Research On Optimization Of Structure Of WSN In Mine And Localization Algorithm

With the development of mobile wireless Internet communication technology, applying the wireless sensor network technology to mine security surveillance system becomes one of the hotspots nowadays. From fixed network nodes deploy and routing algorithm of mobile nodes two aspects, the thesis bases on mine topology structure and the specific condition in underground researching the solutions to improve the WSN performance in underground environment for the optimization problem of WSN structure. For the positioning accuracy problem of mobile nodes (staffs and vehicles) in underground environment, the paper adopts the combination of improved localization algorithm of signal strength and optimized trilateral algorithm as preconditions improving the location accuracy of mobile nodes to promote the application and development of WSN technology in mine.The main works of the paper as follows:1. A kind of fixed nodes deploying method and routing protocol is presented based on a long-chain like mine wireless sensor network. Through the establishment of the fixed nodes energy consumption model, the paper gets a conclusion by analysis and calculation that set up the cluster with the optimal equal spaces could minimize the consumption of whole network energy. The paper determines the number of deployments in clusters through calculating clusters’ energy consumption to balance the chain like wireless sensor network. The calculating formula for optimal intervals and the number of node in each interval are both presented. A sleeping-scheme is related to coverage is adopted in every cluster interval to further reduce the energy consumption to enhance the system’s lifecycle.2. A kind of improved clustering routing algorithm is presented based on the social attribute of underground mobile nodes. Analyzing the social attribute of mobile nodes in underground, the clustering routing algorithm selects the head node in cluster generation phase, taking into account the number of neighboring nodes, the residual energy and the stability of nodes, which ensures the stability of the cluster head nodes in network. The thesis defines a conception of parameter of belonging to limit the communication overhead which caused by nodes leaving or entering the clusters frequently. The parameter of belonging improves the structure stability of clusters while ensuring the connectivity of nodes.3. A location algorithm of signal path fading parameters which are acquired dynamically is proposed in this paper. Updating fading parameters of signal path dynamically which base on the location information of a couple of fixed nodes to neutralize the effects of underground environment parameters which interfere with the result of RSSI ranging.4. The paper introduces a trilateral algorithm base on fixed nodes which are localized in auxiliary. Bringing relatively high stability mobile nodes which their location information is known into anchor nodes localized in auxiliary by defining stability parameter. To resolve the problem that results in the failure of localization which is due to the sparsely or damaged fixed nodes of underground tunnel.The thesis uses MATLAB as the platform to simulate the localization algorithm and underground wireless sensor networks which network structures are improved. The simulation results reveal that the staffs set up nodes with non-uniform but equal interval in cluster and the modified routing protocol could reduce energy consumption, and prolong the system life cycle. The stability of mobile nodes social attribute, the accuracy and effect of modified localization algorithm are better.