A turtle inspired underwater robot based on direct drive

Abstract

This paper reports on development of a turtle-inspired underwater robot. The robot has four fins and each of them is moved by direct drive method, a motor-driven method without any transmission mechanism. First, the swimming mode of the robot is determined as a scraping type, a swimming mode of turtles observed in nature. Next, the geometry and dimensions of the fins are designed by following the shape of the turtle's hands and the muscle-mass relationship available in biology. The designed fin is fabricated using a 3D printed mold and a silicone that is attached to a BLDC motor. The fabricated fin is tested in underwater to confirm its functionality. Finally, a simple turtle robot is fabricated by attaching four motorized fins to a platform and is tested underwater to validate the concept.