Towards Autonomous Subsea Maintenance on Offshore Structures with Unmanned Underwater Vehicles

Along with the expansion in offshore energy and subsea energy supply, the demand for maintenance on subsea pipelines and cables, and offshore structures increases too. In recent years, manually operated Unmanned Underwater Vehicles (UUVs) have replaced divers, however, the need for automation and control becomes increasingly vital for efficiency and larger operating ranges. This study, addresses the main components needed for full-autonomous maintenance on offshore structures, consisting of (1) specialized robotic designs, (2) inspection and planning, (3) solving the localization challenges and (4) robust control strategies. The four topics are investigated, respectively, where the main challenges are highlighted along with novel results of two demonstrated applications. It is concluded that autonomous operations can be made feasible using specialized robotic designs combined with sensing, planning, inspection and control techniques, with the possibility to reduce cost, however, some challenging issues remain, particularly within the sensing and localization domains.