Robust Controller Interpolation via Parameterization

Arbitrarily fast switching or blending among controllers often leads to reduced performance and possible instability. This paper presents a controller interpolation framework for robustly transitioning among controllers with respect to the H∞ norm. The framework leverages a robust controller parameterization, analogous to a Youla parameterization of nominally stabilizing controllers, to greatly simplify the robust controller interpolation problem. In addition, an explicit construction is provided for the robust interpolated controller. A practical example is presented in the form of a robust interpolated controller implemented on an electro-hydraulic test bed.Copyright © 2008 by ASME