Nonlinear analysis of quasi-static response of pneumatic artificial muscles for agonistic and antagonistic actuation modes

Ryan M. Robinson; Curt S. Kothera; Norman M. Wereley

doi:10.1117/12.2012359

8 April 2013 Nonlinear analysis of quasi-static response of pneumatic artificial muscles for agonistic and antagonistic actuation modes

Ryan M. Robinson, Curt S. Kothera, Norman M. Wereley

Author Affiliations +

Proceedings Volume 8686, Bioinspiration, Biomimetics, and Bioreplication 2013; 868604 (2013) https://doi.org/10.1117/12.2012359
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2013, San Diego, California, United States

Abstract

Pneumatic artificial muscles (PAMs) are actuators known for their light weight, high specific force, and natural compliance. Employed in antagonistic schemes, these actuators closely mimic biological muscle pairs, which has led to their use in humanoid and other bio-inspired robotics applications. Such systems require precise actuator modeling and control in order to achieve high performance. In the present study, refinements are introduced to an existing model of pneumatic artificial muscle force-contraction behavior. The force balance modeling approach is modified to include the effects of non-constant bladder thickness and up to a fourth-order polynomial stress-strain relationship is adopted in order to more accurately capture nonlinear PAM force behavior in both contraction and extension. Moreover, the polynomial coefficients of the stress-strain relationship are constrained to vary linearly with pressure, improving the ability to predict behavior at untested pressure levels while preserving model accuracy at tested pressure levels. Additionally, a detailed geometric model is applied to improve force predictions, particularly during PAM extension. By modeling bladder end effects as sections of an elliptic toroid, PAM force predictions as a function of strain are improved. These modeling improvements combine to enable enhanced model-based control in PAM actuator applications.

Citation Download Citation

Ryan M. Robinson, Curt S. Kothera, and Norman M. Wereley "Nonlinear analysis of quasi-static response of pneumatic artificial muscles for agonistic and antagonistic actuation modes", Proc. SPIE 8686, Bioinspiration, Biomimetics, and Bioreplication 2013, 868604 (8 April 2013); https://doi.org/10.1117/12.2012359

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available