Experimental study of a self-propelled two-joint dolphin robot

Abstract

We constructed a self-propelled two-joint dolphin robot as a simplified model of high-speed swimming animals. The total length of the robot is 1.75m, which is similar to the length of actual fast swimming animals. The robot is composed of a streamlined body and a rectangular caudal fin. The first joint is actuated by an air motor connected to a high pressure a air tank. The second joint is moved passively by springs. A measurement system was developed in order to measure the joint torque and joint angle of the first joint. The robot attained a propulsive speed of 1.2 m/s and a propulsive efficiency of 0.35.