Soft dorsal/anal fins pairs for roll and yaw motion in robotic fish

Abstract

Fish has served as model for many bio-inspired underwater robots. However, most of the work on fish-inspired robots is focused on propulsion and turning in the horizontal plane. In this paper we present our work on 3D motion of bio-inspired underwater robots. A pair of actuated soft fins, mimicking the soft dorsal and anal fins of life fish have been designed and tested that generate lateral thrusts whose purpose is to produce both roll and yaw motions. Furthermore, they can be used to provide vertical stabilization in the forward motion to the robot. These fins are composed of Shape Memory Alloy wires (SMAs) embedded in silicone. We demonstrate that these fins are capable of providing a mean for 3D maneuvering. In this work we focus on roll and yaw motions. A key feature of the proposed design is that it is lightweight, compact and waterproof.

A Review of Robotic Fish Based on Smart Materials

“…Only when chasing prey and avoiding tracking will it become rigid to accelerate quickly. At present, most of the bionic robotic fish are rigid structures, and there is a certain gap between them and real fish [ 89 , 93 , 94 ]. In order to make the movement ability of the bionic robotic fish approach the real fish, more practical closed-loop control methods are needed in future research to coordinate the pectoral fin, body and tail fin of the robotic fish, and to integrate and optimize the structure to complete fast and accurate manoeuvres.…”