Docking Techniques and Evaluations Trials of the Swimmer AUV

Abstract The Swimmer Vehicle is a EU -Thermie funded project to develop an autonomous vehicle capable of transporting existing work-class ROVs around sub-sea installations - removing the need for surface support vessels and long umbilical cables. This brings not only brings cost advantages, through reduce deployment costs, but also improves vehicle dynamics - a major problem when operating in ROVs in ultra deep water (1000m - 5000m). As part of the Swimmer project, Liverpool has developed a SRPS (Short Range Positioning System) for the autonomous Swimmer vehicle. The system does not use deployed ultrasonic transponders, but instead uses profile data obtained from high-speed, narrow-beam imaging sonars. The system is based on ASOP (Active Sonar Object Prediction), a novel technique developed at Liverpool. It uses CAD information to derive a 3D model (or map) of the Docking Station on the seabed. This paper gives an overview of the Swimmer vehicle, describes the technical details of the ASOP algorithm used for Swimmer's Short Range Positioning System, and discusses the recent deployment trials.