At-sea testing of the Mesobot midwater robot

Dana Yoerger1, Molly Curran2, Justin Fujii2, Daniel Gomez-Ibanez3, Annette Govindarajan1, Jonathan Howland3, Joel Llopiz2, Peter H Wiebe3, Brett Hobson4, Kakani Katija4, Michael Risi5, Bruce H Robison5, Stephen Rock6, John A Breier Jr7 and Cailean J Wilkinson8, (1)Woods Hole Oceanographic Institution, United States, (2)Woods Hole Oceanographic Institution, Woods Hole, United States, (3)Woods Hole Oceanographic Institution, Woods Hole, MA, United States, (4)Monterey Bay Aquarium Research Institute, Moss Landing, CA, United States, (5)Monterey Bay Aquarium Research Institute, Moss Landing, United States, (6)Stanford University, Aeronautics and Astronautics, Stanford, CA, United States, (7)University of Texas Rio Grande Valley, Edinburg, TX, United States, (8)University of St Andrews, St Andrews, United Kingdom
We present engineering results from our new Mesobot robot from tests in tanks and in the open ocean. Mesobot has been designed to explore the ocean’s mesopelagic regions with the ability to survey with cameras, track organisms autonomously using stereo cameras, and take samples for geochemical and molecular analyses. Mesobot is a hybrid vehicle that can be teleoperated over a lightweight fiber optic tether or it can run autonomously with no tether. Mesobot has been designed to be as unobtrusive as possible, using far-red illumination and thrusters that disturb the environment minimally.

Tank test results include demonstration of basic stability and maneuvering characteristics, automatic heading and depth control, stereo tracking of artificial targets with red light, basic operation on the lightweight tether, and autonomous operation after dropping the tether. During tracking operations, Mesobot’s low-powered, large-diameter thrusters created only very low levels of hydrodynamic disturbance. In later tests from R/V Rachel Carson, we demonstrated at-sea operations including launch and recovery, successful use of the tether and SmartClump to operate to depths of several hundred meters, the transition from teleoperated to autonomous operation, basic acoustic communications, and a brief period of automated target tracking.