外文翻译--多功能汽车底盘测功机

附 录AA. multi-purpose vehicle chassis dynamometer With the rapid development of the automotive industry, traffic accidents and environmental pollution on the growing threat to human life, thus increasing the importance of vehicle detection technology stand out a variety of testing equipment have emerged. As a large-scale laboratory equipment, automobile chassis dynamometer can simulate vehicle road test a variety of conditions, the completion of the cars economy test, power test, evaluation and analysis of emissions performance, reliability test and drive the car on the special test . It is in the automotive testing research, product development and quality testing new cars and the car is essential. Use complete chassis dynamometer test and the type of vehicle quality inspection and road test compared with the usual test speed, high precision, low cost, data stability, comparability and good. In view of chassis dynamometers these advantages, many domestic manufacturers have developed a series of dynamometer products, these products are mainly used to detect the following auto axle load 10 t chassis power output, the maximum absorption power of 150 kW. Test items mainly: chassis power output, the driving force, speed, acceleration, glide performance and the accuracy of the speedometer and odometer, and so on. But domestic dynamometer products there are many imperfections, must be resolved. For example: car in different conditions, different load and other conditions, the dynamic performance can not be achieved continuous measurement and control system, control method is relatively backward. This article is for these deficiencies, the control system, control method has been improved to achieve the different conditions and different load conditions, the cars dynamic performance for accurate and reliable continuous measurement and continuous measurement of emissions to increase functionality. In addition, the light of foreign advanced technology and experience, the use of computer technology for vehicle-related transmission loss, rolling resistance, altitude, temperature and other parameters of simulation and correction. Multi-purpose vehicle chassis dynamometer (hereinafter referred to as dynamometer) is a new chassis dynamometer. Aircraft measurement and control system is the key to achieve its power equipment. Dynamometer testing computer control system to control the use of high performance industrial control computer, the entire control system including computer, monitor, keyboard, mouse, printers, input and output terminal blocks, multi-PC bus interface card, SCR and its control circuit, all components have been installed in the 1.8 m high of the standard 19-inch industrial control cabinet. Dynamometer control system coupled with the mechanical part of the (bench) constitute the entire dynamometer. Bench control system by the pressure sensor, speed sensor, pneumatic lift, and eddy current machines and other equipment to complete the dynamometer measurement and control. PC bus interface board is a multi-computer interfaces and measurement equipment, control channel, on-site analog signal amplification and analog-digital conversion, digital signal measurement done by it, the interface card can also control multiple actuator movements, other The card also provides a counter for frequency measurement of the interface. Wheel drive car in the bench rotating drum, drum rotation by the optical pulse output of the decoder, access multi-function card counter, measuring speed and distance traveled. Car driving in the bench, the driving force can drum machine by the eddy current coupling the pressure sensor, the input channel signal sent to the computer, combined with the speed signal measurable cars dynamic performance. In the actual measurement process, the measured speed signal and set the speed comparison, according to a certain algorithm to adjust bias resistance (eddy current excitation current), so that speed can be stabilized at a given value, complete constant speed under the conditions of the various data measurements. Dynamometer applications from the measurement control program, the login program and database service program structure, program design using advanced C / S (Client / Server) design. Measurement control program and the login program is a client application, they exchange data with the database is a database service procedures are completed, the database structure is transparent to users, to facilitate the system and other motor vehicle testing equipment or manage network connections. User login process is complete the basic information on the vehicle, the initial set of test items; measurement control program is the core of the system program, its main function is to complete the measurement and control hardware signals, according to testing requirements set by the login program to complete the detection task, the program also provides another parameter setting, test results query, print and other auxiliary functions. Eddy current machines, also known as eddy current dynamometer, is based on the eddy current (also known physics Foucault current) work equipment. It consists of two parts, the stator and rotor. The stator frame and the stator part including the exciting coil mounted on top. The stator frame around the hole, the excitation coils installed in the hole. The framework of the central part of the stator hub, with two bearing supports the rotor shaft. Including the rotor shaft and the rotor part fixed on the axis of the two rotors, two rotors are located at both ends of the stator part of the rotor shaft can be driven by external forces and free rotation. The inside of the rotor and the stator end face to maintain a small gap, the gap is called electromagnetic air gap. The inner side of the rotor is a very smooth surface, eddy current is generated in the smooth plane. Eddy current machine field winding access current, flux through the stator, eddy current ring, the air gap, rotor constitute a closed magnetic circuit. When the car wheel and drive roller rotates the rotor eddy current machines, due to changes in magnetic flux density of the surface of the rotor eddy current, the eddy current and magnetic field interact to produce the reverse braking torque, the stator swing around the spindle axis. Pass through the leverage of the brake torque to the pressure sensor, pressure sensor gives the corresponding electrical signals, processed by the calculation, the instantaneous power can be drawn vehicle parameters. Adjust the excitation current size, you can change the eddy current machine braking torque, with a corresponding change in vehicle speed, changing the excitation current and speed the formation of a closed loop, constant speed or constant force and, ultimately, the power measurement. Eddy current machine has a maximum speed and load range. In addition, its small size, low cost, more suitable for control automation. AC motors (induction motors) with a minimum speed (800 1500r/min) and load range, less stable, with a little hard to load features. DC Braking device with high performance, easy operation, stable working conditions, the transition easy and smooth, but its test-bed high cost, low-speed braking torque is small, thus limiting the application. This system was chosen as the eddy current unit load device, because of its external features and cost, reliability, accuracy decision. Currently, the majority of domestic water vortex machine dynamometer, eddy current machine has a small amount of several major water-cooled, easy-to leakage, resulting in corrosion of the bearing parts, easy to magnetic flux leakage, constant speed control accuracy, and the volume weight, need a water cooling system and lubrication system inside the vortex, very easy to use, in northern China, especially in winter does not apply. More importantly, domestic water eddy current machine for almost all the engine power measurement of high-speed power absorption unit (maximum power absorption range of 1500 4000 r / min), does not apply to vehicle chassis dynamometer, which is the maximum power absorption range of 500 1000 r / min. The international production of this special low speed, high torque eddy current machine only company in Spain and France TELMA FRENELSA company, their product mix to air-cooled. As the dynamometer torque and power measurement of the speed and load requirements to a large extent, considering cost, reliability, accuracy in the case we have chosen FRENELSAs F16-160-type air-cooled eddy current machine group 16, the absorption maximum torque speed of 750 r / min, vortex machine voltage is DC96V, current is 35A, the maximum absorption torque of 160 kg. The vortex machine constant high precision, volume weight, simple structure, easy to operate, do not need cooling water, and built-in thermocouple 160 , can overheat when the automatic power-off, to avoid eddy current machine was burned. Eddy current machine is a constant speed control accuracy of the dynamometer test one of the key factors, most of the domestic dynamometer does not really solve the problem. According to standard, constant accuracy should reach 2 km / h (such as China GB86-94), but because of large mechanical movement of the system inertia, and inertia of different models is different from the same time, there are dead out of control, non-linear, lag reaction speed feedback in the difficulty of making the design of constant speed control has become one of the key. Currently, we are to be addressed in several ways, one direct drive as far as possible, reducing the dead zone and hysteresis control response, and digital speed control and adaptive control to solve the different moment of inertia effects. In addition, two large closed-loop speed and current use of different sampling frequency in order to effectively control the vortex dynamics and the feedback current machine. Test proved to be stable to 0.5 km / h, is a standard 1 / 4. Control process is as follows: the car began to accelerate, due to the speed difference between running speed and a larger set, using the experience of the control algorithm that is according to certain rules and gradually increase the resistance; Once the vehicle speed close to the set speed, adaptive control work. Because in the start-up phase, the running speed as soon as possible close to the set speed is the primary goal, and the last way in which speed is not stable in the set under consideration, the experience of control is simple and works well in control. The speed close to the set speed, the speed and stability the only objective, experience, control can not do anything at this time. The actual vehicle operating conditions is very complex, and the speed variation is difficult to predict, and thus the control of any form pre-set parameters are not always achieve the best control action, the effect of operating conditions and with the pros and cons of changing. Adaptive control is to adapt to similar conditions and developed, it can under the conditions and adjust the control parameters in order to achieve real-time optimal control. Car in idle state, the different load conditions, different speeds and different road conditions in the case of the emissions are different, the measured data for vehicle maintenance is important, but more important is to determine whether emissions from vehicles qualified to provide a basis for the environmental protection departments to provide accurate detection and rich data material. The dynamometer with the exhaust gas analyzer can be in different working conditions under the conditions of vehicle emissions testing, testing standards fully in line with the introduction of a new national standard (GB14761-1999). The following chassis dynamometer at constant speed, for example, analysis of measurement results. Experimental conditions: the initial speed of 60 km / h, the termination rate of 80 km / h, speed step of 5 km, constant and stable point 5. Test vehicle for the Santana sedan. In constant speed mode with exhaust gas analyzer, we carried out the engine output power, wheel torque and power output, transmission loss of power, CO, CO2, HC, O2, eight parameters were measured, and the speed, power, torque for real-time monitoring. In this experiment, the wheel and experience the power output values match, the engine output power wheel power output of power and transmission losses and. Maximum power output of the corresponding wheel speed of 75 km / h. Transmission loss of power to test the vehicle drive power is an important parameter passing, it is directly related to the cars dynamic performance. Multi-function chassis dynamometer is a motor transport and maintenance industry, comprehensive performance inspection stations, environmental protection, transportation (cars scrapped in the future will be according to their dynamic performance and emissions performance may be) and other necessary test equipment industry, with broad market prospects. By computer-controlled eddy current dynamometer load to achieve resistance simulation, different conditions can be measured vehicle dynamic performance and environmental performance (emissions performance), and has correction, the actual measurement data closer to the car when driving data. The dynamometer speed control through the adaptive control algorithm to improve the cars constant stability and achieve a dynamic performance and environmental performance of continuous measurement.附 录B多功能汽车底盘测功机随着汽车工业的迅猛发展，交通事故及环境污染对人类生命的威胁越来越大，因而汽车检测技术的重要性日益突出出来，各种检测设备也应运而生。作为大型实验设备，汽车底盘测功机可以模拟汽车道路试验的各种工况，完成汽车的经济性试验、动力性试验、排放性能评价与分析、可靠性试验以及与汽车传动系统有关的专项试验。它在汽车试验研究、产品开发和新车及在用车质量检测中是不可或缺的。使用汽车底盘测功机完成汽车试验及各类型的质量检测与通常的道路试验相比具有试验速度快、精度高、费用低、数据稳定、可比性好等优点。鉴于汽车底盘测功机的以上优点，国内许多厂家先后研制开发了一系列测功机产品，这些产品主要用于检测轴重10 t以下的汽车底盘输出功率，最大吸收功率为150 kW。检测项目主要是：汽车底盘的输出功率、驱动力、车速、加速性能、滑行性能、以及车速表和里程表的准确性等等。但是国内测功机产品还有许多不完善的地方，亟待解决。例如：汽车在不同工况、不同负载等状态下，其动力性能不能实现连续测量，控制系统、控制方法比较落后。本文正是针对这些不足，在控制系统、控制方法上进行了改进，实现了不同工况、不同负载的状态下，对汽车动力性能进行准确可靠的连续测量，并且增加了排放的连续测量功能。此外，参照国外先进技术及经验，利用计算机技术对汽车有关传动损耗、滚动阻力、海拔高度、气温等参数进行模拟和修正。多功能汽车底盘测功机（以下简称测功机）是一种新型底盘测功机。该机的测量和控制系统是实现其强大功能的关键设备。测功机检测控制系统中的控制微机采用高性能的工业控制计算机，整个测控系统包括计算机、显示器、键盘、鼠标、打印机，输入输出端子板，多功能PC总线接口卡、可控硅及其控制电路，所有部件全部安装在18 m高的标准19寸工业控制柜中。测控系统加上测功机的机械部分（台架）构成了整个测功机。测控系统通过台架上的压力传感器、速度传感器、气动举升机和电涡流机等装置，完成对测功机的测量和控制。多功能PC总线接口板是计算机和测量控制通道的接口设备，现场模拟信号的放大和模数转换、开关量信号的测量都由它完成，该接口卡还能控制多个执行机构的动作，另外该卡还提供了用于频率测量的计数器接口。在台架上汽车驱动轮带动滚筒转动，滚筒转动经光电解码器产生脉冲输出，接入多功能卡的计数器，测量速度和行驶距离。汽车在台架上行驶时，其驱动能对滚筒的作用力经电涡流机耦合在压力传感器上，由输入通道将信号送入计算机，与速度信号结合可测量汽车的动力性能。在实际测量过程中，实测的速度信号与设定速度比较，根据偏差按一定的算法调整阻力（电涡流机励磁电流），使车速能稳定在给定值，完成恒速条件下各种数据的测量。测功机的应用软件由测量控制程序、登录程序和数据库服务程序构成，程序设计采用先进的C/S（客户/服务器）设计方法。测量控制程序和登录程序是客户端程序，它们与数据库的数据交换是通过数据库服务程序完成，数据库结构对用户是透明的，方便本系统与其他机动车检测设备或管理网络连接。登录程序完成用户对车辆的基本信息、检测项目的初始设定；测量控制程序是该系统的核心程序，其主要功能是完成对硬件信号的测量和控制、按登录程序设定的检测要求完成各项检测任务，另外该程序还提供参数设定、检测结果查询、打印等辅助功能。电涡流机又称电涡流测功器，是基于涡流电流（物理学上也称傅科电流）进行工作的设备。它由定子和转子两部分组成。定子部分包括定子架和装在上面的励磁线圈。定子框架周围有孔，励磁线圈装在孔内。定子框架中心部分轮毂，借助两个滚动轴承支撑在转子轴上。转子部分包括转子轴和固定在该轴上的两个转子，两个转子分别位于定子部分的两端，转子轴可以被外力带动而自由转动。转子的内侧端面与定子的端面保持很小的间隙，该间隙电磁学上称为气隙。该转子的内侧面是十分光滑的平面，涡流电流就产生在这个光滑平面上。电涡流机的励磁绕组通入电流时，磁通经定子、涡流环、气隙、转子构成闭合磁路。当汽车驱动轮带动滚筒及电涡流机转子旋转时，由于磁通密度发生变化使转子表面产生涡流电流，该涡流电流与磁场相互作用，产生反向制动力矩，使定子绕主轴轴线摆动。该制动力矩通过杠杆传递给压力传感器，由压力传感器给出相应的电信号，经计算处理后，可得出汽车瞬时的动力参数。调节励磁电流大小，即可改变电涡流机的制动力矩，同时相应改变汽车车速，不断变化的励磁电流与车速形成闭合环，并最终实现恒速或恒力下的功率测量。电涡流机具有最大的速度和载荷范围。此外它体积小，造价低，更适合于操纵自动化。交流电机（异步电机）具有最小的速度（8001500r/min）和载荷范围，稳定性较差，小负荷具有很硬的特性。直流电机制动装置具有很高的使用性能，操作方便，工况稳定，过渡简易且平稳，但它的试验台造价高，低速制动扭矩小，因而限制了应用。本系统之所以选择电涡流机作为加载装置，是由于它的外特性及造价、可靠性、测量精度决定的。目前，国产涡流机大部分为水力测功机，少量几种电涡流机也主要为水冷式的，易漏水，导致轴承机件锈蚀，容易漏磁，恒速控制精度差，且体积重量大，需要一套供水冷却循环系统及涡流机内部润滑系统，使用很不方便，在我国北方，冬季尤为不适用。更为重要的是，国产水力电涡流机几乎全部用于发动机功率测量的高转速功率吸收装置（最大功率吸收范围15004000 r/min），不适用于汽车底盘测功，后者最大功率吸收范围为5001000 r/min。国际上专门生产这种低转速，大扭矩电涡流机只有西班牙的FRENELSA公司和法国的TELMA公司，他们的产品结构为风冷式。由于测功机的扭矩和功率测量对速度和载荷范围要求要大，在考虑造价、可靠性、测量精度的情况下我们选择了FRENELSA公司的F16160型风冷16组电涡流机，其最大扭矩吸收转速为750 r/min，涡流机电压为DC96V，电流为35A，最大吸收扭矩为160 kg。该涡流机恒速精度高，体积重量小，结构简单，操作方便，勿需冷却水，且内置160热电偶，可在过热时自动断电，避免涡流机被烧坏。电涡流机的恒速控制是测功机测试精度的关键因素之一，国内大部分测功机未真正解决好这一问题。按标准规定，恒速精度应达到2 km/h（如中国GB8694），但由于机械系统运动惯量较大，且不同车型惯量不同，同时，存在失控死区、非线性、滞后反应等调速反馈方面的难度，使得恒速控制成为设计中的重点之一。目前，我们通过几种途径予以解决，一是尽量采用直接传动，减小失控死区及滞后反应，同时采用数字调速和自适应控制等解决不同转动惯量的影响。此外，大转速及电流两个闭环中采用不同的采样频率以便有效的控制涡流机动态及反馈电流。测试证明可以稳定达到05 km/h，是标准的1/4。控制过程如下：汽车在开始加速时，由于运行速度与设定速度相差较大，采用经验控制算法即按一定的规律逐步增加阻力；一旦汽车运行速度接近设定速度，自适应控制开始工作。因为在启动阶段，使运行速度尽快接近设定速度是首要目的，而最后以何种方式稳定在设定速度则不在考虑之内，经验控制是简单易行且效果很好的控制方式。在运行速度接近设定速度之后，速度的稳定成为唯一目的，此时经验控制就无能为力了。汽车的实际运行工况十分复杂，其速度变化规律难以预测，因而任何预先设定参数的控制形式都不可能一直发挥最佳控制作用，其效果的优劣随运行工况而不断变化。自适应控制正是为适应类似的工况而发展起来的，它能够根据工况而调整控制参数，以实现实时最佳控制。汽车在怠速状态下，不同负载状态下，不同车速状态下以及不同路况的情况下的排放都是不同的，测量到这些数据对于汽车维修保养很重要，但更为重要的是为判断汽车排放是否合格提供依据，为环保检测部门提供精确而丰富的数据材料。本测功机可以配合尾气分析仪在不同工况的条件下进行汽车排放的检测，检测标准完全符合新出台的国家标准（GB147611999）。 下面以恒速底盘测功为例，分析一下测量结果。实验条件：起始速度60 km/h，终止速度80 km/h，速度步长5 km，恒速稳定点为5个。试验车为桑塔那轿车。在恒速状态下配合尾气分析仪，我们进行了发动机输出功率、轮输出扭矩及功率、传动损耗功率、CO、CO2、HC、O2等8个参数的测量，并对速度、功率、扭矩进行了实时监控。在本试验中，轮输出功率与经验数值相符，发动机输出功率为轮输出功率与传动损耗功率之和。轮输出最大功率对应的速度为75 km/h。传动损耗功率是检验汽车驱动功率是否合格的重要参数，它直接关系到汽车的动力性能。多功能汽车底盘测功机是汽车运输维修业、综合性能检测站、环境保护、交通（今后在用车报废将按其动力性能及排放性能而定）等行业所必需的测试设备，具有广阔的市场前景。通过计算机控制电涡流测功器加载实现阻力模拟，可以测量不同的工况下汽车动力性能和环保性能（排放性能），并具有修正功能，测量数据更接近汽车实际行驶时的数据。本测功机通过自适应控制算法控制车速，提高了汽车的恒速稳定性，并且实现了动力性能和环保性能的连续测量。