基于CPN的CBTC地面数据通信系统仿真和分析

Simulation and Analysis of Trackside Data Communication System in Communication Based Train Control (CBTC) with Colored Petri-net

数据通信系统是影响CBTC系统的控制精度、效率和可靠性、安全性的主要因素。充分利用分层赋时有色Petri网(HCPN),综合CBTC系统的实际通信需求,建立了CBTC地面数据通信系统的分层模型,并在HCPN中引入消息的时间标志,实现对数据传输时间特性的分析。对模型进行实时仿真的结果表明基于以太网的DCS地面通信系统的实时性可以满足CBTC系统的需要,而且影响数据帧传输延迟的主要因素是数据帧长度,而与行车密度关系不大。

The data communication system is one of the important factors affecting the control-proficiency, transportation ability, reliability and safety of the CBTC system. Based on the communication requirements of CBTC system, a formalized hierarchy model of trackside DCS with the hierarchy-timed coloured Petri Nets （CPN） was established. Meanwhile, a kind of time-stamp was introduced to analyze the timeliness of message transfer. Lots of simulations were conducted to analyze the real-time quality of the network. Performance evaluation shows that Ethernet is capable of meeting the requirements of CBTC system, and proves that the value and stability of transfer delay may have little to do with the number of the train, but has much more to do with the message length.