Marine Robotics Sensing, modeling and control

Marine robots have been developing rapidly for several decades now. They have acquired undeniable technical maturity, enabling them to be used in many fields, in particular in the oil and gas industry, for military applications (surveillance, mine clearance, etc.) or for scientific research (oceanography, biology, archaeology, etc.). This article provides an overview of the main families of marine or underwater vehicles (USV, AUV, ROV, glider, sailboat robot, bio-inspired robot, profiler, etc.), as well as a detailed description of the equipment used for their localization, perception or communication. For each category of equipment, the operating principles are explained and the essential technical concepts are summarized, to enable readers to select the right equipment for their application.

This technological state-of-the-art is followed by a presentation of the scientific tools used to control marine vehicles: modeling and control. The model presented is the widely-used one defined by SNAME (Society of Naval Architects and Marine Engineers). Based on this model, three control laws are presented, along with their tuning principles. These are PID control, non-linear adaptive feedback control and sliding speed control. Examples illustrating their use are presented, and their advantages and disadvantages explained. Finally, the article concludes with an experimental comparison of the three controls presented, applied to the depth control of a small underwater robot. This allows us to observe the advantages and limitations of the three proposed controls.