一种改进的无线传感器网络节点室内定位方法

An Improved Algorithm of Node Localization for Indoor Environment in Wireless Sensor Network

无线传感器网络节点室内定位准确性问题一直是研究热点。由于室内环境复杂、固定遮挡物以及走动人员均会造成信号衰减,若使用传统的RSSI定位算法其误差太大无法满足实际应用的需求。在不增加硬件开销的基础上,提出一种可以提高定位精度的改进定位算法。该算法首先通过离未知节点最近的三个锚节点划分三角形子区域,再根据RSSI值估算出该区域内路径损耗模型的参数A、n,并进一步通过锚节点的相互协作,得到测距误差模型参数k、Δ,最终计算出精确的位置信息。仿真结果显示:在相同的条件下,改进后的算法具有更高的定位精度,误差在1m以内,可以满足室内定位的要求。

Accuracy of indoor localization about wireless sensor network node has been wildly discussed. The error of traditional RSSI location algorithm is too large to meet the needs of their practical application. The complexity of indoor environment, fixed obstructions and movement of people will cause signal attenuation. So we propose an algorithm to improve the accuracy of localization without increasing the hardware cost. Firstly, we divide triangular sub-region through the last three nodes, and then estimate the path loss model parameters A and n in the region according to the RSSI value, further more obtain the ranging error model parameters k, A through cooperation of the anchor nodes, finally get the precise location by calculation. Simulation results indicate that the improved algorithm gives a higher accuracy than the original one with the same conditions. The error is less than 1 meter, so it can meet the reauirements of indoor localization.