Dynamics Modeling and Validation of a Bio-Inspired Soft Eel Robots for Underwater Motion

This paper presents advancements in our previous research of bio-inspired soft eel robots with a focus on investigating their underwater motion dynamics. An equivalent model is proposed, consisting of rigid links interconnected by rotating joints and springs, with pneumatic pressure activation modeled through joint moments and hydrodynamic forces determined through explicit formulas incorporating motion dynamic parameters. A novel virtual loading method combining kinetic modeling and simulation of the eel robot's deformation is introduced to determine the configuration parameters of the equivalent model. The model is extensively investigated using MSC Adams multibody dynamics simulation software and validated through real-underwater motion experiments. Comparative analysis between experimental and simulation results demonstrates the proposed approach's reliability and accuracy. The findings facilitate the optimization of the eel robot's design and control and can be extended to study other continuous soft robots' dynamics.