Towing with sailboat robots
Résumé
Moving huge objects floating at the surface of the ocean (such as containers
or icebergs) with boats requires many human operators and a lot of energy.
This is mainly due to the fact that when humans operate such equipment, time is
costly. Now, when we have time (as when robots operate, for instance), it is possible
to move arbitrarily large objects, for over long distances, with a limited quantity of
energy. This is a consequence of the fact that in the water, the friction forces are
proportional to the square of the speed (i.e., when we go slowly, we have almost
no friction). This paper proposes the use of a sailboat robot to tow large objects. It
shows which control law could be used is order to (i) avoid loops inside the towing
cable, (ii) avoid collisions between the robot and the towed object, and (iii) move
the object toward the desired direction. The control law is validated on a simulation
where the object to be towed has to follow a trajectory corresponding to a large
circle.