A robustly stable output feedback saturated controller for the boost DC-to-DC converter

The problem of regulating the output voltage of the Boost DC-to-DC power co nverter has attracted the attention of many control researchers for several years now. Besides its practical relevance, the system is an interesting t heoretical case study because it is a switched device whose averaged dynami cs are described by a bilinear second order nonminimum phase system with sa turated input, partial state measurement and a highly uncertain parameter - the load resistance. In this paper we propose an output-feedback saturated controller which ensures regulation of the desired output voltage and is, at the same time, insensitive to uncertainty in the load resistance. Furthe rmore, bounds on this parameter can be used to tune the controller so as to (locally) ensure robust performance, e.g., that the transient has no (unde r) over-shoot. The controller, which is designed following the passivity-ba sed interconnection and damping assignment methodology recently proposed in the literature, is a static nonlinear output feedback. This allows us to i nvoke simple phase-plane techniques to determine the exact domain of attrac tion as well as the admissible initial conditions that ensure the control o bjectives. One final advantage of our controller is that it is computationa lly less demanding than the industry standard lead-lag filters. (C) 2000 El sevier Science B.V. All rights reserved.