Study On Anchor Node-based Localization Algorithm In Wireless Sensor Networks

The wireless sensor network scattered the sensor nodes in a certain area,observing the occurrence of events,but in most cases,only contains the sensor node location information data has a practical significance.Therefore,the positioning of the sensor nodes is the basis for the effective operation of the various wireless sensor networks,the positioning technology of nodes has a very important position in wireless sensor networks.At present,most of the wireless sensor network positioning technology has low positioning accuracy,the need for additional hardware devices,positioning error accumulation,energy consumption and other limitations.Therefore,this paper studies the location of wireless sensor network based on the static anchor nodes and the location of mobile anchor nodes.Aiming at the problem of positioning based on static anchor nodes,a distance independent algorithm(IDV-Hop + IMP)is proposed.In the existing localization algorithm,the range-based localization algorithm has high positioning accuracy,but requires additional hardware equipment and is greatly influenced by the environment.The positioning algorithm based on the range-free location has a high demand for node distribution.In the network with low anchor node density,most of the positioning algorithms adopt the triangular method,the angle method and the position of the unknown nodes obtained by the polygon method according to the position information of the anchor nodes,not only the positioning error is large,but also the accumulation of errors and other issues.Therefore,this paper proposes the IDV-Hop + IMP algorithm,which divides the unknown nodes into three levels according to the number of neighbor nodes in the unknown nodes.Each level adopts different positioning algorithms.The theoretical analysis and experimental results show that the IDV-Hop + IMP algorithm improves the coverage and positioning accuracy of the node location of the wireless sensor network in the sparse anchor node environment,reducing the positioning accuracy and positioning coverage on the anchor node density dependence.Aiming at the problem of positioning based on mobile anchor node,a mobile anchor based on hexagon is proposed.In the static path planning,the anchor nodes move according to the pre-designed path.When the nodes of the measured area are not evenly distributed,the anchor nodes are redundant or unable to reach some unknown nodes,which can not successfully locate the unknown nodes.In the dynamic path planning,the anchor nodes move randomly,but when the measured area environment is complex,it will lead to anchor node location information broadcast redundancy and poor positioning performance.Therefore,in the path planning algorithm proposed in this paper,six optional directions are proposed for the movement of the anchor nodes,let the mobile anchor node perform all the analysis and calculation.The number of unknown nodes neighbor nodes will be used to determine the next moving position of the anchor node.The simulation results show that the MABH algorithm can effectively avoid the traversal of the nodeless region,shorten the path length and be scalable,especially for the irregular network environment.