Abstract
We have developed oscillation wing propulsion type fish robots which was modeled the tuna. In this paper, a Scotch-York type driving mechanism of the caudal fin is used that is powered by the 2.6kW outrunner type sensorless brushless motor. In this report, we introduced cross link mechanism for the spine part to rotate the caudal fin faster and larger than rigid spine. The experimental results showed that cross link mechanism improve the swimming speed. It means that the larger yawing rotation in the propulsion is effective. We also tested our new two types of special caudal fins, rigid fin with loosen ligament and concave curve self-generation fin. In rigid fin with loosen ligament, we prepared several fins to change the shape of wing tip and the length of wing-chord. We also changed the phase restriction angle by changing the length of the loosen ligament. The new-type concave-curve self-generation fin keep its streamline wing shape when it generates concave curve. The experimental results showed that the new type concave curve self-generation fin showed the high efficiency for the swimming speed.
