Sensor Network Coverage Problem Research Based On Rail Transport Of Dangerous Goods

With economic development, the demand for rail transport of dangerous goods continued to increase, accounting for over36%of the railway dangerous goods of the total transport. Due to the particularity of dangerous goods, and uncertainty of rail transport environment, it is prone to accidents, inflicting huge casualties, economic losses and environmental pollution. Thus, in the course of the railway transport of dangerous goods on the security status of the real-time monitoring has become an urgent problem to be solved.Wireless sensor networks which have regional multi-point detection, self-organizing network, data center and low-cost, intelligent, applicability, simple operation and other features, can achieve real-time monitoring and transmitting information, etc. It will be applied to Railway transport of dangerous goods in transit monitoring is of great significance. Node coverage problem in wireless sensor networks is an important issue to be resolved, reasonable and effective deployment of nodes can improve the accuracy and comprehensiveness of the monitoring results, it can also extend the network lifetime through coordinated control. However, currently the node deployment method based on wireless sensor network is proposed mostly for the two-dimensional plane, the method of three-dimensional space node deployment is still relatively few, and due to the special environment of railway transport of dangerous goods, compared with the wild environment and other large-scale monitoring of space, the sensing range of sensor nodes is small, the communication distance between nodes is relatively close, and the monitoring of space is limited. Generally, it has not suitable node deployment method for rail transport of dangerous goods for monitoring process.In the course of the railway transport of dangerous goods, the safety conditions need to be monitored when they are stored and in transit. In boxcars and warehouses which store dangerous goods, it needs to be a reasonable and effective deployment of sensor nodes to achieve the objective of complete coverage of the detection space and the need to ensure effective communication between the nodes. However, the sensing range of the sensor node is a spherical area of approximately, in three-dimensional space, under different conditions of perception radius and communication radius, using packing of spheres method to completely cover the detection area and to maintain node connectivity is a more complex problem. After researched on the study of several polyhedral subdivision of space, this paper propose a node coverage method which is based on space polyhedral subdivision, this method makes the ball covering problem transformed into a polyhedron space coverage. In the case of the ratio of different radius and communication radius of perception, and ultimately to get the corresponding optimal deployment, ensures that the sensing range of the sensor nodes completely cover the detection area, and ensure the effective communication between the sensor nodes.