The Application Of CAN In Electric Vehicle

In 1986, BOSCH company developed CAN bus for automotive. Now only the Polo uses the CAN bus in China. During the development of controller system in electric vehicle supported by National 863 Project foundation of China, the system used the CAN bus in system design for stability and promoted the performance of EV. In the end, CAN bus descreased the bus ring, promoted the reliability and realtime performance. Some practice technology, which based on CAN in EV application, is introduced in this thesis.First, the key problem (bit timing) in CAN bus on the theory and practice are expounded this thesis. In order to balancing the requirement of oscillator difference and bus length, the optimized parameters about bit timing should be found. Then, an EV example for bit timing is taken.Second, the physical layer and the data link layer of CAN protocol have defined in detail. However the application layer of CAN protocol needs to be designed by user. So the EV CAN bus application layer protocol based on SAE J1939 is developed. In the meantime, the RM (rate monotonous) algorithm is used to optimize the CAN application layer. Rate monotonous analysis has been used to analyse the CAN bus schedulability in this thesis. Moreover, the spare capacity factor alpha, which is a measure of robustness of a system, is calculated.Finally, many manufacturers produce the CAN analyzer applicating in EV, but this system has to be improved according to market need. Therefore the CAN tester software system on the basis of the error cycle theory is developed. Otherwise, the embedded operation system and the real time system are introduced in this thesis.Now, the EV system has been accomplished, and runs well. Moreover, the CAN bus has been applicated in aeroplane, architecture, automation, etc.