Autonomous Underwater Vehicle
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An Autonomous Underwater Vehicle (AUV) is a robot which travels underwater. Sometimes called Unmanned Underwater Vehicles, these devices are powered by batteries or fuel cells and can operate in water as deep as 6000 meters. Advances in propulsion systems and power source technology give these robotic submarines extended endurance in both time and distance.
Some of the first AUVs were developed at the Massachusetts Institute of Technology in the nineteen seventies. 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 (although this was not commonly known until much later). In military applications, AUVs are also known as Unmanned Undersea Vehicles (UUVs). They should not be confused with ROVs which are similar unmanned undersea vehicles that are controlled and powered from the surface by an operator/pilot via an umbilical.
The oil and gas industry uses AUVs to make detailed maps of the seafloor before they start building subsea infrastructure. The detailed maps from the AUVs allows the Oil Companies to install pipelines and sub sea completions in the most cost effective manner with the minimum disruption to the environment. A typical military mission for an AUV is to map an area to determine if there are any mines. Scientists use AUVs to study the ocean and the ocean floor.
Although not currently operational, there are several designs of AUV that are capable of subsea intervention (interaction with subsea structures) as opposed to fly-by data collection. The development of subsea processing in deep and ultra deep offshore oilfields and their cost of maintenance will be the most likely drivers to make these vehicles routinely operational.
Primarily oceanographic tools, AUVs carry sensors to navigate autonomously and map features of the ocean. Typical sensors include compasses, depth sensors, sidescan and other sonars, magnetometers, thermistors and conductivity probes. A demonstration at Monterey Bay in California in September 2006 showed that a 21 inch diameter AUV can tow a 300 feet long hydrophone array while maintaining a 3 knot cruising speed.
Today, most AUVs work in conjunction with surface vessels for navigational purposes, although ultra-low-power, long-range variants such as underwater gliders are becoming capable of operating unattended for weeks or months in littoral and open ocean areas, periodically relaying data by satellite to shore, before returning to be picked up.
AUVs can navigate inside a net of acoustic beacons; this is known as Long Base Line (LBL) navigation. When a surface reference such as a support ship is available, Ultra-short baseline (USBL) 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. When it is operating completely autonomously, the AUV will surface and take its own GPS fix. Between position fixes and for precise maneuvering, an inertial navigation system onboard the AUV measures the acceleration of the vehicle and Doppler velocity technology is used to measure rate of travel. A pressure sensor measures the vertical position. These observations are filtered to determine a final navigation solution.
Most AUVs in use today are powered by rechargeable batteries (Lithium ion, Lithium polymer, Nickel metal hydride etc). 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 aluminum based semi-Fuel cells.
Hundreds of different AUVs have been designed over the past 20 or so years, but only a few companies sell vehicles in any significant numbers. The small REMUS 100 AUV developed by Woods Hole Oceanographic Institution in the US and now marketed by Hydroid, Inc. is the most popular AUV in the military and scientific markets today. In the oil and gas industry, the larger Norwegian HUGIN 3000 AUV developed by Kongsberg Gruppen and Norwegian Defence Research Establishment (FFI) dominates. Other notable AUV manufacturers include Bluefin Robotics in the US and International Submarine Engineering Ltd. in Canada.
[edit] See also
- Woods Hole Oceanographic Institution
- MIT
- Monterey Bay Aquarium Research Institute
- Remotely operated vehicle
- University of Michigan
- Office of Naval Research
- National Oceanography Centre, Southampton
[edit] External links
[edit] Collection of groups and projects
[edit] Companies
- Bluefin Robotics
- Hafmynd
- Hydroid, LLC
- International Submarine Engineering, Ltd. - AUVs
- Kongsberg Maritime
- Ocean Server Technology Inc.
- Sias Patterson Inc.
- Alaska Native Technologies
[edit] Research organizations
[edit] Research at universities
- Robotics & Automation Lab, University of Western Australia, also provide a free 3D submarine simulator.
- Department of Naval Architecture & Marine Engineering, University of Michigan
- Department of Ocean Engineering, Florida Atlantic University
- AUVs in operation at UNC Wilmington
- SONIA AUV project developed by undergraduates at École de technologie supérieure (ETS - Canada)
- An AUV project, being developed by students at Faculty of Engineering of the University of Porto (FEUP - Porto, Portugal)
- Mobile and Marine Robotics Research Centre, Universty of Limerick, Ireland
[edit] Application papers
- The Application of Autonomous Underwater Vehicle (AUV) Technology in the Oil Industry – Vision and Experiences
- Beneath the wave of the future.