The Design And Reliability Analysis Of Train Control Data Communication System Based On Train-to-Train Communication

Communication Based Train Control(CBTC)systems are signal systems to ensure the safe operation of rail transit.However,with the increasing demand for the efficiency of rail transit operations,the train control system based on train-ground communication has exposed many problems such as complex system structure and high construction cost.Compared with the train control system based on train-ground communication,the train control system based on train-to-train(T2T)communication has advantages of fast response speed,simple structure,and low operating cost.The data communication,which is the core part of the train control system based on T2 T communication,realizes continuous and large-capacity two-way communication between equipment in the system.Therefore,the reliability of data communication is of great significance for ensuring the safety and efficiency of the train operation.According to the requirements of the train control system based on T2 T communication,the Long Term Evolution(LTE)technology is applied in this thesis to design a data communication system structure based on T2 T communication.At the same time,a performance testing platform is established to test system performance.In order to evaluate the reliability of the designed system,the thesis establishes reliability models of the communication system based on the Deterministic and Stochastic Petri Nets(DSPN).By using the ?-tool and Markov regeneration process theory to solve DSPN models,the reliability index of the system is obtained,and the specific scheme to improve the reliability of the system is also given.The specific research contents are as follows:(1)The thesis proposes a train control data communication system based on T2 T communication,and tests the performance of the system.According to the requirements of the train control system based on T2 T communication,the data communication system is designed for the system by applying LTE.A performance testing platform is built to simulate the wireless transmission environment of urban rail transit,and the performance of the system is tested on the platform.(2)The reliability of the train control data communication system based on T2 T communication is defined,and the transmission scenarios are analyzed.According to the technical characteristics of LTE and the special needs of the train control system,the reliability of the train control data communication system based on T2 T communication is completely defined.To evaluate the reliability of the system,the thesis studies the retransmission,switching,reconnection,and roaming information interaction processes in the communication system.At the same time,the communication processes of the train in the train-to-train communication scenarios and the multi-train communication scenarios are analyzed in detail.(3)The DSPN models of single-link transmission scenarios and multi-train communication scenarios are established.DSPN is adopted to model the single-link transmission scenarios and multi-train communication scenarios.The reliability of those two scenarios is obtained by ?-Tool,and the influence of communication limit time on the reliability of the communication system is investigated.(4)This thesis employs the Markov regeneration process theory to verify the accuracy of DSPN models.The Markov regeneration process steady-state analysis method is used to solve models of train-to-train communication scenarios.The reliability of the simulated train-to-train communication scenarios is verified by comparing simulated reliability values obtained by ?-Tool with theoretical values.The research results show that the T2 T communication system based on LTE designed in this thesis meets the needs of the train control system for communication transmission.The reliability evaluation and verification method adopted in this thesis can complete the reliability modeling and verification of the proposed system.The research in this thesis provides a powerful basis of practice and theory for the design and optimization of train control data communication system based on T2 T communication.