Real‐time predictive control‐based anti‐pitching method for high‐speed multihull with appendages constraints

In order to mitigate the excessive amplitudes of pitch and heave motions, a real-time predictive control method is proposed for the high-speed multihull with strict input constraints of anti-pitching appendages. The vertical control model of the high-speed multihull has been established with T-foil and flap served as anti-pitching appendages, and the motion couplings between heave and pitch have been analyzed. The wave disturbance considered as a kind of colored noise can be whitened so as to obtain the control signal, and then adaptive extended Kalman filtering method can be used to get the online estimates of the heave velocity and pitch angular velocity. The proposed predictive control-based anti-pitching method mainly contains two reformed aspects of the predictive control. One is to take into account the error between the actual and predicted system values, such that the prediction model with linear error correction can be obtained resulting in the enhanced robustness. The other is to employ the Laguerre function to convert the control sequence of moving horizon optimization into the fewer-dimensional Laguerre parameters, and then the computational burden of online optimization can be significantly reduced indicating the improved real-time performance. The closed-loop system stability has also been theoretically analyzed. The simulation and experiment have been carried out to verify the effectiveness of the proposed algorithm in this paper.