无线传感器网络中的节点自适应周期定位

摘要

Nodes self-localization algorithm is an important part of a wireless sensor network system.It is also the basis on which all the applications of such a system can be implemented.A self-adaptive periodic localization algorithm based on least square estimation uses a periodic localization mechanism to control node locations in a network.Range acquisition tech nique based on the strength of received signals is used to acquire the distance between nodes.Localization period is activat ed till localization is finished.For unknown nodes, the primitive location is acquired through the maximum likelihood estima tion, while the final location is determined by least square estimation.Emulational tests show that such an algorithm can sig nificantly improve the localization rates of unknown nodes in a network,thus effectively inhibiting the spread of range acqui sition errors.Accuracy of nodes localization also increases in the process.%无线传感器网络节点自定位算法是无线传感器网络系统的重要组成部分,是无线传感器网络中所有应用得以实现的基础.基于最小二乘估计的自适应周期定位算法采用周期定位机制控制网络中节点定位,使用基于接收信号强度指示的测距技术获取节点间距离,启动定位周期,直至定位周期终止,完成定位.未知节点采用极大似然估计得到初解,使用最小二乘估计获得自身位置坐标的最终解.仿真实验表明,基于最小二乘估计的自适应用期定位算法能显著提高网络中未知节点的定位率,有效抑制测距误差的传播,提高了节点定位精度.