A Constitutive Model for Torsional Loads on Fluid-Driven Soft Robots

For soft robots to be utilized in medical devices, locomotion, industrial automation, and a number of other fields, they require accurate and computationally efficient models that capture both the kinetic behavior and inherent non-linearity. Fiber reinforcement enables soft robots to create useful motions, such as rotation, but poses additional complexity in modeling. The purpose of this paper is to present a constitutive model that relates the kinematic behaviour of a pneumatic fiber-reinforced soft actuator with its torsional loading. This model has the advantage of requiring minimal experimental parameter determination, being inclusive of torsional loads, without requiring large-scale computing systems. Experimental data in multiple kinematic configurations shows agreement between the models moment prediction and the moments that the actuators generate.