An INS/WiFi Indoor Localization System Based on the Weighted Least Squares

For smartphone indoor localization, an INS/WiFi hybrid localization system is proposed in this paper. Acceleration and angular velocity are used to estimate step lengths and headings. The problem with INS is that positioning errors grow with time. Using radio signal strength as a fingerprint is a wi...

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Main Authors: Jian Chen, Gang Ou, Ao Peng, Lingxiang Zheng, Jianghong Shi
Format: Article
Language:English
Published: MDPI AG 2018-05-01
Series:Sensors
Subjects:
Online Access:http://www.mdpi.com/1424-8220/18/5/1458
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author Jian Chen
Gang Ou
Ao Peng
Lingxiang Zheng
Jianghong Shi
author_facet Jian Chen
Gang Ou
Ao Peng
Lingxiang Zheng
Jianghong Shi
author_sort Jian Chen
collection DOAJ
description For smartphone indoor localization, an INS/WiFi hybrid localization system is proposed in this paper. Acceleration and angular velocity are used to estimate step lengths and headings. The problem with INS is that positioning errors grow with time. Using radio signal strength as a fingerprint is a widely used technology. The main problem with fingerprint matching is mismatching due to noise. Taking into account the different shortcomings and advantages, inertial sensors and WiFi from smartphones are integrated into indoor positioning. For a hybrid localization system, pre-processing techniques are used to enhance the WiFi signal quality. An inertial navigation system limits the range of WiFi matching. A Multi-dimensional Dynamic Time Warping (MDTW) is proposed to calculate the distance between the measured signals and the fingerprint in the database. A MDTW-based weighted least squares (WLS) is proposed for fusing multiple fingerprint localization results to improve positioning accuracy and robustness. Using four modes (calling, dangling, handheld and pocket), we carried out walking experiments in a corridor, a study room and a library stack room. Experimental results show that average localization accuracy for the hybrid system is about 2.03 m.
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spelling doaj.art-3d43b2388a384150bf81643b3ad5f7ff2022-12-22T04:08:58ZengMDPI AGSensors1424-82202018-05-01185145810.3390/s18051458s18051458An INS/WiFi Indoor Localization System Based on the Weighted Least SquaresJian Chen0Gang Ou1Ao Peng2Lingxiang Zheng3Jianghong Shi4School of Information Science and Engineering, Xiamen University, Xiamen 361001, ChinaSchool of Information Science and Engineering, Xiamen University, Xiamen 361001, ChinaSchool of Information Science and Engineering, Xiamen University, Xiamen 361001, ChinaSchool of Information Science and Engineering, Xiamen University, Xiamen 361001, ChinaSchool of Information Science and Engineering, Xiamen University, Xiamen 361001, ChinaFor smartphone indoor localization, an INS/WiFi hybrid localization system is proposed in this paper. Acceleration and angular velocity are used to estimate step lengths and headings. The problem with INS is that positioning errors grow with time. Using radio signal strength as a fingerprint is a widely used technology. The main problem with fingerprint matching is mismatching due to noise. Taking into account the different shortcomings and advantages, inertial sensors and WiFi from smartphones are integrated into indoor positioning. For a hybrid localization system, pre-processing techniques are used to enhance the WiFi signal quality. An inertial navigation system limits the range of WiFi matching. A Multi-dimensional Dynamic Time Warping (MDTW) is proposed to calculate the distance between the measured signals and the fingerprint in the database. A MDTW-based weighted least squares (WLS) is proposed for fusing multiple fingerprint localization results to improve positioning accuracy and robustness. Using four modes (calling, dangling, handheld and pocket), we carried out walking experiments in a corridor, a study room and a library stack room. Experimental results show that average localization accuracy for the hybrid system is about 2.03 m.http://www.mdpi.com/1424-8220/18/5/1458INSWiFi fingerprintpre-processing techniquesMDTWWLS
spellingShingle Jian Chen
Gang Ou
Ao Peng
Lingxiang Zheng
Jianghong Shi
An INS/WiFi Indoor Localization System Based on the Weighted Least Squares
Sensors
INS
WiFi fingerprint
pre-processing techniques
MDTW
WLS
title An INS/WiFi Indoor Localization System Based on the Weighted Least Squares
title_full An INS/WiFi Indoor Localization System Based on the Weighted Least Squares
title_fullStr An INS/WiFi Indoor Localization System Based on the Weighted Least Squares
title_full_unstemmed An INS/WiFi Indoor Localization System Based on the Weighted Least Squares
title_short An INS/WiFi Indoor Localization System Based on the Weighted Least Squares
title_sort ins wifi indoor localization system based on the weighted least squares
topic INS
WiFi fingerprint
pre-processing techniques
MDTW
WLS
url http://www.mdpi.com/1424-8220/18/5/1458
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