WSN中存在测距误差的无锚点分布式自定位方法

Abstract

无线传感器网络中,采用RSSI方法进行自定位时,测距误差会影响定位精度。提出了一种分布式的无锚点定位方法,在对测距误差进行正确估计的基础上,求得各节点的相对位置。首先将测距误差定义为一个目标函数,使用最速下降法来分布式地求解全局非线性优化问题,以使这个目标函数最小化,然后利用节点间的估计距离与实际测量距离的偏差值来修正节点的估计坐标。仿真实验对各种影响参数进行了评估,结果证明:在无锚节点且距离测量值存在误差的情况下,满足一定的节点连通度时,能够提高节点定位精度。

In wireless sensor networks,the existing range errors will affect the position accuracy when using RSSI method to locate the nodes' position. Based on the correct estimation of range errors,a distributed location method is proposed,to found the node's position. By using the steepest descent method,an object function of range errors is defined to solve the global nonlinear optimization problem and hence minimize this object function. Due to the estimated distance between the nodes and the deviation value of the actual measurement distance one can update the estimated coordinates of the node. With the existence of range errors and certain requirement of connetivity of nodes,the result shows that the nodes position will be distributed estimated correctly.