The Research Of Mobile Beacon Node Localization Technology In Wireless Sensor Network

Sensor nodes are divided into beacon nodes and unknown nodes in wireless sensors networks,usually,the amount of beacon nodes is small,and beacon nodes can achieve self-positioning by using the GPS.The node localization information plays a key role in the application of wireless sensor network,usually,we make use of the beacon nodes to calculate the location of unknown nodes.In traditional node localization algorithms,the location effect is not very good because the beacon nodes are still,so scholars put forward the mobile beacon node positioning methods to reduce the cost of network and improve the positioning accuracy.The paper focuses on the localization methods based on the mobile beacon nodes,including the path planning of mobile beacon nodes and the node location calculation.(1)In the path planning,the paper adopts three beacon nodes to form a regular triangle,and the beacon nodes set traverses the area with the Gaussian-Markov model.The beacon nodes set can improve efficiency of detection on the basis of avoiding the collinear problem.The GM model makes the motion of beacon nodes directional and purposeful,and the changes of beacon nodes' speed and direction are smooth and steady,the location performance is well.(2)Receive Signal Strength Indicator is vulnerable to environmental factors causing relatively larger error,so the error of the location methods based on the RSSI is also relatively large.This paper manages the RSSI with Kalman filtering in order to make the RSSI approximate true values and reduce the error,then calculate the coordinate values of unknown nodes by modified weighted centroid localization algorithm.The Kalman filtering reduces the RSSI's error by carrying out the linear unbiased estimation.The modified weighted centroid localization algorithm assigns weights reasonably according to RSSI,and better position accuracy is contained by introducing correction factor.Paper uses the MATLAB simulation to verify the above-mentioned methods,the results analysis are good proved the effectiveness of the method.