Proof of concept demonstration of the Hybrid Remotely Operated Vehicle (HROV) light fiber tether system

Abstract

The Hybrid Remotely Operated Vehicle (HROV) Nereus, developed by the Woods Hole Oceanographic Institution (WHOI) with the support of the Space and Naval Warfare Systems Center San Diego (SSC San Diego) and the Johns Hopkins University, is intended to provide a new level of access for deep oceanographic research to a maximum depth of 11,000 meters. Nereus operates in two different modes. The vehicle can operate untethered as an autonomous underwater vehicle (AUV) for broad area survey, capable of exploring and mapping the seafloor with sonars, cameras, and other on-board sensors. Nereus can be converted at sea to become a remotely operated vehicle (ROV) to enable close up imaging and sampling. The ROV configuration incorporates a lightweight fiber optic tether to the surface for high bandwidth real-time video and data telemetry to the surface to enable high-quality teleoperation, additional cameras and lights, a manipulator arm, and sampling gear. Development of the fiber tether system was supported by both simulation and extensive field testing over a three year period. These tests demonstrated that an unprotected optical fiber could survive in the water column for greater than 24 hours and be effectively used as a high bandwidth data link by a remotely-operated, self-powered vehicle. Based on the data from the fiber trials, a robust tether deployment system was designed. The tether deployment system was integrated with the vehicle and demonstrated during field trials in November 2007.