基于最小时间碎片的汽车FlexRay网络设计

Design of automotive FlexRay network based on minimum time debris

FlexRay是新一代汽车总线标准,其消息与网络参数设计对系统运行的安全性和可靠性有着直接影响。针对FlexRay系统,引入网络时间碎片概念,推导出超周期内时间碎片计算公式;分析了静态段消息最坏响应时间,给出其计算方法;在此基础上,以最小时间碎片为目标,以满足消息传输时限为约束,建立信号封装和静态段参数设计的整数优化模型,给出基于‘两步’计算的求解方法。实验结果证明了该方法的有效性,不仅能够确保消息的传输时限,而且可有效减少网络时间碎片。

FlexRay is a new next generation automotive bus,the message and network parameter design of FlexRay has a direct impact on system security and reliability.Aiming at FlexRay system,the concept of network time debris is introduced,and formula of time debris in a super-cycle is deduced.The worst case response time of the message in the static segment is analyzed,and the calculation method is given.On this basis,with the goal of minimal time debris,with the constraint of message transmission to meet the time limit,integer optimization model of signal package is established,and parameter design of static segment and the solution method of the model is given based on ‘ two-step＇.The experimental results demonstrate that the proposed method is effective,not only can ensure the FlexRay message transmission time limit,and can effectively reduce the time debris.