Abstract
It is thought that the swimming behavior of fishes can propose a new, highly effective method of underwater propulsion. When an eel swims, we can watch the phenomenon that the amplitude of lateral undulation increases from a head towards a tailpiece. We thought that each joint of an eel generates the same flexure power, but the amplitude might increase naturally because the body has the elasticity and then it would be effective for propulsion power and efficiency. In this research, we developed the eel-like robot for which we used the elastic joints. It was put micro computer and batteries on the head of the robot. In addition, we used 8 servomotors for actuators of joints and used 7 copper sheets for the elastic joints. We installed them to the robot from the head in turn. When the robot undulates, arguments of each servomotors change on Sin wave of the same amplitude that put off phase as time goes by. We made simple simulation of eel-like robot in consideration of inertia and drag in a static fluid. The amplitude of the midlines of swimming robot increased from a head towards a tailpiece in results of both simulation and experiment.
