The Research On Localization Technology Of Wireless Sensor Network

Wireless sensor network (WSN) is a new wireless communication network system. It is integration of multi-point data acquisition, wireless transmission and information processing technology. As an emerging technology in the 21 st century, wireless sensor networks have aroused great concern. For the past few years, WSN has accessed rapid development. and has important value of research and use in many fields, just like the daily life of human beings, industry, agriculture, environment, medical treatment, national defense and so on. The localization technology of sensor nodes is one of pivotal technologies of wireless sensor networks. The localization technology of WSN has been the basis of most of uses in WSN. In most of the applications, to obtain the position of nodes is an important precondition; otherwise, there will be no meaningful of the perception data. What's more, the localization of nodes is also the premise of some technologies, such as target tracking and geographical routing, network management, topology control. Above all, it is absolutely vital to research the technology of nodes localization.The research of this paper is based on the analysis of a great deal of recent technical reports and research results on WSN. Its main work includes:The research background, practical utility and present investigatory headway of WSN at home and abroad are introduced. And the research status of localization technology for WSN is summarized based on the study of a lot of related literatures.Some related techniques of WSN and the concept and basic principles of node localization in WSN are also introduced, and some main performance evaluating criterions of localization in WSN are analyzed. At last it analyzes and compares some typical localization algoritlim.RSSI ranging model are analyzed, and several factors Interfere with the signal propagation are find by Experiments; the data for determining the model parameters is optimized, finally, it marked an experiment in the Nodes, and proved its effectiveness.DV-distance localization algorithm is analyzed. Based on the shortage of DV-distance algorithm, considering the actual situation of node hardware, and draws on the characteristics of DV-hop, an improved scheme for the typical distributed localization algorithm in wireless sensor network is proposed. At last it gives some Simulation experiment to verify its performance. Based on the characteristics of DV-Distance and centroid location algorithm, a novel hybrid localization algorithm based on DV-Distance and the twice-weighted centroid is proposed. The main principle of the hybrid scheme is using the DV-Distance localization algorithm to get the cumulative distance and the rough-estimated coordinate for calculating twice weighted factors. Twice-weighted centroid computation by weighted factors reflects that diffferent anchor nodes have respective influence degrees in the process of determining the localization coordinate.The improved model of the RSSI and the two new algorithms improve the range measurement and localization accuracy to some extent. In some application environments have a certain utility.