基于RSSI的无线传感器网络节点定位

摘要

研究基于Zigbee技术的无线传感器网络中未知节点的定位问题.针对传统的Two-phase positioning循环求精定位算法复杂,且在RSSI节点测距阶段存在某些点的测距误差较大,导致定位精度大大下降.为了解决测距误差大的节点对定位精度的影响,提高定位精度,首先采用RSSI测距法测出未知节点和锚节点距离,用最小二乘法粗略定位,其次通过距离关系算出每个粗略定位点的权值,引入权值阀,舍去在权值阀外的点,最后在求精阶段采用三角形加权重心算法.此方法可以最大限度的减少测量误差大的节点对定位精度的影响.经实验证明,改进算法也存在一定的误差,但比传统的算法更加精确,提高了定位精度.%Study unknown nodes location in wireless sensor network which is the bass of Zigbee technology. To solve the problem that the traditional two-phase positioning algorithm is complexed, and some distance measurement error exists during RSSI stage, resulting in positioning accuracy dramatically reduced, the paper firstly used RSSI ranging method to measure distance between unknown nodes and anchor nodes, and also least square was used in the rough location stage. Then the weight of each rough location node was worked out by distance relationship, the valve of node weight was introduced, and the node was discarded, whose value of weight was outside the minimum weight. Finally, the weighted triangle center of gravity algorithm was used in the refinement stage. This method minimizes the influence brought by the nodes with large measurement error. Simulation results show that the errors exist by using this algorithm, but it is more accurate than traditional algorithm, and location precision can be improved.