无线传感器网络环境自适应定位算法研究

Research on Environment Self-adaptive Localization Algorithm for Wireless Sensor Networks

节点自身定位是无线传感器网络应用的关键技术之一;针对基于接收信号强度指示(RSSI)的加权质心定位算法,研究了实际环境中节点的接收信号强度指示(RSSI)特性,考虑到RSSI测距模型中信号衰减因子等参数对测距精度的影响,根据信标节点间距离和接收信号功率的关系利用最小二乘法在线拟合环境测距参数,从而获得适用的信号衰减模型进行测距,将估算的距离转换为权值,再结合质心算法实现定位;MATLAB仿真结果显示,文中算法比加权质心算法具有更好的环境自适应性和鲁棒性。

Localization is one of the supporting technologies in wireless sensor networks,and accuracy is a significant criterion to evaluate the practical utility of localization algorithm.The characteristic of received signal strength indicator（RSSI） is studied in this paper.Considering the effect of environment parameters like path loss exponent to measurement accuracy in received signal strength indicator（RSSI）,according to the relationship between the distance and received signal power among beacon nodes,least squares method（LSM） is introduced to acquire current environment parameters and estimated distance is converted to an appropriate weight,then the location information of nodes can be calculated out by weighted Centroid localization algorithm（WCLA）.Simulation results in MATLAB show that our algorithm（SWCLA） has good self-adaptability and robustness to the uncertain environment.