Fault Propagation Modeling,Analysis And Tool Implementation For Interface Model

In China’s railway domain,Chinese Train Control System(CTCS)is the key equipment and one of the core technology.Chinese Train Control System is a typical safety-critical system,once failure of CTCS occurred,will cause very serious consequences,it may cause the interruption of traffic,even lost a lot of property damage and casualties.Therefore,it is very important to carry out safety analysis of the CTCS.In this paper,the method of safety analysis based on model is studied,and the method of describing the behavior of the system by interface automata model is given.The interaction between system components and components is described according to the grammatical semantics of interface automata.The description is flexible,highly reusable,and improves the quality and efficiency of the safety analysis of the CTCS.The main work of this paper is as follows:(1)The interface automation system is used to model the CTCS.According to the grammar semantics of interface automata,the related basic faults and propagation faults are defined,and the fault behavior of the system is described according to the interface model state and motion migration.(2)The safety analysis based on the interface automaton model requires the state space of the interface automaton combination as the calculation target.Because the state space of complex system is very large,the state space reconstruction strategy is given,and the state space has been divided into safety area,triggering area and hazard core.Through the reachability analysis,it will remove the irrelevant action migration and merge the same state and make the state number effectively reduced,to achieve state space reconstruction.(3)Based on breadth first search algorithm,the heuristic search algorithm has been designed,and the search tree is trimmed with the smaller bounded k value.That is,all the paths in the state space are searched by a simple reachable path to achieve the formation of the minimal cut sets.(4)In order to realize the automation of interface automata modeling and safety analysis,an interface automaton model tool has been developed.The tool is a graphical interface built by Java Swing,which integrates three functions about interface automata modeling,safety analysis and fault tree generation,can better assist the research work of this paper.(5)Combined with the RBC handover process in the CTCS-3 level control system,in strict accordance with the RBC handover process specification,Considered the status,migration path,input and output actions of each component and the possible fault events in the actual operation scene,the RBC handover process system with interface automaton model is studied in this paper.With the help of the interface automaton model tool,the model is established,and the algorithm is used to generate the minimal cut set of the fault event after the safety analysis,and the analysis result is presented in the form of fault tree.