CONTENTS
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Introduction
Topics dealt with…
Underwater gliders
Working of an underwater glider
Applications
Objective of the experiment
Glider operations
Future developments and applications at the Institute Of Ocean
Technology
ASMT
Laboratory scale glider
Conclusion
Thank you…
INTRODUCTION
Sampling of oceans has traditionally been
conducted from ships.
HMS challenger(1872-1876).
Took an awesome period of 23yrs.to
compile the results.
Emergence of alternative technologies
Has brought us a long way from the
“CHALLENGER CRUISE”.
TOPICS DEALT WITH…
AUVs ( Autonomous underwater vehicles)
AOSN-2 field expt in Monterey bay,
California.
Current efforts to develop a laboratory scale
glider.
Underwater gliders
Represent a rapidly maturing technology
Large cost saving potential
Working of an Underwater Glider
Buoyancy engine to change their weight in
water.
Generation of hydrodynamic lift and drag
forces
Closed loop control of attitude and depthperformed by an on-board computer that
executes a pre-programmed mission while
submerged
A receiver to compare the position with the desired
position from the mission plan
Position error used to compute the average current
flow encountered…… which is used to correct the dive
parameters for the next dive cycle.
Communication at the surface using an IRIDIUM
satellite connection.
Antennae’s are integrated into the gliders
For a SLOCUM glider antennae and receiver are
embedded within the rudder assembly.
Glider collects data from their scientific sensors
Besides CTD sensors, they even carry PAR sensors
and Fluorometers
APPLICATIONS
Autonomous Ocean Sampling Network 2Monterey Bay 2003
Conducted during the summer of 2003 in
Monterey Bay, California
Bay was chosen for its accessibility, resident
research institutions with on site hardware
(ships, airplanes, AUVs) and its interesting
bathymetry.
A certain drawback due to additional sensors as well
as frequent communication and shallow dives is:
Increase in power consumption thereby a reduction in
mission length.
OBJECTIVE OF THE EXPERIMENT
To demonstrate the feasibility of an integrated ocean observation ,modeling and
prediction system.
This expt differs from the previous efforts because of its high degree of system
integration
GLIDER OPERATIONS
Two types of gliders were available: SPRAY
gliders & SLOCUM gliders
Prior to the expt all gliders were shipped to
the MBARI in Moss landing, California.
Sensor data were closely monitored during
the course of the experiment.
Undue advantage of the different depth
capabilities of gliders were taken
.communication to and from the gliders using
IRIDIUM satellite.
Due to more frequent inflections and higher sensor
load SLOCUM gliders were recovered during the
course of the experiment.
After recovery ,gliders battery packs were
replaced system re-ballasted, checked out and
readied for deployment.
A real time operational display was made available
at the control center at MBARI.
The display was improved during the course
of the expt. (display was automated)
FINDINGS
Gliders sometimes advanced marginally
over the course of some several hours
Far above its theoretical limits
This phenomenon was observed 3-4 times
 The performance of several multi-vehicle expts shows
the potential for added value by using coordinated
control strategies
 New tools are under development that allow for
improved planning and monitoring of the observational
assets which will provide a higher degree of autonomy
during future deployments.
FUTURE DEVELOPMENTS AND
APPLICATIONS AT THEINSTITUTE
OF OCEAN TECHNOLOGY
Newfoundland Ocean Observation, modeling
and prediction facility (NOOMPF)
A Team of researchers from NRC-IOT, Memorial
University of Newfoundland (MUN) and the
department of fisheries and oceans (DFO)
Currently developing a plan to implement a
regional coupled ocean observation and modeling
system in Newfoundland (NOOMPF)
Possible sites –Conception Bay, Trinity Bay and
Placentia Bay.
Goal is to develop a capability for
automated coupled ocean
observation and model predictions on a
regional scale.
 Enhance our ability to predict and manage the
ocean
 Observations will be based on a suite of different
sampling platforms
 Conventional observations + data available from
satellites + autonomous mobile platforms.
 NRC-IOT ’s role is to develop the control and
communication infrastructure necessary to
direct and monitor the observational assets.
ASMT
WILL SERVE AS THE MAIN CONTROL
AND MONITORIG SURFACE.
LABORATORY SCALE GLIDER
 NRC-IOT is considering developing a lab. Scale
glider
 Purpose of a lab. Scale glider is to conduct expts.
for hydrodynamic testing and control and to
provide a test –bed for new actuation and flow
sensing technologies
 Design alternatives and constraints of a buoyancy
engine
 Vertical motion tests
 After completion of design of buoyancy engine –
hydrodynamic design of the glider
CONCLUSION
 Autonomous underwater vehicles, and in
particular autonomous underwater gliders
represent a maturing technology with a large
cost saving potential over current ocean
sampling technologies for sustained (month
at a time) real time measurements.
THANK YOU.