中文摘要：

针对现有无线传感器网络中RSSI定位算法易受外部环境影响、定位精度低的问题,提出一种基于RSSI的改进加权质心定位修正算法.该算法先根据RSSI测距值,利用极大似然法对未知节点位置进行初步估计,根据估计坐标值计算未知节点与RSSI信标节点间的近似距离,剔除误差较大的测量组,然后根据＂能与未知节点通信的三个信标节点构成的三角形三边相等时定位误差最小＂这一理论,得出权值公式,利用加权质心定位算法,结合TDOA信标节点计算未知节点的坐标并修正.仿真结果表明,该算法较传统的RSSI定位算法可有效减小定位误差,提高定位精度.

英文摘要：

Aiming at problem that the RSSI localization algorithm is vulnerable to the environment and it has low localization precision in wireless sensor networks,this paper proposed an improved weighted centroid localization correction algorithm based on RSSI.The algorithm estimated roughly the coordinate of unknown node by using RSSI values through maximum likelihood estimation,then it used the coordinate to calculate the approximate distance between the unknown node and the beacon nodes.The algorithm removed the measurement group whose error were large and it got the weighted formula by the theory that the positioning had the least error when the triangle was trilaterally equal and consisted of three beacon nodes which can communicated with the unknown nodes.The algorithm calculated and corrected the coordinate of unknown node with the help of TDOA beacon nodes through weighted centroid localization algorithm.The simulation shows that the algorithm can effectively reduce positioning errors compared with traditional RSSI localization algorithm and it can also improve localization accuracy.