| Wireless sensor networks, which integrate technologies of micro-electro-mechanism, sensing, embedded computing, distributed information processing and wireless communication, lead to a new pattern of information gathering and processing. The fundamental problems of sensor networks are deployment and coverage, localization, and networking protocols. And localization, which has been focused as a basic problem, is the precondition of many applications of sensor networks, such as target identification, surveillance and tracking.The location techniques for WSN can be divided into two categories: Range-based approaches and Range-free approaches. Range-based methods have better accuracy, but require additional hardware at the sensor nodes. Range-free methods have lower accuracy and requirement of hardware. The thesis mainly focuses the investigation on the range-based algorithms for WSN. Because the number of the anchor nodes determines the difference of the localization algorithms, the algorithms are investigated in the two cases-the dense anchor nodes and the thin anchor nodes. In the situation of the dense anchor nodes, when three anchor nodes is in line ,the localization error is most and when the triangle which three anchor nodes form is equilateral triangle, the localization error is least. According to the above principle, a angular weighted localization algorithm is presented. In the situation of the thin anchor nodes, DV-distance localization algorithm improved, an improved DV-distance error correction localization algorithm is presented. Simulations show that the two algorithms can improve the localization accuracy on certain degree.A key problem of the localization with a mobile anchor node is the mobile path. The thesis discusses the problem of the mobile path in the area of WSN. The Bounding-box localization algorithm is applied to the mobile anchor node localization. At the base, an improved Bounding-box localization algorithm is presented. |
PDF Full Text Request