摘要： 在已有的FlexRay网络时间优化模型基础上，提出一种快速确定FlexRay动态段时间长度的近似解析方法。引入指数函数模拟网络中动态帧的最坏响应时间(WCRT)特性，将原优化问题转化为连续函数的极值问题。给出确定指数函数中参数的具体方法，并推导出FlexRay网络中最优动态段长度的解析表达式。实例分析结果表明，在一定的精度范围内，该方法能够快速确定FlexRay网络的动态段 长度。

关键词: 现场总线, FlexRay网络, 动态段, 坏响应时间, 指数函数

Abstract: Based on the presented network parameter optimization model by previous literature, an approximate analytical method is proposed to determine the Dynamic Segment(DS) length in a FlexRay network. By introducing an exponential function to analogize the Worst Case Response Time(WCRT) of the dynamic frames in the network, the original optimization model is transformed to an extreme-value problem of a continuous function. A detailed approach to obtain the parameters in the introduced exponential function is presented, and an analytical expression of the optimal dynamic segment length is derived as well. Through practical example it is concluded that the approximate analytical method is fast and efficient to acquire the dynamic segment duration in a FlexRay network to certain degree of accuracy.

Key words: field bus, FlexRay network, Dynamic Segment(DS), Worst Case Response Time(WCRT), exponential function

中图分类号: 

• TP393