Theoretical Modeling and Experimental Analysis of a Pressure-Operated Soft Robotic Snake

For a mobile robot undergoing serpentine locomotion, an accurate dynamic model is a fundamental requirement for optimization, control, navigation, and learning algorithms. Such algorithms can be readily implemented for traditional rigid robots, but remain a challenge for nonlinear and low-bandwidth soft robotic systems. This article addresses the theoretical modeling of the dynamics of a pressure-operated soft snake robot. A general framework is detailed to solve the 2D modeling problem of a soft snake robot, which is applicable to most pressure-operated soft robots developed by a modular kinematic arrangement of bending-type fluidic elastomer actuators. The model is simulated using measured physical parameters of a soft snake robot prototype. The theoretical results are verified through a detailed comparison to locomotion experiments on a flat surface with measured frictional properties. Experimental results confirm that the proposed model describes the motion of the robot accurately.