Since Unmanned Underwater Vehicles have numerous applications and are affordable, they are used frequently. Accurate position estimation makes UUVs more useful, and suitable for more applications. In this thesis, the author investigates an autonomous, mobile, and light-based method for tracking UUVs.
Abstract: Unmanned underwater vehicles (UUVs) are being deployed continuously and the frequency of deployment is increasing because UUVs are more cost effective than manned submersibles. They have many applications, like aquaculture and offshore oil & gas, can be submerged for many hours, and can operate at depths dangerous for scuba divers. Whatever application UUVs are deployed for, the UUVs need to have accurate position detection with respect to their position relative to the water body’s surface and world position. Having accurate position detection can mean longer periods of submersion, potentially more data collection, and it is easier for researchers to return to an underwater area where something important was found. A challenge with an underwater positioning system is the tracking between the UUV and its reference platform, like a mobile unmanned surface vehicle. This master’s thesis investigated a new kind of autonomous, mobile, and light-based, also referred to as intensity-based, method for tracking a UUV’s underwater position and showing the UUV’s position relative to the waterbody’s surface and approximate world position. With two UUVs of the same design, one UUV was outfitted with a beacon, referred to as the UROV, and the other UUV was outfitted with a camera and programmed to maneuver itself to stay approximately centered over the beacon while staying at the surface of the water, referred to as the ASV. The light-based tracking method was evaluated based upon the ASV’s ability to adjust its position with the UROV’s beacon position along a straight course in the Engineering tank at the University of New Hampshire, Durham, NH, USA. The results revealed that this tracking system, on average, managed to keep the ASV within 3441 mm or 65.59% of the UROV’s position in a 3D plane, while tracking the UROV’s beacon up to 5.87 meters below the surface.This tracking method is an inexpensive, robust, and effective alternative to sound-based and laser-based underwater tracking methods.
Author: Whitaker, C.
Journal: University of New Hampshire
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