Peter Dorato

Survey paper: Static output feedback-A survey

This paper reviews the static output feedback problem in the control of linear, time-invariant (LTI) systems. It includes analytical and computational methods and presents in a unified fashion the knowledge gained in the decades of research into this important open problem. The paper shows that although many approaches and techniques exist to approach different versions of the problem, no efficient algorithmic solutions are available.

Technical Communique: Finite-time control of linear systems subject to parametric uncertainties and disturbances

In this paper we consider finite-time control problems for linear systems subject to time-varying parametric uncertainties and to exogenous constant disturbances. The main result provided is a sufficient condition for robust finite-time stabilization via state feedback. It can be applied to problems with both non-zero initial conditions and unknown constant disturbances. This condition is then reduced to a feasibility problem involving linear matrix inequalities (LMIs). A detailed example is presented to illustrate the proposed methodology.

Survey of robust control for rigid robots

Current approaches to the robust control of the motion of rigid robots are surveyed, and the available literature is summarized. The five major design approaches discussed are the linear-multivariable approach, the passivity approach, the variable-structure approach, the saturation approach, and the robust-adaptive approach. Some guidelines for choosing a method are offered.<<ETX>>

Non-fragile controller design: an overview

In this paper we give an overview of nonfragile controller design for linear systems. The controller fragility problem is basically the problem of performance deterioration of a feedback control system due to inaccuracies in controller implementation. The literature on the fragility problem is reviewed and methods for designing nonfragile controllers are summarized.

Static output feedback: a survey

This paper reviews the static output feedback problem in the control of linear, time-invariant (LTI) systems. It includes analytical and computational methods and presents in a unified fashion, the knowledge gained in the decades of research into this most important problem.<<ETX>>

Delayed Positive Feedback Can Stabilize Oscillatory Systems

This paper expands on a method proposed in [1] for stabilizing oscillatory system with positive, delayed feedback. The closed-loop system obtained is shown (using the Nyquist criterion) to be stable for a range of delays.

Robust Multi-Objective Feedback Design by Quantifier Elimination

This paper shows how certain robust multi-objective feedback design problems can be reduced to quantifier elimination (QE) problems. In particular it is shown how robust stabilization and robust frequency domain performance specifications can be reduced to systems of polynomial inequalities with suitable logic quantifiers, ? and ?. Because of computational complexity the size of problems that can solved by QE methods is limited. However, the design problems considered here do not haveanalyticalsolutions, so that even the solution of modest-sized problems may be of practical interest.

A historical review of robust control

A historical review of recent results in robust control is presented. The robust control problem, i.e., the problem of designing accurate control systems in the presence of significant plant uncertainties, is classical. However, over the past 15 years, significant new theory has been developed for the solution of this problem, especially with respect to linear multivariable systems characterized in the frequency domain, and the term robust control for this classical problem is only of recent vintage (1972). Some of the major contributions of modern robust control theory include the development of synthesis techniques for robust stabilization, and H2andH^{\infty}sensitivity optimization of multivariable systems. In this review, we confine the term robust control to the design of fixed controllers. Thus, only nonadaptive or nonself-tuning solutions to the problem of controlling uncertain systems are reviewed. Finally, it should be noted that the review is largely limited to the literature published in IEEE journals and conference proceedings, and some English-language journals. It is, of course, recognized that many significant related contributions have appeared elsewhere.

Robust, non-fragile and optimal controller design via linear matrix inequalities

In this article, we introduce a robust nonfragile state feedback controller which is also optimal with respect to a quadratic performance index, using linear matrix inequalities (LMI). The uncertainties are assumed to be polytopic, both in the controller gains and the system dynamics. A numerical example is presented to demonstrate the efficiency of this method, and the controller turns out to be robust with respect to the uncertainties in the plant and the controller.

Bibliography on robust control

Abstract This bibliography includes a compilation of selected books and journal articles written on the subject of Robust Control during the period 1987–1991. Papers are further divided into theory and applications. The theoretical subject matter of each article is identified by appropriate acronyms and application papers are separated into specific areas.