Risk Assessment and Mantenance Priority Decisionmaking Method for Falure of Subsystem of CODAS-based CBTC Onboard System

CBTC is an important part of the urban rail transit signal system, where the CBTC onboard system is the core of CBTC. The high precision and refined reliablity evaluation aiming at the system is the theoretical basis to ensure the safe and efficient operation of urban rail trains. Ths paper presented a CODAS-based method for the subsystem fault risk assessment and maintenance priority decisionmakng for the CBTC onboard system. Firstly, the faut interval time collected during operation was fitted before the K-S test method was used to select the optimal dstribution model. Based on the optimal dstribution model, the reliablity function curves of the CBTC onboard system and its subsystems were solved, and the reliablity mpact degree of each subsystem was represented by the curve similarity based on Flecher dstance. Secondy, a faut risk assessment index system was constructed based on reliablity mpact degree, nverse average utilization rate, faut occurence degree and emergency degree of faut occurence. Based on the entropy power method CO-DAS, the faut risk of each subsystem was evaluated and ranked At the same time, based on the average maintenance time, the Euclidean dstance and Taxicab dstance of each subsystem obtained in the process of faut risk assessment, a maintenance priority decisionmakng index system was estabished, and the optimal maintenance order of the subsystems was determined by using entropy power method-CODAS. Finally, the hstorical operation and maintenance data of the CBTC onboard system of a line of Beijing subway was used for exampe analysis. The method can provide a theoretical basis for the development of maintenance programs in practice, and has positive significance for guiding the reliability maintenance of CBTC onboard systems. © 2023 Science Press. All rights reserved.