基于TRDP的网络优先级调度优化方法研究

Research on network priority scheduling optimization method based on TRDP

将实时以太网应用于列车是未来列车通信网络发展的必然趋势。基于应用列车实时数据协议(train real-time data pro-tocol, TRDP)的车载设备搭建列车网络系统模拟试验平台,研究列车通信过程中各子控制系统的时延特性。通过测试多种发送周期下过程数据和消息数据的网络诱导时延来分析网络性能表现,为改善对实时性要求较高的消息数据传输时延,提出一种优化的优先级调度方法。使用网络演算方法对TRDP协议默认优先级调度方法和优化方法分别进行时延上界推导,最后在试验平台上应用该优化方法的同时测得多组时延数据。两种调度方法下的测试数据对比结果表明,该优化方法可在满足其它优先级数据传输时延要求的前提下,将较高优先级消息数据的时延在本地和跨编组网络下有效减少8.621 ms和13.545 ms,以此验证了该研究对提升列车实时以太网络性能的可行性。

The application of real-time Ethernet to trains is the inevitable trend of the development of train communication network in the future. To study the delay characteristics of each sub-control system in the process of train communication, a train network system simulation test platform is set up based on TRDP(train real-time data protocol) vehicle equipment. The performance of the network is analyzed by measuring the network induced delay of process data and message data in various transmission cycles, for the aim at improving the delay condition of message data transmission which requires higher real-time performance, an optimization priority scheduling method is proposed. The network calculus method is used to deduce the delay upper bound for the default priority scheduling method of TRDP protocol and the optimization method respectively, finally the optimization method is applied to the test platform and several groups of the data are measured meanwhile. The comparison of measured data between the two scheduling methods shows that the proposed optimization method can effectively reduce the time-delay of higher priority message data by 8.621 ms and 13.545 ms in ECN and ETB networks respectively, on the premise of satisfying other priority data transmission delay requirements, which verifies the feasibility of this research to improve the performance of train real-time Ethernet network.