Research For Railway Hazardous Material Cargo Monitoring And Energy Conservation Technologies Based On Wireless Sensor Networks

With the rapid development of China's economy, the demand for rail transport of goods is also growing rapidly, including the transportation of hazardous material. However if there is accident take place, it will course great harm for the people's lives, property and environment along the railway. Therefore, the real-time monitoring of the hazardous material status has become an urgent problem. On the way in transit, the train may be dissolution, re-grouping and other operations, rail freight vehicles do not have power and networks supply, the environment is often very poor, and addition, dust, vibration, shock and electromagnetic interference effects. These factors are the great challenge to monitoring of the hazardous material status in transit.Wireless sensor network (WSN) with intelligent, low cost, applicability, simple, easy to deploy, provide a new solution for this problem. Energy conservation technology is the hot research area in WSN. Especially in this system:the trains for goods are generally not supply power, so the wireless sensor networks need to use battery power. The power of battery is limited; and in this scenario, the rail transport always far away and take a long time, the replacement of battery is very inconvenient. Once the power is running out, the senor nodes will failure. The energy efficiency of the system directly related to the system can be applied to practice and to large-scale promotion or not. This thesis is focus on the design and implementation of energy conservation in WSN in the background of rail transit hazardous material.First, introduces WSN and the basic structure of de detection system. Then I analyzes the energy consumption every parts of the system and studies existing energy conservation technology, combined with the actual situation of this system. This thesis design four energy-efficient mechanisms both in hardware and software, which include sleep and weak up mechanism, variable frequency of data collection mechanism, dynamically changing transmit power mechanism and the external circuit control mechanism.WSN collected status of the hazardous material to the server on the ground thought the gateway by GPRS. The gateway is a most important part of this system, because it connects the devices on the train to the server. For the goods may have different destination, the carriages may be separate or recombined in the station on the way. So every carriage must have a full gateway function. In this thesis, I not only achieve a single gateway solution, but also analysis the shortcoming. Finally proposed a multi-gateway cooperation solution, which is both energy efficient and improve system availability.The great feature of this thesis is that the system is under the real background, the application is real create, and run on the hardware, The Experimental data is real rather than the simulation results. This system has being use in the railway and proved it can satisfy the demand for monitoring. This thesis is great meaning for the Wireless sensor networks based on in-transit train safety monitoring system for further research and widely used.