Citation: Gutnik, Y.; Avni, A.;
Treibitz, T.; Groper, M.
On the Adaptation of an AUV
into a Dedicated Platform for
Close Range Imaging Survey
Missions. J. Mar. Sci. Eng. 2022, 10,
974. https://doi.org/10.3390/
jmse10070974
Academic Editor: Giacomo Picardi
Received: 12 June 2022
Accepted: 11 July 2022
Published: 15 July 2022
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Journal of
Marine Science
and Engineering
Article
On the Adaptation of an AUV into a Dedicated Platform for
Close Range Imaging Survey Missions
Yevgeni Gutnik * , Aviad Avni, Tali Treibitz and Morel Groper
The Hatter Department of Marine Technologies, Leon H. Charney School of Marine Sciences, University of Haifa,
199 Aba Khoushy Ave. Mount Carmel, Haifa 3498838, Israel; aavni@univ.haifa.ac.il (A.A.);
ttreibitz@univ.haifa.ac.il (T.T.); mgroper@univ.haifa.ac.il (M.G.)
* Correspondence: ygutnik@campus.haifa.ac.il; Tel.: +972-548022772
Abstract:
This study presents the redesign of an existing autonomous underwater vehicle (AUV)
with limited maneuverability, transforming it into a platform optimized for autonomous, near-seabed
visual imaging missions. This work describes the enhancement of the AUV’s maneuverability
through the addition of thrusters, the leveraging of a state-of-the-art thrust allocation algorithm,
and the development of both a path-following controller and a dedicated imaging system. The
performance of the optimized platform is demonstrated in a simulation and in actual real sea visual
survey missions.
Keywords:
dynamics of underwater vehicles; hovering autonomous underwater vehicle (AUV);
hydrodynamic coefficients; path following; thruster allocation; underwater imaging; visual survey
1. Introduction
Visual surveys of the seabed enable us to quantify underwater benthic communi-
ties
[1,2]
, explore archaeological sites [
3
], inspect sub-sea structures [
4
], and map the
seabed [
5
,
6
]. These attributes make them extremely important tools in marine research. The
underwater medium, however, presents significant challenges to imaging survey platforms.
The rapid attenuation of light and the water turbidity force such platforms to operate close
to the surveyed object, in particular when high-resolution data are required. Consequently,
to map a large area, sets of images must be collected and stitched together into a photo-
mosaic [
7
,
8
]. High-quality photomosaics comprise images collected under homogeneous
optical conditions and depend on the amount of overlap between the images in the set [
6
,
9
].
Acquiring such an image set requires roaming the camera with high precision along the
mapping transects while maintaining constant altitude and orientation.
Often, image sets are collected by scuba divers; however, divers are limited by dive
time and depth. In addition, they are unable to precisely navigate long transects while
maintaining their cameras at a constant orientation and altitude. The development of ad-
vanced underwater platforms such as remotely operated vehicles (ROVs) and autonomous
underwater vehicles (AUVs) has allowed researchers to execute complicated missions while
extending the effective time and depth, improving data quality and eliminating the inherent
risks of human involvement. ROVs are generally powered and remotely controlled from
surface support vessels via a tether that provides power, real-time control and video stream
channels. The tether, however, limits the range and mobility of the vehicle. Furthermore,
the deeper the missions are, the higher the deployment complexity is [3].
AUVs are increasingly employed in underwater missions previously performed by hu-
man divers or by ROVs. Multiple on-board sensors allow AUVs to navigate autonomously
through predefined missions without the need for constant human supervision. In addition,
their untethered operation enables them to maneuver freely without the risk of tether en-
tanglement, in particular when operated close to the seabed and in
complex environments
.
J. Mar. Sci. Eng. 2022, 10, 974. https://doi.org/10.3390/jmse10070974 https://www.mdpi.com/journal/jmse
