Design and Yaw Control of a Two-Motor-Actuated Biomimetic Robotic Fish

This paper addresses the design and control of a novel tuna-inspired robotic fish able to realize both fast swimming and high maneuverability. A two-stage transmission mechanism is proposed, aiming at reducing the volume and mass of caudal peduncle. Benefited by it, both volumes and mass of moving parts can be reduced to allow higher swing frequency. At the same time, two joints driven by two motors ensure the flexibility of steering. The robotic fish achieves a maximum speed up to 1.65 body lengths per second (BL/s) and a minimum turning radius less than 0.35 body lengths (BL), based on the open-loop control designed by Central Pattern Generator (CPG) method. Furthermore, a yaw control is proposed to maintain course angle at high swimming speed, and simulation in Automatic Dynamic Analysis of Mechanical Systems (ADAMS) software reveals the effectiveness. The results show that the proposed yaw control method can regulate the fluctuation of anterior body to desired range but without compensation of sideways drift.