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52

Annual Report 2016

SAMCoT

In April 2016 SAMCoT PhD candidate Petter Norgren

participated in an experiment to explore the possibility

of combining R/V Gunnerus, the autonomous underwater

vehicle (AUV) Hugin, the unmanned aerial vehicle (UAV)

X8, and the unmanned surface vehicle (USV) Mariner

in a network of heterogeneous unmanned vehicles.

Different institutions participated, among them NTNU,

the Norwegian Defence Research Establishment

(Forsvarets forskningsinstitutt, FFI), Kongsberg Seatex,

the Laboratório de Sistemas e Tecnologia Subaquática

(LSTS) at the University of Porto and Maritime Robotics.

Communication, maneuvering, onboard processing,

and operational complexity are essential components

in such networks. The Kongsberg marine broadband

radio (MBR) system was used for communication.

Norgren was involved with the AUV operation and on the

processing of the data collected.

The participants defined a scenario with seabed

mapping and target recognition to show the capabilities

of the proposed system. The experiment made it

apparent that these networks have the potential to save

significant data collection costs in marine research

and management by reducing ship time. To unlock fully

INTEGRATED AUTONOMOUS OPERATIONS

the potential of networks of heterogeneous unmanned

vehicles, the objectives of each individual vehicle will

need to be better integrated into the overall mission.

Autonomous Tethering of AUVs

using the USV Jetyak

A standard AUV survey requiring high-accuracy navi-

gation currently requires a ship to follow the AUV and

provide position updates. Moving this task to an USV,

that autonomously follows the AUV, could potentially

save significant ship time. Autonomous tethering of

AUVs using a USV can also provide a real-time commu-

nication link between an operator station and an AUV,

which is often a desired feature for monitoring progress

and status. To prepare for research on autonomous

tethering, the NTNU/UiT USV Jetyak was equipped with a

range of new sensors.

Norgren extended the hardware of the USV Jetyak

control system to allow logging and control of the

new sensors through a Kongsberg MBR 144. The main

goal of the new hardware interface on the Jetyak was

to allow acoustic communication, as well as Wi-fi

connectivity, with the Light AUVs (LAUVs) through the

AUV expedition with students from the

UNIS course AT334 in Longyearbyen, August 2016

MBR. The upgrade of the Jetyak control system also

allowed inclusion of several new sensors, and to extend

the feasible operating area for the Jetyak in the Arctic

polar night, Norgren also equipped the Jetyak with

a SIMRAD 4G radar and an infrared IP camera. The

scientific payload of the Jetyak was also extended to

include a Norbit multibeam sonar, in addition to the old

payload consisting of sidescan sonar and an acoustic

zooplankton and fish profiler (AZFP).

Example track of the Icebreaker Oden through various ice regimes, reconstructed from the camera images,

and the corresponding extreme load distribution fit for a part of the track.

To facilitate Heyn’s research, four inertial measurement

units (IMUs) were mounted on different locations in

the vessel to monitor the ice-induced accelerations

of the icebreaker hull during both station-keeping

operations and transit through the sea-ice. The IMU

motion data were also supported by a system of 11

cameras that continuously monitored the ice conditions

and icebreaking processes 360 degrees around, and

especially ahead of the vessel. The conjecture here is

that the acceleration measurement of the IMUs will

contain information on the ice loads acting on the ship’s

hull similar to that which could be obtained from strain

gauges. SAMCoT’s research attempts to use the IMUs,

cameras and radar data for the online tracking and

short-term prediction of the extreme ice loads acting

on the vessel, estimation of local ice drift velocity and

direction relative to the vessel and real-time estimation

of global ice loads on the vessel. In addition to functi-

oning as an important image documentation system for

validation purposes, the camera images are further used

to estimate the local ice concentration and floe size

distribution and possibly to identify ice features such as

ridges and melt ponds.