On constrained control of fin, rudder or combined fin-rudder stabilizers: A quasi-adaptive control strategy

Abstract This paper considers a simple quasi-adaptive constrained control strategy that can be used for fin, rudder, or combined fin-rudder stabilizers. The strategy estimates the parameters of a linear output disturbance model for the wave induced roll motion using roll and roll rate measurements taken before closing the control loop. This model is then used to implement a constrained predictive control strategy. The strategy can thus be adaptive with respect to changes in the sea state and sailing conditions. The work also explores the benefit of penalizing roll accelerations as well as roll angle in the associated cost.