基于截止期价值度优先的CAN消息实时调度算法∗

摘要

为了保证CAN总线网络中实时性消息的截止期，同时减小紧迫性消息的传输延迟，综合考虑了CAN网络中实时消息的截止期和价值度两个参数，提出了截止期-价值度优先( Deadline-Value First)实时调度算法，简称DVF算法。给出了算法遵循原则和设计过程，对截止期因素进行分段线性处理的方法，使得算法在保证消息截止期的前提下尽量让关键性消息优先发送。以 EDF 算法和HVF( higest value first)算法为基准，从关键消息的相对延迟、丢帧率和丢失价值率这三个方面对DVF算法进行性能分析，实验表明DVF算法相比于EDF算法和HVF算法有很大改善。%In order to guarantee the deadline of real-time message in CAN network and reduce the transmis-sion delay of Emergency messages, a real-time scheduling algorithm named DVF ( Deadline-Value First) is proposed, Considered deadline and value of real-time message in CAN network. The Principle and way of the algorithm is given. By disposing the deadline element in subsection-linear method, this algorithm can send the most critical message firstly with no loss of other message’ s deadline. The performance of the DVF (deadline-value first) algorithms is analyzed by comparing it with EDF(earliest deadline first) algorithm and HVF ( highest value first) algorithm based on value lose ratio, miss message ratio and relative transmis-sion delay. The experiment shows that HVF algorithms can improve the performance compared to the classi-cal EDF algorithm and HVF algorithm under all workload conditions.