Journal of Bionic Engineering (2024) 21:1223–1237 https://doi.org/10.1007/s42235-024-00494-7

An Underwater Biomimetic Robot that can Swim, Bipedal Walk and Grasp

Qiuxuan Wu1,2,4  · Liwei Pan1 · FuLin Du1 · ZhaoSheng Wu1 · XiaoNi Chi3 · FaRong Gao1 · Jian Wang1,2 · Anton A. Zhilenkov4 

1 School of Automation, Hangzhou Dianzi University, Hangzhou 310018, China

2 International Joint Research Laboratory for Autonomous Robotic Systems, Hangzhou 310018, China

3 GEELY Automotive Institute, Hangzhou Vocational and Technical College, Hangzhou 310018, China

4 Institute of Hydrodynamics and Control Processes Sankt-Petersburg, Saint Petersburg State Marine Technical University, Sankt-Petersburg, Russia

Abstract

In developing and exploring extreme and harsh underwater environments, underwater robots can efectively replace humans to complete tasks. To meet the requirements of underwater fexible motion and comprehensive subsea operation, a novel octopus-inspired robot with eight soft limbs was designed and developed. This robot possesses the capabilities of underwater bipedal walking, multi-arm swimming, and grasping objects. To closely interact with the underwater seabed environment and minimize disturbance, the robot employs a cable-driven fexible arm for its walking in underwater foor through a bipedal walking mode. The multi-arm swimming ofers a means of three-dimensional spatial movement, allowing the robot to swiftly explore and navigate over large areas, thereby enhancing its fexibility. Furthermore, the robot’s walking arm enables it to grasp and transport objects underwater, thereby enhancing its practicality in underwater environments. A simplifed motion models and gait generation strategies were proposed for two modes of robot locomotion: swimming and walking, inspired by the movement characteristics of octopus-inspired multi-arm swimming and bipedal walking. Through experimental verifcation, the robot’s average speed of underwater bipedal walking reaches 7.26 cm/s, while the horizontal movement speed for multi-arm swimming is 8.6 cm/s.

Keywords Underwater soft robots · Underwater bipedal walking · Multi-arm swimming · Cable drive