Experiments and identification of an ostraciiform fish robot

Abstract

The ostraciiform swimming mode allows the simplest mechanical design and control for fish robot swimming. Propulsion is achieved via the flapping of caudal fin without the undulatory body motion. In this research, some rigid caudal fins were used to identify the effects of flapping frequency and flapping amplitude on the swimming velocity of an ostraciiform fish robot. Experiments were conducted to measure the drag coefficient and the added mass of the fish robot. The experimental data were identified with a theoretical model of caudal fin propulsion. It can be shown that the terminal velocity was proportional to the flapping frequency and to the 2/3 power of the flapping amplitude.