Reliability Analysis Of Train-ground Communication System Of CTCS-3

China train control system at level 3(CTCS-3)is a key technology and core equipment that speeds of 300km/h or more to ensure the safety and efficiency of train operation,which can realize the information that continuous and two-way between the ground and the train through the GSM-R network.And train-ground communication system of CTCS-3 is one of the most important parts of train control system,which can provide the location,movement authority,temporary speed limit and other safety related information to the train control system.Once the failure occured,it will endanger the safety of train operation,and cause heavy casualties and huge property losses.So it is very significant for operating reliability analysis and determining the maintenance mode on this system.This thesis took train-ground communication system of CTCS-3 as the research object with bayesian network(BN)was applied in its reliability analysis.In the past,the research on train-ground communication system of CTCS-3 was mainly aimed at the business process of GSM-R network,and the reliability analysis of communication of the train control system was not carried out as a whole.BN was introduced in this thesis to analysis the reliability of system.Firstly,the fault tree(FT)model of train-ground communication system of CTCS-3 was constructed on the basis of its structure and function.Secondly,the reliability and weak links of CTCS-3 were analyzed by considering the effect of factors such as maintenance,common cause failure(CCF).Finally,the corresponding maintenance strategies were presented for the weak links.The results show that the BN model can not only analyze train-ground communication system of CTCS-3 had the high reliability but also identify the weak links of system.It is vital significant for improving system performance,reducing the costs associated with maintenance and ensuring operation safety of high-speed railway.According to the different coverage modes of GSM-R network,the communication reliability of the network was analyzed in the case of hardware failure and communication node equipment redundancy.Firstly,the system structure and the transmission network structure of GSM-R was analysis.Then,the BN model of GSM-R network was established on the basis of the qualitative analysis of the failure mode of the GSM-R network,and the failure rate and the weak link in different coverage modes were obtained respectively.The results show that the higher the redundancy of wireless network,failure rate of the system is more lower,and the reliability of the system is more higher.When the redundancy of the communication node device is lower,the reliability of communication system is lower.Analysis of the intertwined site double-layer coverage network reliability 0.999999 is higher than the same site double-layer coverage reliability 0.999976,the results are in line with the actual situation,and it can be used as a reference for selecting the wireless network structure flexibly.