Monitoring System Research And Development For Automobile Transmission Life Testing

Entering 21st century, the auto industry of our country gets the development at full speed. As our country joins WTO, the auto industry of our country faces more severe challenge and keen competition. The automobile trade, as the pillar industry of a lot of countries, has represented the industrial level of a country and influence the national economy of a country too, so it is particularly important to improve the competitiveness of the automobile products. To raise automobile quality, it becomes important and necessary to make strict demand on automobile spare parts.The automobile transmission is an important part in the power driveline. Transmission manufacturers and the qualification units all hope to confirm the life-span of the transmission accurately through the test. The skid bank fatigue life test of automobile transmission assembly has a long periodic time, which should go on under certain temperature and load. It is very important to guarantee strictly the experimental condition, and necessary to monitor the process. There are many kinds of fault happening during the test and the occurrence of faults is highly random. All these bring great difficulties to test personnel. The parts are made singly at the initial stage of development, so the processing course is relatively long. It is possible that the transmission is destroyed at a large scale just because of a certain local problem, but it is unavoidable to go wrong at the initial stage. Therefore, it is a requirement to measure and control the working state of the transmission in real time during the process of the test and find the early trouble in time to avoid the destroying of other parts because of a fault of one part. In this thesis, by means of synthesizing a great amount of material home and abroad, this monitoring system of automobile transmission fatigue life testing was designed. The hardware design of the monitoring system is explained. After displaying the measurement principles of the temperature, rotational speed, torque and vibration, the measurement and control of them are explained. We compared two kinds of method of diagnosing faults of gears in automobile transmissions and pointed out the limitation of wavelet packet, so we adopted the method to diagnose faults of gears, which is to set up the file of amplitudes of gears' vibration. The network is an important part of this project. Combined SQL Server 2000 with C++ Builder, the intact network was made up. To program is a very important part of designing the monitoring system. In this thesis, some program modules are partly explained after explaining the programming procedure, in order to make readers easily understand the whole monitoring system. This system has already been applied for a year in an enterprise. It is normal to run at present and has improved the accuracy of life test of transmission, which is in leading position in the domestic same filed and has got higher appraisal.