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Norm-bounded Uncertainty (norm-bounded + uncertainty)

Distribution by Scientific Domains
Engineering75%

Selected Abstracts

Robust decentralized H, control for interconnected descriptor systems with norm-bounded uncertainties,,

ASIAN JOURNAL OF CONTROL, Issue 1 2009
Ning Chen
Abstract This paper considers a robust decentralized H, control problem for interconnected descriptor systems. The uncertainties are assumed to be time-invariant, norm-bounded, and existing in both the system and control input matrices. Our interest is focused on dynamic output feedback. A sufficient condition for an uncertain interconnected descriptor system to be robustly stabilizable H, control with a specified disturbance attenuation level is derived in terms of a nonlinear matrix inequality (NMI). A two-stage homotopy method is employed to solve the NMI iteratively. First, a decentralized controller for the nominal descriptor system is computed by imposing block-diagonal constraints on the coefficient matrices of the controller gradually. Then, the decentralized controller is gradually modified from the nominal descriptor system (without uncertainties) to the original system with uncertainties. On each stage, groups of variables are fixed alternately at the iterations to reduce the NMI to linear matrix inequalities (LMIs). An example is given to show the usefulness of this method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]

A sliding mode control approach for systems subjected to a norm-bounded uncertainty

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 4 2007
Anis Sellami
Abstract This paper proposes a design approach of continuous sliding mode control of uncertain systems, the uncertainty being norm bounded. The two steps of the design methodology are investigated. The existence step, in which we choose the sliding surface that gives good behaviour during the sliding mode, is formulated as a pole assignment of linear uncertain system in a sector through convex optimization. The solution to this problem is therefore numerically tractable via linear matrix inequalities (LMI) optimization. In the reaching step, we propose a continuous nonlinear control strategy ensuring a bounded motion about the ideal sliding mode, thus approximating the ideal dynamic behaviour in the presence of uncertainty. Finally, the validity and the applicability of this approach are illustrated by a flight stabilization benchmark example. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Robust Kalman filtering for uncertain discrete-time linear systems

INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 13 2003
Germain Garcia
Abstract This paper presents a steady-state robust state estimator for a class of uncertain discrete-time linear systems with norm-bounded uncertainty. It is shown that if the system satisfies some particular structural conditions and if the uncertainty has a specific structure, the gain of the robust estimator (which assures a guaranteed cost) can be calculated using a formula only involving the original system matrices. Among the conditions the system has to satisfy, the strongest one relies on a minimum phase argument. It is also shown that under the assumptions considered, the robust estimator is in fact the Kalman filter for the nominal system. Copyright © 2003 John Wiley & Sons, Ltd. [source]

LMI Approach to Guaranteed Cost Control for Networked Control Systems

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3-4 2005
Shanbin Li
This paper addresses the time-varying but bounded delay issue of networked control systems (NCS) within the framework of a discrete-time linear state-delayed system with norm-bounded uncertainty. A delay-dependent sufficient condition for the existence of a guaranteed cost controller for NCS is presented by a new Lyapunov-Krasovskii functional. The condition is formulated as a set linear matrix inequalities (LMIs). The resulting controller can not only asymptotically stabilize the system but also guarantee an adequate level of performance. Theoretical analysis and simulation results show that the control strategy presented in this paper is effective and feasible. [source]