Improved APIT Localization Algorithm Base On The Angle Of The Judgment In Wireless Sensor Networks

With the rapid development of information technology, people’s perception of objective things growing, wireless sensor networks (WSN) as a reflection of the objective world media pay attention to it gradually. Typically, wireless sensor network’s nodes are a large-scale random deployment, leading to many nodes not to determine then-own location, affected the performance of wireless sensor network applications. Therefore, the network nodes must determine their exact location, in order to bring into play better in all aspects of the performance of the network. Localization technology not only can be applied target tracking and positioning, but also can improve the efficiency and performance of the routing of network security. Due to the wireless sensor network’s characteristics, the traditional positioning technology is not fully applicable. Therefore, many scholars working on wireless sensor network localization, and made a number of localization algorithm for wireless sensor networks. On the basis of the existing wireless sensor network node localization algorithm over a large number of studies, research on the positioning technology made the following tasks:Firstly, this paper will be a brief introduce the development process of wireless sensor network, and wireless sensor network node localization research background and content of the subject are introduced. Analysis of the common localization systems principles and several common localization algorithms, pointed out complementary and deficiencies.Then, the paper describes on APIT range-free localization algorithm implementation process in detail. In the APIT range-free localization algorithm, the nodes in the network irregular deployment will give rise to the occurrence of two false positives, and the nodes can’t be satisfied of APIT localization algorithm condition which can be uncertain node.Finally, this paper presents the basic of angle improved APIT localization algorithm for the algorithm shortcomings existed. Modification of APIT localization algorithm analysis the original algorithm’ problem that the algorithm has two false positives, according to points in the two different conditions inside and outside the triangle, with the apex of the triangle formed by the angle between the different characteristics, present a method to improve the test point in the triangle, the nodes can be located more accurate in the network, and in particular analysis the case that the point locate near the boundary of the triangle, in order to make the algorithm has more accurate positioning accuracy, the algorithm is not discussed the node where the area is, effectively reducing the occurrence of false positives, increasing the node’s localization accuracy. In the original algorithm, due to the irregularity of the node deployment may cause some nodes in the network does not meet the conditions for the implementation of the localization algorithm, the improved algorithm analysis of such cases, for different reasons which can’t locate is divided into two categories, and how each type of positioning the case described, effectively reducing the proportion of the network nodes which can’t be locate and increase the node’s coverage, and effectively improves the precision of the nodes localization in the wireless sensor network.