Hierarchical Modeling Of High-Speed Maglev Train Decentralized Control System Based On CPN

ABSTRACT:The high-speed maglev train's Decentralized Control System is the backbone of the operation control system. It implements the operational command and train security protection. Decentralized Control System is one of the key subsystems. which has higher reliability and safety requirements.In the dissertation, on the base of the analyzing in Decentralized Control System's functions and structure, the Decentralized Control System was modeled by CPN. Research is focus on the followings:Firstly, the research of high-speed maglev train operation mechanism and the application of CPN modeling in the railway system were analyzed;Secondly, the detailed functions of Decentralized Diagnosis Computer, Decentralized Control Computer, Decentralized Safety Computer, Decentralized Propulsion Shutoff and Decentralized Switch Model were analyzed。The main steps of each function are summarized and a sequence diagram is drawn, different states are defined based on the sequence diagram, and a state diagram is drawn. Using CPN Tools and the existed state diagram, the hierarchical CPN models are modeled;Thirdly, in view of a complete train operation process, the tasks of Decentralized Control System which are to be executed and the sequence of those tasks in this process was analyzed; the communication between Decentralized Control System and Centralized Control System, Vehicle Control System and Propulsion Control System were analyzed.Based on this, the main steps of each function are summarized and a sequence diagram is drawn, different states are defined based on the sequence diagram, and a state diagram is drawn. Using CPN Tools and the existed state diagram. the hierarchical CPN models are modeled。Based on the behavior properties of the CPN models, a test path and a test case is generated. The valuation to the generated test path and test case is made and future research is reviewed in the end.