Modeling And Safety Verification Of Zone Controller In CBTC With UML

The Communication-Based Train Control (CBTC) system is an advanced train control system which makes use of bi-directional and big-capacity digital communication between wayside and train, to transfer the information of the status of the train, as well as the controlling information. Communication Based Train Control (CBTC) is the trend of urban railway traffic control system in the future. Zone Controller(ZC) playes an core role in CBTC system,have very high request to the rationality and safety of the application software design.In the paper, the general principle and structure of ZC device was introduced, according to the safety critical system development framework, from the perspective of the functional requirement, combined with the security requirement of security computer platform,accomplished the function partition of ZC application software. Then carried on the design of application sofeware which based on the blue print method, incarnated the characteristics of the structural design.In this paper, the Unified Modeling Language(UML) and the real-time embedded software development Rhapsody was brought in to build the model of Zone Controller in CBTC system. After describes the model of Zone Controller application software, then accurately describes the function modules which play a key role in Zone Controller subsystem, improve the overall function. Through the formal modeling and analysis, the effectively eliminates the existing contradictions and the ambiguity in the system original design. Through the formalized modeling and analysis, ensure that the Zone Controller application software's design meets funcational requirements and security requirement.After the UML model being established, the model will be imported into Safety-Critical Application Development Environment(SCADE) to carry on the related security verification to the design of Zone Controller application software. By means of the simulation, formal verification and Model Test Coverage, verify the safety of the design, the comleteness of the function and the model coverage degree, provided the theoretical basis for the design of Zone Controller subsystem, meanwhile the reference and the instruction to improve the design of application software.