engleski

Tracking Divers : An Autonomous Marine Surface Vehicle to Increase Diver Safety

Diving is a high–risk activity due to hazardous environment, dependency on technical equipment for life support, complexity of underwater navigation, and limited monitoring from the surface. This article describes a new concept of using an autonomous surface vehicle as a ”private satellite” that tracks divers, thus significantly increasing diving safety. Since the vehicle is at all times above the diver, acoustic communication with the diver interface in a form of an underwater tablet is more efficient and robust, which enhances diver navigation and enables reliable monitoring from the surface. The article focuses on diver tracking control structure that uses a diver motion estimator to determine diver position even in cases when acoustic position measurements are not available. Conducting experiments with divers presents a challenge due to uncertainties, such as those introduced by the environment, unmodelled dynamics, acoustic sensors and divers themselves (emission of air bubbles). A step–by–step experimental plan which includes a virtual diver (VD), remotely operated underwater vehicle (ROV) and a human diver allows identification of different uncertainties. The results show that the mean tracking error with a VD (influenced only by environment and unmodelled dynamics) is around 0.5 m, with ROV (including the influence of acoustic sensor) around 1 m, and with a human diver around 1.8 m. This data is validated against ground truthing video imagery.

marine robotics ; diver tracking ; personal robots ; sensor fusion ; performance metrics

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