Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)

Safety is one of the most important issues in rehabilitation assist suits. We have proposed and developed a rehabilitation assist suit equipped with a velocity-based mechanical safety device (VBMSD) to address this issue. The assist suit aids flection and extension of a patient’s knee joint. The VBM...

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Main Authors: Tsubasa KANEDA, Yoshihiro KAI, Masahito SUGIYAMA, Kenichi SUGAWARA, Masayoshi TOMIZUKA
Format: Article
Language:Japanese
Published: The Japan Society of Mechanical Engineers 2019-08-01
Series:Nihon Kikai Gakkai ronbunshu
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/transjsme/85/876/85_19-00146/_pdf/-char/en
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author Tsubasa KANEDA
Yoshihiro KAI
Masahito SUGIYAMA
Kenichi SUGAWARA
Masayoshi TOMIZUKA
author_facet Tsubasa KANEDA
Yoshihiro KAI
Masahito SUGIYAMA
Kenichi SUGAWARA
Masayoshi TOMIZUKA
author_sort Tsubasa KANEDA
collection DOAJ
description Safety is one of the most important issues in rehabilitation assist suits. We have proposed and developed a rehabilitation assist suit equipped with a velocity-based mechanical safety device (VBMSD) to address this issue. The assist suit aids flection and extension of a patient’s knee joint. The VBMSD switches off the motor of the assist suit when the angular velocity of the patient’s knee joint exceeds a preset threshold level. The VBMSD works even under failure of the assist suit’s computer, because it consists of only passive mechanical components without controllers, actuators, and batteries. In this VBMSD, the time delay between the instance of the velocity exceeding the threshold and the instance of the motor switched off is an important parameter. If the time delay is excessive, the motor may move a patient’s leg at unexpected high velocities. Therefore, it is necessary to analyze the length of time delay and to experimentally validate the analysis. The analysis will also be useful for the design of future VBMSDs. In this paper, we theoretically derive the time delay using the transient response analysis of the VBMSD. Furthermore, we simulate how quickly the VBMSD responds to a rapidly increasing velocity by using the derived time delay. Finally, we present experimental results to verify the analysis and simulation.
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spelling doaj.art-aea00b1fda5d44288cf47818fc9997372022-12-22T04:35:16ZjpnThe Japan Society of Mechanical EngineersNihon Kikai Gakkai ronbunshu2187-97612019-08-018587619-0014619-0014610.1299/transjsme.19-00146transjsmeDevelopment of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)Tsubasa KANEDA0Yoshihiro KAI1Masahito SUGIYAMA2Kenichi SUGAWARA3Masayoshi TOMIZUKA4Department of Mechanical Engineering, Tokai UniversityDepartment of Mechanical Engineering, Tokai UniversityDepartment of Mechanical Engineering, Tokai UniversityDepartment of Rehabilitation, Kanagawa University of Human ServicesDepartment of Mechanical Engineering, University of California, BerkeleySafety is one of the most important issues in rehabilitation assist suits. We have proposed and developed a rehabilitation assist suit equipped with a velocity-based mechanical safety device (VBMSD) to address this issue. The assist suit aids flection and extension of a patient’s knee joint. The VBMSD switches off the motor of the assist suit when the angular velocity of the patient’s knee joint exceeds a preset threshold level. The VBMSD works even under failure of the assist suit’s computer, because it consists of only passive mechanical components without controllers, actuators, and batteries. In this VBMSD, the time delay between the instance of the velocity exceeding the threshold and the instance of the motor switched off is an important parameter. If the time delay is excessive, the motor may move a patient’s leg at unexpected high velocities. Therefore, it is necessary to analyze the length of time delay and to experimentally validate the analysis. The analysis will also be useful for the design of future VBMSDs. In this paper, we theoretically derive the time delay using the transient response analysis of the VBMSD. Furthermore, we simulate how quickly the VBMSD responds to a rapidly increasing velocity by using the derived time delay. Finally, we present experimental results to verify the analysis and simulation.https://www.jstage.jst.go.jp/article/transjsme/85/876/85_19-00146/_pdf/-char/enrobotdesignmechanismrehabilitation assist suitmechanical safety devicetransient response analysistime delay
spellingShingle Tsubasa KANEDA
Yoshihiro KAI
Masahito SUGIYAMA
Kenichi SUGAWARA
Masayoshi TOMIZUKA
Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)
Nihon Kikai Gakkai ronbunshu
robot
design
mechanism
rehabilitation assist suit
mechanical safety device
transient response analysis
time delay
title Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)
title_full Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)
title_fullStr Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)
title_full_unstemmed Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)
title_short Development of a knee joint assist suit with a velocity-based mechanical safety device (Transient response analysis of the safety device and experiments)
title_sort development of a knee joint assist suit with a velocity based mechanical safety device transient response analysis of the safety device and experiments
topic robot
design
mechanism
rehabilitation assist suit
mechanical safety device
transient response analysis
time delay
url https://www.jstage.jst.go.jp/article/transjsme/85/876/85_19-00146/_pdf/-char/en
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