Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms

The aim of this study was to develop a physical activity advisory system supporting the correct implementation of sport exercises using inertial sensors and machine learning algorithms. Specifically, three mobile sensors (tags), six stationary anchors and a system-controlling server (gateway) were e...

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Main Authors: Justyna Patalas-Maliszewska, Iwona Pajak, Pascal Krutz, Grzegorz Pajak, Matthias Rehm, Holger Schlegel, Martin Dix
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/23/3/1137
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author Justyna Patalas-Maliszewska
Iwona Pajak
Pascal Krutz
Grzegorz Pajak
Matthias Rehm
Holger Schlegel
Martin Dix
author_facet Justyna Patalas-Maliszewska
Iwona Pajak
Pascal Krutz
Grzegorz Pajak
Matthias Rehm
Holger Schlegel
Martin Dix
author_sort Justyna Patalas-Maliszewska
collection DOAJ
description The aim of this study was to develop a physical activity advisory system supporting the correct implementation of sport exercises using inertial sensors and machine learning algorithms. Specifically, three mobile sensors (tags), six stationary anchors and a system-controlling server (gateway) were employed for 15 scenarios of the series of subsequent activities, namely squats, pull-ups and dips. The proposed solution consists of two modules: an activity recognition module (ARM) and a repetition-counting module (RCM). The former is responsible for extracting the series of subsequent activities (so-called scenario), and the latter determines the number of repetitions of a given activity in a single series. Data used in this study contained 488 three defined sport activity occurrences. Data processing was conducted to enhance performance, including an overlapping and non-overlapping window, raw and normalized data, a convolutional neural network (CNN) with an additional post-processing block (PPB) and repetition counting. The developed system achieved satisfactory accuracy: CNN + PPB: non-overlapping window and raw data, 0.88; non-overlapping window and normalized data, 0.78; overlapping window and raw data, 0.92; overlapping window and normalized data, 0.87. For repetition counting, the achieved accuracies were 0.93 and 0.97 within an error of ±1 and ±2 repetitions, respectively. The archived results indicate that the proposed system could be a helpful tool to support the correct implementation of sport exercises and could be successfully implemented in further work in the form of web application detecting the user’s sport activity.
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spelling doaj.art-f8011e45bdf341d2a1c877f4ab39067e2023-11-16T17:56:43ZengMDPI AGSensors1424-82202023-01-01233113710.3390/s23031137Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning AlgorithmsJustyna Patalas-Maliszewska0Iwona Pajak1Pascal Krutz2Grzegorz Pajak3Matthias Rehm4Holger Schlegel5Martin Dix6Institute of Mechanical Engineering, University of Zielona Góra, 65-417 Zielona Gora, PolandInstitute of Mechanical Engineering, University of Zielona Góra, 65-417 Zielona Gora, PolandInstitute for Machine Tools and Production Processes, Chemnitz University of Technology, 09126 Chemnitz, GermanyInstitute of Mechanical Engineering, University of Zielona Góra, 65-417 Zielona Gora, PolandInstitute for Machine Tools and Production Processes, Chemnitz University of Technology, 09126 Chemnitz, GermanyInstitute for Machine Tools and Production Processes, Chemnitz University of Technology, 09126 Chemnitz, GermanyInstitute for Machine Tools and Production Processes, Chemnitz University of Technology, 09126 Chemnitz, GermanyThe aim of this study was to develop a physical activity advisory system supporting the correct implementation of sport exercises using inertial sensors and machine learning algorithms. Specifically, three mobile sensors (tags), six stationary anchors and a system-controlling server (gateway) were employed for 15 scenarios of the series of subsequent activities, namely squats, pull-ups and dips. The proposed solution consists of two modules: an activity recognition module (ARM) and a repetition-counting module (RCM). The former is responsible for extracting the series of subsequent activities (so-called scenario), and the latter determines the number of repetitions of a given activity in a single series. Data used in this study contained 488 three defined sport activity occurrences. Data processing was conducted to enhance performance, including an overlapping and non-overlapping window, raw and normalized data, a convolutional neural network (CNN) with an additional post-processing block (PPB) and repetition counting. The developed system achieved satisfactory accuracy: CNN + PPB: non-overlapping window and raw data, 0.88; non-overlapping window and normalized data, 0.78; overlapping window and raw data, 0.92; overlapping window and normalized data, 0.87. For repetition counting, the achieved accuracies were 0.93 and 0.97 within an error of ±1 and ±2 repetitions, respectively. The archived results indicate that the proposed system could be a helpful tool to support the correct implementation of sport exercises and could be successfully implemented in further work in the form of web application detecting the user’s sport activity.https://www.mdpi.com/1424-8220/23/3/1137mobile sensors (tags)anchorsfitness trackingpersonal trainingsport activitiessport activity advisory system
spellingShingle Justyna Patalas-Maliszewska
Iwona Pajak
Pascal Krutz
Grzegorz Pajak
Matthias Rehm
Holger Schlegel
Martin Dix
Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms
Sensors
mobile sensors (tags)
anchors
fitness tracking
personal training
sport activities
sport activity advisory system
title Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms
title_full Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms
title_fullStr Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms
title_full_unstemmed Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms
title_short Inertial Sensor-Based Sport Activity Advisory System Using Machine Learning Algorithms
title_sort inertial sensor based sport activity advisory system using machine learning algorithms
topic mobile sensors (tags)
anchors
fitness tracking
personal training
sport activities
sport activity advisory system
url https://www.mdpi.com/1424-8220/23/3/1137
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AT iwonapajak inertialsensorbasedsportactivityadvisorysystemusingmachinelearningalgorithms
AT pascalkrutz inertialsensorbasedsportactivityadvisorysystemusingmachinelearningalgorithms
AT grzegorzpajak inertialsensorbasedsportactivityadvisorysystemusingmachinelearningalgorithms
AT matthiasrehm inertialsensorbasedsportactivityadvisorysystemusingmachinelearningalgorithms
AT holgerschlegel inertialsensorbasedsportactivityadvisorysystemusingmachinelearningalgorithms
AT martindix inertialsensorbasedsportactivityadvisorysystemusingmachinelearningalgorithms