基于 AUTOSAR 的 FlexRay 动态段调度

摘要

Aimed at the scheduling problem of dynamic segment of FlexRay ,the formulas both for message transmission pe-riod and the length of message frame are put forward firstly which are unrelated to FID assignment based on the AUTOSAR specifi-cation ,and then a BIP model is built based on the load balancing of parallel multi-processor scheduling model .To solve the large scale message scheduling problem ,a period increasing longest-processing-time-first (PILPT ) algorithm is proposed as well as a phase reserving LPT (PRLPT ) algorithm ,which is proposed to prevent the longer period message from occupying the position of the shorter ,and a general suggestion for the choice between the two algorithms is given finally .The simulation results show that , whether for the fixed message set of J1939 or variable message set with a large number of messages and wide length distribution , PILPT and PRLPT algorithms both have outstanding performance in optimizing ratio ,load balance and the calculating speed .%针对FlexRay的动态段调度难题，提出了一种基于AUTOSAR规范的与FID分配无关的消息传输周期及其长度确定方法，建立了基于并行处理器负载平衡调度的BIP模型，设计了一种适合大规模消息调度的周期递增LPT算法PILPT和一种防止长周期消息占用短周期消息位置的相位保留LPT算法PRLPT ，最后给出了在实际应用环境中PILPT算法和PRLPT算法的一般性选择依据。仿真实验结果表明，不论是对J1939消息集还是对消息数量更多、消息长度分布更广的可变消息集，PILPT算法和PRLPT算法在优化比率、负载均衡以及算法速度上均达到了较好的调度性能。