Research And Application Of Localization Algorithms For Wireless Sensor Networks

With the development of sensor technology, Micro-Electro-Mechanism System (MEMS) and Wireless Sensor Network (WSN) comes out and develops gradually. After many years'research and development, Wireless Sensor Network has been applied in a lot of fields such as environment detecting, medical treatment guarding, traffic management, storage management and military affairs reconnaissance. As research's going deeper, localization algorithm in wireless sensor networks has become a hot issue lately.In this thesis, we give a detailed introduction to Wireless Sensor Network localization algorithms proposed by now, and analyze the actuality and shortcomings of existing work. Based on this, the paper proposes a novel localization algorithm in wireless sensor networks. The main idea of the proposed algorithm is based on a property of perpendicular bisector. The perpendicular bisector of two anchors (whose location has been already identified) divides the area into to two parts. A sensor (whose position needs to be located) is considered to be in one part if it is less-hops away from one anchor. In multi-anchors situation, algorithm uses perpendicular bisectors of different pairs of anchors to restrict the position of sensor into a polygon. Finally algorithm calculates the centroid of the polygon which is considered as the estimated position of the sensor. Moreover this paper introduces a weighted method into the proposed algorithm to further enhance its performance. The proposed method can enhance the accuracy of the localization without requiring extra hardware. The simulation results demonstrate the estimate accuracy of our algorithm is better than the well-known Wireless Sensor Network localization algorithm method.At the end of this paper, we put the theory into practice to design a smart home system, and introduce its hardware structures, layered structure in protocol and workflow. Its remote control utilizes mobile phone and website, while its inner network utilizes ZigBee. All of those make a smart home system which is easy in mounting and expanding. And it also can realized the self management of the nerwork. The system has got the high value in applying.