基于Tikhonov正则化方法的WSN空间定位算法

WSN 3D localization algorithm based on Tikhonov regularization method

位置信息是无线传感器网络(wireless sensor networks,WSN)节点监测信息的重要组成部分。基于RSSI测距的空间定位无需额外增加成本,定位功耗小,符合WSN的发展要求,但由于多径衰减等问题造成测距误差较大,导致空间定位问题的不适定性,表现为解不稳定或无解。基于Tikhonov正则化方法进行求解,在三维空间中建立了定位模型,利用偏差原理解决了最优正则化参数选择问题。室内定位实验结果表明三维空间定位正则化参数可以选取55,定位误差可以控制在2m左右,优于经典的极大似然法。

3-dimension （3D） node localization plays a critical role in wireless sensor network （WSN） applications. Received signal strength indicator （RSSI） based node localization does not need additional cost, has less power consumption and meets the development requirements of WSN. But the distance measurement error caused by multi-path attenuation leads to ill-posed problem, which manifests as unstable solution or no solution in 3D localization. In this paper, a localization algorithm based on Tikhonov regularization method is proposed for the ill-posed problem in 3D localization ; the location model and regularization parameter α are studied. Test results show that the localization pre- cision of the proposed algorithm is better than that of the maximum likelihood estimation （MLE） method, and the localization error is less than 2 meters while regularization parameter α is about 55.