Research On Sensor Network Technical Architecture Of Train Running State Security Detection

Great-leap-forward development of the railway industry puts forward a higher demands on the security detection of train running state.In order to ensure the safe operation of trains and achieve variety of gradually perfect and rich auxiliary functions,a large number of vehicle electrical and ancillary equipments and distributed sensors need to be installed on the trains.The sensor network of train running state security detection can detect train running status in real time,transfer train control commands and provide passenger information services,which has great significance for ensuring the safe operation of trains.The security detection sensors,train communication network and other vehicle equipments constitute a train sensor network which has the capabilities of comprehensive state sensing,informations aggregation and business collaboration.Firstly,the three-tier architecture of sensing layer,network layer and application layer of the sensor network of train running state security detection is analysed in this paper.On the basis of analyzing the feasibility of the Ethernet used in the vehicle communication network,sensor network structure schemes of ring,multi-ring and ladder are designed.Secondly,the real-time and reliability of various sensor network structures are analyzed.The Ethernet delay,Ftp download response time and video conferencing packet end-to-end delay of the above-mentioned sensor network are analyzed by using OPNET simulation software.The simulation results show that the multi-ring sensor network has optimal performance,the second is the ladder sensor network and the last is the ring sensor network.Again,addressing scheme of network equipments adopts the IPv4 dynamic addressing mode,which uses private IP address domains to form a internal private network of train.The implementation process of inauguration is elaborated based on the sensor network device addressing.VLAN technology can achieves the division of the broadcast domains of sensor network through the way of port division.Finally,overall structure of the wireless communications platform is explained briefly,and then Ethernet interface and 3G wireless communication module are designed.Train real-time positioning which uses GPS/BD combination positioning way is discussed.