AUTOMATED LANDING AND MOORING IN DEEP-SEA ENVIRONMENT USING SUCTION BUCKETS FOR UNMANNED VEHICLES

摘要

Autonomous underwater vehicles (AUVs) depend primarily on electrical power. Monitoring the deep-sea ocean floor efficiently requires easily accessible recharging techniques. In contrast to conservative ship-dependent charging processes on the surface, the Subsea Monitoring via Intelligent Swarms (SMIS) consortium uses a seabed station (SBS) as a power supply for AUVs. This paper describes the fully automated secure landing procedure of the SBS followed by a ground mooring maneuver on sandy sediments or soft clays. The unmanned seabed station is equipped with various sensors for status detection and environmental observation. In order to control the freefall and grounding without endangering the valuable components, an innovative procedure was implemented. Once landed, the nearly buoyancy-neutral station is moored using down-scaled suctions buckets that are normally used in immobile offshore oil rig foundations. Laboratory full-scale experiments in modified test tanks for different length-to-diameter ratios endorse the design process. The feasibility of landing, mooring and ascending techniques was proven in field-tests in the Baltic Sea and the Atlantic Ocean.