Research And Development Of Train Communication Technology Based On Real-time Ethernet

At present,the total length of China ’ s high-speed rail line ranks first in the world with36,000 km,and China ’ s high-speed rail is leading the world with independent innovation and intelligence.As the core of train operation,train control system has entered the stage of independent innovation from the stage of technology introduction.Due to the shortcomings of traditional train communication technology and the rapid development of Ethernet technology,using Ethernet technology to improve the quality of train communication will become the main development trend of TCN(Train Communication Network)in the future.Therefore,the research of train communication network based on real-time Ethernet is of great significance to train communication system.In this paper,the real-time Ethernet train communication technology is studied by combining theoretical analysis with experimental verification.Firstly,this paper analyze the two-layer network architecture of ETB(Ethernet train backbone)and ECN(Ethernet Consist Network)in the train communication network.The principle and mechanism of PD(Process Data)and MD(Message Data)communication in TRDP(Train Real-Time Data Protocol)are analyzed,and the model of providing network Qo S(Quality of Service)and the evaluation index of communication performance are discussed.Design and develop a train real-time data communication and display software based on Linux,select Qt Creator for software development environment.Software development includes communication programs and interface displays,programs include process data communication and message data communication,the program calls the TRDP static link library file generated by cross compilation to realize communication,and the interface display implemented by GUI program controls associated with slot functions,and design of Timeout Monitoring Program for monitoring process data Communication.The test platform build a linear redundant structure of ETB and a star structure of ECN,the process data and message data communication in the two-layer network structure are realized,and the communication and interface display are completed,realize the real-time monitoring of the overtime monitoring program.In the research on the real-time performance of train communication,by setting different transmission cycle and different load rates tests,which is verified that the transmission cycle has little effect on the round-trip delay,but the round-trip delay is greatly affected by the load rate.Therefore,Diff Serv(Differentiated service)is proposed for process data communication with high real-time requirements.The experimental results show that after using Diff Serv,the communication round-trip delay is improved and the influence of load is significantly reduced.For the bandwidth utilization of train communication,IGMP Snooping(Internet Group Management Protocol Snooping)technology is used to reduce the multicast communication load and improve the bandwidth utilization.