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

  Objectives  Considering the large motions of heave and pitch of high-speed mult-hull ship with the strict input constraints of installed anti-pitching appendages, a predictive control method is proposed for vertical stabilization based on Kalman filtering.

  Methods  A high-speed multi-hull vertical control model is established with T-foils and flaps serving as anti-pitching appendages, and the motion couplings of heave and pitch are analyzed. In order to obtain an anti-pitching control signal, the wave-induced colored noise is whitened and an adaptive extended Kalman filter is adopted for the online estimate of heave velocity and pitch angular velocity. On this basis, predictive control is proposed for vertical stabilization with input constraints. Defining the error between actual state and predicted state, a predictive control model with linear varying error correction is obtained. Error feedback correction is used to improve the robustness of the anti-pitching control, the problem of anti-pitching control is transformed into a quadratic programming (QP) problem with input constraints, and a rolling optimization solution of predictive control is realized through numerical solution.

  Results  The simulation results show that under the effects of predictive control considering feedback correction, hull heave is reduced by about 40% and pitch angle is reduced by about 50%.

  Conclusions  Predictive anti-pitching control with feedback correction can improve the control accuracy and robustness of the system, which is of great significance for practical engineering applications.