Research And Implementation On The Localization Algorithms Of Wireless Sensor Networks

With the development of mobile communications and wireless networking technology, people have increasingly high demand for automation equipment. Currently, wireless sensor network technology draws more and more people’s attention, and it has been used in many fields,such as aerospace, military, medical, disaster rescue and medical area. Positioning technology plays a very important role in wireless sensor networks. In most cases, a wireless sensor node without location information is of no value useless. Currently, positioning technology is divided into the localization algorithm based on ranging and localization algorithm based on non-ranging. The localization algorithm based on ranging first get relevant information, such as the distance between nodes, the signal reaches the angle or temporal difference. Afterward it uses mathematical models to calculate location information. Localization algorithm based on non-ranging estimate targeted nodes location with the information whether node and beacon link together in wireless sensor networks and the hop number between them.Firstly, the paper introduces the basic principles of the localization algorithms based on ranging and non-ranging. On the basis of these, we investigated common two-dimensional and three-dimensional localization algorithm for wireless sensor networks. On two-dimensional localization algorithm, we introduce the trilateral localization algorithm, Bounding-Box positioning algorithm, maximum likelihood estimation algorithm, centroid localization algorithm and perform experiments verify that the Bounding-Box positioning algorithm has higher accuracy and better stability in a laboratory environment. On three-dimensional localization algorithm, we introduce IRSSI-3D localization algorithm, Landscape-3D algorithms and Ou positioning algorithm, then analyze the advantages and disadvantages of improved Bounding-Box-3D algorithm.The wireless signal suffers path loss while spreading in the medium, which affect the accuracy of positioning. In order to improve the accuracy of positioning, environmental adaptive wireless sensor positioning technology are developed to compensate for signal losses under different circumstances. Finally, this paper build Positioning Systems Laboratory test environment and finished the analysis and comparison of common localization algorithm based on the received signal strength indication, verifying that the proposed energy adaptive positioning algorithm is effective in the laboratory environment.