WSN基于节点位置相对关系定位的数学属性研究

Research on Mathematical Properties of Localization Algorithm Based on Sensor Relative Position in WSN

为解决无线传感器网络基于位置相对关系进行定位算法中,定位精度过度依赖信标节点密度问题,通过3种非测距定位算法、质心算法、APIT(Approximate Point in Triangulation)算法及AIGS(Annulus Intersection and Grid Scan)算法的原理研究,给出了信标节点密度与定位精度和能耗之间的数学关系,并提出基于迭代的改进算法。3种算法定位精度正比于信标节点密度,算法能耗正比于信标节点密度,在同一个监测区域,信标节点比例相同情况下,AIGS算法定位精度最高,质心算法定位精度最低。当信标节点稀疏时,将部分未知节点通过质心算法转化为信标节点迭代算法,在较低信标节点比例条件下提升3种算法定位精度。

Three kinds Point In Triangulation） research on the math of range-free localization algorithms including Centroid algorithm, APIT （Approximate algorithm and AIGS （Annulus Intersection and Grid Scan） algorithm are studied. We ematical relationship between density of anchors, location precision, and energy consumption. Research shows that the three algorithms can all get more accurate location when enhance the density of anchors. However, all of those cause more energy consumption. In the monitoring area with the same proportion of anchors, comparing about positioning accuracy, AIGS algorithm is better than APIT algorithm, but APIT algorithm is better than Centroid algorithm. When density of anchors is low, we propose an iterative scheme which transforms unknown nodes after localization to beacon nodes. The new scheme can increase localization accuracy of WSN （Wireless Sensor Network） with low density of anchors.