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Dynamics and stability of running on rough terrains

Stability of running on rough terrain depends on the propagation of perturbations due to the ground. We consider stability within the sagittal plane and model the dynamics of running as a two-dimensional body with alternating aerial and stance phases. Stance is modelled as a passive, impulsive colli...

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Autores principales: Dhawale, Nihav, Mandre, Shreyas, Venkadesan, Madhusudhan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458357/
https://www.ncbi.nlm.nih.gov/pubmed/31032027
http://dx.doi.org/10.1098/rsos.181729
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author Dhawale, Nihav
Mandre, Shreyas
Venkadesan, Madhusudhan
author_facet Dhawale, Nihav
Mandre, Shreyas
Venkadesan, Madhusudhan
author_sort Dhawale, Nihav
collection PubMed
description Stability of running on rough terrain depends on the propagation of perturbations due to the ground. We consider stability within the sagittal plane and model the dynamics of running as a two-dimensional body with alternating aerial and stance phases. Stance is modelled as a passive, impulsive collision followed by an active, impulsive push-off that compensates for collisional losses. Such a runner has infinitely many strategies to maintain periodic gaits on flat ground. However, these strategies differ in how perturbations due to terrain unevenness are propagated. Instabilities manifest as tumbling (orientational instability) or failing to maintain a steady speed (translational instability). We find that open-loop strategies that avoid sensory feedback are sufficient to maintain stability on step-like terrains with piecewise flat surfaces that randomly vary in height. However, these open-loop runners lose orientational stability on rough terrains whose slope also varies randomly. The orientational instability is significantly mitigated by minimizing the tangential collision, which typically requires sensory information and anticipatory strategies such as leg retraction. By analysing the propagation of perturbations, we derive a single dimensionless parameter that governs stability. This parameter provides guidelines for the design and control of both biological and robotic runners.
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spelling pubmed-64583572019-04-26 Dynamics and stability of running on rough terrains Dhawale, Nihav Mandre, Shreyas Venkadesan, Madhusudhan R Soc Open Sci Biology (Whole Organism) Stability of running on rough terrain depends on the propagation of perturbations due to the ground. We consider stability within the sagittal plane and model the dynamics of running as a two-dimensional body with alternating aerial and stance phases. Stance is modelled as a passive, impulsive collision followed by an active, impulsive push-off that compensates for collisional losses. Such a runner has infinitely many strategies to maintain periodic gaits on flat ground. However, these strategies differ in how perturbations due to terrain unevenness are propagated. Instabilities manifest as tumbling (orientational instability) or failing to maintain a steady speed (translational instability). We find that open-loop strategies that avoid sensory feedback are sufficient to maintain stability on step-like terrains with piecewise flat surfaces that randomly vary in height. However, these open-loop runners lose orientational stability on rough terrains whose slope also varies randomly. The orientational instability is significantly mitigated by minimizing the tangential collision, which typically requires sensory information and anticipatory strategies such as leg retraction. By analysing the propagation of perturbations, we derive a single dimensionless parameter that governs stability. This parameter provides guidelines for the design and control of both biological and robotic runners. The Royal Society 2019-03-13 /pmc/articles/PMC6458357/ /pubmed/31032027 http://dx.doi.org/10.1098/rsos.181729 Text en © 2019 The Authors. http://creativecommons.org/licenses/by/4.0/ Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
spellingShingle Biology (Whole Organism)
Dhawale, Nihav
Mandre, Shreyas
Venkadesan, Madhusudhan
Dynamics and stability of running on rough terrains
title Dynamics and stability of running on rough terrains
title_full Dynamics and stability of running on rough terrains
title_fullStr Dynamics and stability of running on rough terrains
title_full_unstemmed Dynamics and stability of running on rough terrains
title_short Dynamics and stability of running on rough terrains
title_sort dynamics and stability of running on rough terrains
topic Biology (Whole Organism)
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6458357/
https://www.ncbi.nlm.nih.gov/pubmed/31032027
http://dx.doi.org/10.1098/rsos.181729
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