Review of High-maneuverability Biomimetic Robotic Fish:Mechanism Innovation and Hydrodynamic Dynamic Gain Effects

WANG Xiaoguang   ZHONG Yong

(Shien-Ming Wu School of Intelligent Engineering, South China University of Technology, Guangzhou, Guangdong 511442, China)

Abstract: As underwater operational environments shift from vast oceans to unstructured and complex waters, traditional autonomous underwater vehicles face significant challenges due to insufficient maneuverability. This paper reviews the latest research progress in high-maneuverability biomimetic robotic fish, focusing on mechanical innovation, fluid dynamic gain, and performance evaluation. Firstly, based on biological observations, it analyzes the locomotion mechanisms by which fish achieve high maneuverability through body variable stiffness, multi-fin coordination, and endogenous attitude regulation. Secondly, it elaborates on the design paradigms of the mechanical systems of high-maneuverability biomimetic robotic fish, comparing variable stiffness technologies such as cable-driven antagonistic mechanisms, jamming-based variable stiffness structures, and smart material-based actuators, as well as the implementation approaches for multi-fin vector propulsion. Thirdly, from the perspective of unsteady fluid dynamics, it reveals the fluid dynamic gain mechanisms of transient bursts, vector propulsion, and vortex manipulation, and discusses high-maneuverability control strategies based on central pattern generators and reinforcement learning. Finally, it summarizes the current challenges in biomimetic robotic fish, including dynamic modeling and computation, flow field perception and control, hardware integration and actuation, and validation in real marine environments, while offering insights into future development directions.

Keywords: biomimetic robotic fish; high maneuverability; variable stiffness; multi-fin synergy; unsteady hydrodynamics; hydrodynamic dynamic gain