The AUV System
Autonomous Underwater Vehicles
What is an AUV?
An AUV is an autonomous underwater vehicle that navigates without a human crew onboard and without cables connecting it to a research vessel at the sea surface. It is launched either by hand or by a launch system aboard a research vessel depending on the vehicle’s size. After entering the water, the vehicle navigates acoustically by communicating with separate anchored transponders. Each vehicle has three motors that operate the propeller and two pairs of fins used for steering and diving. An onboard computer, similar to that in a laptop, coordinates the movements of these motors according to the mission plan downloaded onto the AUV by engineers before launch.
As the AUV travels back and forth on its programmed path through the water, it is said to be “mowing the lawn,” creating overlapping lanes of sea floor data with numerous onboard sensors. These lanes combine to create a cohesive map representing the ocean bottom. Once the vehicle has finished its pre-programmed course, it returns to the surface, where it is recovered and brought onboard the research vessel. Operators are able to download the collected data from the AUV and program it with a set of instructions for the next area of seafloor to be mapped.
The CATALYST AUVs
The CATALYST Program makes available to the scientific community the Waitt Institute’s two REMUS 6000 Autonomous Underwater Vehicles (AUVs). The CATALYST AUVs have been designed to operate in depths ranging from 25 meters (82ft) to 6000 meters (19,685ft or 3.73 miles). This innovative and efficient new technology can be used for numerous exploration and mapping purposes, including marine conservation, ocean health studies, geological charting, and archaeological investigation.
The CATALYST AUVs can be configured to include a wide array of sensors depending upon expedition requirements. They can be used for hydrographic surveys, environmental monitoring, debris and field mapping, search and salvage operations, fishery operations, scientific sampling and mapping. As versatile research tools, the CATALYST AUVs can be outfitted with dual frequency side-scan sonar, sub-bottom profilers, conductivity/temperature sensors, pressure sensors, acoustic modems, fluorometers, optical sensors, still cameras, and acoustic imaging.
The REMUS 6000 AUV was designed under a cooperative program involving the Naval Oceanographic Office, the Office of Naval Research, and the Woods Hole Oceanographic Institution in support of deep-water autonomous operations and continues to be developed at WHOI’s Oceanographic Systems Laboratory. Hydroid Inc. of Pocasset, MA now manufactures the vehicles.
Hydroid, Inc was founded in 2001 by the inventors of REMUS and has grown at an amazing rate. The company now boasts over 150 AUV system sales to a variety of domestic and international customers. To support this growth, Hydroid now has a staff of over forty full and part-time employees and is located in a state-of-the-art facility in Pocasset, Massachusetts. Hydroid’s mission is to support the spread of the remarkable REMUS technology and to provide for continuous product development.
The LARS System
The REMUS Launch and Recovery System (LARS) is a self-contained system that was engineered at the Oceanographic Systems Lab (OSL) at WHOI. It enables the launch and recovery of the REMUS 6000 in sea states up to those created by the Beaufort Scale 5 wind and is installed on the stern of a ship. For launch, the LARS has a built-in A-frame, which tilts the cradle up and over, while leaving the vehicle hanging by its nose. The cradle stabilizes the vehicle until it is a safe distance from the vessel and where the vehicle can be lowered into the water, tail first. When ready, the AUV is commanded to release its towline and begin its mission.
When the vehicle surfaces at the end of a mission, it notifies the operators onboard the research vessel with its GPS coordinates. The vessel then approaches the AUV and commands it to release its recovery float and line, which then make an easy target for a grapple toss. Once the line is on-board the AUV, the vehicle is put in tow and the line is attached to the LARS for recovery. The vehicle is pulled back onto the ship and remains in the LARS where it may be prepared for its next mission.