Nonlinear active disturbance rejection controller research of autopilot for ship course tracking

Applying mathematics model of nonlinear ship control and the wave disturbances to the design of autopilot tracking the ship course, and considering the uncertainty of model parameters and the characteristics of rudderpsilas servo-system makes the model have the unmatched uncertainty correspondingly. In order to solve the difficulty, an active disturbance rejection nonlinear control strategy is proposed, and a ship course tracking ADRC controller is designed. The simulation results of ship course tracking and keeping show that the controller has good adaptabilities on the system nonlinearity and strong robustness to parameter perturbations of the ship and environmental disturbances. And the course switching is fast and smooth with small rudder turning volume, thus achieved high-accurate ship course control.