Anke Xue

Delay-dependent robust stability and stabilization for uncertain singular system with time-varying delay

The problems of delay-dependent robust stability and stabilization for uncertain singular systems with time-varying delay are addressed in this paper. The uncertainty is assumed to be norm bounded. By establishing an integral inequality based on quadratic terms, a new delay-dependent robust stability criterion is derived and expressed in terms of linear matrix inequality (LMI). Based on the criterion, the problem of robust stabilization is solved via state feedback controller, which guarantees that the resultant closed-loop system is regular, impulse-free and stable for all admissible uncertainties. An explicit expression for the desired controller is also given. Numerical examples are given to demonstrate the applicability and the less conservatism of the proposed method.

New stability criteria for singular systems with time-varying delay and nonlinear perturbations

This paper concerns the stability analysis for singular systems with time-varying delay and nonlinear perturbations. Two cases of time-varying delay, which is differentiable (Case 1) or not differentiable (Case 2), are considered. The considered nonlinear perturbations includes the norm-bounded uncertainties as a special case. Some delay-dependent stability criteria are derived by using a delay decomposition approach. In the delay decomposition approach, the entire delay interval is divided into multiple sub-intervals for which different energy functions are defined for building new Lyapunov–Krasovskii functional. Some numerical and practical examples are given to show the effectiveness and significant improvement of the proposed method.

Mode-dependent quantised H∞ filtering for Markovian jump singular system

This paper considers the H∞ filtering problem for Markovian jump singular systems. In addition, when taking into account the effect of the quantisation, the designed filter not only guarantee admissibility but also satisfy a prescribed H∞ filtering performance for the filter error system. By using Lyapunov method, a new bounded real lemma is proposed in terms of linear matrix inequalities (LMIs) to ensure that the filtering error system has the mentioned properties. Furthermore, a sufficient condition for the existence of filter is obtained in terms of LMIs. Finally, a numerical example is provided to demonstrate the effectiveness of the proposed approach.

Quantized H∞ Filtering for Different Communication Channels

In this paper, we consider the H∞ filtering problem for linear systems using quantized measurements. The communication channel we consider consists of two cases: the ideal one and the unreliable one. For the ideal channel, we designed a filter to mitigate the quantization effects, which ensured not only the asymptotical stability but also a prescribed H∞ filtering performance. For the unreliable channel, we introduced the stochastic variable satisfying Bernoulli random binary distribution to model the lossy measurements. We also designed a filter to cope with the losses and mitigate quantization effects simultaneously which ensured not only stochastic stability, but also a prescribed H∞ filtering performance. Furthermore, we derive sufficient conditions for the existence of the above filters. Finally, a numerical example is given to illustrate that the proposed approach is effective and feasible.

Stability of stochastic systems with nonlinear uncertainties and time-varying delays

This paper considers stability of stochastic systems with nonlinear uncertainties and time-varying delays. By introducing some slack matrix matrices, a delay-dependent stability criterion is obtained based on Lyapunov-Krasovskii theory. The proposed condition, which is formulated in terms of linear matrix inequalities (LMIs), is constructed without using the model transformation and cross term bounding techniques. Some term which was ignored in previous methods is considered in our result. Two numerical examples are provided to demonstrate the less conservatism of the method.

Delay-dependent H ∞ filtering of uncertain stochastic systems with delays

The problem of delay-dependent H∞ filtering for uncertain stochastic time-delay systems with norm-bounded uncertainties is investigated in this paper. By introducing an additional vector, a new integral inequality in the stochastic setting is established. Based on this new inequality and free-weighting matrix technique, a delay-dependent sufficient condition for the existence of an H∞ filter for uncertain stochastic delay systems is developed. A numerical example is provided to demonstrate the effectiveness of the proposed method.

Delay-dependent robust stability criteria for neutral singular systems with time-varying delays and nonlinear perturbations

This paper concerns the problem of the delay-dependent robust stability for neutral singular systems with time-varying delays and nonlinear perturbations. Based on integral inequalities, some both discrete-delay-dependent and neutral-delay-dependent stability criteria are obtained and formulated in the form of linear matrix inequalities(LMIs). Neither model transformation nor bounding technique for cross terms is involved. Numerical examples are given to show the less conservatism of the proposed results.

Observer-Based H∞ Control for Stochastic Systems with Delays and Nonlinear Perturbations: LMI Approach

Abstract This paper considers the problem of observer-based H ∞ control for a class of Ito-type stochastic delay systems with nonlinear perturbations. An observer-based controller is constructed based on Lyapunov-Krasovskii approach, which guarantees the closed-loop system is robustly stochastically asymptotically stable in the mean square with prescribed H ∞ disturbance attenuation level for all admissible nonlinear perturbations. Sufficient condition for the existence of desired controller is presented in terms of a strict linear matrix inequality (LMI) if the control matrix B is full column rank. A numerical example is provided to demonstrate the effectiveness of the proposed method.

Coherent integration weak target detection algorithm based on short time sliding window

For the problem of weak target detection under lower signal noise ratio in radar detection system, a key technique is to enhance target echo energy by long time coherent integration. During the integration period, the target echo may occur range migration with integration time increasing. Direct coherent integration will lead to echo energy spread and deteriorate integration effect. A coherent integration algorithm based on short time sliding window is proposed in this paper. Radar signal is formed into a first in first out queue. The queen is continually renewed by the sliding window. The produced queens are coherent integrated at last. Simulation result shows that the proposed algorithm can prevent range migration efficiently and improve coherent integration capability.

Mean-Square Stability of Stochastic Markovian Jumping Systems with Variable Delay

Abstract The mean-square stability of stochastic Markovian jumping systems with variable delay is investigated in this paper. Based on Lyapunov-Krasovskii functional (LKF) method, new stability criteria are presented by applying generalized Finsler lemma (GFL). Convex analysis property is applied to use the information of the time-varying delay such that the worst-case enlargement for variable delay is avoided. The result is formulated in terms of a set of linear matrix inequalities (LMIs). Numerical examples are given to show the effectiveness of the approach.