Design And Verification Of RBC Core Functions In Train Control System For Low Density Lines In Western China

The CTCS-LDL train control system used for low-density lines in western China is currently at the stage of theoretical study and laboratory simulation.In the CTCS-LDL system,virtual track circuit,virtual balise and virtual signal are used to replace the real ones for the purpose of reducing investment and maintenance cost,and CNSS technology is used for train positioning,which demands higher realibiity and safety for the ground equipment.The RBC system is the core ground equipment of CTCS-LDL whose core functions include section block management,virtual track section occupancy detection and movement authority generation.In this thesis,the modelling method of colored Petri nets of SysML activity diagrams was selected to conduct design,modelling and simulation on the core function modules of the RBC system.Firstly the requirements analysis on the core functions of RBC system is conducted according to the characteristics of train control system for low-density lines in western China.The core functions were divided into two modules including virtual track section occupancy detection and movement authority generation.The SysML activity diagram is used to analyze and design the core functional modules because it can express the dynamic behavior and describe functional structures of the system.Further,this thesis studied the algorithm for detection of virtual track section occupancy as well as the method for generation of movement authority under different operation scenarios.Secondly the formal conversion rules of SysML activity diagram were established by analyzing the relationship between SysML activity diagram and Petri net,and the model of core functional module of RBC was converted through the rules above,the verifiable CPN models of movement authority module and track occupancy detection module were established under different operation scenarios.Meanwhile,the CPN Tool was used to generate the corresponding state space reports and reachable graphs for further analyzing system dynamic performance.Meanwhile,the state space inquiry functions were applied to conduct detailed verification on main functional logics;based on successful verification of the functional logics,the time model of movement authority calculation under RBC/RBC handover scenario was established;the control monitors of CPN Tools were used to collect the simulation data.Further,the RBC/RBC handover successful rate and handover time performance were analyzed under different network transmission conditions,so as to provide theoretical basis for the RBC software simulation and improvement of the overall technology schemes of western train control system.Finally,based on modeling analysis,the core functional modules of RBC were designed and implemented under Visual Studio 2013.By simulating the real line from Ganlong to Nanshankou in western China,the correctness and reasonability of core function of RBC system were verified.