Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking

This paper presents a new method to investigate the multivariable time-varying behavior of the ankle during human walking, and provides the first experimental results from treadmill walking. A wearable ankle robot with an ensemblebased linear time-varying system identification method enabled identif...

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Main Authors: Lee, Hyunglae, Krebs, Hermano I, Hogan, Neville
Other Authors: Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences
Format: Article
Published: ASME International 2018
Online Access:http://hdl.handle.net/1721.1/119388
https://orcid.org/0000-0001-5366-2145
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author Lee, Hyunglae
Krebs, Hermano I
Hogan, Neville
author2 Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences
author_facet Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences
Lee, Hyunglae
Krebs, Hermano I
Hogan, Neville
author_sort Lee, Hyunglae
collection MIT
description This paper presents a new method to investigate the multivariable time-varying behavior of the ankle during human walking, and provides the first experimental results from treadmill walking. A wearable ankle robot with an ensemblebased linear time-varying system identification method enabled identification of transient ankle mechanical impedance in 2 degrees of freedom, both in the sagittal and frontal planes. Several important issues of the ensemble-based identification method in practical measurements are discussed, especially a strategy to solve the limitation of the method which assumes that the system undergoes the same time-varying behavior on every stride. The suggested method was successfully applied to 15 minutes of human walking on a treadmill. Experiments with 10 young healthy subjects showed clear time-varying behavior of ankle impedance across the gait cycle, except the mid-stance phase. Interestingly, most subjects increased ankle impedance just before heel strike in both degrees of freedom. Interpretation of impedance changes was consistent with analysis of electromyographic signals from major muscles related to ankle movements.
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spelling mit-1721.1/1193882022-09-30T01:37:49Z Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking Lee, Hyunglae Krebs, Hermano I Hogan, Neville Massachusetts Institute of Technology. Department of Brain and Cognitive Sciences Massachusetts Institute of Technology. Department of Mechanical Engineering Lee, Hyunglae Krebs, Hermano I Hogan, Neville This paper presents a new method to investigate the multivariable time-varying behavior of the ankle during human walking, and provides the first experimental results from treadmill walking. A wearable ankle robot with an ensemblebased linear time-varying system identification method enabled identification of transient ankle mechanical impedance in 2 degrees of freedom, both in the sagittal and frontal planes. Several important issues of the ensemble-based identification method in practical measurements are discussed, especially a strategy to solve the limitation of the method which assumes that the system undergoes the same time-varying behavior on every stride. The suggested method was successfully applied to 15 minutes of human walking on a treadmill. Experiments with 10 young healthy subjects showed clear time-varying behavior of ankle impedance across the gait cycle, except the mid-stance phase. Interestingly, most subjects increased ankle impedance just before heel strike in both degrees of freedom. Interpretation of impedance changes was consistent with analysis of electromyographic signals from major muscles related to ankle movements. Toyota Motor Corporation. Partner Robot Division Gloria Blake Endowment Fund Samsung Fellowship 2018-12-03T16:39:00Z 2018-12-03T16:39:00Z 2012-10 2018-11-30T18:59:46Z Article http://purl.org/eprint/type/ConferencePaper 978-0-7918-4529-5 http://hdl.handle.net/1721.1/119388 Lee, Hyunglae, Hermano Igo Krebs, and Neville Hogan. “Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking.” Volume 1: Adaptive Control; Advanced Vehicle Propulsion Systems; Aerospace Systems; Autonomous Systems; Battery Modeling; Biochemical Systems; Control Over Networks; Control Systems Design; Cooperativ (October 17, 2012). https://orcid.org/0000-0001-5366-2145 http://dx.doi.org/10.1115/DSCC2012-MOVIC2012-8674 Volume 1: Adaptive Control; Advanced Vehicle Propulsion Systems; Aerospace Systems; Autonomous Systems; Battery Modeling; Biochemical Systems; Control Over Networks; Control Systems Design; Cooperativ Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf ASME International ASME
spellingShingle Lee, Hyunglae
Krebs, Hermano I
Hogan, Neville
Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking
title Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking
title_full Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking
title_fullStr Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking
title_full_unstemmed Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking
title_short Linear Time-Varying Identification of Ankle Mechanical Impedance During Human Walking
title_sort linear time varying identification of ankle mechanical impedance during human walking
url http://hdl.handle.net/1721.1/119388
https://orcid.org/0000-0001-5366-2145
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