A Practice of BLE RSSI Measurement for Indoor Positioning

Ramiro Ramirez; Chien-Yi Huang; Che-An Liao; Po-Ting Lin; Hsin-Wei Lin; Shu-Hao Liang

doi:10.3390/s21155181

Sensors (Jul 2021)

A Practice of BLE RSSI Measurement for Indoor Positioning

Ramiro Ramirez,
Chien-Yi Huang,
Che-An Liao,
Po-Ting Lin,
Hsin-Wei Lin,
Shu-Hao Liang

Affiliations

Ramiro Ramirez: Department of Industrial Engineering and Management, National Taipei University of Technology, Taipei 106344, Taiwan
Chien-Yi Huang: Department of Industrial Engineering and Management, National Taipei University of Technology, Taipei 106344, Taiwan
Che-An Liao: Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei 106335, Taiwan
Po-Ting Lin: Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei 106335, Taiwan
Hsin-Wei Lin: Department of Mechanical Engineering, National Taiwan University of Science and Technology, Taipei 106335, Taiwan
Shu-Hao Liang: Industry 4.0 Implementation Center, National Taiwan University of Science and Technology, Taipei 106335, Taiwan

DOI: https://doi.org/10.3390/s21155181
Journal volume & issue: Vol. 21, no. 15
p. 5181

Abstract

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Bluetooth Low Energy (BLE) is one of the RF-based technologies that has been utilizing Received Signal Strength Indicators (RSSI) in indoor position location systems (IPS) for decades. Its recent signal stability and propagation distance improvement inspired us to conduct this project. Beacons and scanners used two Bluetooth specifications, BLE 5.0 and 4.2, for experimentations. The measurement paradigm consisted of three segments, RSSI–distance conversion, multi-beacon in-plane, and diverse directional measurement. The analysis methods applied to process the data for precise positioning included the Signal propagation model, Trilateration, Modification coefficient, and Kalman filter. As the experiment results showed, the positioning accuracy could reach 10 cm when the beacons and scanners were at the same horizontal plane in a less-noisy environment. Nevertheless, the positioning accuracy dropped to a meter-scale accuracy when the measurements were executed in a three-dimensional configuration and complex environment. According to the analysis results, the BLE wireless signal strength is susceptible to interference in the manufacturing environment but still workable on certain occasions. In addition, the Bluetooth 5.0 specifications seem more promising in bringing brightness to RTLS applications in the future, due to its higher signal stability and better performance in lower interference environments.

Published in Sensors

ISSN: 1424-8220 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology: Chemical technology
Website: http://www.mdpi.com/journal/sensors

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