Modeling And Verification Of Radio Block Center Subsystem Handover Based On Colored Petri Net

Radio Block Center (RBC) is the key system of Chinese train control system level 3(CTCS-3). Sending Movement Authority (MA) and Controlling the Distance between trains are the main functions of RBC. RBC handover is the one of the key functions of RBC system; it has an important effect on controlling precision, efficiency, reliability of CTCS-3. In order to improve reliability of the entire RBC system, this paper analyzed the functional requirement of RBC handover, discussed the flow of RBC handover and compartmentalized RBC handover function to several parts. On this basis, established the top model and all sub-models of RBC handover by Colored Petri Net, finally verified the functions and capability of the model.Firstly, RBC system research status was described in this paper, gained the significance and impendency of RBC in CTCS-3 train control system depending on compartmentalizing of CTCS-3, the importance of RBC handover was obtained with the help of such analysis.Secondly, the "V" shape developed structure of RBC handover function was given based on the requirement of safety integrity level, and then the flow of RBC handover software was designed. In additional, this paper divided RBC handover functions into several parts according as RBC handover requirement. The important information of RBC handover was given.Thirdly, Colored Petri Net was used to model the RBC handover progress. According to hierarchical CPN, this paper set up RBC system model, and because there has two different tactics to complete RBC handover function, so two different top models were established. Based on the functional requirements and partition, all sub-models were established particularly. At the same time, combining with the important information, Timed CPN models of RBC handover were established as well because of time influence.Finally, On the basis of the models, the state space analysis and simulation analysis were brought forward to analyze and validate the application software of RBC handover. The model of 2 MT2 equipped for ON-Board was chosen to be seriously studied. The functional verification and safety analysis of this model carried out by the method of state space analysis. The successful rate of RBC handover was given under different GSM-R net quality. The different performances between two handover statics was described on the base of communication delay. Some advice of improvement to theperformance was given at last.