一种改进的质心定位及误差校正算法

AN IMPROVED CENTROID LOCALIZATION AND ERROR CORRECTION ALGORITHM

在信标节点分布不均匀的情况下,为了使节点定位的误差尽可能小以及在误差校正过程更加有效和可靠,提出一种改进的质心定位算法。该算法首先确定未知节点通信范围内的信标节点,然后取部分这些信标节点作为顶点构成凸多边形,通过RSSI获取未知节点与凸多边形的各个顶点的距离,之后将质心定位的凸多边形内的所有信标节点都作为校正节点,由这些校正节点得到相对应的校正因子,通过添加权重因子综合所有的校正因子来替换未知节点的测距误差因子,对测距误差进行补偿,最后利用加权质心定位方法确定未知节点的最终位置。仿真实验表明:在信标节点分布不均匀的情况下,在100 m×100 m的监测区域内,该算法相比于其他定位算法具有更强的抗干扰能力,而且平均定位误差至少减少12%,是一种定位精度更高的算法。

In order to make the error of node location as small as possible and more effective and reliable in the error correction process,an improved centroid location algorithm is proposed in the case of nonuniform beacon distribution.The algorithm firstly determines the beacon nodes in the communication range of unknown nodes,and then takes some of these beacon nodes as vertices to form convex polygons. The distance between the unknown node and each vertex of the convex polygon is obtained through the RSSI. Then all the beacon nodes in the convex polygon of the center of mass are taken as correction nodes,and the corresponding correction factors are obtained by these correction nodes. By adding the weighting factor,all the correction factors are combined to replace the ranging error factor of the unknown node,and the error of the ranging is compensated. Finally,the final position of the unknown node is determined by the weighted centroid localization method. Simulation results show that the algorithm has stronger anti-jamming capability than other localization algorithms in the 100 m × 100 m monitoring area,and the average positioning error is reduced by at least12% when the beacon nodes are distributed unevenly,the algorithm is a more accurate location algorithm.