Research On Risk Assessment Of CTCS-3 Train Control System

With the rapid development of high-speed railway in China,the speed of high-speed railway and passenger dedicated line is also increasing,and the running interval is also shrinking.As an important part of high-speed railway signal system,CTCS-3(Chinese Train Control System at level 3)Train Control system directly affects the safety and efficiency of train operation.Once an accident occurs,it will cause great loss to human life and property.The goal of risk assessment is to identify potential risk factors,analyze system risks,determine whether the system meets the requirements of relevant safety integrity level(SIL),and reduce accidents by putting forward risk control measures and countermeasures.Therefore,in order to measure the safety of the system,it is necessary to know the level of system risk and control the risk within the allowable range,so it is of great practical significance to carry out risk assessment for CTCS-3 Train Control System.Firstly,Based on the brief description of the composition structure and basic working principle of CTCS-3 Train Control System,according to the “man-machine-environment”system engineering theory created by Qian Xuesen,and referring to a large number of relevant literature,the risk identification of CTCS-3 Train Control System is carried out in four aspects of “human”,“machine”,“environment” and “management”.Among them,the risk factors affecting the safety of CTCS-3 Train Control system are identified from the perspective of human factors,mainly including three aspects: the technical ability,psychological quality and fatigue degree of the staff of railway electrical department.The risk factors affecting the safety of CTCS-3 Train Control System are identified from the perspective of equipment factors,including four aspects: family quality history,performance parameters,service life and operation status of CTCS-3 Train Control equipment.Identify the risk factors affecting the safety of CTCS-3 Train Control System from the perspective of environmental factors,mainly including five aspects: electromagnetic interference,civil mobile communication network interference,lightning,raining and snowing and other natural environment,indoor environment such as air conditioning and fire fighting,and foreign matter invasion.Identify the risk factors affecting the safety of CTCS-3 Train Control System from the perspective of management factors,mainly including six aspects: safety inspection related system,equipment regular inspection related system,equipment maintenance related system,risk accident tracking and disposal,fault responsibility investigation and assessment,emergency control process and measures.Accordingly,according to the principle of index system construction,the risk assessment index system of CTCS-3 Train Control System is established,and the assessment criteria are quantified.Secondly,By studying the defining characteristics of risk level,the risk level of CTCS-3Train Control System is divided into four levels: high risk,higher risk,lower risk and low risk.Aiming at the fuzzy and uncertain factors of CTCS-3 Train Control system risk assessment,a risk assessment model based on AHP-DEMATEL(Analytic Hierarchy Process-Decision Making Trial and Evaluation Laboratory)method and fuzzy grey clustering is established.AHP-DEMATEL method is based on the calculation of the initial weight of indicators by AHP method,considering the influence degree between indicators,introducing DEMATEL method to calculate the index centrality,and determining the comprehensive weight of indicators by processing the initial weight and centrality of indicators.Fuzzy grey clustering refers to the introduction of grey clustering into the fuzzy comprehensive evaluation.The clustering coefficient is determined by the system whitening weight function established by the center triangle whitening weight function clustering model.The matrix constructed by the clustering coefficient is taken as the membership matrix of the fuzzy comprehensive evaluation method,and then the fuzzy operator is used for the comprehensive evaluation.Finally,Taking Shanghai Kunming high speed railway as an example,AHP-DEMATEL method and fuzzy grey clustering method are used to evaluate the risk of CTCS-3 Train Control System of Shanghai Kunming railway.The results show that the risk value of CTCS-3 Train Control System of Shanghai Kunming railway is 12.197,the risk level is R3,and the risk is lower,which is in line with the actual requirements of the site,and the relevant risk control countermeasures are put forward accordingly.The case study shows that the risk assessment model based on AHP-DEMATEL method and fuzzy grey clustering method can get the risk value of CTCS-3 Train Control System,which can not only effectively assess the risk level of CTCS-3 Train Control System,but also track the impact of different factors on the overall risk of CTCS-3 Train Control System in real time,and formulate the corresponding maintenance and spare parts strategies in advance to ensure driving safety and improve driving efficiency.