Journal of Bionic Engineering (2025) 22:654–669 https://doi.org/10.1007/s42235-024-00646-9

Hydrodynamic Characteristic Analysis of a Biomimetic Underwater  Vehicle-Manipulator System

Hongfei Chu1  · Xiaolong Hui1  · Xuejian Bai3  · Min Tan1,2 · Yu Wang1,2

1 State Key Laboratory of Multimodal Artificial Intelligence  Systems, Institute of Automation, Chinese Academy of  Sciences, Beijing 100000, China 

2 School of Artificial Intelligence, University of Chinese  Academy of Sciences, Beijing 100000, China 

3 School of Electrical Engineering, Liaoning University of  Technology, Jinzhou 121000, China

Abstract 

The propulsion mechanisms of biomimetic underwater vehicles using bionic undulatory fins have been extensively studied  for their potential to enhance efficiency and maneuverability in underwater environments. However, the hydrodynamic  interactions between the vehicle body, robotic manipulator, and fluctuating motion remain less explored, particularly in  turbulent conditions. In this work, a Biomimetic Underwater Vehicle-Manipulator System (BUVMS) propelled using  bionic undulatory fins is considered. The propulsion mechanism and hydrodynamic performance of fluctuating motion are  analyzed by numerical simulation. The drag coefficients of the BUVMS at different Reynolds numbers are calculated, and  the investigation of vortex generation during the motion of the BUVMS reveals that vortex binding and shedding are the  key factors for propulsion generation. Various moving modes of the BUVMS are developed in conjunction with the propulsion mechanism. The hydrodynamic loads during the motion of the underwater robotic arm in a turbulent environment  are analyzed. A simple motion strategy is proposed to reduce the effect of water drag on the manipulation of the robotic  arm and on the overall stability of the BUVMS. The results of the hydrodynamic analysis offer systematic guidance for  controlling underwater operations of the BUVMS. 

Keywords Biomimetic underwater vehicle-Manipulator system (BUVMS) · Computational fluid dynamics (CFD) ·  Hydrodynamics · Bionic undulatory fins · Propulsion mechanism