of brushless DC motors applied to electric vehicles.IEEE Trans.on1–5Desai,Ali Emadi2005A novel digital control technique for brushless DC motor drives:Current control.IEEE Trans.326–331Jun-Uk Chu,In-Hyuk Moon,Gi-Won Choi,Jei-Cheong Ryu,Mu-Seong Mun2004Design of BLDC motor controller for electric power wheelchair.IEEE Trans.94–95Kevin E Brown,Rafael M Inigo,Barry W Johnson1990Design,implementation,and testing of an adaptable optimal controller for an electric wheelchair.IEEE Trans.on Industry Application26(6): 1144–1157NamhunKim,Hamid A Toliyat,Issa M Panahi,Min-Huei Kim2007BLDC motor control algorithm for low-cost industrial applications.IEEE Trans.1400SPRU160C June1999TMS320F/C24x DSP Controllers reference guide CPU and instruction set.Literature number:Texas Instruments EuropeSPRU161C June1999TMS320F/C240DSP controllers reference guide—Peripheral library and spe-ciﬁc devices.Literature number:Texas Instruments Europe。

外文翻译--液压助力转向系统(节选)

中文3000单词,2000单词，1万英文字符本文来自于/cms/title_Electric-Power-Steering/A_110661/article.htmlThe conventional hydraulically-assisted power steering used in most cars is soon to be replaced with electric power steering. Already, many manufacturers are using electronically controlled hydraulic systems, while some car manufacturers have recently introduced purely electric systems to their vehicles. In addition to reducing engine loads, full electric power steering allows steering responsiveness to be automatically varied depending on speed, road conditions - and even the driver's ability!Traditional Hydraulic Power-Assisted SteeringHydraulic Power Assisted Steering has been used in automotive applications for about 50 years. The systems use an engine-driven hydraulic pump, a control valve, steering cylinder and connecting hydraulic hoses. The pump is usually of a vane design with an integrated internal bypass. It is sized so that - even at idle rpm - it delivers enough oil flow to provide a suitable degree of power assistance.The control valve uses a flexible torque-measuring device (such as a torsion bar, spiral spring or leaf spring) to convert the steering torque into a small control movement. This movement is transferred to a valve that regulates fluid flow to the power assistance mechanism. In rack and pinion steering, a double-ended hydraulic ram mounted parallel to the rack (within the rack assembly) is used, while recirculating ball systems incorporate the mechanism into the steering box. Note that in the Nissan system shown here, the fluid reservoir is incorporated into the pump.A major problem with simple conventional hydraulic steering systems is that the assistance level is not reduced at high speeds, giving a lack of steering feel. American cars of the Fifties and Sixties were particularly well known for their feather-light steering effort during parking, a characteristic which resulted in extreme vagueness at high speeds. To overcome this problem, most conventional hydraulic steering systems of the last few decades have incorporated mechanisms that reduce steering assistance as either engine speed increases, or (less frequently) as road speed increases. The reason that engine speed was morecommonly used as is that such a system can remain purely hydraulic, whereas using road speed as the control variable requires the use of an electronic system.Electronically-Controlled Hydraulic SteeringThe introduction of electronic speedometers - and subsequently, full engine management - meant that an electronic road speed signal became available, allowing the widespread use of electronically-controlled hydraulic steering systems. These vary steering effort depending on road speed and also, in some cases, other factors as well.A number of different hydraulic approaches to regulating steering assistance are used. These are:Flow ControlA solenoid valve is located on the discharge port of the hydraulic pump. Electronic control is used to control the solenoid valve opening, so regulating the fluid flow. The flow is reduced at high road speeds, reducing the degree of assistance provided.Cylinder BypassA solenoid valve and associated bypass line is located between the two chambers of the hydraulic cylinder, allowing the reduction of the pressure difference between them. The solenoid valve opening is controlled electronically, its opening being greater at high road speeds. This reduces the degree of assistance that is provided.Hydraulic Reaction ForceA hydraulic force is enabled that works against the power assistance. As speed increases, the reaction force is increased. Since fluid flow to the power cylinder is not affected, the steering response rate can remain high without reductions occurring in feel.In their electronically-controlled hydraulic steering system, Hyundai use an ECU equipped with an 8-bit microprocessor. Two major inputs - vehicle speed and the speed of steering wheel movement - are used. From these inputs, the ECU determines the driving condition and via a 3-dimensional look-up map, provides the appropriate current flow to a hydraulic solenoid valve.Three different driving conditions are recognised:Parking - maximum current is supplied to the solenoid valve, resulting in maximum steering assistance.High Speed - minimum current is supplied to the solenoid valve, resulting in minimum steering assistance.Evasive Steering - a large and sudden steering input causes the ECU to supply a current to the solenoid proportional to the speed of the steering input.There are plenty of speed-sensitive hydraulic steering systems around. This diagram shows the layout of a Mazda MX6 system where the degree of assistance is based on road speed and steering angle. (1) steering wheel; (2) steering shaft; (3) intermediate shaft; (4) steering gear assembly; (5) pressure hose; (6) return hose; (7) oil pump; (8) solenoid valve; (9) ECU;(10)reserve tank; (11) steering angle sensor; (12) check connector.Hybrid Hydraulic/Electric Power Steering SystemsHybrid hydraulic steering systems use an electric motor to drive the hydraulic pump, rather than having the pump driven directly by the engine. This approach allows the steering effort to be easily controlled by varying the pump speed. Because flow can be better matched to actual requirements, the power drain is reduced - fuel economy savings of up to 0.2 litres/100 km are possible.The control approach that is taken can be of three types -Driving Mode - where driving conditions (such as city, country, highway, etc) are automatically judged with appropriate levels of assistance then provided.Steering Wheel Input Mode- where the speed of the steering wheel movement is used to determine the degree of assistance required.Steering Load Mode - where demand for power assistance is indicated by the counter-pressure of the hydraulic fluid, sensed through variations in the motor current load.The General Motors hybrid hydraulic steering system shown here uses Steering Load Mode to determine the actual steering loads and so the degree of assistance that needs to be provided. The 3-phase brushless DC motor (12) is supplied power by the Motor Power Circuit. The EHPS control provides a control signal to the Motor Power Circuit in response to input signals fromthe motor angle sensor, motor current sensor and battery current sensor as well as operating system voltage. The temperature of the hydraulic fluid is also monitored.Electric Power-Assisted SteeringElectric Power-Assisted Steering completely replaces the hydraulic system that previously has always been associated with power steering. Electric power steering systems assist driver effort by the use of an electric motor which acts through a reversible gearbox and in some cases, also an electromagnetic clutch. An electronic control unit determines the degree of assistance that is rendered.Electric power steering has some significant advantages over any form of conventional hydraulic steering, both for the owner of the car and its manufacturer. The reduction in engine load of an electric power steering system (it can be as low as 4 watts when the car is being driven in a straight line) means that the fuel economy of a car equipped with electric power steering is very similar to that of a car with no form of power steering. Analyses provided by manufacturers of electric power steering systems indicate potential fuel savings of 4-8 per cent over cars equipped with conventional hydraulic steering, with the lighter mass of an electric power steering also having an impact here. The independence of the system from engine operation also means that should the engine stall, steering assistance does not change.From a manufacturer's perspective, using electric power steering reduces assembly line time, allows the easy software tuning of the steering assistance characteristics to suit a variety of cars (eg a sports car or a limousine - more on this in a minute), and has the potential to improve reliability - 53 per cent of all power steering warranty claims are from pump and hose problems. Environmental gains are also possible from the decreased production and disposal of hydraulic fluid (worldwide, an estimated 40 million litres of power steering fluid was in use in 1995) and from the decreased requirement for the non-recyclable polymers used in hydraulic hoses.Features BenefitsEngine independence Reduced engine power drainImproved fuel economy andaccelerationInstant-on power steeringAssistance available even should theengine stallSimplified packagingElimination of pump, hoses, fluid, drivebeltand pulleyEnvironmental compatibilityReduced massModular design and integrated controller Reduced assembly timeDesign and packaging flexibility Multi vehicle use Design and packaging flexibilitySoftware tuning Wide assistance rangeIn-vehicle laptop PC tuningTuning process reduced from monthsto hoursCost-effective advanced features Variable effort steering,Assisted return to centreSteering damping capabilityDepending on the location of the electric assist unit, the electric drive assistance can be transmitted to the steering mechanism by a number of means. These are:Method Electric Assist UnitLocationPower TransmissionPinion assist Under the dashboard on thesteering columnMotor > worm gear > column shaft >pinion shaftOn the steering rack inputpinionMotor > gear train > pinion shaftRack assist On the steering rack Motor > ball screw > rack shaftOn a second pinion on thesteering rackMotor > planetary geartrain > anothershaft pinion > rack shaftSo, How Good is Your Driving?One of the most interesting aspects of electric power steering is the ability that the manufacturer has to tune the system's responsiveness. As indicated earlier, this allows the easy software matching of a single electric power steering to applications as diverse as a two-seater sports car or luxury sedan, but it also means that system responsiveness can be made to vary in different driving situations in the one car. When this approach is taken, the input by the driver of a certain amount of steering lock does not always result in the same degree of assistance - should the ECU determine that such a steering movement is notappropriate for the conditions, the steering assistance may be reduced or the steering input even actively resisted!As an indication of the far-reaching implications of this, Honda has very recently developed an electric power steering system that estimates the skill of the driver and provides steering assistance to match. In the Honda system, a 'driver skill estimation device' is used, having inputs from:• a GPS system(!);• a vehicle speed sensor;• a steering sensor that provides information on steering angular speed, angular acceleration and torque input;• a brake pedal sensor that detects braking stroke, speed and force;• a throttle pedal sensor that detects accelerator stroke and speed;• a yaw rate sensor;• a road friction estimate input.The road friction estimate is determined by the undertaking of an audio frequency analysis of the sound of the tyres on the road! From this it is determined whether the road is dry, wet, snowy, powdery snow or icy. (Note that while the GPS and yaw rate inputs are included in the Honda patent of the system, Honda state that the system can still work effectively without them.)The 'driver skill estimation device' analyses the actual path taken by the vehicle and compares this with a computed target trajectory. Using this and data on the vehicle wheelbase, the distance that the front and rear wheels are from the vehicle centre of gravity (and other factors), the system awards the driver an ability that varies on five levels from "very poor" to "very good". A very good driver is rewarded with very little steering force resistance (the driver gets what he or she asks for), while a poor driver will encounter steering that actively does not allow major steering inputs to be made at high speed.According to Honda, this allows the skilled driver to "positively control the turning behaviour of the vehicle so as to briskly manoeuvre the vehicle. Conversely, if the vehicle operator is not skilled, the control system produces a reaction which prevents the vehicle operator from over-reacting to the vehicle response, and (so) stabilises the vehicle."But you have to wonder what happens when a 'very poor' driver suddenly needs to swerve around a child that runs out onto the road.... However, the Honda system does provide a very strong indication of the direction that electric power steering systems can be expected to follow in the future.在大量车上使用传统的液压助力转向系统很快将被电子控制转向系统代替。

汽车转向系统的历史外文文献翻译、中英文翻译、外文翻译

汽车转向系统的历史汽车转向系统在车辆系统中是最基础的系统，驾驶员通过方向盘操纵和控制汽车的行驶方向，从而实现了他的行驶意图。

100多年里，汽车行业中机械和电子技术的发展。

如今，汽车已经不是纯粹的机械，它是机械、电子和其他材料等的综合产品。

汽车产业的转向系统的发展，经过了漫长的变革。

传统的转向系统是机械转向系统，汽车的方向盘通过试点，通过这样一系列的机械零件使方向盘实现偏转，从而实现转向的控制。

由于在20世纪50年代，液压助力转向系统在汽车上的应用，标志着转向系统又进入一个新的开始。

汽车转向系统的动力源从人力转变为液压助力转向。

转向系统增加了液压助力器，高压钠灯（液压助力转向）是基于机械和液压系统。

液压系统和发动机，发动机开始时一部分是汽车发动机的功率，另一部分的功率是液压系统的动能。

由于其工作可靠，成熟的技术已被广泛使用。

转向系统的主要特点是流体的压力，减少驾驶员在方向盘的支持，提高了转向灯和自动运行的稳定性。

但同时，也有一些液压动力系统的缺陷。

针对汽车设计和制造，完成后的车辆转向动态特性无法改变。

其直接后果是，在低功率时汽车的部分的动力特性可以得到很好的发挥，但在高速期间有良好的方式来检测，因为是不可调整的动力特性，没有更好的方式驱动，当动力学特征高功率时，而不是非常善于低段的效果好。

如果没有看准车辆的液压系统，还必须是发动机驱动。

因此，能源消耗提高燃油发动机，现有的液压油泄漏问题不仅污染环境，容易到其他组件，针对气温低，液压系统的性能较差。

近年来，随着电子技术的广泛应用，转向系统也越来越多地使用电子设备。

变成电子控制系统，因此，相应的出现了电动助力转向系统。

电液动力转向可以分为两大类：电动液压转向系统（电液压动力 - EHPS）和电动液压转向，电控ECHPS转向（液压助力转向）。

电动液压助力转向系统是在液压系统的液压助力系统的发展的基础上，不同的是，在液压系统动力源的电动液压动力系统，但不是由汽车发动机电机驱动液压系统，节约能源和减少发动机的燃料消耗。

汽车电动助力转向系统中英文对照外文翻译文献

汽车电动助力转向系统中英文对照外文翻译文献(文档含英文原文和中文翻译)原文：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 adjusterrefers 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 the hydraulic 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 and the 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 typevehicle 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 andother 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 steeringtorque 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 housingconverts 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 potentialcomes 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 present invention, 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 couplingmembers 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 which measures 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。

中英文文献翻译—助力电机

附录附录APower motor for EPS provide the power, the power source of the system is EPS, according to the instructions of the unit, and the output ECU for the aid of torque. Power motor performance in largely decided to the EPS system performance, so EPS system to motor performance requirements of the high. Compared to normal motor, electric power steering system with the motor should have the following characteristics. First of all because most vehicle power supply for 12 V dc, therefore, ask dc motor power supply electricity down and have big rated current of the rated power; and Secondly, the volume as low as possible, inertia, wide range of speed regulation of small, control characteristic, smooth operation, and low torque fluctuation little, low speed. High speed, big gear ratio will increase of mechanical system, the influence of system dynamic performance inertia; In turn blocking when can also provide power torque. For large vehicles, or even should be able to provide the opposite direction of power and rotational torque.附录B助力电机为EPS提供动力，是EPS系统的动力源，它根据ECU单元的指令，输出适宜的助力转矩。

EPS电动助力转向文献综述

在国外，各大汽车公司对汽车电动助力转向系统（Electric power steering-EPS,或称Elec-tric Assisted Steering-EAS）的研究有20多年的历史。

为了解决转向系统“轻”与“灵”的矛盾[1]，采用现代控制技术和电子技术的电动助力转向系统(EPS)应运而生。

关键词：工作原理、分类、发展1.EPS的工作原理及特点电动助力转向系统是在传统机械转向系统的基础上发展起来的。

其结构示意图如图1所示。

图1 带双小齿轮的电动机机械转向助力器总体视图1.1EPS的优点1.1.1节约了能源消耗。

没有转向油泵，且电动机只是在需要转向时才接通电源，所以动力消耗和燃油消耗均可降到最低。

1.1.2对环境无污染。

该系统应用电力作为能源，消除了由于转向油泵带来的噪声污染。

也不存在液压助力转向系统中液压油的泄漏与更换而造成的污染。

同时该系统由于没有使用不可回收的聚合物组成的油管、油泵和密封件等配件，从而避免了污染。

1.1.3增强了转向跟随性。

汽车转向控制中英文对照外文翻译文献

汽车转向控制中英文对照外文翻译文献(文档含英文原文和中文翻译)中英文对照翻译汽车的转向控制控制系统稳定性是针对提高驾驶安全性提出的一系列措施中最新的一个。

这个系统能够在40毫秒内实现从制动开始到制动恢复的过程，这个时间是人的反应时间得七倍。

他们通过调整汽车扭矩或者通过应用汽车左侧或右侧制动，如果需要甚至两者兼用，来实现准确的行车路线。

这个系统已被应用于奔驰S600汽车了。

稳定的机械自动系统能够在制动时发现肇端，并且在驾驶人员发现能够反应以前实现车辆的减速。

安全玻璃，安全带，撞击缓冲区，安全气囊，ABS系统，牵引力控制系统还有现在的稳定调节系统。

汽车安全系统的连续升级，已经产生了一种为保护汽车所有者安全的设计模式。

稳定调节系统帮助驾驶员从不可控制的曲线制动中解脱出来，从而避免了汽车的摆动滑行和交通事故。

利用计算机和一系列传感器，稳定调节系统能够检测到制动轮的打滑并且比人更快的恢复对汽车的方向控制。

系统每百万分之一秒作出一次快速捕捉，以及断断汽车是否在按照驾驶员的路线行驶。

如果检测到汽车行驶路线和驾驶员驾驶路线存在一个微小的偏差，系统会在瞬间纠正发动机扭矩或者应用汽车左右制动。

过程的标准反应时间是40毫秒----人的平均反应时间的七分之一。

罗伯特博世工程系统负责人安东·范·桑特解释说：“一个稳定的控制系统能够‘感觉到”驾驶员想要运动的方向，通过控制转向角度，油门踏板的位置，制动板的状态来确定汽车实际运动路线的偏航比率（汽车偏离方向轴的角度）和横向加速度”。

项目负责人阿明·马勒领导着范桑特的工作小组和奔驰汽车公司的工程师发明了第一个完全有效的稳定调节系统，该系统由发动机扭矩控制系统，制动系统，牵引控制系统组成以实现理想与现实运动之间的最小差距。

汽车安全专家相信稳定调节系统能够减少交通事故的发生，至少是在伤亡严重的事故方面。

安全统计表明，多数的单车撞击事故伤亡（占伤亡事故发生的4%），事故能够通过应用这项新技术避免。

转向系统--中英文翻译

转向系统转向系统是驾驶员按自己的意愿操纵汽车或者卡车，通过转动前轮在路面上实现左右转动。

转向系统有两种形式，机械式和动力式。

1.动力转向系统动力转向系统中增加了一对重要的机构齿轮齿条机构和循环球机构。

2.泵叶片泵为转向系统提供液压动力（见下面的图表），泵是由汽车的发动机通过皮带传动的动力而运动的。

泵的内腔中有一组可旋转的叶片当叶片快速旋转时，他们从低压口内吸入液压油同时从高压口排出。

油泵提供的流量与汽车的发动机转速有关。

在发动机不转的时候叶片泵必须提供足够的油液。

结果，当发动机以快速运转时泵必须提供更多的液压油。

泵里有卸压装置来实现泵里压力不是太高，尤其在发动机高速运转时油液的进出很多时。

3. 滑阀驾驶员通过操纵动力转向系统来实现车轮的转向（仅仅当开始转动时）。

当驾驶员没有施加压力时，转向系统是不工作的。

滑阀时驾驶员在操纵中有路感。

旋转的关键是转向轴。

转向轴是一个金属杆，当对它施加扭矩时开始运动。

当驾驶员旋转方向盘时，转向轴传递扭矩到车轮，使车轮旋转。

驾驶员为了使车轮旋转的角度增大就需要有更大的扭矩。

转向阀关键是一根扭力杆。

扭力杆是细金属杆，在传递扭矩是运动。

扭力杆的顶端被连接到方向盘，而且它的底部被连接到齿轮或蜗杆上( 转轮子) ，因此，它传递的力矩跟驾驶员操纵方向盘所施加的扭矩相等。

为了是车轮的转动角度增大就需要增加扭矩。

从输入轴输入的扭矩部分进入伺服阀。

并且它连接到扭力杆的最底端。

扭力杆的底端连接到伺服阀的外部。

在其他的汽车转向中扭力杆也从转向传动装置输出, 连接到其他的转向齿轮或蜗杆上。

当扭力杆旋转时它是从伺服阀的内部向外部传递动力。

由于伺服阀的内部也连接在转向轴 ( 或直接到方向盘) ，在伺服阀的内部和外部之间的力矩大小以来于驾驶员作用于方向盘多少转力矩。

在伺服阀中的转动方向来自于方向盘的转动。

当方向盘没有被旋转的时候,两边的液体是相通的内部压力相当。

但是当它从一个位置旋转到另一个位置时，内部两端的压力将会改变。

转向器英文文献翻译

1 英文文献翻译1.1 Electronic power steering systemWhat it is：Electrically 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 drivingsituations. 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 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.click here to see a biggerElectric 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 oneout 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 present invention, there is provided an electrically powered driven mechanism for providingpowered 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 there between 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, and Figure 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 which measures 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 undercertain 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/or in the wrong direction or in the case where the motor and/or gear box have 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 two SAW 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 d epending 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 inresponse 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 programmable gate array for example a XC 4005 as supplied by Xilinx. Such a controller does not rely upon software and so is able to function more reliably in a car vehicle environment. It is envisaged that a logic sequence not having a field programmable array may be used.Electronic power steering system (English as EPS), and hydraulic power steering system (HPS) compared to, EPS has many advantages.The advantage is that the EPS:1) high efficiency. HPS efficiency is very low, generally 60% to 70%, while EPS and electrical connections, high efficiency, and some can be as high as 90 percent.2) less energy consumption. Automobile traffic in the actual process, at the time to about 5 percent of the time travelling, the HPS system, engine running, the pumps will always be in working condition, the oil pipeline has been in circulation, so that vehiclefuel consumption rate by 4 % To 6%, while EPS only when needed for energy, vehicle fuel consumption rates only increased by 0.5 percent.3) "Road sense of" good. Because EPS internal use of rigid, system of the lag can be controlled by software, and can be used in accordance with the operation of the driver to adjust.4) back to being good. EPS simple structure of small internal resistance, is a good back, get back to being the best characteristics, improve vehicle handling and stability.5) little environmental pollution. HPS hydraulic circuit in the hydraulic hoses and connectors, the existence of oil leaking, but hydraulic hoses can not be recovered, the environmental pollution are to a certain extent, while EPS almost no pollution to the environment.6) can be independent of the engines work. EPS for battery powered devices, as long as sufficient battery power, no matter what the condition for the engine, can produce power role.7) should have a wide range.8) easy to assemble and good layout.Now, power steering systems of some cars have become the standard-setting, the whole world about half of the cars used to power steering. With the development of automotive electronics technology, some cars have been using electric power steering gear, the car of the economy, power and mobility has improved. Electric power steering device on the car is a new power steering system device, developed rapidly in recent years both at home and abroad, because of its use of programmable electronic control devices, the flexibility in the same time there are also potential safety problems. In the analysis this unique product on the basis of the author of the characteristics of electronic control devices, security clearance just that the factors that deal with security measures, and discusseda number of concerns the safety of specific issues. The results showthat: Existing standards can not meet the electric power steering device security needs and made the electric power steering device safety evaluation of the idea.Research work on the electric power steering device development and evaluation of reference value.2 中文翻译2.1 电子动力转向系统图1电子动力转向系统的工作原理：电子动力转向系统是通过一个电动机来驱动动力方向盘液压泵或直接驱动转向联动装置。

EPAS电动助力转向

EPAS 电动助力转向
技术介绍：
EPAS 系统示意图
EPAS 的英文全称是ElectricalPowerAssistedSteering ，中文意思是“电动助力转向”。

动力转向的目的是减少驾驶员操纵车辆转向时作用在方向盘上的力，常用的动力转向有液压式、气压式、电动式。

电动助力转向是由电动机提供直接辅助转矩的动力转向系统。

当转向轴转动时，和转向轴连接在一起的转矩传感器把输入轴和输出轴在扭杆作用下产生的相对转动角位移变成电信号传给电子控制单元（ECU ），ECU 根据车速传感器和转矩传感器的信号控制电动机的旋转方向和助力大小，实时控制助力转向。

因此EPAS 可以很容易地实现在车速不同时提供电动机不同的助力效果，保证汽车在低速转向行驶时轻便灵活，高速转向行驶时稳定可靠。

EPAS 的电机只有在转向时才工作，不用像液压管路中为了较高的油压，需要油泵经常工作。

所以相比较现在车辆中使用较多的液压助力转向，EPAS 更经济环保，而且还能省去液压助力这部分油管，减轻重量。

技术应用情况：
目前国内市场上使用EPAS 和EPS 的车型还不多，不过由于EPAS 和EPS 的技术不断成熟、价格更加合理，盖世汽车网认为EPAS 和EPS 将以很快的速度，在各类新款轿车中普及。

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