Sensor Network Positioning Technology

In recent years, the localization technology of the Wireless Sensor Networks (WSN) has received the domestic and foreign researchers's enormous attention. Today, most of the localization algorithms are tested by simulation, after quantifying the network environment, we use the simulated tools to analyze and design the algorithms. However, the simulation can't cover all the possible conditions, so all the algorithms that are proposed in this paper are tested in the real hardware environment, and can be evaluated in a more effective way.First, we design the communication protocols related with sensor localization to prolong the deadline of the networks, and we propose the weighted centroid localization algorithm. We use weighted coefficients which are decided by the influence of different beacons to unknown nodes, to prompt localization accuracy. The advantage of weighted centroid localization algorithm is simple and less communication is needed while they are locating. Second,we propose two kinds of localization algorithms that are based on hop: DHE and EBDL.DHE only use the connectivity and distance vector information to locate the unknown nodes; EBDL need less calculate steps and energy wastage, and it is a kind of distributing localization algorithm. Third, we propose the sensor localization algorithms that are based on cluster,topology .We called them CBSL and TBSL. CBSL can restrain the transmission error and cumulating error, so to improve the precision; To some node that can't obtain its position on account of unreasonable distributing, TBSL can identify and localize them, so it can improve the cover rate of the nodes in wireless sensor networks. Last, in the real hardware platform, we realize a prototype localization system to evaluate and analyze the performance of the algorithms.