Study On Technology Of Localization For Wireless Sensor Networks

The wireless sensor network node location technology is an important supporting technology for WSN. The node position information of WSN is not only the premise of monitoring events, but also it is the basis of the network topology from the self-configuration, improve routing efficiency and reporting the information required to observers. If we do not know the position information, the information we are interested will lose its proper meaning. Wireless sensor network nodes are randomly deployed. How to maximize the localization accuracy of localization is a difficult research area in wireless sensor networks for the effect of the layout environment and factors of its own. Therefore,the research for the wireless sensor network node location technology has important theoretical and practical significance.This paper introduced the development course of wireless sensor network and the architecture model of the wireless sensor network, analyzed the key technology for wireless sensor networks, and thoroughly discussed wireless sensor network node location technology. Focused on the concept of node localization,the location classification,the basic principles and methods of localization, and the criteria of positioning performance evaluation are made a more detailed analysis and research, while some typical existing location algorithms and systems are made a brief introduction and comparison. The paper focused on the Range-free positioning algorithm of wireless sensor networks DV-hop in-depth study, and analyzed the reasons for the existence of error in detail. Then, this paper presented the improved localization algorithms in two-dimensional and three-dimensional environment respectively.( 1 ) The paper presented a new DV-hop localization algorithm in the two-dimensional environment to improve localization accuracy error of traditional DV-hop algorithm. The average hop-distance weight,hop weight and distance error were introduced into the algorithm to improve the node average hop-distance, then the calculated distance through using the average hop-distance will be closer to real distance; And then the anchor node teams which have better topology and are closer to the unknown node are selected through co-linearity threshold and hop threshold to estimate location and get a series of locations. Finally, the final coordinates can be got through using Centroid algorithm. Simulation results show that the novel DV-hop algorithm can provide more accurate location estimation. (2)For the novel DV-hop localization algorithm have the problem of low coverage, a location algorithm which upgraded the virtual anchor nodes algorithm was presented. In order to solve the coverage problem, the paper made a further improvement for the novel algorithm by upgrading unknown nodes which can meet some requirements as anchor nodes. Simulation results show that the method can effectively solve the coverage problem, and can improve the location accuracy.( 3 ) In the three-dimensional environment, the paper presented a new three-dimensional localization algorithms by employing the distance vector hop ideas of DV-hop and principles of mathematical geometry and Centroid algorithm to estimate node position. Simulation results show the feasibility of the algorithm.