A Compact Autonomous Underwater Vehicle With Cephalopod-Inspired Propulsion

Abstract

In this paper, a bioinspired, compact, cost-effective autonomous underwater vehicle system is presented. Designed to operate in a heterogeneous, multivehicle collaboration hierarchy, the presented vehicle design features 3D printing technology to enable fast fabrication with a complex internal structure. Similar to a previous vehicle prototype, this system generates propulsive forces by expelling unsteady, pulsed jets, inspired by the locomotion of cephalopods and jellyfish. The novel thrusters enable the vehicle to be fully actuated in horizontal plane motions, without sacrificing the low-forward-drag, slender vehicle profile. By successively ingesting water and expelling finite water jets, periodic actuation forces are generated at all possible vehicle velocities, eliminating the need for control surfaces used in many conventional underwater vehicle designs. A semiactive buoyancy control system, inspired by the nautilus, adjusts the vehicle depth by passively allowing water flowing into and actively expelling water out of an internal bladder. A compact embedded system is developed to achieve the control and sensing capabilities necessary for multiagent interactions with the minimum required processing power and at a low energy cost. The new vehicle design also showcases an underwater optical communication system for short-range, high-speed data transmission, supplementing the conventional acoustic communication system. Experimental results show that, with the thruster motors powered at a 60% duty-cycle, the new vehicle is able to achieve a 1/4 zero-radius turn in 3.5 s and one-body-width sway translation in 2.5 s.

The Current State of Cephalopod Science and Perspectives on the Most Critical Challenges Ahead From Three Early-Career Researchers

“…Today, some of the most unique characteristics of cephalopods are also inspiring various technological developments, including adaptive camouflage based on cephalopod skin that can display a variety of patterns ( Wang Q. et al, 2014 ; Yu et al, 2014 ) or spontaneously match its surroundings ( Pikul et al, 2017 ), suction cups for wound repair ( Choi et al, 2016 ), propulsion and buoyancy systems for Autonomous Underwater Vehicles (AUV, Song et al, 2016 ), distributed cognitive control systems for artificial intelligence ( Íñiguez, 2017 ) and the design of soft robots ( Laschi et al, 2012 ; Renda et al, 2012 ).…”

Controlling the deformation space of soft membranes using fiber reinforcement

“…In addition, fiber reinforcement helps to prevent rupture in the membrane, which could occur more easily in an unreinforced membrane. We plan to integrate the fiber-reinforced buoyancy bladder into our bioinspired AUVs, the CephaloBot (Krieg et al, 2011) and daughter vehicle (Song et al, 2016).…”

Design of a 3-D Printed, Modular Lateral Line Sensory System for Hydrodynamic Force Estimation

“…Our group has worked on several generations of bio-inspired underwater vehicles including five generations of mother vehicles (Krieg et al, 2011) and two generations of daughter vehicles (Song et al, 2016). Our group emphasizes research in hierarchical, swarm-based control (Song et al, 2017) with capable mother vehicles supporting smaller daughter vehicles.…”