最早截止期优先算法在CAN FD网络中的改进  

Improvement of Earliest Deadline First Algorithm in CAN FD Bus

作　　者：管银凤 张凤登[1] 张海涛 张宇辉 GUAN Yinfeng;ZHANG Fengdeng;ZHANG Haitao;ZHANG Yuhui(School of Optical-Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093

出　　处：《电子科技》2023年第2期29-36,共8页Electronic Science and Technology

基　　金：国家自然科学基金(71840003);上海市自然科学基金资助项目(15ZR1429300)。

摘　　要：针对应用于CAN FD网络中的调度算法,平均分区编码方式的最早截止期算法对报文进行非抢占调度时,其对大范围的截止期编码能力有限,报文易出现较大概率优先级反转以及总线负载较高等问题。通过分析造成报文传递延迟的各种原因并结合之前相关分区调度算法的不足,文中提出了基于指数–幂函数分区的最早截止期优先算法对报文进行调度的改进方式,即在对报文的截止期进行指数分区的基础上,进一步采用幂函数分区细分。文中对该算法的可调度性进行了分析,并使用CANoe进行了仿真验证。实验表明,与现有的平均分区调度算法相比,改进后的算法扩大了截止期的表示范围,降低了总线负载,优化了优先级反转问题,达到了更好的调度效果。For the scheduling algorithm applied in CAN FD network,when the earliest deadline algorithm of average partition coding method performs non-preemptively scheduling on messages,it will have the problems of limited encoding ability for a large range of deadlines,high probability of priority reversal of messages and high bus load.By analyzing various causes that cause of message transmission delay and combining with the shortcomings of previous partition scheduling algorithms,this study proposes an improved method of message scheduling based on the earliest deadline first algorithm based on exponential-power function partition,that is,on the basis of exponential partition of message deadline,power function partition subdivision is further adopted.In this study,the schedulability of the algorithm is analyzed and verified by simulation using CANoe.Experiments show that compared with the existing average partition scheduling algorithm,the improved algorithm expands the representation range of deadline,reduces bus load,optimizes priority inversion problem,and achieves better scheduling effect.

关 键 词：CAN FD 车载网络 最早截止期优先算法 可调度性 总线负载 幂函数分区 指数-幂函数分区 优先级反转 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置] TN99[自动化与计算机技术—控制科学与工程]