Du Yuanfeng, Yang Dongkai, Xiu Chundi
School of Electronic and Information Engineering, Beihang University, Beijing 100191, China.
Sensors (Basel). 2015 Apr 10;15(4):8358-81. doi: 10.3390/s150408358.
With the rapid development of WIFI technology, WIFI-based indoor positioning technology has been widely studied for location-based services. To solve the problems related to the signal strength database adopted in the widely used fingerprint positioning technology, we first introduce a new system framework in this paper, which includes a modified AP firmware and some cheap self-made WIFI sensor anchors. The periodically scanned reports regarding the neighboring APs and sensor anchors are sent to the positioning server and serve as the calibration points. Besides the calculation of correlations between the target points and the neighboring calibration points, we take full advantage of the important but easily overlooked feature that the signal attenuation model varies in different regions in the regression algorithm to get more accurate results. Thus, a novel method called RSSI Geography Weighted Regression (RGWR) is proposed to solve the fingerprint database construction problem. The average error of all the calibration points' self-localization results will help to make the final decision of whether the database is the latest or has to be updated automatically. The effects of anchors on system performance are further researched to conclude that the anchors should be deployed at the locations that stand for the features of RSSI distributions. The proposed system is convenient for the establishment of practical positioning system and extensive experiments have been performed to validate that the proposed method is robust and manpower efficient.
随着WIFI技术的飞速发展,基于WIFI的室内定位技术已被广泛研究用于基于位置的服务。为了解决广泛使用的指纹定位技术中所采用的信号强度数据库相关问题,本文首先介绍一种新的系统框架,它包括一个改进的接入点(AP)固件和一些廉价的自制WIFI传感器锚点。有关相邻接入点和传感器锚点的定期扫描报告被发送到定位服务器并用作校准点。除了计算目标点与相邻校准点之间的相关性外,我们还充分利用了回归算法中信号衰减模型在不同区域会有所变化这一重要但容易被忽视的特征,以获得更准确的结果。因此,提出了一种名为RSSI地理加权回归(RGWR)的新方法来解决指纹数据库构建问题。所有校准点自身定位结果的平均误差将有助于最终决定数据库是否是最新的,或者是否必须自动更新。进一步研究了锚点对系统性能的影响,得出应将锚点部署在代表RSSI分布特征的位置的结论。所提出的系统便于建立实际的定位系统,并且已经进行了大量实验来验证所提出的方法是稳健且人力高效的。