Research On Rage-free Localization Algorithm In Wireless Sensor Networks

Wireless Sensor Network(WSN) system consists of sensor nodes, the sink nodesand the manager nodes. A large number of sensor nodes are randomly distributed inthe monitoring area, through the self-organizing way to organize networks. WSNtechnology can be applied in the field of environmental monitoring, intelligenthousehold, logistics, military field and so on. Localization technology as one of thekey technologies of WSN, is the foundation for target detection, tracking and otherapplications. It is meaningless if there are no sensor nodes localization applications.Node localization algorithm is usually divided into rage-based and rage-free.Rage-free localization algorithm does not need additional hardware equipment tomeasure the distance, angle information between nodes, thus the research scholars paymore attention to it. This article selects Centroid algorithm and DV-Hop algorithm asthe research object, the main work of this paper includes:First of all, through simulation analysis the error sources of the Centroidalgorithm and DV-Hop algorithm, and propose the improved algorithm separately tothe two algorithm. For Centroid algorithm, puts forward the Centroid algorithm basedon error correction, the error correction formula is obtained by using maximumlikelihood method. For the DV-Hop algorithm, using the whole network average hopdistance instead of the anchor nodes closest to the unknown node’s average hopdistance, in the third phase of original DV-Hop algorithm, when the unknown nodeestimate location information, using simulated annealing algorithm to optimize thepositioning result, then the article put forward the hybrid localization algorithm basedon anchor node threshold thought.Second, the anchor nodes are very important in the localization algorithm, ratioand the position of the anchor nodes will be a large impact on the localizationaccuracy. To this, this paper put the transmission line sag online monitoring as thebackground of the localization algorithm. For DV-Hop algorithm, this paper isproposed the improved DV-Hop algorithm based on grid deployment anchor node and anchor node optimal combination, the proposed algorithm not only makes thepositioning accuracy is improved, but also enhance the localization algorithmpractical significance.Finally, through the Matlab software to simulate localization algorithm,respectively considering the ratio of the anchor node,node communication radius andnode number to the influence of localization error, the simulation results show that theimproved localization algorithm can improve the positioning error about8%-10%.