Robotic manta ray propelled by servo actuated pectoral fin

Abstract

Manta Ray is natural sample for lift based propelling robotic fishes. Pectoral fins that exhibit flapping motions are crucial for actuation of bio-mimic robotic Rays. In this research, a two-dimensional maneuverable bio-mimic robotic manta ray propelled by servo actuated pectoral fins is developed and modeled by a nonlinear dynamic model for easy and efficient control. Based on locomotion of natural manta ray an adept design is developed for robotic manta ray. A CFD analysis is done to understand the 3 dimensional dynamics involved in the flapping of manta ray. To fulfill the driving requirements for propelling the robotic manta ray, a single fin ray is used for each pectoral fin. Two servos are used to drive the fin rays and generate required deformations on the pectoral fins. Experimental study revealed that linear velocity was in a nearly linear relation with flapping frequency while angular velocity depends on difference between flapping frequencies of fins. Linear Speed of 0.53 Body-length/s and angular velocity of nearly 1.25 rad/s are accomplished by developed prototype in experimental tests.