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...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2023-01-01
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| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0281944 |
| _version_ | 1797848193851981824 |
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| author | Paul S Pridham Leia Stirling |
| author_facet | Paul S Pridham Leia Stirling |
| author_sort | Paul S Pridham |
| collection | DOAJ |
| 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. |
| first_indexed | 2024-04-09T18:23:27Z |
| format | Article |
| id | doaj.art-9f16fc17ced04f7b873cb3960e079ef8 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-09T18:23:27Z |
| publishDate | 2023-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-9f16fc17ced04f7b873cb3960e079ef82023-04-12T05:31:55ZengPublic Library of Science (PLoS)PLoS ONE1932-62032023-01-01182e028194410.1371/journal.pone.0281944Ankle exoskeleton torque controllers based on soleus muscle models.Paul S PridhamLeia StirlingPowered 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.https://doi.org/10.1371/journal.pone.0281944 |
| spellingShingle | Paul S Pridham Leia Stirling Ankle exoskeleton torque controllers based on soleus muscle models. PLoS ONE |
| 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 |
| url | https://doi.org/10.1371/journal.pone.0281944 |
| work_keys_str_mv | AT paulspridham ankleexoskeletontorquecontrollersbasedonsoleusmusclemodels AT leiastirling ankleexoskeletontorquecontrollersbasedonsoleusmusclemodels |