Design And Realization Of Control Network For Electric Vehicle Based On CAN

As one of the most important developing tendencies of vehicle control system, the inner vehicle control system should have better abilities of real-time and fault-tolerance. Based on the synthetic analysis of the research actuality and development trends of electric vehicles (EV) and their control network, in this paper, a kind of control network, namely the CANBUS-based control network, for the fuel cell EV is studied.First of all, the systematic architecture and technological characteristics of CANBUS are introduced, and then its real-time character is analyzed. By the way, a method of RM-based message dispatched analysis is proposed and a CANBUS-based network structure of the control system is put forward for the EV.Because of the worse electromagnetic environment of the electric vehicles and the higher transmitting speed of the control network, it is very difficult for the traditional transmission media to meet the need of reliability. In this paper, a message transmission scheme by the optical fiber based on CANBUS with the structure of redundant double ring is presented so as to greatly improve the reliability of network transmission. Furthermore, the related interface circuit of optical fiber based on CANBUS is designed and the CPLD-based control logic for the optical fiber is realized.To meet the need of message transmission of electronic control unit (ECU) in the electric vehicle, in this paper, a new kind of the application layer protocol is developed for the EV control network after the analysis of different application layer protocol of CANBUS. Also, its real-time character is studied to guarantee all message transmission during their deadline. Finally, in the paper, a realization method of a PC-based CANBUS network protocol analyzer is introduced. With this method, the developing efficiency of CANBUS network system can be evidently improved.