Robust Output Regulation for a Flexible Wing System with Output Disturbances

Robust output regulation has been addressed by two observer based tracking error feedback controls for disturbances and references from an exosystem. However, output disturbances and references can not be considered together, since it is impossible to only use tracking errors to distinguish the output disturbances and references. In this paper, the robust output regulation of a flexible wing system is addressed in the presence of arbitrary output disturbances. Based on two tracking errors only, two new exosystems are defined to make the state feedback control have known coefficients, and further estimated by two new exosystems. Two observer based robust controls are then obtained so that the exponential convergence of the tracking errors can be guaranteed. A simulation example is provided to show the robust output regulation problem.