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 t