UDE-based linear robust control for a class of nonlinear systems with application to wing rock motion stabilization

In this paper, robust UDE-based linear control strategy is developed for a class of second-order nonlinear uncertain systems with disturbances. After revealing the control structure and performing stability analysis, the robust control strategy is used to suppress wing rock motion. The approach is based on the uncertainty and disturbance estimator, which calculates and robustly cancels system uncertainties and input disturbances via appropriate filtering. The information regarding the known part of the linear plant dynamics is used by the controller; the terms containing the nonlinear functions are treated as additional uncertainties to the system. The algorithm provides excellent performance in suppressing the wing rock dynamics and rejecting disturbances. Simulations are given to show the effectiveness of the strategy via an application to an experimentally derived delta wing rock model.