Vision-based ROV horizontal motion control: Near-seafloor experimental results

In this paper the problem of high-precision motion control of remotely operated vehicles (ROVs) in the proximity of the seabed through vision-based motion estimation is addressed. The proposed approach consists of the integration of a cheap monocular vision system for the estimate of the vehicle's linear motion with a conventional dual-loop hierarchical architecture for kinematics and dynamics control. Results obtained by operating at sea the Romeo ROV are presented, demonstrating the system capability in performing station-keeping in the presence of external disturbance and relatively high accuracy in horizontal motion control.