CBTC系统中计轴失效处理的研究

Research on Failure Processing of Axle Counter in CBTC System

[目的]CBTC系统多采用计轴来提供列车辅助定位功能。然而,在计轴出现故障时,如果一律按“占用”处理,将会显著影响系统运营效率;而如果选择在实际无车时按“空闲”处理,则该处理方式不应降低系统安全性。因此,有必要研究CBTC系统在计轴失效时应如何处理。[方法]基于IEEE 1474系列国际标准和CZJS/T 0033—2015《城市轨道交通基于通信的列车运行控制系统(CBTC)接口规范-互联互通接口规范互联互通系统总体要求》,分析了CBTC系统内部计轴区段的状态处理,提出了CBTC系统内部计轴区段的状态机模型,并给出了CBTC系统内部处理计轴故障报告占用的方法。同时,还探讨了CBTC系统直接对实际空闲的计轴故障占用区段进行复位的可行性,并对两种提高计轴系统可用性的方法进行了比较。[结果及结论]IEEE 1474系列标准并不强制在CBTC系统中装备计轴。然而,考虑到CBTC系统的降级模式,通常在CBTC系统中装备计轴。在计轴出现故障并永久报告占用时,可采取的处理方法包括:人工复位以清除计轴故障、通过CBTC处理使CBTC列车正常运行,以及配置计轴监督区段以规避单一计轴区段失效对系统功能的影响。

[Objective]The communication-based train control(CBTC)system usually uses the axle counter to provide train auxiliary positioning functions.However,in the case of axle counter failure,if it is always processed as"occupied",the system operating efficiency will be significantly affected;while if it is chosen to be processed as"idle"when there is no vehicle in reality,this processing method should not reduce the system safety.So it is necessary to research how to process axle counter faults in CBTC system.[Method]Based on the requirements of IEEE 1474 series international standards and CZJS/T 0033—2015 Interface Specification of Communication Based Train Control System for Urban Rail Transit-Interface Specification for Interoperability-General System Requirements for Interoperability,the state processing of the axle counter section inside the CBTC system is analyzed,and the state machine model of the axle counter section inside the CBTC system is proposed,and the method of processing the axle counter fault report occupancy inside the CBTC system is given.At the same time,the feasibility of CBTC system directly resetting a fault occupied axle counter section which is actually idle is discussed,and two methods for improving the availability of the axle counter system are compared.[Result&Conclusion]The IEEE 1474 series standards do not require axle counter system configured in CBTC system as mandatory.However,considering the degradation mode of CBTC systems,axle counters are usually equipped in CBTC systems.When the axle counter system is in fault and permanently reports occupancy,such processing methods can be used:manual reset to clear the axle counter fault,CBTC processing to enable the CBTC trains to operate normally,and configuring an axle counter supervisory section to avoid single axle counter section failure impact.