Robust Output Tracking: The VTOL Aircraft Example

We study the tracking problem in the presence of smooth, bounded uncertainty and show that, if the un-certainty satisfies a suitable matching condition, one can design a partial information controller (i.e., an output feedback controller) achieving arbitrarily small steady-state tracking error without employing high-gain feedback. We illustrate a preliminary application of these results to the control of the (simplified) model of a VTOL aircraft affected by uncertainty.