No abstract

No abstract

No abstract

No abstract

No abstract

This paper proposes a MCS (Motion Control System) with trajectory tracking capability for observation class ROVs (Remotely Operated Vehicle) used to carry out automated high-resolution image capturing missions, e.g. inspections, mappings, and surveys. The trajectory tracking capability is a key feature to enable the end users of the ROV technology to acquire sequential high-quality images at proper pace to construct consistent representations of the objects or of the environments of interest. Four degrees-of-freedom are controlled -surge, sway, heave, and yaw. The MCS consists of an output feedback control system that is composed of a high-gain state observer and a MIMO (Multiple-Input-Multiple-Output) PID (ProportionalIntegral-Derivative) controller, that works aided by reference feedforward. Plant linearisation is performed aiming at improving the tracking performance. Stability and satisfactory performance of suitable and smooth reference trajectories are attained despite the presence of unmodelled dynamics, plant parameter variations, measurement noise, and environmental disturbances. Simulated results based on the model of the NTNU's ROV Minerva are presented.

This paper deals with the generation of sufficiently smooth position, velocity, and acceleration references for guiding the motion of an ROV along purposefully defined curvature-continuous paths in automated missions. The references are meant to be employed in high-performance trajectory tracking and dynamic positioning applications. The path planning problem is not in the scope of this work. A reference model that synthesises references concerning a single Degree-of-Freedom (DoF) motion is initially described. Then, the use of the synthesised references as the parametrisation for other references concerning multiple DoF motion along curvature-continuous paths is exploited. Results from computer simulations and full-scale sea trials, both based on the NTNU's ROV Minerva, are presented and discussed.Keywords: Guidance system, Path generation, Reference model, ROV, Trajectory tracking. List of acronyms and abbreviations

No abstract