Irregular Surface Under The Environment Of Wireless Sensor Network Node Localization Algorithm Research

With good prospects for development and a broad market demand, wireless sensor network is one of the key technologies of21st century what can bring tremendous value. As a main support technology of the wireless sensor network, node localization has been a challenging and valuable research focus. Most of mature wireless sensor network node localization algorithms are based on two-dimensional environment, but many practical applications are based on three-dimensional surface, such as mountains, hills and so on. Compared to random distribution on three-dimensional space, we call distribution on surface of space as pseudo three-dimensional distribution. Because of the introduction of the unknown quantity of high, many problems generate, such as ranging-error larger, unknown location information increased. The problems result in poor stability of equation-solving, low positioning-accuracy and serious error accumulation. Therefore, the study of positioning scheme based on pseudo three-dimensional is the research priority of the future.This thesis studies the localization algorithm from the angle of the pseudo three-dimensional and the mobile anchor node. It proposes a range-based algorithm based on electronic map and a range-free algorithm based on mobile anchor nodes, the main content of this thesis are summarized as follows:1) Directing at the binding relationship between the anchor node density and network traffic of wireless sensor network positioning, this thesis introduces mobile anchor node instead of the static anchor node to assist node localization. It designs a triangle-based path planning program, and uses the program to achieve a range-based and rang-free three-dimensional positioning algorithm.2) In the range-based positioning algorithm, the aircraft equipping with mobile anchor node flies at the same altitude. The use of the same height difference between unknown node and anchor nodes can simplify the unknown quantity of localization equations, reducing the computational complexity. Based on the program, this paper designs an anchor node selection strategy to ensure that the three anchor nodes form an equilateral triangle to improve positioning accuracy.3) Three-dimensional global localization for wireless sensor network can’t simply using ranging and direction-finding, topological relation measurement to achieve precise positioning in complex environments. Thus, this paper introduces accurate electronic map information into wireless sensor network positioning technology can simply dimension and reduce the node positioning error. Simulation results show that the location scheme based on topographic information has the advantages of high positioning accuracy and low computational complexity.4) In-depth analysis of three-dimensional localization scheme for wireless sensor network based on sphere intersections. Aim at the existing problems for approximate point in sphere (APIS) arithmetic, this paper adopt mobile anchor node and path-loss model to improve. In order to reduce the positioning error and improve the positioning speed, a limited area search strategy is proposed. The simulation results show that the algorithm has better performance and fast positioning.