Oscillation and direction control strategies for a robotic fish

Abstract

This paper discusses oscillation and directional control for a body and caudal fin type robotic fish. The robotic fish is modelled as a free-floating kinematic chain, and two possible control solutions are proposed based on deadbeat and feedback principles. Results demonstrate that the choice of controller has a significant effect on the resultant system dynamics and performance. While the deadbeat approach delivers excellent signal tracking with relatively little computational cost, H∞ feedback results in a significantly lower total power cost, at the expense of a larger rise time and threefold increase in computational complexity. The findings suggest that for the stated application, the performance characteristics of the H∞ strategy were superior.