FlexRay静态段消息调度优化研究

Research on scheduling optimization of FlexRay static segment messages

为提高FlexRay网络的静态段带宽利用率,对基于时隙复用的FlexRay静态段进行优化研究。将传输的信号编码成消息帧,把编码问题转换为数学意义上的带约束装箱问题,将发送周期呈倍数关系的信号封装成一个消息帧,并运用BFD算法求解。之后基于封装的消息帧,提出一种调度方法使静态段带宽利用率最大化和帧ID数目最小化。最后在FlexRay底盘综合控制系统上验证该方法。结果证明,该算法使带宽利用率提升了18.7%,将每个通信周期内所占的FID个数降低了90.47%,并且把循环周期内静态时隙利用率提升了41.52%。

In order to improve the bandwidth utilization,this paper researched on optimization of the static segment of FlexRay based on slot multiplexing.It encoded the transmitted signal into a message frame,and transformed the problem into a constrained packing problem.It encapsulated the signal with multiple relationships into a message frame and solved it by BFD algorithm.Based on this,it put forward a method that could maximize the bandwidth and minimize the number of frame ID.Finally,the verification object was the FlexRay chassis synthesis control and safety system.Experimentally,the proposed algorithm increases the bandwidth utilization by 18.7%,reduces the proportion of FID in each communication cycle by 90.47%,and increases the static time slot utilization in the cycle by 41.52%.