Research On The Safety Risk Assessment Of Radio Block Center Based On Matter-element Theory And Evidence Theory

With the rapid development of high-speed railway technology in China,the requirements for the safety and reliability of railway signal equipment are higher and higher.As the ground core subsystem in Chinese Train Control System at level 3,radio block center is a vital equipment to ensure safe and efficient operation of the high-speed train.Radio block center is a safety critical signal control system based on computer platform which guides failure to safe side.Once a failure occurs,it may influence the operation efficiency and even threaten the operation safety.Therefore,carrying out safety risk assessment research on radio block center in order to improve the safety and reliability of the equipment and better ensure the safe and reliable operation of the train within its jurisdiction.Firstly,on the premise of analyzing the basic structure and working principle of radio block center,risk identification is carried out from the functional,information interface unit and operational security level.The fault mode and effect analysis method is used to identify the failure modes of movement authority function and temporary speed restriction function of radio block center,and the causes and possible influence of the failure are summarized.The hazard and operability analysis method is used to identify the safety risks existing in the information interface unit of radio block center,and the causes and possible consequences of the risks are summarized.Based on the system engineering theory,establishes the operational security risk assessment index system of radio block center from the perspectives of personnel,equipment,environment and management.Secondly,taking the movement authority function of radio block center as the object of safety risk analysis,and taking its failure mode as the risk factor,an evaluation model based on matter-element theory and evidence theory is established.On the basis of risk ranking,experts are invited to determine the evaluation value of risk factors in light of actual conditions.Using game theory weighting method,the risk factor weights calculated by intuitionistic fuzzy analytic hierarchy process method and entropy weight method are combined optimally to determine the comprehensive weights.The correlation matrix of risk factors subordinate to risk level is determined by matter-element theory,which is transformed into basic probability assignment function evaluation matrix of evidence theory by constructing normalization function,and the risk level of movement authority function of radio block center is determined by using evidence fusion method based on weight factor to realize safety risk analysis.The applicability of this model is verified by comparing the cloud-based method and the extension-based method with this model.Finally,according to the risk level of movement authority function of radio block center function determined by the risk analysis,the risk control measures are put forward from the aspects of system hardware,software and other equipment design,as well as personnel,environment,management and other operational maintenance levels,to provide reference for improving the system security design and formulating operational maintenance programs.