A Preliminary Study of Soft Material Robotic Modelling: Finite Element Method and Cosserat Rod Model

Soft material robotic systems are a rather new but a promising field of research. Compared to their rigid counterparts, soft material robots show great advantages when operating in unknown environments or handling objects with unknown geometry or irregular topology. To make use of the advantages of soft material robotic systems, it essential to find a proper methodology for modelling and analyze these regarding control strategies and model-based control. Unlike rigid robots, soft material robotic systems can show highly nonlinear material behavior and undergo large deformation. Capturing nonlinearities in a time efficient model is a challenge that will be addressed in this paper in a preliminary comparison of two modelling approaches as well as in a first naïve approximation attempt of nonlinear force-displacement relationship. In the following we will show how to finite element modelling may be utilized for the identification of parameter used in a Cosserat rod model using the example of a soft pneumatic actuator (SPA).