Session: 06-05: Continuum Robotics

Paper Number: 111027

111027 - A Cosserat Rod Model for a Hyperelastic Continuum Robot Actuated by Twisted and Coiled Artificial Muscles 

Bioinspiration in soft robotics has yielded significant advancements in the field, particularly in the realm of continuum arms which seek to mimic the behavior of octopus tentacles. At the same time, growing interest in finite dimensional modeling techniques, such as the Cosserat rod model, has been driven by the need to accurately predict the behavior of these systems at low computational cost for feedback and controller formulation. However, there is often disconnect between the formulation of mathematical modeling methods and the construction of physical systems. To this end, we present a continuum robot constructed from silicone and actuated by twisted and coiled artificial muscles (TCAM), as well as an accompanying Cosserat rod model. This model uses a hyperelastic constitutive law to accurately model the system’s deformation in response to the force profiles generated by the TCAMs and gives adequate feedback to generate a closed loop controller for the system.  Further, we use measured TCAM temperature in conjunction with previously proposed physics-based TCAM models to predict the force contribution of individual artificial muscles to the system. The result is a verifiable model for a physical system which captures all modes of deformation. This model can be solved in real time in MATLAB with data collected from thermistors embedded inside individual artificial muscles to provide feedback for a closed loop L1 adaptive controller implemented in Simulink.

Presenting Author: Maxwell Hammond University of Iowa

Presenting Author Biography: Max Hammond is a 3rd year PhD student at the University of Iowa in the Mechanical Engineering department.