A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation

This paper proposes a method of estimating the knee joint angle during walking using nine-axis motion sensors in a varying magnetic field. The nine-axis motion sensor comprises a three-axis gyro sensor, a three-axis acceleration sensor, and a three-axis geomagnetic sensor. It can estimate joint angl...

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Main Authors: Ayuko SAITO, Yuto NARA, Kazuto MIYAWAKI
Format: Article
Language:Japanese
Published: The Japan Society of Mechanical Engineers 2019-05-01
Series:Nihon Kikai Gakkai ronbunshu
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/transjsme/85/873/85_19-00061/_pdf/-char/en
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author Ayuko SAITO
Yuto NARA
Kazuto MIYAWAKI
author_facet Ayuko SAITO
Yuto NARA
Kazuto MIYAWAKI
author_sort Ayuko SAITO
collection DOAJ
description This paper proposes a method of estimating the knee joint angle during walking using nine-axis motion sensors in a varying magnetic field. The nine-axis motion sensor comprises a three-axis gyro sensor, a three-axis acceleration sensor, and a three-axis geomagnetic sensor. It can estimate joint angles during exercise by correcting the drift of the three-axis gyro sensor using information obtained from the other two sensors. However, the magnetic field cannot be measured correctly using a three-axis geomagnetic sensor in a variable magnetic field. Therefore, the joint angle estimation accuracy is lowered. For this study, the authors corrected the outputs of a three-axis geomagnetic sensor using the three-axis angular velocity obtained from a three-axis gyro sensor. During the laboratory experiment, the 3D motion analysis system and two nine-axis motion sensors measured walking exercise. The knee joint angle results estimated using the two nine-axis motion sensors using corrected outputs of a three-axis geomagnetic sensor generally agreed with the 3D motion analysis system results. Furthermore, two nine-axis motion sensors measured walking exercise outside for about one hour. In the results of knee joint angle estimation using uncorrected outputs of a three-axis geomagnetic sensor, the boundaries between swing phases and stance phases were unclear. Results of knee joint angle estimation using corrected outputs of a three-axis geomagnetic sensor indicate a similar tendency to that found for results of the walking cycle from the laboratory experiment that comprised swing phases and stance phases. This analytical method is anticipated for use in estimating motion in a varying magnetic field.
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spelling doaj.art-4f86e2c4e8f44b948ef89553cc79c5112022-12-22T04:16:11ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612019-05-018587319-0006119-0006110.1299/transjsme.19-00061transjsmeA study on estimating knee joint angle using motion sensors under conditions of magnetic field variationAyuko SAITO0Yuto NARA1Kazuto MIYAWAKI2Department of Mechanical Engineering and Robotics, National Institute of Technology, Akita CollegeDepartment of Mechanical Engineering and Robotics, National Institute of Technology, Akita CollegeDepartment of Mechanical Engineering and Robotics, National Institute of Technology, Akita CollegeThis paper proposes a method of estimating the knee joint angle during walking using nine-axis motion sensors in a varying magnetic field. The nine-axis motion sensor comprises a three-axis gyro sensor, a three-axis acceleration sensor, and a three-axis geomagnetic sensor. It can estimate joint angles during exercise by correcting the drift of the three-axis gyro sensor using information obtained from the other two sensors. However, the magnetic field cannot be measured correctly using a three-axis geomagnetic sensor in a variable magnetic field. Therefore, the joint angle estimation accuracy is lowered. For this study, the authors corrected the outputs of a three-axis geomagnetic sensor using the three-axis angular velocity obtained from a three-axis gyro sensor. During the laboratory experiment, the 3D motion analysis system and two nine-axis motion sensors measured walking exercise. The knee joint angle results estimated using the two nine-axis motion sensors using corrected outputs of a three-axis geomagnetic sensor generally agreed with the 3D motion analysis system results. Furthermore, two nine-axis motion sensors measured walking exercise outside for about one hour. In the results of knee joint angle estimation using uncorrected outputs of a three-axis geomagnetic sensor, the boundaries between swing phases and stance phases were unclear. Results of knee joint angle estimation using corrected outputs of a three-axis geomagnetic sensor indicate a similar tendency to that found for results of the walking cycle from the laboratory experiment that comprised swing phases and stance phases. This analytical method is anticipated for use in estimating motion in a varying magnetic field.https://www.jstage.jst.go.jp/article/transjsme/85/873/85_19-00061/_pdf/-char/enmotion sensorsensor fusionmagnetic fieldjoint anglewalking
spellingShingle Ayuko SAITO
Yuto NARA
Kazuto MIYAWAKI
A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
Nihon Kikai Gakkai ronbunshu
motion sensor
sensor fusion
magnetic field
joint angle
walking
title A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
title_full A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
title_fullStr A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
title_full_unstemmed A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
title_short A study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
title_sort study on estimating knee joint angle using motion sensors under conditions of magnetic field variation
topic motion sensor
sensor fusion
magnetic field
joint angle
walking
url https://www.jstage.jst.go.jp/article/transjsme/85/873/85_19-00061/_pdf/-char/en
work_keys_str_mv AT ayukosaito astudyonestimatingkneejointangleusingmotionsensorsunderconditionsofmagneticfieldvariation
AT yutonara astudyonestimatingkneejointangleusingmotionsensorsunderconditionsofmagneticfieldvariation
AT kazutomiyawaki astudyonestimatingkneejointangleusingmotionsensorsunderconditionsofmagneticfieldvariation
AT ayukosaito studyonestimatingkneejointangleusingmotionsensorsunderconditionsofmagneticfieldvariation
AT yutonara studyonestimatingkneejointangleusingmotionsensorsunderconditionsofmagneticfieldvariation
AT kazutomiyawaki studyonestimatingkneejointangleusingmotionsensorsunderconditionsofmagneticfieldvariation