基于临近信标节点修正的APIT算法改进

Improved APIT algorithm based on adjacent beacon node

定位技术在无线传感器网络中占有重要的地位。近似三角形内点测试算法(APIT)是一种硬件要求低,定位性能良好的定位算法。APIT算法在节点密度较低的场合,易产生PIT误判,S-APIT算法采用面积和判断进行近似三角形内点测试,改善了APIT算法的PIT测试,但是在存在测距误差时,S-APIT算法并不能有效的减少PIT误判的发生。针对该问题,提出了一种将未知节点的临近信标节点作为修正节点的N-APIT算法,仿真结果表明:算法能够改善环境因素的影响,减少测距误差,改善定位精度。

Positioning technology occupies an important position in the wireless sensor network. Approximate Point-InTriangulation（APIT） is a kind of algorithm that has low hardware requirements and good positioning performance. APIT algorithm is prone to PIT misjudgment when the node density is low. SAPIT algorithm uses summation of areas to do the PointIn-Triangulation test, and improves the PIT test of APIT. But when there is a ranging error, S-APIT algorithm cannot reduce PIT misjudgment effectively. A new kind of N-APIT algorithm that used adjacent beacon node as fixed beacon node is proposed, which can be dealt with the problem of S-APIT＇s easily affected by the ranging error caused by PIT＇s misjudgment.The simulation results show that the new algorithm can decrease the influence of ranging error, and improve the positioning accuracy that influenced by the environment factors.