Micro Autonomous Robotic Ostraciiform (MARCO): Design and Fabrication

Abstract

This paper presents the design and fabrication of a robotic ostraciiform. The robot's design is inspired by the highly stable and fairly maneuverable boxfish. Boxfish with its multiple fins can maneuver in confined spaces with a near zero turning radius and it has been found that its unusual boxy shape is responsible for a self correcting mechanism that makes its trajectories immune to water disturbances. The Micro Autonomous Robotic Ostraciiform (MARCO) project aims to apply these features in a novel underwater vehicle design. Miniature underwater vehicles with these characteristics have a variety of applications, such as environmental monitoring, ship wreck exploration, inline pipe inspection, forming sensor networks, etc. Tail fin hydrodynamics have been investigated experimentally using robotic flapper mechanisms to arrive at a caudal fin shape with optimal shape induced flexibility. Fluid simulation studies were utilized to arrive at the body shape that can result in self correcting vorticity generation. The robotic ostraciiform prototype was designed based on the above results. Ostraciiform locomotion is implemented with a pair of 2-DOF pectoral fins and a single DOF tail fin. The finalized body shape of the robot is produced by 3D prototyping two separate halves.