Design and dynamics modeling of a hybrid drive bionic robotic fish

Abstract

While recent advancements in hybrid propulsion systems for bionic robotic fish—combining biomimetic mechanisms with classical vector thrusters—demonstrate enhanced locomotion capabilities and application potential, challenges remain in modeling the coupled dynamics of heterogeneous propulsion mechanisms. This paper presents a hybrid-drive robotic fish architecture that synergistically integrates pectoral-fin-mounted propellers with a caudal-fin-based propulsion system. A three-dimensional dynamical model is developed to characterize the coupled interactions between the dual propulsion modes, incorporating a hydrodynamic computation framework that accounts for propeller wake effects on caudal fin performance. Systematic experimental validation confirms the model’s fidelity through quantitative analysis of swimming performance metrics, including cruising speed, turning radius, and trajectory tracking. The results show that the proposed hybrid propulsion strategy can effectively improve the swimming performance of the robotic fish, and the model can effectively predict the motions such as speed, turning diameter, and trajectory of the robotic fish, which provides a new idea for the development of bionic robotic fish.