Modeling Research Of Train Tracing In Zone Control System With UML

A Communications-based train control (CBTC) system is a continuous, automatic traincontrol system utilizing high-resolution train location determination, independent of trackcircuits; continuous, high-capacity, bidirectional train-to-wayside data communications; andtrain-borne and wayside processors capable of implementing automatic train protection (ATP)functions, as well as optional automatic train operation (ATO) and automatic train supervision(ATS) functions[3]. It ensures the safe operation of rail vehicles using data communicationbetween various control entities that make up the system. As a core equipment of CBTC,Zone Controller（ZC）plays an important role in ensuring intervals between trains and the safeoperation of trains.A detailed analysis of system requirements is the prerequisite to establish a reliablesystem. This paper clarifies the roles of the various subsystems of CBTC system especiallythe ZC subsystem via the descriptions of basic structure and block mode of CBTC system,especially the detailed descriptions of concept and role of the Movement Authorization (MA).The allocation and execution of MA is the core of the CBTC system and the allocation of MAis undertaken by ZC subsystem.This paper clarifies the needs to be done by Train Tracking by the analysis of therequirements of ZC subsystem. Train Tracking is one of the core functions of ZC subsystemand it is the foundation of the allocation of MA. It is because of the very high securityrequirements of the Train Tracking function, the security and rationality must be guaranteedduring the design and implementation of Train Tracking function. The design flaws can bedetected early to ensure the rationality of the Train Tracking by the analysis and verificationof the tracking model established by the UML-based development environment.In order to establish the tracking model, we need to know how the Train Tracking works.This paper describes how the Train Tracking function designs especially how the core subfunctions of Train Tracking design on the basis of detailed analysis of the functional requirements on the Train Tracking. On that basis, we establish the models of Train Trackingand then we verify the reasonableness of the Train Tracking by validating the models of thecore sub functions of Train Tracking with Rhapsody.