Distance measurements in UWB-radio localization systems corrected with a feedforward neural network model

Krapež, Peter (author), Vidmar, Matjaž (author), Munih, Marko (author)

An ultra-wideband (UWB) localization system is an alternative in a GPS-denied environment. However, a distance measurement with UWB modules using a two-way communication protocol induces an orientation-dependent error. Previous research studied this error by looking at parameters such as the received power and the channel response signal. In this paper, the neural network (NN) method for correcting the orientation-induced distance error without the need to calculate the signal strength, obtain the channel response or know any parameters of the antenna and the UWB modules is presented. The NN method utilizes only the measured distance and the tag orientation, and implements an NN model obtained by machine learning, using measurements at different distances and orientations of the two UWB modules. The verification of the experimental setup with 12 anchors and a tag shows that with the proposed NN method, 5 cm better root mean square error values (RMSEs) are obtained for the measured distance between the anchors and the tag compared to the calibration method that did not include orientation information. With the least-square estimator, 14 cm RMSE in 3D is obtained with the NN model corrected distances, with a 9 cm improvement compared to when raw distances are used. The method produces better results without the need to obtain the UWB module’s diagnostics parameters that are required to calculate the received signal strength or channel response, and in this way maintain the minimum packet size for the ranging protocol.

• Language: English
• Keywords: ultra-wideband technology, real-time localization system, distance measurement, error mitigation, tag orientation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 18 str.
• Numbering: Vol. 21, iss. 7, art. 2294
• PID: 20.500.12556/RUL-135211
• UDC: 621.39:004
• ISSN on article: 1424-8220
• DOI: 10.3390/s21072294
• COBISS.SI-ID: 57251843
• Publication date in RUL: 01.03.2022

Record is a part of a journal

• Title: Sensors
• Shortened title: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• COBISS.SI-ID: 10176278

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 01.04.2021

Secondary language

• Language: Slovenian
• Keywords: širokopasovni radio, sistemi za lokalizacijo v realnem času, meritve razdalj, zmanjševanje napake, orientacija uporabnika

Projects

• Funder: ARRS - Slovenian Research Agency
• Project number: P2-0228
• Name: Analiza in sinteza gibanja pri človeku in stroju