3. What Are AUVs?
An autonomous underwater vehicle (AUV) is a robot which travels
underwater without requiring input from an operator. AUVs constitute part of
a larger group of undersea systems known as unmanned underwater vehicles,
a classification that includes non-autonomous remotely operated underwater
vehicles (ROVs) – controlled and powered from the surface by an
operator/pilot via an umbilical or using remote control. In military
applications AUVs are more often referred to simply as unmanned undersea
vehicles (UUVs)
4. And..
Autonomous Underwater Vehicles (AUV), also known as unmanned
underwater vehicles, can be used to perform underwater survey missions
such as detecting and mapping submerged wrecks, rocks, and
obstructions that pose a hazard to navigation for commercial and
recreational vessels. The AUV conducts its survey mission without
operator intervention. When a mission is complete, the AUV will return to
a pre-programmed location and the data collected can be downloaded
and processed in the same way as data collected by shipboard systems
*What’s the difference between an AUV and a Remotely Operated
Vehicle (ROV)?
AUVs operate independently of the ship and have no connecting cables.
6. Underwater Vehicles
Under water vehicles are broadly classified of 3 types;
the names are used interchangeably sometimes.
1
• Remote operated
vehicle(RUVs)
2
• Unmanned underwater
vehicle(UUVs)
3
• Autonomous Underwater
Vehicle(AUVs)
7. Early AUVs
• The first AUV was developed at the Applied Physics
Laboratory at the University of Washington as early as 1957
by Stan Murphy, Bob Francois and later on, Terry Ewart. The
"Special Purpose Underwater Research Vehicle", or SPURV,
was used to study diffusion, acoustic transmission, and
submarine wakes.
• Other early AUVs were developed at the Massachusetts
Institute of Technology in the 1970s. One of these is on
display in the Hart Nautical Gallery in MIT. At the same time,
AUVs were also developed in the Soviet Union
8. Basic 2 - Dimensional Structure
• The vehicle is 21" (53 cm) in diameter, and about 8
ft. (2.5 m) long.
• It weighs about 450 lbs. (200 kg).
• It is capable of operating at water depths up to
4500 m with a nominal velocity of 3 kts (1.5 m/s). In
a survey mode it has a maximum range of about 50
km i.e. (31.0686).
11. Various Parameters of the
AUVs
Sensor Systems & Processing
Navigations
Propulsion
Power & Energy
Communications
Autonomy
12. Sensor Systems & Processing
• An AUV is simply a platform on which to mount sensors and
sensing systems. Initial efforts to develop AUV technology
was more concerned about the basic technologies required
to allow reliable vehicle operation. As that reliability was
achieved, sensors were added to the vehicle system to
acquire data from the ocean environment
• Typical sensors include:
compasses
depth sensors
side-scan SONAR
magnetometers
thermistors
13. Navigation
• AUVs can navigate using an underwater acoustic positioning system. When
operating within a net of sea floor deployed baseline transponders this is
known as LBL navigation.
• When a surface reference such as a support ship is available, ultra-short
baseline (USBL) or short-baseline (SBL) positioning is used to calculate where
the subsea vehicle is relative to the known (GPS) position of the surface craft
by means of acoustic range and bearing measurements.
• Inertial navigation is a dead reckoning type of navigation system that
computes its position based on motion sensors. Once the initial latitude and
longitude is established, the system receives impulses from motion detectors
that measure the acceleration along three or more axes enabling it to
continually and accurately calculate the current latitude and longitude.
• Its advantages over other navigation systems are that, once the starting
position is set, it does not require outside information, it is not affected by
adverse weather conditions and it cannot be detected or jammed.
14. Propulsion
• AUVs can rely on a number of propulsion techniques, but propeller based
thrusters or Kort nozzles are the most common by far. These thrusters are
usually powered by electric motors and sometimes rely on a lip seal in
order to protect the motor internals from corrosion.
15. Power & Energy
• Most AUVs in use today are powered by rechargeable batteries (lithium
ion, lithium polymer, nickel metal hydride etc.), and are implemented
with some form of Battery Management System.
• Some vehicles use primary batteries which provide perhaps twice the
endurance—at a substantial extra cost per mission.
• A few of the larger vehicles are powered by aluminium based semi-fuel
cells, but these require substantial maintenance, require expensive refills
and produce waste product that must be handled safely.
• An emerging trend is to combine different battery and power systems with
Ultra-capacitors.
• Endurance of AUVs has increased from a few hours to 10s of hours. Some
systems now contemplate missions of days and, a very few, of years. This
extended endurance, however, is at the expense of sensing capability, as
well as very limited transit speeds.
16. Communications
• In the underwater environment acoustic communications is
probably the most viable communication system available
to the system designer.
• Some development programs have investigated and
evaluated other technologies such as laser communication
at short range and relatively noise free communications
over larger ranges using RF current field density techniques.
• In the past 10 years there has been significant advances in
acoustic communications such that relatively low error rate
communications is possible over ranges of kMs at bit rate
of a few kbps [Comms]. This remains an active area of
investigation.
17. Autonomy
• In the 1980s there was effort placed into understanding how to give an AUV a
level of intelligence necessary to accomplish assigned tasks. Issues such as
intelligent systems architectures design, mission planning, perception and
situation assessment were investigated.
• These are all hard problems and there were few successes that led to in-water
evaluation. As the capabilities required by the first generation AUVs became clear,
the tasks the AUVs were to perform seemed not to demand a high level of
intelligent behaviour. In fact many of the tasks being assigned to today’s AUVs
required only a list of pre-programmed instructions to accomplish a task. For this
reason, there has not been a significant level of development, recently, that is
focused on AUV autonomy.
• The problem of autonomy still remains unsolved. There have been some successes
with other autonomous systems, but those advances have not been brought into
the AUV community. There are very few programs funded to address these issues
and the problem remains.
• As AUV operations increase, it will become apparent that more investigation is
needed. This will again emphasize the need for more development along the lines
of making AUV systems more intelligent and better able to adapt to the
environment within which they exist.
18. Applications Of AUVs
Commercial Applications
The oil and gas industry uses AUVs to make detailed maps of the seafloor
before they start building subsea infrastructure; pipelines and sub sea
completions can be installed in the most cost effective manner with
minimum disruption to the environment.
The AUV allows survey companies to conduct precise surveys of areas
where traditional bathymetric surveys would be less effective or too
costly.
Military Applications
A typical military mission for an AUV is to map an area to determine if
there are any mines, or to monitor a protected area for new unidentified
objects.
AUVs are also employed in anti-submarine warfare, to aid in the detection
of manned submarines.
19. Research Applications
Scientists use AUVs to study lakes, the ocean, and the ocean floor. A
variety of sensors can be affixed to AUVs to measure the concentration of
various elements or compounds, the absorption or reflection of light, and
the presence of microscopic life.
Additionally, AUVs can be configured as tow-vehicles to deliver
customized sensor packages to specific locations.
Investigation Applications
Autonomous underwater vehicles, for example AUV ABYSS, have been
used to find wreckages of missing airplanes, e.g. Air France Flight 447
20. AUV – 150 from INDIA
• AUV (Autonomous Underwater Vehicle) - 150 is an unmanned
underwater vehicle (UUV) being developed by Central Mechanical
Engineering Research Institute (CMERI) scientists in Durgapur in the
Indian state of West Bengal. The project is sponsored by the
Ministry of Earth Sciences and has technical assistance from IIT-
Kharagpur.
• The vehicle was built with the intent of coastal security
like mine counter-measures, coastal monitoring
and reconnaissance.
• AUV 150 can be used to study aquatic life, for mapping of sea-floor
and minerals along with monitoring of environmental parameters,
such as current, temperature, depth and salinity.
• It can also be useful in cable and pipeline surveys. It is built to
operate 150 metres under the sea and have cruising speed of up to
four knots.
22. Characteristics of AUV - 150
Structure
• AUV-150 is cylindrical-shaped with streamlined faring to reduce hydrodynamic
drag. It is embedded with advanced power, propulsion, navigation, and control
systems.
• The UUV includes a pressurized cabin which is necessary for the diving and
flotation system to work properly; this also helps to increase its sealing power
against water leakage into the cabin.
• The AUV 150 weighs 490 kg, is 4.8 metres long and has a diameter of 50 cm.
Control system
• The AUV is autonomous, that is automatic and self-controlled. It has an on-board
computer that can be pre-programmed to dive to pre-set depths, move along pre-
set trajectories, and return to the base after completing the assigned tasks. A
remote control option is provided in order to perform special tasks.
Propulsion
• It is propelled by water-jet propulsion which comprises thrusters for generating
motion in different directions to control surge, sway, heave, pitch, and yaw, while
preventing the vehicle from rolling. Two arrays of cross-fins have also been fixed at
the two ends to provide additional stability to the AUV.
23. Navigation
• The autonomous vehicle is equipped with a number of navigational equipment to
locates its own geographical position Such as inertial navigation system, depth
sonar, altimeter, Doppler velocity log, global positioning system through ultra-short
baseline system and forward looking sonar to facilitate obstacle evasion and safe
passage.
Payload
• It is equipped with an underwater video camera that can send wireless video
pictures from underwater to a monitor above water surface along with side scan
sonar.
• The submarine is equipped with CTD or conductivity-temperature-depth recorder
and several sensors that can measure orientation, current and speed.
Communication
• For smooth communication and distant intervention, the vehicle is equipped with
hybrid communication system: it uses radio frequency while on surface and
acoustic under water.
Power
• The vehicle uses a Lithium polymer battery and can operate up to depths of 150
metres at speeds of 2-4 knots.
24. AUV Manufacturers!
• Kongsberg Maritime
• Hydroid (now a wholly owned subsidiary
of Kongsberg Maritime)
• Bluefin Robotics
• Teledyne Gavia (previously known as
Hafmynd)
• International Submarine Engineering (ISE) Ltd.
25. Research & Development
• Current AUV development programs are, in many cases, being
supported by funding that results from the political process as
opposed to market need or technical merit. This, however, is a
current reality within which development of AUV technology
advances.
• Although these programs are very visible due to the level of activity,
it is short sited to over emphasize some of these activities over
smaller, less advertised work.
• There are a number of organizations in the USA, and elsewhere,
actively working on important research problems.
• As mentioned above, there is much to be understood regarding
technologies such as Autonomy, Energy, Navigation, Sensors, and
Communications. These are very much open research topics
26. Evolving Markets
• At this point in time we are seeing a number of markets
beginning to form. Although not clearly defined the level of
enthusiasm of a number of individuals and organizations
suggests that we will see many opportunities for
commercializing AUV technology over the next few years.
• Individual companies, as well as teams of organizations,
have begun efforts to make operational AUVs part of the oil
& gas industry toolkit. Missions have been defined,
contracts let, vehicle systems designed, and fabrication of
the operational systems begun.
• The next fewyears will provide insight into the real
capability of the commercial AUV
27. The Future of AUV Technology
• AUV technology has followed a path not unlike other
technologies. It has gone through stages where academic
curiosity was followed by research investigation and
prototype development.
• Applications have recently surfaced that seem to have
sufficient financial backing to develop operational systems.
Certainly the timing of AUV technology was good. It has
been able to leverage its development by utilizing many
technologies developed for other markets.
• The next five years will see the expansion of AUV
technology into the commercial marketplace. The size of
that market is unclear but the move into the marketplace
has begun. There are still many important research
investigations to be undertaken. Autonomy is probably the
most important issue to be addressed but others, such as
those described above, certainly must be addressed.
28. • It is clear that the limit to the capability of any AUV is the amount of
energy it has on board. There have been many discussions that
suggest that fuel cell technology has reached a point where it may
well be possible to use this technology in AUV systems.
• The increase in endurance will be substantial. Is this the “silver
bullet” for AUVs? I would suggest that there is no “silver bullet,” but
rather a continuum of activity that spans a wide spectrum. Basic
research into some of the enabling technologies must be
supported.
• The development of operationally reliable systems must be
undertaken. Unique markets where AUV technology can make a
significant impact must be identified. Most important, the AUV
community must educate the user community of the future about
AUV systems capabilities and operational reliability