Research On Risk Coupling Analysis Method For Temporary Speed Restriction Operation Scenarios Of The Train Control System Based On STAMP And Timed Automata

The train control system is the key technology and core equipment of high-speed railway signal system,which can effectively ensure safe,punctual,comfortable,high-speed and high-density uninterrupted operation of trains,and is the "brain and central nerve" of high-speed railway.As a safety-critical system,the train control system will lead to very serious traffic accidents if it fails dangerously.Therefore,how to systematically and comprehensively identify potential hazardous events and scientifically analyze the risk coupling paths between hazardous events is one of the urgent problems to be solved in the field of train control system security in view of the train control system operation scenarios under complex interaction.According to the complexity,blending and timing of the train control system,this thesis takes the Temporary Speed Restriction(TSR)operation scenario of train control system as the research object,and uses the method based on STAMP and timed automata to study and propose the risk coupling analysis method for the TSR scenario of the following control systems under complex interaction.This article has completed the following work:(1)From the perspective of system theory and cybernetics,based on the stamp theory and STPA risk analysis method,the safety analysis of the temporary speed limit scenario of the train control system is carried out: the system-level risk is determined,the hierarchical control structure model is constructed,the unsafe control behavior of the system is identified,the control defect analysis is carried out to obtain the dangerous cause of unsafe control action,the system safety constraint is extracted for the dangerous cause,and finally the danger log of the TSR scenario is constructed.(2)By using timed automata theory and UPPAAL tools,the normal scenario analysis and formal modeling of the TSR scenario in the train control system are carried out,and the timed automata model of normal TSR scenario is obtained.Then,the risk factors obtained by STPA analysis are injected into the normal timed automata model of the system as state transition conditions,and the risk factors are obtained timed automata model of the TSR scenario in the train control system.(3)Based on graph theory,the breadth-first and depth-first search algorithms are used to automatically search the system state transition path for the TSR scenario timed automata model containing risk-causing factors,and finally the risk coupling path for the temporary speed limit scene of the train control system is obtained.The method proposed in this thesis can systematically identify the risk-causing events of the train control system under the TSR operation scenario,and scientifically analyze the risk coupling paths between the risk-causing events,which is helpful to deeply reveal the complex risk-causing mechanism of the train control system,provide scientific support for risk early warning and safety management and control,and has important theoretical significance and application value for improving the operation safety of the train control system and ensuring traffic safety.