posted on 2022-08-22, 08:24authored bySatja Sivčev
This thesis describes a body of research work focused on the domain of marine
robotics and underwater manipulator control systems in particular. Work-class
marine ROVs equipped with hydraulic manipulators are widely used in offshore
industry for undersea inspection and intervention operations. In standard subsea
operations setup, a human pilot employs telemanipulation technology to operate
both vehicle and manipulators based on the worksite visual feedback provided by
camera and sonar systems. In the emerging marine renewable energy industry, target
devices are in motion due to their location in challenging environments of high
energy winds, currents, and waves offshore. In such high energy sites, current
commercial ROV technology capabilities are not sufficient for inspection, repair, and
maintenance operations and utilising a traditional teleoperation approach is likely to
fail even with very skilled pilots. This research describes the development of robotic
manipulator control systems beyond the state-of-the-art capable of executing tasks
in challenging conditions of the dynamic wave/current environment. A particular
focus is on automation solutions that can be easily retrofitted to existing off-theshelf
underwater manipulator systems on the global fleet of commercial work-class
ROVs without any hardware or software modifications. The thesis describes a
developed kinematics control engine that allows human pilots to operate ROV
manipulators with auto-assist, utilising enhanced manual, semi-automatic, and fully
automatic (visual) servo control modes of operation while addressing stationary
and moving targets. A developed collision detection and avoidance algorithm for
subsea manipulators for safe, reliable, and efficient operations is also described. The
control solutions for automated manipulation have been developed, implemented, and
verified in simulation, dry laboratory experimental tests, and through subsea trials
on a commercial work-class ROV with industry standard hydraulic manipulators.
The developed control systems have a potential to reduce the task load, operational
time, and costs of subsea inspection and intervention operations and significantly
extend the window of operating conditions for marine ROV inspection, repair, and
maintenance in the marine renewable energy and other sectors.
Funding
Vibrational Energy Transfer and Shock Waves in Molecular Materials