Abstract:

Three kinds of range-free localization algorithms including Centroid algorithm, APIT(Approximate Point In Triangulation) algorithm and AIGS(Annulus Intersection and Grid Scan) algorithm are studied. We research on the mathematical 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.

Key words: wireless sensor network(WSN), range-free localization algorithms, density of anchors, energy consumption, iterative ideology