Regulation of a manned sea-surface vehicle via stochastic optimal control

A control system is proposed for the regulation problem of the roll-motion of a manned sea-surface vehicle. Taking into account the roll-ship equations coming from the Conolly theory, a novel stochastic model has been proposed for the uncertainties driving the total mechanical torque acting on the vehicle, deriving from the wind and/or the sea-wave action. The proposed model results in a bilinear stochastic system to which a feedback controller is applied, giving linear-optimal performance with respect to a classical quadratic index. Open loop simulations carried out on real data validate the choice of the stochastic model of the uncertainties, producing a ship-roll time evolution which resembles the real data. Closed loop simulations on a virtual ship show the effectiveness of the proposed control scheme.