Research And Realization Of Localization System Based On RFID

Along with the research and development of wireless sensor network, node localization, which is one of the most important technologies in wireless sensor network, is defined as a significant topic by more and more experts and scholars. For many applications of WSN (wireless sensor network), if we have no idea about the location information of sensor nodes, there will be no meaning to get data with sensors. So in relevant systems, only when we make sure the exact location information of sensor nodes, can we retrieve the target location, so as to locate and track the external target. This paper concerns the research and improvements of the existing localization algorithm, and proposes an implementation of the localization system based on radio frequency identification technology.This system realizes the functionality of monitoring on entities in some areas, such as real-time localization, running track view, system user management, log management, history records management and so on. It can satisfy most small or middle size localization system and it is easy to expand and merge new functionalities. This paper mainly does the following task:Firstly, we research the status of the WSN localization technology at home and abroad, state the theory of the WSN localization technology and analyze localization algorithm which is widely used.Secondly, centroid localization algorithm is simple in principle, and be used widely, but its accuracy of localization is low, this paper improves and optimizes the algorithm using two kinds methods. The one, if the distance from anchor node to unknown node is different, the influence to localization’s accuracy is different.so we improve it by weighting to anchor nodes and error correction. The other, the optimization method based on genetic algorithm obtains the optimized iterative formulate of genetic algorithm by converting the practical problems to mathematical problems and establishing models, and the accuracy is improved.Thirdly, we design the system architecture, database and function module, and finally, realize all the functionalities of localization system. we carry the function test to all the modules, especially to the real-time localization module, the result comes to the expected range and the accuracy is improved obviously.