ADRC controller used in dynamic positioning system of a rescue ship

Dynamic positioning system of marine vehicles has been undergoing a rapid development and application. In this paper a maneuvering mathematical model and a pure sway motion model with three degrees of freedom are established, an ADRC controller for the dynamic positioning system of a rescue ship is designed. The results of simulation indicate that the control performance and robustness of ADRC is significantly better than conventional PID controller, the outputs of rudder angle and pitch of CPP are smoother and gentler improved, the steady state accuracy of control output is better, the adaptability of parameters is extensive. Taking pure sway motion of the rescue ship for example, rapidity and effectiveness of a proposed multi-mode controller are verified.