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附 录附录A 外文资料翻译Study on the testing system of the auto AC chassisDynamometerWith the incessant progress of the science and technology, the automobileindustry of developes rapidly. The structure of automobile becomes perfect and the performance gets enhanced. On the one hand, the higher demand of automobile performance accelerates the coalescent between traditional automobile technique and modern electron technology,and the automobile technical indexes have been enhanced greatly.On the other hand it accelerates the development of integrated automobile detection technique, and speeds up the research and renovation of the automobile testing equipments.There are two methods for automobile performance test. One is the outdoor road test, the other one is the indoor frame test. The weather,condition of the road and the driving skills have great influence on the road test. However these factors have little influence on the results of indoor frame test. So the indoor frame test gets popular in the automobile test. Automobile chassis dynamometer plays an important role in the automobile detection and diagnosis. Dynamic performance test can been done on the auto chassis dynamometer test bed. With the help of fuel consumption instrument and automotive flue exhaust analyzer, fuel economy test and the analysis of exhaust gas can been done easily. The domestic auto chassis dynamometers get behind that of the developed country. The domestic chassis dynamometers are mainly eddy current dynamometer and hydraulic dynamometer. Generally these dynamometers are equipped with flywheels to simulate the accelerate resistance.By control of the electromagnetic clutch,assemble the required flywheels according to the weight of the car.But the limited flywheels cant realize the continuous simulation of the inertia.They cant satisfy the testing demand of the various cars nowadays.And the test precision needs being improved.Thus this thesis puts forward a new method with the help of an AC electric dynamometer.The principle of AC electric dynamometer is similar as the asynchronous electromotor.With the rapid development of frequency converter,the AC electric dynamometer becomes more popular and easy to be controlled.The paper includes these main points as follows.1. Simply introduce the principle and structure of the automobile chassis dynamometer.Adopts the anti-swing device for the driving wheel, and solves the swing of front-wheel drive cars. In order to recur the road resistance of the automobile,analyse the resistances of the car driving on the road and on the chassis dynamometer,draw a resistance equation separately about the car.Then make contrast of the two equations,find their difference and put forward the electric simulation model.It provides the theoretic basis for the next electric simulation on the AC electric dynamometer.+ mgsin+The model displays as follows.2. Give the general technical demands.Analyse the principle of AC electric dynamometer.It has three running conditions according the difference of the slip.They are regeneration condition,electric drive condition and electromagnetic brake condition.For this reason the AC electric dynamometer is proper to be used in chassis dynamometer and can satisfy the demand.Use the advanced AC variable frequency technique to control the dynamometer.This system adopts the direct torque control of frequency converter.By the control of frequency converter the system can realize the auto speed regulate,auto torque regulate and auto load regulate.3. After choosing the proper sensors for the system, design the part of data collection and analysis,and analyse the amplification of analog signals in detail.In order to do the electric simulation the speed and acceleration are necessary.The system uses an improved method to measure the speed, and uses least square method to get the acceleration.It has excellent precision at low speed and high speed.Analyse the interferential factors,and adopt proper measures to restrain the disturb and assure the veracity of the results.4. The testing system is based on Windows XP and program with VC+6.0. The testing system can operate alone and can operate online. The software of the system adopts blocking design according to the system design demand.That is to say,if any one logic part of the software was changed,it wouldnt affect other parts.And any module can be transferred by other modules.The testing interface is friendly.Take the acceleration test and sliding performance test for example, introduce their testing process. At last give the flow of the whole program.5. Analyse the reason of the error, demarcate the speed sensor and force sensor to see the quality of the linearity of the sensors.The results show the two sensors have good linearity and satisfy GB/T18276-2000 Test method and evaluation index for the automobile dynamic frame benches.Use a truck do the acceleration test from 30km/h to 90km/h on the road and on the chassis dynamometer separately,then make contrast of the results and show that the electric simulation model is correct basically.The automobile chassis dynamometer itself is very complicated.The thesis cant describe every aspect in detail.And it is hard to avoid some mistakes and disadvantages.The testing system needs to been further researched and improved,and needs doing more experiments to validate its feasibility汽车交流底盘测功机测试系统研究随着科学技术的不断进步，汽车工业得到了迅猛的发展。汽车结构不断完善，汽车性能不断提高。人们对汽车性能要求的不断提高，一方面促进了传统的汽车技术与现代电子技术的结合，使汽车的经济技术指标在最近几十年有了大幅度的提高；另一方面，它促进汽车综合性能现代检测技术的发展和广泛应用，大大提高了汽车新产品的开发速度和出厂产品质量的控制能力。汽车性能测试分为室外道路试验测试和室内台架测试，由于道路试验受气候、道路条件状况及驾驶技术等因素的影响比较大，汽车检测以室内台架测试为主。汽车底盘测功机是一项重要的汽车检测设备，在汽车检测行业扮演着十分重要的角色。利用底盘测功机，我们不仅可以对汽车进行动力性能检测，在配备油耗仪和尾气分析仪的基础上，我们还可以在不同工况下对汽车的燃油经济性和尾气排放进行测试分析。目前的底盘测功机主要以电涡流测功机和水力测功机为主，通常配备一些惯性飞轮来对汽车的惯性阻力进行相应模拟。通过控制电磁离合器的吸合与断开来控制不同飞轮的组合，以实现对不同质量汽车运动惯量的模拟。但有限数量的飞轮，不能实现汽车惯量的无级模拟，不能满足当前各种类型汽车的检测需求，而且模拟精度有待提高。由此本文提出了采用交流测功机模拟汽车行驶阻力。这样不仅省去了繁琐的惯性飞轮，简化了机械结构，而且可实现惯量的无级模拟。本文从总体上进行系统设计与分析，主要包括以下几点。1对汽车底盘测功机的原理和结构进行简单介绍，采用课题组自行开发的汽车车轮防偏摆机构，有效解决了前轮驱动型汽车在测功机上运行时的横摆问题，并保证了测试时的安全性。为了在底盘测功机上真实再现汽车道路行驶工况，需要真实反映汽车的道路行驶阻力。文章分别对汽车在道路上和底盘测功机上的运行状况进行了力学分析，建立了交流测功机电模拟的数学模型。+ mgsin+该数学模型为进一步交流测功机的电模拟提供了理论依据。2对系统提出总体技术要求，分析交流测功机的工作原理，在转差率不同的情况下，交流测功机分别运行于发电测功状态，拖动状态以及电磁制动状态。由于交流测功机既可以运行于发电测功状态，又可以运行于拖动状态，适合用于底盘测功机中。利用目前先进的变频调速技术来控制测功机。系统采用变频器中的直接转矩控制技术，通过计算机控制变频器可实现底盘测功机的恒转速控制、恒转矩控制及道路模拟方式控制。3对系统采用的传感器做出合理选型之后，进而对数据的采集和处理进行了分析，并就如何对模拟信号进行放大做了具体分析。采用合理的数据采集卡将数据输入计算机。由于电模拟需要测得速度和加速度，针对本文选用的光电编码器，本文采用了一种新的测试速度和加速度的方法，测试精度有所提高。分析系统干扰产生的机理，并就干扰问题采取了相应的措施进行抑制。4本测试系统以 Windows XP 为平台，采用 VC+6.0 进行编程。系统既可以单机运行，也能适应检测线联网检测的要求。系统的软件部分根据系统的设计要求，程序采用模块化，即程序中某一程序段内的任何逻辑部分都可以任意更改而不影响程序的其它部分，每一模块程序都可以作为一个子程序供其它程序调用。测试系统界面友好，以加速性能测试和滑行性能测试为例进行了介绍，并给出整个测试系统的软件流程图。5对误差的产生做简单介绍之后，对系统中的速度传感器和拉压力传感器进行了相关标定工作。通过标定试验，表明传感器线性度良好，测量精度满足 GB/T 18276-2000汽车动力性台架试验方法和评价指标中对底盘测功机测试精度的要求。以汽车在道路上和底盘测功机上进行了 3090km/h 的加速性能测试，通过测试结果的分析，证明了本文建立的测功机电模拟模型的正确性。由于汽车底盘测功机本身就是一件十分复杂的设备，论文不可能对每处都做到详细论述。该测试系统还存在很多不足之处，有待进一步完善，与传统汽车底盘测功机进行比较，并通过大量试验进行验证分析5
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