Research On The Realization Of Train Network Based On Real-time Ethernet PowerLink

The train communication network plays an important role in the operation of the subway train,which is related to safe operation of the train and comfort of passengers.According to the requirements of business,there are a variety of networks in traditional train network,each of which plays an irreplaceable role,such as train's operation control system,train's safety monitoring system,train's broadcast service system and so on.Many of these systems lead to adverse influence,for example,serious waste of network resource,low efficiency,complex network management and difficult later maintenance.With the continuous development and maturity of information technology,many of business for ensuring safety and providing services for passengers are often subject to network bandwidth restricts,causing difficulty achieving the upgrading of technology and general management of network resources.So the study for multi-service integration of the train network technology is imperative,which is an important symbol in the next generation of subway train to achieve intelligent safe operation and humanized services as well as other advanced services.With the advantages such as high transmission rate,good compatibility,strong integration ability and low cost,real-time industrial Ethernet will became the main solution and future research hotspot about train communication network.This thesis is based on the national science and technology project "next generation subway train network integration technology research" of "the next generation train key technology research and prototype manufacturing project" and IEC 61375 standard of the train network technology.The application of industrial Ethernet in train communication network is studied.This thesis analyzes the characteristics of real-time Ethernet PowerLink technology and combines with the requirements of China's subway train business to build a typical 4M2T train network system.The main contents of this thesis are as follows:(1)In depth study of IEC and IEC 61375-3-4 standards,we analyzed the network structure,data classification and performance indicators of the Ethernet backbone network and Ethernet train network.According to the development status and characteristics of industrial Ethernet and train communication network,we studied the application of industrial Ethernet in train communication network.(2)Understanding the real-time Ethernet PowerLink technology,including communication mechanism and function characteristics.On the basis of analyzing the influential factors of the PowerLink of the real-time communication mechanism,an optimization scheme is put forward,which uses Kalman filter algorithm to solve the problem of precise synchronization between master and slave nodes,optimizing the number of polling frames to shorten the communication cycle length,effectively reducing the data delay of subway train network and ensuring the reliability of data,which is also the innovation of this thesis.(3)Through the OPNET simulation software to modeling various of topologies,and analysis of business indicators,train network topology is designed at the best optimal with the actual operating condition.Finally,the reliability of train network topology is verified by using two binary decision diagrams.(4)Firstly,on the OMNeT++ network simulation platform,the synchronization performance of Kalman filter algorithm is validated by the master and slave nodes.From the experimental results,it can be seen that the synchronization accuracy is greatly improved.Secondly,according to according to the business requirements described in(1),we use PCs to set up the train communication network based on the Windows operating system.The simulation results show that the optimized real-time Ethernet PowerLink technology meets the requirements of the train communication network in terms of delay and reliability.