Research On The High Accuracy Localization Algorithm For Three-dimensional WSN

Wireless sensor networks(WSNs), which consists of a large number of simple sensor nodes, is a self-organized wireless network. It can be widely applied in environment monitoring, disaster relief, target tracking, medical care, and so on. In these applications, it is important for the sensor nodes to acquire their own locations, because sensed data is always meaningless without relating to its physical position. Therefore, localization has become an important subject in WSNs and is a key for WSNs applications.A brief introduction of WSN is given to describe the structure of WSN. Then the localization algorithm is discussed particularly. Localization algorithms can be divided into two types:range-based schemes and range-free schemes. The most representative range-based schemes and range-free schemes, such as TOA algorithm, AOA algorithm, DV Hop, APIT, are discussed in this paper. Advantages and disadvantages of these schemes are analyzed. But these schemes are based on two-dimensional (2D) plane. However, sensor networks may often be deployed over complex 3D space in real applications. As a result, high accuracy localization schemes become a key subject for 3D WSNs.Iterative calculation of secondary grid division localization scheme (ICSGDLS) divides the located cube in 3D space grid division scheme, and calculated the position of the node. First, ICSGDLS divides the 3D space into many cubes, and all anchors vote for every cube. The cube with most votes is the most possible cube, in which the node consists. Then the cube is divided again, and anchors vote for every smaller cube again. The centroid of the smaller cube with most votes is assumed the estimated position of the node. ICSGDLS increases the localization accuracy greatly, and decreases the calculation amount of sensor nodes.Finally, a simulation model is created based on MATLAB, and impact of different factors is analyzed. Simulation indicates that the accuracy of ICSGDLS increased by 67.7%, and localization time decreased by 42.3% than grid division scheme.