Research On Positioning Technology Based On Wireless Sensor Networks

With the rapid development of the Internet of Things,the wireless sensor networks(WSN),as a significant part of the Internet of Things,is widely applied in environmental data acquisition,buildings safety monitoring,moving target tracking and other scenarios for its advantages of light weight,small size and large number of nodes.As one of the key technologies of WSN,the positioning technology has been extensive attentions in current WSN research field.The advantages of target positioning depend on the accuracy and costing.The network system of WSN depends strongly on the environment.So the realization of WSN needs to design different plan according to different environment,and there are different positioning algorithms for different scenarios with different requirements of positioning.In this paper,we study the poisoning technology of WSN,especialy for the improved DVHop poisoning algorithm without distance measurement and the improved RSSI triangular centroid positioning algorithm based on distance measurement.The simulation results show that the improved algorithm can effectively improve the positioning accuracy.In addition,we design and test systematically the improved RSSI triangular centroid positioning algorithm based on distance measurement on the ZigBee platform.The test result shows the positioning system has good performance under the positioning accuracy.The main contents are as follows:1.The positioning theory of WSN is analyzed,and several kinds of basic node position calculation methods are demonstrated.Then we introduce several typical positioning algorithms based on ranging and without ranging,and explaine the performance evaluation indicators of positioning algorithm.2.We improve the DV-Hop algorithm without ranging and the RSSI triangular centroid algorithm based on ranging.In the improvement of the DV-Hop algorithm,the beacon node density is used as a measure to compensate for the average hop distance of the beacon node.Then the coordinates of the unknown node are corrected by using the node density of the nearest beacon node.In the improvement of the RSSI based triangular centroid algorithm,thepropagation model of wireless signals and the basic methods of RSSI ranging are introduced in detail,and the positioning principle is analyzed,and the weighting factor of multiplying the distance by reciprocal is proposed.In MATLAB software,simulation experiments and analysis of two improved algorithms and their source algorithms are performed.The results show that the two new algorithms have improved localization accuracy.3.The ZigBee node's functional hardware is established,and the ZigBee application software and its function modules is designed.The positioning system based on distance measurement RSSI triangle centroid improved algorithm is tested.The results show that the system has good performance and meets the requirements of positioning accuracy.Our research results have important significance and application value.