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。
The electric field environment under high-voltage direct current(HVDC)transmission lines is an important design consideration.In the wireless sensor networks for electric field measurement system under the HVDC transmission lines,it is necessary to obtain the electric field distribution with multiple sensors.The accurate localisation of sensing nodes is essential to the analysis of measurement results.However,most current techniques are limited to constant measurement environment with fixed and known path-loss exponent.Here,the authors report a localisation method based on received signal strength indication with unknown path-loss exponent for the localisation of one-dimensional linear topology wireless networks in the electric field measurement system.The optimisation method is utilised to obtain the optimal pass-loss parameter without involving the previous environment parameters.Afterwards,simulations are employed to demonstrate the feasibility and the effectiveness of the proposed method by comparing with other methods.
