Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints
Human motion analysis using inertial measurement units (IMUs) has recently been shown to provide accuracy similar to the gold standard, optical motion capture, but at lower costs and while being less restrictive and time-consuming. However, IMU-based motion analysis requires precise knowledge of the...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-12-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/22/24/9850 |
| _version_ | 1797455295562121216 |
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| author | Daniel Laidig Ive Weygers Thomas Seel |
| author_facet | Daniel Laidig Ive Weygers Thomas Seel |
| author_sort | Daniel Laidig |
| collection | DOAJ |
| description | Human motion analysis using inertial measurement units (IMUs) has recently been shown to provide accuracy similar to the gold standard, optical motion capture, but at lower costs and while being less restrictive and time-consuming. However, IMU-based motion analysis requires precise knowledge of the orientations in which the sensors are attached to the body segments. This knowledge is commonly obtained via time-consuming and error-prone anatomical calibration based on precisely defined poses or motions. In the present work, we propose a self-calibrating approach for magnetometer-free joint angle tracking that is suitable for joints with two degrees of freedom (DoF), such as the elbow, ankle, and metacarpophalangeal finger joints. The proposed methods exploit kinematic constraints in the angular rates and the relative orientations to simultaneously identify the joint axes and the heading offset. The experimental evaluation shows that the proposed methods are able to estimate plausible and consistent joint axes from just ten seconds of arbitrary elbow joint motion. Comparison with optical motion capture shows that the proposed methods yield joint angles with similar accuracy as a conventional IMU-based method while being much less restrictive. Therefore, the proposed methods improve the practical usability of IMU-based motion tracking in many clinical and biomedical applications. |
| first_indexed | 2024-03-09T15:52:23Z |
| format | Article |
| id | doaj.art-376b3ab12ee34b3b99ecccf05d566810 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-09T15:52:23Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-376b3ab12ee34b3b99ecccf05d5668102023-11-24T17:56:22ZengMDPI AGSensors1424-82202022-12-012224985010.3390/s22249850Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF JointsDaniel Laidig0Ive Weygers1Thomas Seel2Control Systems Group, Technische Universität Berlin, 10623 Berlin, GermanyDepartment Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, GermanyDepartment Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91052 Erlangen, GermanyHuman motion analysis using inertial measurement units (IMUs) has recently been shown to provide accuracy similar to the gold standard, optical motion capture, but at lower costs and while being less restrictive and time-consuming. However, IMU-based motion analysis requires precise knowledge of the orientations in which the sensors are attached to the body segments. This knowledge is commonly obtained via time-consuming and error-prone anatomical calibration based on precisely defined poses or motions. In the present work, we propose a self-calibrating approach for magnetometer-free joint angle tracking that is suitable for joints with two degrees of freedom (DoF), such as the elbow, ankle, and metacarpophalangeal finger joints. The proposed methods exploit kinematic constraints in the angular rates and the relative orientations to simultaneously identify the joint axes and the heading offset. The experimental evaluation shows that the proposed methods are able to estimate plausible and consistent joint axes from just ten seconds of arbitrary elbow joint motion. Comparison with optical motion capture shows that the proposed methods yield joint angles with similar accuracy as a conventional IMU-based method while being much less restrictive. Therefore, the proposed methods improve the practical usability of IMU-based motion tracking in many clinical and biomedical applications.https://www.mdpi.com/1424-8220/22/24/9850anatomical calibrationsensor-to-segment calibrationkinematic constraintshuman motion analysiselbow jointinertial sensor |
| spellingShingle | Daniel Laidig Ive Weygers Thomas Seel Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints Sensors anatomical calibration sensor-to-segment calibration kinematic constraints human motion analysis elbow joint inertial sensor |
| title | Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints |
| title_full | Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints |
| title_fullStr | Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints |
| title_full_unstemmed | Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints |
| title_short | Self-Calibrating Magnetometer-Free Inertial Motion Tracking of 2-DoF Joints |
| title_sort | self calibrating magnetometer free inertial motion tracking of 2 dof joints |
| topic | anatomical calibration sensor-to-segment calibration kinematic constraints human motion analysis elbow joint inertial sensor |
| url | https://www.mdpi.com/1424-8220/22/24/9850 |
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