Research On Key Techniques Of Wireless Sensor Network For Railway Monitoring Applications

The safety of railway transportation becomes an important problem that operationmanagement department must face. There are also about two thirds of China’s railwayoperations in the western and middle mountains that areas are complex geological conditionsand disaster-prone mountains. A large number of railway accidents imply that the driver of atrain can’t get information about natural disasters along the track or train position in time, thisleads to a large number of railway accidents. Therefore, the task of researching and designingwireless sensor network which is used to accomplish real-time monitoring natural disastersalong the track and train’s position is urgent affairs. This technique can provide technicalguarantee for safety driving and is of great significance for the railway safe transportation.There are a number of characteristics such as low cost, low power consumption,self-organizing and advantages that strong ability of the data acquisition and processing forwireless sensor nodes. Compared to the wired sensor pattern, the wireless sensor networkshave considerable advantages in the equipment cost, deployment environment, maintenanceand upgrade, stabilization and reliability, and so on. In the field of social production andliving, wireless sensor networks has a very broad application prospects. Research ontechniques of wireless sensor network for railway monitoring applications is carried out inthis background.This thesis adopts the advantage of wireless sensor network that can be rapid deploymentand sets up the wireless sensor network upper information transmission platform, which isused to realize train positioning and collection and transmission of information along the railtrack. Sink node can manage wireless sensor nodes in clusters and collect monitoringinformation from those nodes, these information can be sent to sink node and the monitoringcenter by upper wireless information transmission platform. Computers of train or monitoringcenter can process that information and calculate the distance between two trains in the track,offer warning information that influence the safety of transportation and inform drivers oftaking corresponding measures to prevent railway accidents from taking place.Several aspects of mainly research work in this thesis are carried out as following:(1) Based on the study of domestic and foreign literatures, this paper points out thetechnical challenges in the related research work and related techniques about applications,and studies the architecture of wireless sensor network and ZigBee technology throughreading a large number of literatures.(2) Based on analysis of the requirements and characteristics of wireless sensor networksfor railway monitoring applications, the hierarchical architecture of wireless sensor networkinformation transmission platform is put forward and designed in this thesis. Upper information transmission platform is comprised of the ground-sink node which is deployedalong the rail track, it can get location information of the train, collect and transmitmonitoring information of areas along the rail track.(3) The model of wireless sensor network for railway monitoring application, whichcould satisfy the requirement of connectivity and coverage, is improved in this thesis.According to the functional requirements of sink node, the design scheme of hardware andsoftware for sink node are carried out.(4) Based on research of the wireless sensor node localization algorithm and the methodsof train positioning, a positioning scheme of combining odometer and wireless sensor nodeswhich is used to locating train, is proposed in this thesis. The idealized model of locatingmethod is set up which is used to quantitative analysis, it is concluded that the absolute errorand relative error of the positioning. The improved method for further improving highaccuracy of wireless sensor node localization is proposed in this thesis, but it is not provedbecause of time for solving this work is not enough.(5) By introducing energy consumption model and the formula of time delay,quantitative analysis in theory for power consumption and delay performance of node in theplanar and hierarchical architecture of network is carried out, and the results of the analysis isgiven out in this thesis.Exploratory research for the coverage model and the positioning technique of wirelesssensor network are carried out in this thesis. Railway monitoring based on wireless sensornetwork is a complex system, involving extensive of research directions and contents, due tothe limitation of research time, the job need to be further improved. Achievements in projecthad laid a good foundation for the next phase research of wireless sensor network inmonitoring information along the rail track.