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Ankle exoskeleton torque controllers based on soleus muscle models
Powered exoskeletons are typically task-specific, but to facilitate their wider adoption they should support a variety of tasks, which requires generalizeable controller designs. In this paper, we present two potential controllers for ankle exoskeletons based on soleus fascicles and Achilles tendon...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970081/ https://www.ncbi.nlm.nih.gov/pubmed/36848340 http://dx.doi.org/10.1371/journal.pone.0281944 |
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author | Pridham, Paul S. Stirling, Leia |
author_facet | Pridham, Paul S. Stirling, Leia |
author_sort | Pridham, Paul S. |
collection | PubMed |
description | Powered exoskeletons are typically task-specific, but to facilitate their wider adoption they should support a variety of tasks, which requires generalizeable controller designs. In this paper, we present two potential controllers for ankle exoskeletons based on soleus fascicles and Achilles tendon models. The methods use an estimate of the adenosine triphosphate hydrolysis rate of the soleus based on fascicle velocity. Models were evaluated using muscle dynamics from the literature, which were measured with ultrasound. We compare the simulated behavior of these methods against each other and to human-in-the-loop optimized torque profiles. Both methods generated distinct profiles for walking and running with speed variations. One of the approaches was more appropriate for walking, while the other approach estimated profiles similar to the literature for both walking and running. Human-in-the-loop methods require long optimizations to set parameters per individual for each specific task, the proposed methods can produce similar profiles, work across walking and running, and be implemented with body-worn sensors without requiring torque profile parameterization and optimization for every task. Future evaluations should examine how human behavior changes due to external assistance when using these control models. |
format | Online Article Text |
id | pubmed-9970081 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-99700812023-02-28 Ankle exoskeleton torque controllers based on soleus muscle models Pridham, Paul S. Stirling, Leia PLoS One Research Article Powered exoskeletons are typically task-specific, but to facilitate their wider adoption they should support a variety of tasks, which requires generalizeable controller designs. In this paper, we present two potential controllers for ankle exoskeletons based on soleus fascicles and Achilles tendon models. The methods use an estimate of the adenosine triphosphate hydrolysis rate of the soleus based on fascicle velocity. Models were evaluated using muscle dynamics from the literature, which were measured with ultrasound. We compare the simulated behavior of these methods against each other and to human-in-the-loop optimized torque profiles. Both methods generated distinct profiles for walking and running with speed variations. One of the approaches was more appropriate for walking, while the other approach estimated profiles similar to the literature for both walking and running. Human-in-the-loop methods require long optimizations to set parameters per individual for each specific task, the proposed methods can produce similar profiles, work across walking and running, and be implemented with body-worn sensors without requiring torque profile parameterization and optimization for every task. Future evaluations should examine how human behavior changes due to external assistance when using these control models. Public Library of Science 2023-02-27 /pmc/articles/PMC9970081/ /pubmed/36848340 http://dx.doi.org/10.1371/journal.pone.0281944 Text en © 2023 Pridham, Stirling https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Pridham, Paul S. Stirling, Leia Ankle exoskeleton torque controllers based on soleus muscle models |
title | Ankle exoskeleton torque controllers based on soleus muscle models |
title_full | Ankle exoskeleton torque controllers based on soleus muscle models |
title_fullStr | Ankle exoskeleton torque controllers based on soleus muscle models |
title_full_unstemmed | Ankle exoskeleton torque controllers based on soleus muscle models |
title_short | Ankle exoskeleton torque controllers based on soleus muscle models |
title_sort | ankle exoskeleton torque controllers based on soleus muscle models |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9970081/ https://www.ncbi.nlm.nih.gov/pubmed/36848340 http://dx.doi.org/10.1371/journal.pone.0281944 |
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