Adaptive backstepping-based nonlinear disturbance observer for fin stabilizer system

In this paper, an adaptive backstepping controller based on nonlinear disturbance observer (DOB) is proposed for the nonlinear fin stabilizer system. DOB is responsible for disturbance rejection and uncertainty compensation, while the adaptive backstepping scheme is proposed for dealing with uncertain parameters of the fin stabilizer model. The designed controller guarantees uniform ultimate boundedness of all the signals in the closed-loop system and the tracking errors converge to a small neighborhood of the origin. The advantages of the proposed control scheme comprise that the DOB shorten the response time and observes the whole disturbances of the fin stabilizer system. Simulation example is presented to show the preciseness and robustness of the stabilization control realized by the proposed method.