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 converter has attracted the attention of many control researchers for several years now. Besides its practical relevance, the system is an interesting theoretical case study because it is a switched device whose averaged dynamics are described by a bilinear second order non-minimum phase system with saturated input, partial state measurement and a highly uncertain parameter-the load resistance. In this paper we provide a solution to the problem of designing 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. Furthermore, 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 (under)over-shoot. The controller, which is designed following the energy-balancing methodology recently proposed by Ortega, van der Schaft and Maschke, is a simple static nonlinear output feedback, hence it is computationally less demanding than the industry standard lead-lag filters