Predictive control anti-pitching for high-speed multi-hull ship with appendages constraints

Abstract

Objectives Considering the large motions of pitch and heave together with the strict input constraints of installed anti-pitching appendages, a predictive control method is proposed for vertical stabilization based on Kalman filtering. Methods The vertical control model of high-speed multihull has been established with T-foil and flap served as anti-pitching appendages, and the motion couplings of heave and pitch has been analyzed. In order to obtain the anti-pitching control signal, the wave-induced colored noise has been whitened, and adaptive extended Kalman filter has been adopted for online estimates of heave velocity and pitch angular velocity. On this basis, the predictive control has been proposed for vertical stabilization with input constraint. Defining the error between the actual state and predicted state, the predictive control model with linear varying error correction can then be obtained. Error feedback correction is used to improve the robustness of anti-pitching control, and the problem of anti-pitching control is transformed into a quadratic programming (QP) problem with input constraints, and the rolling optimization solution of predictive control is realized through numerical solution. Results The simulation results show that under the effect of predictive control considering feedback correction, the hull heave is reduced by about 40%, and the pitch angle is reduced by about 50%. Conclusions The predictive anti-pitching control with feedback correction can improve the control accuracy and robustness of the system, which is of great significance in practical engineering applications.