Active disturbance rejection control for ship course tracking with parameters tuning

Abstract

A course tracking control law is designed based on the active disturbance rejection control (ADRC) technique for ships with unknown dynamic parameters and unknown time-varying disturbance under input saturation, which consists of feed-forward compensation and an error feedback proportional-derivative (PD) control law. The compound uncertainties, due to the unknown dynamic parameters, unknown time-varying disturbance, and input saturation, are viewed as a total disturbance, which is estimated through an extended state observer (ESO) and effectively compensated in the feed-forward path. Subsequently, an extremum seeking algorithm without steady-state oscillation (ESA-SSO) is introduced to tune the design parameters of the ADRC-based ship course tracking control law so as to obtain the better performance of ship course tracking control. The strict stability analysis shows that the resulting closed-loop course tracking control system of ships is uniformly stable. Finally, simulation results and comparisons on a frigate are presented to illuminate the effectiveness and the superiority of the designed control law.