基于RSSI技术提高直流线路电场测量无线网络节点定位精度的算法

An RSSI-Based Location Algorithm to Improve Location Accuracy of Wireless Electric Field Measurement Nodes Under DC Transmission Line

在基于无线传感器网络的直流线路合成电场测量系统中,传感器节点位置的自动获取可以有效地减少测量工作量,提高测试效率。传统的接收信号强度(received signal strength indicator,RSSI)定位方法利用经验值选取路径衰减指数,易导致定位误差较大。为提高传感器节点的定位精度,提出一种实时估计路径衰减指数的定位方法。该方法利用参考节点间距离和未知节点收到的RSSI值来实时估计路径衰减指数,并利用它来估算距离,从而减小定位误差,提高算法对不同环境的适应性。实验结果表明,在公园草坪、学校操场以及特高压直流试验基地直流试验线段电磁环境测试场3种典型的电场测量环境下,该算法的定位精度均较其他RSSI算法高。

In wireless sensor network （WSN） based total electric field measurement system under DC transmission line,automatic acquisition of sensor node position can reduce the workload of measurement effectively and improve the test efficiency.In traditional location method by received signal strength indicator （RSSI） the path loss exponent is selected by empirical values and it is easy to cause larger location error.To improve the location accuracy of sensor nodes,a new location method,in which the real-time estimation of the path loss exponent is adopted,is proposed.In the proposed method,the distances among reference nodes and the RSSI value received by unknown node are used to perform the real-time estimation of the path loss exponent and is used to estimate the distance,thus the location error can be reduced and the adaptability to different kinds of environments can be enhanced.Experimental results show that under three typical electric field measurement environments,namely the park lawn,the school playground and the electromagnetic environment test field under test line in UHVDC test base,the location accuracy by the proposed method is higher than those by other RSSI algorithms.