Research On Detecting Strategy Of Railway Hazardous Articles' Safety Status Based On Wireless Sensor Network

With the rapid development of economy, demand for railway hazardous articles transportation increases year by year. However, in the course of railway dangerous goods transportation, accidents once happen, it will course great harm for people's lives, property, and environment along the railway. Consequently, the problem how to monitor the status of hazardous articles in the railway transportation in real time has become urgent to be solved. Railway transport vehicle generally do not have power supply system and network connection, so the existing dangerous goods monitoring system can't be directly applied in railway dangerous goods transport. Wireless Sensor Network with strong adaptability, simple operation, flexible network deployment, self networking, low cost and intelligent characteristic, provides a new solution for monitoring railway hazardous articles safety states.This thesis studies detecting strategy of railway hazardous articles'safety status based on Wireless Sensor Network. Design for detecting strategy has dramatic objectivity and applicability. Thus based on specific dangerous goods, it is necessary to design specific detection objects and detection strategy. Detection strategy is the basic and important step of the monitoring system. In addition, one of the key technologies of wireless sensor network is energy saving. On the one hand, energy of nodes by batteries is limited; On the other hand, according to the typical application, battery replacement is extremely inconvenient, and once the power is exhausted, node will fail, so it is significant to study the energy-saving technology to ensure the system get a large-scale promotion and practical application. In addition, combining with wireless sensor networks, the energy-saving technology of the detecting strategy research is one of the important research content and the important features of this thesis. System detecting strategy with energy-saving design can effectively prolong survival life of the system, which is the necessary condition for system to be applied in actual railway transportation. Starting from the above two points, this thesis'mainly contents is:1) Chooses two typical kinds of dangerous goods (flammable liquids and explosives) as the research object, analyses the wireless sensor network detection quantity, sensor type selection, sensor deployment scheme and detecting scheme design.2) Analyses power consumption of every parts of this system and studies existing energy-saving technologies, and proposed five energy-efficient mechanisms from two aspects of hardware and software, which include low power consumption hardware circuit, variable frequency mechanism, detecting data fusion and send mechanism, sleep-wake mechanism, and peripherals power control mechanism.3) Designs and implement experiment system, demonstrates detection function of nodes via simulation, and analyses realization and effect of energy-saving schemes from the data and chart obtained from the experiment. These experiments show that node function design and energy-saving mechanisms are feasible with remarkable energy saving and full complement of basic function of sensor node in the Wireless Sensor Network. The research in this thesis has satisfied actual application requirements, and it has important meaning for further research and application of railway hazardous articles'safety status in the way monitoring system based on Wireless Sensor Network.