Application And Research Of FlexRay Network Communication Protocol In Vehicle System

With the increasing number of electronic control units (ECU) in modern vehicle, traditional in-vehicle network will cause a series of complex internal wiring, slow communication rate, poor security issues. As the standard of next-generation automotive network bus, the FlexRay is the bus technology with the advantage of faster communication, strong security, fault tolerance, as well as certainty. The FlexRay bus can be used as a vehicle data network backbone resolving the problems of insufficient bandwidth and slow communication rate in-vehicle currently. With the trend of the intelligentization and high-speedization of vehicles today, the X-by-Wire system can provide an important mean to improve the performance of vehicles. If combining with the FlexRay bus technology characterized with high speed, high tolerance and high safety, it can bring much more excellent performance and much brighter application for vehicles in the future.FlexRay bus characteristics and its application in Automotive X-by-Wire system were researched in this paper, FlexRay communication protocol specifications was analysed. When studying the FlexRay network time, the impact of the configuration of the slot length in the static segment on the cycle length and the timeliness of message responses was discussed first as well as time consumption of sending static messages. Then the corresponding optimization methods of message packing and partition for the issues were raised.After that, the impact of ID of message and pLatestTx value of node on the arrangement and responsiveness of dynamic messages was proposed. Then based on the study of the worst-case-response-time(WCRT) of dynamic messages, an integer linear programming based configuration was put forward.With deeply understanding of FlexRay communication protocol and time characteristics, data backbone network base on FlexRay of four-wheel independent driven electric vehicle was designed. After analysing differential problem of electric vehicle, electronic differential control model was builded, and FlexRay network clusters parameter was deployed. Then soft and hardware design of the FlexRay network central controller node and the motor controller node base on TMS320F28335and MFR4310were accomplished. Finally a hardware network test platform for system testing and analysis is carried out. Through system testing and analysis, the correctness of FlexRay physical layer of communication network timing and the feasibility of FlexRay bus using in the application of electronic differential control system were verified..