Online speed optimization for sailing yachts using extremum seeking

This paper briefly presents the main points on the development and testing of an extremum seeking controller used to maximize the longitudinal velocity of surface sailing vehicles by changing the angle of the sail. The algorithm is suitable for sailing purposes since it requires only the measurements of the vehicle's velocity and the sail angle. As an illustration, we present a few simulation results on our previously-obtained sailing yacht simulator, which was developed based on a 4 DOF nonlinear dynamic model for surface sailing vehicles, showing that the proposed extremum seeking controller is capable of maximizing the sailing yacht's speed performance through online sail tuning. Furthermore, the proposed sail optimization algorithm is tested at sea on an experimental platform, i.e. a small scale autonomous sailboat, illustrating the potential of the controller.