The Electronically Controlled Automatic Transmission Fault Diagnosis

With the development of automobile industry, the requirements for automobile have become more and more exigent. Fault diagnosis is among the advanced technologies which is applied to automobiles. Fault diagnosis improves the safety and stability of automobiles and has great significance to the safety of people. The content of this paper is the apply of advanced fault diagnosis to the electric-control automatic transmission of heavy-duty automobile in order to improve the fault diagnosis technology of electric-control automatic transmission to a new level.This task is one part of the important task which is applied by the technological center of development of China National Heavy Duty Truck Group Co., Ltd. (CNHTC) and research center of NC (numerical control). The main object is to design the hardware system and to write the applied program.At first, the means and trend of fault diagnosis are explained to the point.Then, a summary is given about the system of fault diagnosis. The fault diagnosis is based on thorough understanding of the whole structure and function of the system. On the basis of thorough understanding of AMT of heavy-duty automobile, the faults of AMT is explained and classified in detail. The symptoms of faults and causes of faults as well as their relationship are also known. The way to deal with faults and the measure meeting at an emergency are also simply discussed.The hardware system is designed based on the fault explained and the data required. This paper analyses the course of fault diagnosis of AMT and the sensors as well as signals required.TMS320LF2407 is expanded according to the needs. Components of hardware system and their type are confirmed. The circuit diagrams are also given.This paper designed the structure of software in TMS320LF24070. The transplantation of UC/OS-II to TMS320LF2407 is also explained in particular. The flow of software of USB is showed.In this paper, Neural Networks is chosen to realize the fault diagnosis of AMT. These two theories are put into practice. The course of fault diagnosis of AMT using BP Neural Networks is realized. The practical program is also written. So we can get the causes of faults by the symptoms of faults to guide mends of automobile .At last we do some experiments and it turns out that the system of faults diagnosis is correct and effective.