无线传感器网络定位技术的研究

Research on Localization Technology of Wireless Sensor Networks

提出了一种新的接收信号强度指示(RSSI)定位修正算法。该算法采用改进的退火算法对极大似然估计处理后的距离进行优化,有效解决在实际环境中遇到的一些问题,使算法更符合实际。同时,能有效降低运算的复杂度,并排除具有特征相似性的一些奇异点,提高精度。依据邻近节点间的距离,分析前后两组估计坐标间的关系,用目标函数判断两组解的优劣,由退火思想只接受比前一组优的新解进行迭代循环,可以得到一组移动点的估计坐标。将满足条件的移动点看做参考点,重复运算,直至没有移动点可以升为参考点为止,输出最终结果。实验结果表明,改进的算法有效可行,且定位精度和稳定性有明显的提高,是一种可行的节点定位方案。

The research of the current wireless location algorithms generally has exist the problems of low positioning accuracy and high computational complexity. A new RSSI location algorithm is proposed in this paper. The improved annealing algorithm is used to optimize the distance of the maximum likelihood estimation. It can effectively solve some of the problems encountered in the actual environment and make the algorithm more practical. At the same time,it can effectively reduce the complexity of computing. It rules out some singular points with characteristic similarity,which can improveso that the accuracy is improved. Based on the distance between adjacent nodes,the relationship between the two sets of estimated coordinates is analyzed. They can judge the advantages and disadvantages of the two sets of solutions with the objective function. By Because the annealing algorithm only accepts a previous group optimizational point to implement iteration,it can get the estimated coordinates of a set of mobile points,and can find the mobile point which meets the conditions as a reference point. Then the operation is repeated until no moving point can be raised as a reference point,and the final result is outputted. The experimental results show that the improved algorithm is effective and feasible. The positioning accuracy and stability are obviously improved. It is a feasible node localization scheme.