Modeling of Soft Manipulators with Couplings between Actuations and Body Deformations

Abstract

Various models have been proposed recently to describe the motion of soft robots-robots made from soft materials. However, all of existing models separate the modeling of the actuation (e.g., cable or pneumatic) and the deformation of soft materials that host the actuation. In this paper, we aim to propose a model for soft robots when there exists coupling between the actuation and soft materials, and apply this model to soft manipulators actuated by twisted-and-coiled actuators (TCAs), a newly-discovered thermal-driven artificial muscle. The model is accomplished by coupling a Cosserat Rod model for the soft body to the actuation model of TCAs to obtain a set of ordinary differential equations to solve both the forward and inverse kinematics problem. Simulation results for soft manipulators with multiple TCAs validate the proposed model. The proposed model can be applied to other soft robots with embedded actuators (artificial muscle) where the coupling between the soft body and actuation exists.