Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis
Estimating the contact forces and moments (CFMs) between exoskeletons’ feet and the ground is a prerequisite for calculating exoskeletons’ joint moments. However, comfortable, portable, and high-precision force sensors for CFM detection are difficult to design and manufacture. In addition, there are...
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MDPI AG
2023-11-01
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author | Hongwu Li Haotian Ju Junchen Liu Ziqi Wang Qinghua Zhang Xianglong Li Yi Huang Tianjiao Zheng Jie Zhao Yanhe Zhu |
author_facet | Hongwu Li Haotian Ju Junchen Liu Ziqi Wang Qinghua Zhang Xianglong Li Yi Huang Tianjiao Zheng Jie Zhao Yanhe Zhu |
author_sort | Hongwu Li |
collection | DOAJ |
description | Estimating the contact forces and moments (CFMs) between exoskeletons’ feet and the ground is a prerequisite for calculating exoskeletons’ joint moments. However, comfortable, portable, and high-precision force sensors for CFM detection are difficult to design and manufacture. In addition, there are many unknown CFM components (six force components and six moment components in the double-support phase). These reasons make it challenging to estimate CFMs precisely. In this paper, we propose a novel method for estimating these CFMs based on a proposed dynamic decoupled coordinate system (DDCS) and the minimum energy hypothesis. By decomposing these CFMs into a DDCS, the number of unknowns can be significantly reduced from twelve to two. Meanwhile, the minimum energy hypothesis provides a relatively reliable target for optimizing the remaining two unknown variables. We verify the accuracy of this method using a public data set about human walking. The validation shows that the proposed method is capable of estimating CFMs. This study provides a practical way to estimate the CFMs under the soles, which contributes to reducing the research and development costs of exoskeletons by avoiding the need for expensive plantar sensors. The sensor-free approach also reduces the dependence on high-precision, portable, and comfortable CFM detection sensors, which are usually difficult to design. |
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issn | 2313-7673 |
language | English |
last_indexed | 2024-03-08T20:57:29Z |
publishDate | 2023-11-01 |
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series | Biomimetics |
spelling | doaj.art-2eab1c4acac84a72881489fb256a8cbf2023-12-22T13:55:28ZengMDPI AGBiomimetics2313-76732023-11-018855810.3390/biomimetics8080558Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy HypothesisHongwu Li0Haotian Ju1Junchen Liu2Ziqi Wang3Qinghua Zhang4Xianglong Li5Yi Huang6Tianjiao Zheng7Jie Zhao8Yanhe Zhu9State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, ChinaEstimating the contact forces and moments (CFMs) between exoskeletons’ feet and the ground is a prerequisite for calculating exoskeletons’ joint moments. However, comfortable, portable, and high-precision force sensors for CFM detection are difficult to design and manufacture. In addition, there are many unknown CFM components (six force components and six moment components in the double-support phase). These reasons make it challenging to estimate CFMs precisely. In this paper, we propose a novel method for estimating these CFMs based on a proposed dynamic decoupled coordinate system (DDCS) and the minimum energy hypothesis. By decomposing these CFMs into a DDCS, the number of unknowns can be significantly reduced from twelve to two. Meanwhile, the minimum energy hypothesis provides a relatively reliable target for optimizing the remaining two unknown variables. We verify the accuracy of this method using a public data set about human walking. The validation shows that the proposed method is capable of estimating CFMs. This study provides a practical way to estimate the CFMs under the soles, which contributes to reducing the research and development costs of exoskeletons by avoiding the need for expensive plantar sensors. The sensor-free approach also reduces the dependence on high-precision, portable, and comfortable CFM detection sensors, which are usually difficult to design.https://www.mdpi.com/2313-7673/8/8/558ground contact force and moment estimationexoskeletondynamic decoupled coordinate systemminimum energy hypothesis |
spellingShingle | Hongwu Li Haotian Ju Junchen Liu Ziqi Wang Qinghua Zhang Xianglong Li Yi Huang Tianjiao Zheng Jie Zhao Yanhe Zhu Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis Biomimetics ground contact force and moment estimation exoskeleton dynamic decoupled coordinate system minimum energy hypothesis |
title | Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis |
title_full | Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis |
title_fullStr | Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis |
title_full_unstemmed | Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis |
title_short | Ground Contact Force and Moment Estimation for Human–Exoskeleton Systems Using Dynamic Decoupled Coordinate System and Minimum Energy Hypothesis |
title_sort | ground contact force and moment estimation for human exoskeleton systems using dynamic decoupled coordinate system and minimum energy hypothesis |
topic | ground contact force and moment estimation exoskeleton dynamic decoupled coordinate system minimum energy hypothesis |
url | https://www.mdpi.com/2313-7673/8/8/558 |
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