Adaptive dynamic surface control based on fuzzy disturbance observer for drive system with elastic coupling

This paper proposes an adaptive control strategy by employing dynamic surface control (DSC) technique and fuzzy disturbance observer (FDO) for the two-inertia system with uncertainties and external disturbance. Firstly, the unknown elements including uncertainties and external disturbance are estimated by using a fuzzy disturbance observer which does not need a priori information of these unknown dynamics. Next, the estimations of unknown disturbance are integrated into DSC design by using recursive feedbacks to damp torsional vibration. The 'explosion of complexity' in conventional backstepping technique is avoided by introducing first-order filters. The stability analysis of the design scheme is verified based on the Lyapunov stability theory. All the signals in the closed-loop system are guaranteed to be uniformly ultimately bounded and the tracking error can be made arbitrarily small by adjusting the design parameters. Comparative simulations and experiments demonstrate the effectiveness and applicability of the proposed method.