Conference Papers-Robust Control

Communications & Networks

Image & Signal Processing

Load Balancing

Microwave Propelled Sail

Randomized Algorithms

Time Delay

Multi-Agent Coordination

Engineering Education

Iterative Learning

Neural Networks

Robust Control

Various

Note: The papers on this website may differ from the published versions, both in format and in content.

21. P. Dorato, W. Yang and C. T. Abdallah, "Application of Quantifier Elimination Theory to Robust Multi-Objective Feedback Design", Journal of Symbolic Computation, 1997.   [pdf]

    Abstract: This paper shows how certain robust multi-objective feedback design problems can be reduced to quatifier 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 be solved by QE methods is limited. However the design problems considered here do not have analytical solutions, so that even the solution of modest sized problems may be of practical interest.




22. M. Bredemann, C. T. Abdallah and P. Dorato, "Polynomial Solutions for Simultaneous Stabilization", 2nd IFAC Symposium on Robust Conrol Design, pp. 193-198,Budapest, Hungary, 1997.   [pdf]  [ps]

    Abstract: In this paper, we present a new necessary and sufficient condition for simultaneous stabilization and new sufficient conditions for the existence of a simultaneously stabilizing controller, both derived from a polynomial approach. The additional requirements for the controller itself to be either stable or a Unit in H^∞ are also given. These new sufficient conditions are general in nature and are shown to reduce in special cases to several published papers. Examples illustrate the extensions.




23. P. Dorato, C. T. Abdallah and D. Famularo, "Robust Short-Time Stability Design via Linear Matrix Inequalities", IEEE Conference on Decision and Control, pp. 1305-1306, San Diego, CA, 1997.   [pdf]

    Abstract: For Linear systems with polytopic uncertainties, the problem of robust finite-time stabilization is reduced to a system of Linear Matrix Inequalities.




24. D. Famularo, C. T. Abdallah, A. Jadbabaie, P. Dorato, W.M. Haddad, "LQ Robust Synthesis with Non-fragile Controllers: The Static State Feedback Case", 1997.   [pdf]  [ps]

    Abstract: This paper describes the synthesis of Non-fragile or Resilient regulators for linear systems. The general framework for fragility is described using state-space methodologies, and the LQ/H₂ static state-feedback case is examine in detail. We discuss the multiplicative structured uncertainties case, and propose remedies for the fragility problem. The benchmark problem is taken as example to show how an "uncertain" or resilient static state feedback controller can affect the performance of the system.




25. R.A. Luke, P. Dorato, C.T. Abdallah, "Linear-Quadratic Simultaneous Performance Design", Proceedings of the American Control Conference0, pp. 3602-3605, Albuquerque, NM, June 1997.   [pdf]

    Abstract: In this paper the problem of designing a fixed state feedback control law which minimizes an upper bound on linear-quadratic performance measures for m distinct plants is reduced to a convex programming problem.




26. W. Yang, P. Dorato, and C.T. Abdallah, "Robust Multiobjective Feedback Design via Combined Quantifier Elimination and Discretization", Proceedings of the American Control Conference, pp. 1843-1847, Albuquerque, NM, June 1997.   [pdf]

    Abstract: This paper is concerned with the application of computerized quantifier elimination (QE) methods for robust multiobjective design (RMOD), when design objectives are specified in the frequency domain. The class of design problems considered here has no analyical solutions, so that computerized solution are of interest, even for relatively simple problems. However because of the computational complexity of pure QE algorithms, a combined QE-discretization approach is proposed and illustarted with a single example




27. W.M. Haddad, J.L. Fausz,V. Cellaboina, C.T. Abdallah, "Optimal Discrete-Time Control for Nonlinear Cascade Systems", Proceedings of the American Control Conference, pp. 2175-2176, Albuquerque, NM, June 1997.   [pdf]

    Abstract: In this paper we develop an optimality-based framework for designing controllers for discrete-time nonlinear cascade systems. Specifically, using a nonlinear-nonquadratic optimal control framework we develop a family of globally stabilizing backstepping-type controllers parametrized by the cost functional that is minimized. Furthermore, it is shown that the control Lyapunov function guaranteeing closed-loop stability is a solution to the steady-state Bellman equation for the controlled system and thus guarantees both optimality and stability.




28. W.M. Haddad, V. Kapila, C.T. Abdallah, "Stabilization of Linear and Nonlinear Sytems with Time Delay", Proceedings of the American Control Conference, pp. 1-5, Albuquerque, NM, June 1997.   [pdf]

    Abstract: This paper considers the problem of stabilizing linear and nonlinear continuous-time sytems with state and measurement delay. For linear systems we address stabilization via fixed-order dynamic output feedback compensators and present sufficient conditions for stabilization involving a system of modified Riccati equations. For nonlinear systems we provide sufficient conditions for the design of static full-state feedback stabilizing controllers. The controllers obtained are delay-independent and hence apply to systems with infinite delay.




29. R. Luke, P. Dorato, and C. T. Abdallah, "A Survey of State-Feedback Simultaneous Stabilization Techniques", Proceedings Intelligent Automation and Control, vol.4, pp.481-488, Montpellier, France, 1996.   [pdf]

    Abstract: This paper surveys the control theory literature having to do with the simultaneous stabilization of countably finite sets of systems in the state-space domain. Design methods based upon control parameterization, linear equation solution and linear matrix inequalities are discussed. The roles of nonlinear programming and convex programming techniques are included, as is a brief description of the applicability of software-based quatifier elimination techniques.




30. M. Bredemann, C. T. Abdallah and P. Dorato, "On the Relative Degree of Simultaneously Stabilizing Controllers", International Federation of Automatic Control, 1996.   [pdf]  [ps]

    Abstract: In this brief paper, we present new necessary and sufficient conditions on the controller for the existence of a single controller to stabilize a set of n SISO plants: P1, P2, ..., Pn. As is well known this is equivalent to the existence of a single stable controller that stabilizes n-1 plants (strong stabilization). It was shown in (Blondel, 1994) that the simultaneous stabilization problem is transcendental and cannot be solved using algebraic functions. Our only hope in approaching the general solution to the simultaneous stabilization problem using algebraic functions is either to enlarge the class of controllers for which sufficient conditions exist, or to restrict the class of controllers from which a controller must exist. This paper restricts the search for existence of simultaneously stabilizing controllers to the class of exactly proper controllers. 

<< previous | next >>