容错模式下TTCAN系统矩阵的实时调度

TTCAN协议是一种CAN总线高层协议,在现行CAN协议的基础上引入了时间触发机制.由于消息组中的消息具有多样性,各个消息的周期可能相差很大.针对这一问题,采用最大公约数(GCD)方法来加以解决;利用遗传算法对调度表进行优化,提高了网络利用率,并且提高了事件触发任务的实时性能.对调度表的容错性能进行了分析,并提出了基于后面优先原则的仲裁窗方法.实验结果表明,该算法优化系统网络调度,保证了传输的实时性.

Real-Time Scheduling for Time-Triggered CAN Systematic Matrix in Fault-Tolerant Mode

TTCAN(time-triggered CAN) is a protocol based on CAN bus and it considers the advantages of time-triggered mechanism. Since messages are diverse, it is hard to schedule real-time tasks which constitute TTCAN systematic matrix. So, a greatest common divisor (GCD) method is proposed to solve the problem, where genetic algorithm (GA) is used to optimize the scheduling table to improve the network utilization and timeliness in event-triggered tasks. Finally, fault-tolerant performance is analyzed and a method of behind-priority principle for arbitration windows is proposed. Experimental results indicate that the algorithm can optimize the scheduling table, thereby ensuring real-time transfer.