Research And Implementation Of High Speed Communication Technology For Train Control Safety Computer Based On Time Trigger

The train control system is the control center of rail transit system,which guarantees the efficient and safety of the train operation.With the continuous development of information technology,countries are studying the next generation train control system,which distributes the functions of the original ground equipment to the on-board equipment to make the function allocation more reasonable.Train control system based on train-to-trian communication is the development direction of the next generation train control system,where the direct communication and relay communication between trains reduces the number of trackside equipment,reduces the cost and improves the integration degree of each system,and at the same time,the on-board equipment will handle more and more tasks,and the safety computer system will have higher and higher needs for data communication and stricter requirements for the communication bus.Accordingly,a high-speed communication protocol based on the time-trigger is proposed in this paper,which combines the mature technology of high-speed optical fiber communication.Firstly,by studying the communication protocols of the existing train control safety computer platform,it can be seen that the train control system requires high reliability of communication,but the communication speed is relatively low,which can not meet the communication requirements of the next generation train control system.Therefore,based on the advantages of the high speed and anti-interference ability of optical fiber communication,a time-triggered high-speed communication protocol for train control system is designed.The dual-ring network design and token scheduling mechanism are used to allocate time slices for each node to avoid communication conflicts and ensure real-time and reliability of communication.And then,the performance of the designed communication protocol is modeled and analyzed by formal verification tools,which shows that the protocol meets the design requirements.Secondly,the coding design is carried out on the Zynq-7000 platform,which is divided into two parts according to the function:FPGA and ARM,and FPGA is mainly used to complete high-speed optical fiber communication,parse the data received from the optical fiber with the data distribution processing module,forward the data to the optical fiber or transmit the data to the memory for further processing based on the address information of the data packet,and send the ARM data to the optical fiber.And after simulations and tests,it is verified that the design of the FPGA can accurately complete the functions of high-speed data transmission,filtering and parsing,which lays a foundation for the subsequent ARM data processing.Finally,the software part is designed.The ARM processor is connected with the FPGA through the high-speed AXI bus to complete the high-speed data exchange tasks;the token scheduling task is performed to complete the time slice allocation,fault monitoring and recovery function of all nodes in the bus;and the data processing task is carried out to simulate normal communication task to realize the generation and processing of test data.Then the token distribution and data communication of the system are tested,and the results show that the actual effective communication rate can reach 3.6 Gbps,which means that the designed high-speed optical fiber communication protocol for train control safety computer based on time-trigger can work normally,meet the design requirements and achieve the design objectives as well.There are 44 figures,18 tables and 44 references.