Design And Research On Fault Diagnosis Function For A Pure Electric Car

CAN industrial local area networks, called controller area network, which is a serial bus with high speed, high reliability, and low cost for distributed real time control applications, are widely used in the framework of real-time distributed industrial applications and distributed processing systems. An application method of fault diagnosis for an electric car based on CAN bus was introduced in this paper, which is universal and intelligent.First of all, the paper introduced the energy and environmental problems, the current state of fault diagnosis for vehicle, as well as the basic conception of CAN bus. Through analyzing the principle of CAN bus communication, it summarized the advantage of CAN bus communication, it also established the application layer protocol of fault diagnosis based on the protocol ISO15765.Secondly, this paper put forward that the realization of the function for the electric car fault diagnosis can use vehicle controller unit, which can achieve the function of security monitoring, fault processing and diagnostic communication. In front of the design of vehicle control unit, this paper also discussed the fault monitoring objects and fault diagnosis methods.Then, based on the detail analysis of the fault diagnostic function, this paper developed the hardware system and software system, and realized the diagnosis services, including to read fault information, to clear fault codes, to read the data flow.Finally, simulation and hardware in the loop testing was carried out to verify the fault diagnosis performance of the VCU. The results showed that the vehicle control unit was reliable and also can make the demand of vehicle fault diagnosis requirements.The fault diagnosis for electric vehicle has an important economic value and broad application prospects in the future, the study in this paper may provide a good reference for future research in this area.