CAN总线中改进的EDF调度算法可调度性分析

Schedulability analysis of the improved EDF scheduling algorithm in the CAN-bus

摘要:

针对于CAN总线的调度问题，因现有的平均分区EDF调度算法在对于优先级反转问题上收效甚微，从而导致消息缺乏一定的可调度性，故提出一种改进的基于幂函数分区的EDF算法；同时借助量化误差的概念，对该调度算法进行可调度性分析，充分论证了在该调度算法下，消息可调度的判定条件；采用CANoe平台进行实验仿真，对比平均分区EDF调度算法和双幂函数分区EDF调度算法，经试验测试验证了双幂函数分区EDF调度算法的可行性和优越性，改善了消息的最坏响应时间，提高了CAN网络通讯的实时性。

Abstract:

For the scheduling problem of CAN bus, an improved method based on power function division of deadline is presented, due to the current prevent average division of deadline method has little effect on the priority inversion problem, and then the messages lack some schedulability. On this basis, the concept of quantization cost is used to analyze the schedulability of the algorithm, and the decision condition of message schedulability under this algorithm is fully demonstrated. CANoe platform was used for experimental simulation, compared to the average division of deadline and Double-power function division of deadline, and the feasibility and superiority of the algorithm which based on Double-power function division of deadline are verified by experiments. At the same time, the worst response time of message is improved, and the real-time of CAN network communication is improved.