Development of an underwater robot with undulation propulsion

This paper presents the design and construction of a biomimetic swimming robot inspired by the locomotion of rays. These fishes move by flapping their pectoral fins and creating a wave that moves in the opposite direction to the direction of motion, pushing the water back and giving the fish a propulsive force due to momentum conservation. While this motion is similar to other fishes in terms of efficiency, it gives better maneuverability and agility in turning. The robot's fins are molded from silicone rubber and moved by servo motors driving mechanisms inside the leading edge of each fin. The traveling wave, mimicking the movement of the fin, is passively generated by the flexibility of the material. The robot is also equipped with a tail that acts as a rudder, helpful in performing maneuvers and maintaining the desired attitude. The rigid central body of the robot is the housing for motors, electronics, and batteries. Sensors embedded in the robot allow to estimate its behavior, to compare different swimming strategies, and evaluate the best algorithm to control the robot.