基于CAN总线的列车头尾端冗余测速测距系统

Redundant Speed and Distance Measuring System at Train Head and End Based on CAN Bus

[目的]既有的列车测速测距技术大多经由ATP(列车自动防护)系统进行数据互联互通及交互,其实现过程较为复杂,且容易因时序问题造成列车定位失效,需要研究更为可靠、有效的技术方法,以实现列车的实时、精确定位。[方法]介绍了列车单端测速测距系统功能的实现流程,以及基于CAN(控制局域网)总线的列车头尾端冗余测速测距系统功能的实现流程,进一步对比了二者在数据处理流程上的不同。针对列车头尾端冗余测速测距系统,建立了列车运行速度计算模型及列车运行距离计算模型。在此基础上,考虑了列车车长及头尾端数据传输和处理过程存在延时等因素,进一步建立了列车运行速度校正模型及列车运行距离校正模型。搭建了列车运行仿真系统,用以模拟列车头端定位设备故障工况,分析该工况下列车头尾端冗余测速测距系统头尾端切换后数据的有效性。[结果及结论]在列车头端定位设备故障情况下,该系统可以持续输出有效的测速测距数据,准确描述列车的速度位置信息。

[Objective]Data interconnection and interaction are realized through ATP(automatic train protection)system in most of the existing train speed and distance measuring technologies.However,the implementation process is complicated,and the train positioning is failure prone caused by timing sequence problems.It is necessary to explore a more reliable and effective technical method to realize real-time and accurate train positioning.[Method]The function realization flows of the speed and distance measuring system at single end of the train,and the redundant speed and distance measuring system at both ends of the train based on CAN(control LAN)bus are introduced.The differences of the data processing flow between the above two systems are further compared.Calculation models for train running speed and distance are established in terms of the redundant speed and distance measuring system at both ends of the train.On this basis,the train speed and distance correction models are also established considering the train length factors and the delay in data transmission and processing process between the train ends.A train operation simulation system is built to simulate the fault condition of the train head-end positioning equipment,and analyze the validity of the data under the above fault condition after switching between redundant speed and distance measuring systems at train head-end and tail-end.[Result&Conclusion]The system can continuously output valid speed and distance measuring data in the event of train head-end positioning equipment failure,accurately describing the train speed and position information.