Research on Failure Processing of Axle Counter in CBTC System

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.