Bioinspired pursuit with a swimming robot using feedback control of an internal rotor

Theoretical guarantees of capture become complicated in the case of a swimming fish or fish robot because of the oscillatory nature of the fish heading. Building on the connection between a swimming fish and the canonical Chaplygin sleigh, a novel state feedback control law is shown to result in closed-loop dynamics that exhibit a limit cycle resulting in steady forward-swimming motion in a desired heading. Analysis of this limit cycle reveals boundaries on the size of the oscillations around the desired heading, which are then used to specify under what conditions (e.g. prey speed, predator speed, control gains) capture is guaranteed. By changing the desired swimming direction in response to prey movements, the control law is shown to be capable of pure pursuit, deviated pure pursuit, intercept, and parallel navigation in simulation. An experimental demonstration of pure pursuit by a flexible fish-inspired robot actuated with an internal reaction wheel is described.