Modeling And Simulation Of C2/C3 Level Transition In CTCS Based On Stochastic Petri Net

At present, our country has the longest high-speed railway running mileage in the whole world, meanwhile, people pay more and more attentions into the safety and efficiency of high-speed railway. The level transition of train control system is common in the process of high-speed train running scene, whether its function has be performed under the provisions of the safety requirements that will impact the efficiency of train-control in the train control system and even affect the security of high-speed railway.In this paper, the goal is studying the safety execution of C2/C3 level transition in CTCS and researching the process and function realization of C2/C3 level transition which is separately attained by using the formal modeling techniques (stochastic Petri net) and computer simulation technology(VC++). The stochastic Petri net which is more advanced is extended on the basis of general Petri net, its transition is attained with a strict time limit, so it can be used into the modeling and analysis of level transition in CTCS. Through the software emulation, we can intuitively observe and monitor the whole process of level transition in CTCS. In this paper, the studying about C2/C3 level transition is based on the C3 entire technical specifications in CTCS, so the stochastic Petri net and computer simulation all have theoretical foundation and research basis.First of all, this paper describe the definition of the train control system level transition, meanwhile it analyze the research status of CTCS and ETCS level transition. Then, the theory of stochastic Petri net and TimeNET are been briefly described, and the feasibility of using stochastic Petri net to establish the level transition model in CTCS is been examined. After, according to level transition principles, we established three C2/C3 level transition cases by using stochastic Petri nets, including the normal C2/C3 level transition model, the normal C3/C2 level transition model and the failure downgrade model in CTCS; at the meantime, using stochastic Petri net analysis software TimeNET analyzes the three models’ performance and conclude that the C2/C3 level transition can be reached under the premise of functionality and real-time requirements which will be strong theoretical support for the simulation next. Furthermore, the simulation about three C2/C3 level transition cases has been completed based on the formal modeling and analysis. Finally, using VC++ software simulation platform which can realize the simulation software development and testing,the overall process monitoring and maintenance about C2/C3 level transition is been implemented and it can prove the validity and feasibility of C2/C3 level transition.