Safety-guided Design Of Medium-speed Maglev Train Vehicle Operation Control System

The 200km/h medium-speed maglev train has the advantages of small turning radius,strong climbing ability and low noise.It is an efficient and convenient transport mitigating the traffic congestion in densely populated megacities and urban agglomerations.As one of the core subsystems of medium-speed maglev transportation system,operation control system is a typical safety-critical system.Therefore,it is of great theoretical significance and application value to study the safety design method of medium-speed maglev train operation control system.This thesis studied the safety-guided design of medium-speed maglev train vehicle operation control system by integrating safety analysis into the whole process of system design.Firstly,an initial design scheme of medium-speed maglev vehicle control system is proposed.Then,potential causes of system hazards and the corresponding safety constraints are obtained via modeling and safety analysis.Thirdly,an optimal design of medium-speed maglev train vehicle control system,which meets the safety constraints,is proposed.Finally,the functional and safety requirements of the system are verified via formal verification.The main works of the thesis are as follows:(1)Considering the technical features of 200km/h medium-speed maglev train and the experience of existing maglev train control system,the functional requirements of medium-speed maglev train vehicle control system and implemented the initial design of the system are analyzed,including functional module partitioning and interface design.(2)the STAMP(Systems-Theoretic Accident Model and Process)model of the medium-speed maglev vehicle operation control system was established,where the hierarchical control structure of each functional module was defined,the corresponding process model was established by OCL language,and the control algorithm was illustrated via UML state diagram.Besides,the model-checking tool UPPAAL was used to establish the timed automaton model of the system.(3)In order to obtain the causes of system hazard,STPA safety analysis was conducted on the basis of above STAMP model,through the steps of system-level hazard identification,inappropriate control action identification and control flaw analysis.Safety constraints of the system were identified according to the safety analysis results.(4)The optimal design of the medium-speed maglev vehicle operation control system was proposed according to the safety constraints,and the updated timed automaton model of the system was established in UPPAAL.Besides,the functional requirements and the safety requirements of the system were converted into BNF statement and verified in UPPAAL verifier.The thesis completed the safety-guided design of medium-speed maglev train vehicle operation control system,which has proved the effectiveness of the method of combining STPA safety analysis and model checking and provides a feasible approach for the design of safety-critical system.This thesis contains 62 figures,16 tables and 55 references.