The Research Of Key Technology On Automobile Brake Tester

The testing of the automobile brake performance is one of important parts in vehicle safety check. With the amount of the automobile increasing rapidly in our nation, the affect of automobile to the environment is concerned by more and more people. The brake performance of automobile has the relation with the safety of people. Therefore, it is necessary to find best methods and tools of testing automobile brake performances quickly and accurately. The paper is the research of key technology in automobile brake tester.Firstly, the paper give a brief introduction about present automobile brake tester and future tendency in the world.The paper analyzes the process of the braking of auto, and present the methods of testing brake performance, compares the advantages and disadvantages of various testing methods, discusses the criterions of assessing brake performances and national standards.It goes dynamic analysis of braking automobile on the tester, explains the principle of testing automobile brake performance, analyzes the main factors for brake testers.It analyses the total construction of the drum type automobile brake tester, gives the methods of choosing the sizes, speed, surfaces material of tester drums, as well as reasons of choosing tester motor, gearbox, and other main parts.According to the auto brake tester, it has been designed that the hardware circuit of the testing system based on 89C55 single-chip microcomputer, including A/D circuits for sensor interfaces, D/A circuits for needle indicating type display device, driving circuits for brake motors, the communication interface circuitbetween the single-chip microcomputer and pc, etc.The programs has been developed for the PC computer used for data managements, the functions of the programs are data evaluation, printing test reporters and information inquires and so on. The communication protocol between the single-chip computer and the PC computer has been set up. All of the software has been tested. The software of the single-chip microcomputer has been developed according to hardware circuit of the testing system for the brake tester. The brake pedal sensor is added in this paper, it is used to help recording the relationship between the brake force and time. The paper also analyses the brake data and gives the reasons and methods of diagnosing brake troubles by PC computer automatically.The adjustment and testing has been done for the auto brake tester, from mechanical parts to the hardware circuits and the software of the testing system of the brake tester. The communication of the single-chip computer and the PC computer has been tested, and the brake tester has also been calibrated. Finally, the accurate testing of automobile brake performances has been attained by the brake tester, predicted results have required.