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This study deals with (Q,S,R) ‐ γ ‐dissipative output feedback control design for a class of switched systems with time‐varying delay and unmeasurable states. The purpose is to design an observer‐based controller and a switching rule to ensure both exponential stability and strict dissipativity of the resulting closed‐loop switched systems. Using an augmented switched Lyapunov–Krasovskii functional with triple sum and the improved reciprocally convex combination approach, new sufficient conditions are developed in terms of linear matrix inequalities. Simulation examples are included to demonstrate the validity and effectiveness of the proposed design technique. [ABSTRACT FROM AUTHOR]

Summary: This paper investigates the problem of control design for a class of uncertain switched singular systems with time‐varying delay. Under mode‐dependent average dwell time and using an appropriate Lyapunov‐Krasovskii functional, the exponential admissibility of the system is analyzed. In order to obtain less conservative conditions, the delay partitioning technique is adopted as well as the improved reciprocally convex approach. By means of the developed admissibility condition, a static output feedback controller is then designed using linear matrix inequality approach. Moreover, by solving an optimization convex problem with constraints, the switched controller is developed to ensure simultaneously the stability of the closed‐loop system and satisfy an optimized upper bound of both the linear quadratic guaranteed cost and the H∞ norm. Numerical examples are proposed to verify the efficiency and the merits of the method proposed. [ABSTRACT FROM AUTHOR]

This paper discusses the problem of delay-dependent robust filtering design for polytopic systems with a time-varying delay. A new model transformation is firstly applied by employing a three-term approximation for the delayed state, which leads to a smaller approximation error than the two-term approximation. Then, based on the scaled small-gain Theorem combined with an appropriate Lyapunov-Krasovskii Functional, the performance analysis of the filtering error system is examined and then the full- and reduced-order filters are designed in terms of linear matrix inequalities via a simple linearisation technique. Before the end, a sufficient condition is presented to solve the problem of filtering design for a time-delay system without polytopic uncertainties. Finally, illustrative examples are presented to demonstrate the validity of the proposed methods. [ABSTRACT FROM AUTHOR]

Abstract This work deals with the robustness analysis of LPV (Linear Parameter-Varying) systems. The degree of robustness of a system makes possible to know if the defined level of performance is guaranteed or not. The robustness of a system is characterized by its capacity to reject perturbations, by criterion of speed, of precision or by taking into account a certain degree of imprecision of the model, often introduced during a necessary phase of linearization. It is then necessary to manipulate relatively sophisticated models in order to take all these parameters into account. The representation of the LPV systems is such a sophisticated modeling. Fuzzy Takagi–Sugeno, polytopic and norm-bounded representations are often used to describe the behavior of nonlinear dynamics of the system. This paper proposes a generic model that encompasses these representations (fuzzy TS, polytopic and norm-bounded). This generic model is denoted uncertain BPV (Bi-linear Parameter Varying). A robustness analysis technique, allowing the generation of a robustness criterion, is then proposed. It can be applied to the case of state or output feedback, as well as to paremeter-dependent controllers. The concept of D -stability is considered and the tools are expressed in terms of LMI. [ABSTRACT FROM AUTHOR]

This study investigates the problem of delay‐dependent stability and stabilisation of uncertain delta operator systems with time‐varying delay. A new model transformation is proposed using a three‐term approximation, which has a smaller approximation error than the existing methods based on one or two terms. On the basis of scaled small gain theorem (scaled small gain) and an appropriate Lyapunov–Krasovskii functional, a new stability criterion is proposed in terms of linear matrix inequalities. Finally, numerical examples are presented to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this study, the analysis and design problems of H∞ filtering for a class of discrete‐time‐varying delay systems are investigated. The authors' attention is focused on the filter design using scaled small gain (SSG) approach guaranteeing the robust asymptotic stability of the filtering error system with a prescribed H∞ performance. A novel transformation model of the filtering error system is obtained via three‐term approximation method and input–output approach based on SSG theorem. Then, the desired filter design is obtained through a convex optimisation problem resolution under a set of linear matrix inequality constraints. Finally, the use of many examples from the literature demonstrates the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper investigates the design problem of robustH∞filtering for uncertain two-dimensional (2D) continuous systems described by Roesser model with polytopic uncertainties and frequency domain specifications. Our aim is to design a new filter guaranteeing anH∞performance level in specific finite frequency (FF) domains. Using the well-known generalised Kalman Yakubovich Popov lemma and homogeneous polynomially parameter-dependent matrices of arbitrary degrees, sufficient conditions for the existence ofH∞filters for different FF ranges are proposed and then unified in terms of solving a set of linear matrix inequalities. Illustrative examples are provided to show the usefulness and potential of the proposed results. [ABSTRACT FROM PUBLISHER]

SUMMARY This paper is concerned with the stability analysis and robust dynamic output feedback controller synthesis for uncertain continuous singular systems with time-delay. First, on the basis of the Lyapunov functional method and by resorting to the delay-partition technique, improved delay-dependent sufficient conditions are presented to ensure the nominal unforced system to be admissible (i.e., to be regular, impulse-free, and stable). Second, with the help of the obtained admissibility criterion, an observer-based controller is designed by solving a set of LMIs. Finally, the validity and applicability of the proposed approach is shown by examples. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

This paper deals with the sensorless field oriented control based on Takagi Sugeno (TS) observer. In the proposed algorithm, we present a nonlinear induction machine by Takagi-Sugeno (T-S) fuzzy model which is valid in large speed domain instead of linearized model around equilibrium point. In addition we design sliding mode observer known for its robustness against parametric uncertainties and external perturbations. The design conditions of the fuzzy sliding mode observer are formulated by LMI (Linear Matrix Inequalities) terms. Then implemented in DSP-TMS320F240, a control tool, the simulation and experimental results given by the combination of the observer and the establish sensorless with field oriented control (FOC), demonstrate good performance of the proposed observer on open loop and closed loop. [ABSTRACT FROM AUTHOR]