Dynamic Modeling and Validation of Soft Robotic Snake Locomotion

TL;DR

This paper develops a comprehensive spatial dynamic model for soft robotic snakes, enabling the analysis and validation of complex locomotion gaits through numerical simulations and experimental tests.

Contribution

It introduces a novel dynamic modeling approach that incorporates distributed contact forces for soft robotic snakes, advancing beyond previous kinematic-only models.

Findings

The model accurately predicts locomotion trajectories.

Experimental results validate the numerical simulations.

The approach enables analysis of complex gaits like rolling.

Abstract

Soft robotic snakes made of compliant materials can continuously deform their bodies and, therefore, mimic the biological snakes' flexible and agile locomotion gaits better than their rigid-bodied counterparts. Without wheel support, to date, soft robotic snakes are limited to emulating planar locomotion gaits, which are derived via kinematic modeling and tested on robotic prototypes. Given that the snake locomotion results from the reaction forces due to the distributed contact between their skin and the ground, it is essential to investigate the locomotion gaits through efficient dynamic models capable of accommodating distributed contact forces. We present a complete spatial dynamic model that utilizes a floating-base kinematic model with distributed contact dynamics for a pneumatically powered soft robotic snake. We numerically evaluate the feasibility of the planar and spatial rolling gaits utilizing the proposed model and experimentally validate the corresponding locomotion gait trajectories on a soft robotic snake prototype. We qualitatively and quantitatively compare the numerical and experimental results which confirm the validity of the proposed dynamic model.