A jellyfish robot based on two-bar and four-spring tensegrity structures

Abstract

Traditional underwater robots primarily use propellers, which have the disadvantages of producing considerable noise and having a large impact on the marine environment. In this study, we design a jellyfish robot based on the tensegrity structure, and the properties of the tensegrity structure are used to enable the underwater robot to move like a jellyfish. First, we analyse the motion characteristics and hydrodynamic properties of jellyfish, establish a 3D model of a jellyfish robot using a 2-bar tensegrity structure, and then analyse the stability of the tensegrity structure. Next, kinematic simulation of the 3D model was performed by Adams to test the rationality of the mechanism design. Then, we used 3D printing technology to create a jellyfish robot prototype and conduct some on-land testing. This robot has a height of 322 mm and a diameter of 209 mm. Finally, we investigated the CFD results of the paddle structure and the whole 3D model of the prototype using SolidWorks Flow Simulation. Additionally, controlled experiments were conducted on the paddle. The properties of the jellyfish robot were tested through horizontal velocimetry experiments on the jellyfish robot prototype and diving experiments on the robot. The experiments showed that the tensegrity-based jellyfish robot could swim at a speed of 0.02 m/s, thus illustrating the performance of our robot design.