The Problem of Robust Compensation for Systems with Unmodeled Dynamics

This report describes the results obtained during the two years of funding extending from 1/88 to 1/90 in support of our project entitled 'The problem of Robust Compensation for Systems with Unmodeled Dynamics.' The project has consisted of several lines of research which are quite distinct, but which show great promise toward combining them into a single comprehensive theory. Our goal has been to explore the problem of designing feedback control systems that are insensitive to the presence of high-frequency dynamics not accounted for explicitly in the mathematical model of the plant. Some of our previous work suggests that it is possible to design controllers which simultaneously stabilize a given nominal system as well as a large class of small singular perturbations of the system. Attached are six papers summarizing work which has been supported all or in part by the present grant and which either have appeared, have been accepted, or have been submitted for publication.