Design and experiments of robot fish propelled by pectoral fins

This paper described our work in probing into fish robot with pectoral fin propulsion. The aim of this project is to develop a robot fish mimicking cownose ray that swims with flexible pectoral fins in oscillation motion. According to the analysis of cownose ray´motion, a novel robot fish prototype propelled by pectoral fins was designed, The effect of flapping parameters (frequency and amplitude) and flexibility of fins on the propulsive performance was studied through a series of experiments underwater. Experiments showed that the velocity was almost in linear relationship with flapping frequency and amplitude below 2.0Hz, and the propulsive efficiency without chord-wise or span-wise ribs is higher than that with ribs. The conclusion is deduced that if the flexibility was selected properly, the pectoral fins with flapping mode would be an efficient propulsion mode for underwater vehicles.