一种用于无线传感器网络三维定位的迭代估计方法

3D Node Localization Algorithm Based on Iterative Computation for Wireless Sensor Network

现有无线传感器网络三维定位算法大部分借鉴并基于相对成熟并且算法性能较好的二维定位算法原理,将其扩展至三维空间以实现节点定位,相比二维定位算法具有更好的定位精度。基于质心迭代估计的无线传感器网络二维定位算法通过对连通锚节点所围成平面的质心进行迭代计算,缩小了未知节点所在二维平面的范围,提高了节点的定位精度。基于此二维定位方法的原理,提出了一种用于无线传感器网络三维定位的迭代估计方法。首先,该算法计算当前连通锚节点所张成三维空间的质心坐标及其与未知节点间的接收信号强度;其次,以该质心节点为虚拟锚节点替代距离未知节点最远的连通锚节点,为未知节点自身的定位提供帮助。由于节点定位精度随着未知节点所处三维空间范围的缩小而不断提高,因此通过多次迭代后可以获得理想的定位精度。在3.50GHz电脑平台上模拟实际无线传感器网络环境,利用交互式数据语言对所提算法进行仿真,以验证算法的性能。仿真结果表明,所提算法与基于质心迭代估计的无线传感器网络二维定位算法相比,其定位精度可提高3%~6%;与三维质心定位算法相比,其定位精度可提高5%~23%。同时,所提算法具有较好的抗RSSI测量误差的能力,并通过多次迭代定位使得节点定位覆盖率可以达到99%以上,是一种适用于无线传感器网络三维定位的有效方法。

The existing three-dimension localization algorithm for wireless sensor networks(WSN)is mostly based on the principle of two-dimension localization algorithm with mature and good performance.Compared with the two-dimensional localization algorithm,most of the three-dimension localization algorithms have better localization accuracy.Two-dimensional localization algorithm for wireless sensor networks based on centroid iteration estimation reduces the range of two-dimensional plane of unknown nodes and improves the positioning accuracy of nodes by iterating the centroid of the plane surrounded by connected anchor nodes.Based on the theory of the two-dimension centroid localization algorithm,this paper proposed a novel approach of three-dimensional node localization algorithm based on iterative computation.First,the centroid coordinates of the three-dimensional space enclosed by the current connected anchor nodes as well as the received signal strength(RSSI)between the unknown node and the centroid node are calculated.Then,the current connected anchor node with the weakest RSSI is replaced with the centroid node in order to reduce the three-dimensional space enclosed by the connected anchor nodes.The location accuracy can be improved through multi-itera-tions with an appropriate threshold.Simulation results are obtained with interactive data language(IDL)on a PC of 3.50 GHz.Judging from the simulation results,there is an improvement of 3%to 6%in location accuracy compared with the two-dimension localization algorithm,and an improvement of 5%to 23%in location accuracy compared with the 3D centroid localization algorithm.What’s more,the proposed algorithm performs well for RSSI error disturbance and can reach more than 99%of localization coverage after multi-iterations.