Department of Electrical and Electronics Engineering, Korea Maritime and Ocean University, #727 Taejong-Ro, Youngdo-Gu, Busan 49112, Korea.
Division of Electronics and Electrical Information Engineering, Korea Maritime and Ocean University, #727 Taejong-Ro, Youngdo-Gu, Busan 49112, Korea.
Sensors (Basel). 2018 Oct 10;18(10):3390. doi: 10.3390/s18103390.
Fingerprint is a typical indoor-positioning algorithm, which measures the strength of wireless signals and creates a radio map. Using this radio map, the position is estimated through comparisons with the received signal strength measured in real-time. The radio map has a direct effect on the positioning performance; therefore, it should be designed accurately and managed efficiently, according to the type of wireless signal, amount of space, and wireless-signal density. This paper proposes a real-time recursive radio map creation algorithm that combines Wi-Fi and geomagnetism. The proposed method automatically recreates the radio map using geomagnetic radio-map dual processing (GRDP), which reduces the time required to create it. It also reduces the size of the radio map by actively optimizing its dimensions using an entropy-based minimum description length principle (MDLP) method. Experimental results in an actual building show that the proposed system exhibits similar map creation time as a system using a Wi-Fi⁻based radio map. Geomagnetic radio maps exhibiting over 80% positioning accuracy were created, and the dimensions of the radio map that combined the two signals were found to be reduced by 23.81%, compared to the initially prepared radio map. The dimensions vary according to the wireless signal state, and are automatically reduced in different environments.
指纹是一种典型的室内定位算法，它通过测量无线信号的强度来创建无线电地图。使用该无线电地图，通过与实时测量的接收信号强度进行比较来估计位置。无线电地图对定位性能有直接影响；因此，应根据无线信号类型、空间大小和无线信号密度，准确地设计并有效地管理无线电地图。本文提出了一种实时递归无线电地图创建算法，该算法结合了 Wi-Fi 和地磁。所提出的方法使用地磁无线电地图双重处理（GRDP）自动重新创建无线电地图，从而减少了创建所需的时间。它还通过使用基于熵的最小描述长度原理（MDLP）方法主动优化其维度来减小无线电地图的大小。在实际建筑物中的实验结果表明，所提出的系统在地图创建时间上与使用 Wi-Fi 无线电地图的系统相似。创建了地磁无线电地图，其定位精度超过 80%，并且与最初准备的无线电地图相比，结合两种信号的无线电地图的维度减少了 23.81%。维度根据无线信号状态而变化，并在不同环境中自动减小。
