基于RMA方法的汽车车身CAN总线优化设计

针对汽车车身控制信息的高实时性和车身CAN系统扩充的高灵活性等特殊要求,介绍用于实时系统分析的速率单调分析(RMA)方法,在原总线利用率、信息最坏响应时间等实时性指标基础上引入总线扩展灵活性因子进行车身CAN总线方案的寻优设计,并以典型汽车车身控制系统为例,对单信号方案和信号组合方案进行实时性和扩展灵活性对比分析,在线试验结果验证了理论分析数据的正确性。

Optimization Design of CAN Bus in Vehicle Body Based on RMA Algorithm

An optimization design of CAN bus in vehicle body is conducted in this paper.In view of the real time requirements of car body control information,the rate monotonic analysis(RMA) technique is used as general convention.But in addition to bus utilization factor and real time indicators including the worst-case response time,a bus expansion flexibility factor is also introduced for the special requirements of car body CAN on high expansion flexibility.A comparative analysis on real time capability and expansion flexibility between single-signal scheme and signal-group scheme for CAN bus is performed.The result of online test shows that the signal-group scheme saves bandwidth utilization resource and improves the expansion flexibility of CAN bus for car body.