Showing papers by "Huijun Gao published in 2008"
TL;DR: A sampled-data networked control system with simultaneous consideration of network induced delays, data packet dropouts and measurement quantization is modeled as a nonlinear time-delay system with two successive delay components in the state and the problem of network-based H"~ control is solved accordingly.
1,143 citations
TL;DR: A new model based on the updating instants of the holder is formulated, and a linear matrix inequality (LMI)-based procedure is proposed for designing state-feedback controllers, which guarantee that the output of the closed-loop networked control system tracks theoutput of a given reference model well in the Hinfin sense.
Abstract: This paper is concerned with the problem of Hinfin output tracking for network-based control systems. The physical plant and the controller are, respectively, in continuous time and discrete time. By using a sampled-data approach, a new model based on the updating instants of the holder is formulated, and a linear matrix inequality (LMI)-based procedure is proposed for designing state-feedback controllers, which guarantee that the output of the closed-loop networked control system tracks the output of a given reference model well in the Hinfin sense. Both network-induced delays and data packet dropouts have been taken into consideration in the controller design. The network-induced delays are assumed to have both an upper bound and a lower bound, which is more general than those used in the literature. The introduction of the lower bound is shown to be advantageous for reducing conservatism. Moreover, the controller design method is further extended to more general cases, where the system matrices of the physical plant contain parameter uncertainties, represented in either polytopic or norm-bounded frameworks. Finally, an illustrative example is presented to show the usefulness and effectiveness of the proposed Hinfin output tracking design.
389 citations
TL;DR: A new approach to the problems of analysis and synthesis for quantized feedback control systems with logarithmic quantizers, leading to less conservative results, which is shown both theoretically and through numerical examples.
354 citations
TL;DR: A controller design procedure based on mean-square asymptotic stability is derived for the closed-loop networked control systems, and based on this, an inverted pendulum system is utilized to show the effectiveness and applicability of the proposed results.
Abstract: This paper presents a new approach to solving the problem of stabilization for networked control systems. Mean-square asymptotic stability is derived for the closed-loop networked control systems, and based on this, a controller design procedure is proposed for stabilization purpose. An inverted pendulum system is utilized to show the effectiveness and applicability of the proposed results.
353 citations
TL;DR: Sufficient conditions for the existence of a desired filter are established in terms of linear matrix inequalities (LMIs), and the corresponding filter design is cast into a convex optimization problem which can be efficiently solved by using commercially available numerical software.
348 citations
TL;DR: All proposed conditions for the existence of positive observers and dynamic output-feedback controllers for positive linear systems with interval uncertainties are expressed in terms of the system matrices, and can be verified easily by effective algorithms.
Abstract: This paper is concerned with the design of observers and dynamic output-feedback controllers for positive linear systems with interval uncertainties. The continuous-time case and the discrete-time case are both treated in a unified linear matrix inequality (LMI) framework. Necessary and sufficient conditions for the existence of positive observers with general structure are established, and the desired observer matrices can be constructed easily through the solutions of LMIs. An optimization algorithm to the error dynamics is also given. Furthermore, the problem of positive stabilization by dynamic output-feedback controllers is investigated. It is revealed that an unstable positive system cannot be positively stabilized by a certain dynamic output-feedback controller without taking the positivity of the error signals into account. When the positivity of the error signals is considered, an LMI-based synthesis approach is provided to design the stabilizing controllers. Unlike other conditions which may require structural decomposition of positive matrices, all proposed conditions in this paper are expressed in terms of the system matrices, and can be verified easily by effective algorithms. Two illustrative examples are provided to show the effectiveness and applicability of the theoretical results.
246 citations
TL;DR: A new criterion of asymptotic stability is derived by introducing a new kind of Lyapunov-Krasovskii functional and is formulated in terms of a linear matrix inequality (LMI), which can be readily solved via standard software.
Abstract: In this brief, the problem of global asymptotic stability for delayed Hopfield neural networks (HNNs) is investigated. A new criterion of asymptotic stability is derived by introducing a new kind of Lyapunov-Krasovskii functional and is formulated in terms of a linear matrix inequality (LMI), which can be readily solved via standard software. This new criterion based on a delay fractioning approach proves to be much less conservative and the conservatism could be notably reduced by thinning the delay fractioning. An example is provided to show the effectiveness and the advantage of the proposed result.
188 citations
TL;DR: The focus is on the design of a robust fault detection filter, or a residual generation system, which is stochastically stable and satisfies a prescribed disturbance attenuation level.
Abstract: This paper investigates the problem of robust fault detection for uncertain systems with missing measurements. The parameter uncertainty is assumed to be of polytopic type, and the measurement missing phenomenon, which appears typically in a network environment, is modelled by a stochastic variable satisfying the Bernoulli random binary distribution. The focus is on the design of a robust fault detection filter, or a residual generation system, which is stochastically stable and satisfies a prescribed disturbance attenuation level. This problem is solved in the parameter-dependent framework, which is much less conservative than the quadratic approach. Both full-order and reduced-order designs are considered, and formulated via linear matrix inequality (LMI) based convex optimization problems, which can be efficiently solved via standard numerical software. A continuous-stirred tank reactor (CSTR) system is utilized to illustrate the design procedures.
179 citations
TL;DR: The robust asymptotic stability problem of genetic regulatory networks with time-varying delays and polytopic parameter uncertainties is investigated by using a Lyapunov functional approach and linear matrix inequality (LMI) techniques.
Abstract: In this paper, we investigate the robust asymptotic stability problem of genetic regulatory networks with time-varying delays and polytopic parameter uncertainties. Both cases of differentiable and nondifferentiable time-delays are considered, and the convex polytopic description is utilized to characterize the genetic network model uncertainties. By using a Lyapunov functional approach and linear matrix inequality (LMI) techniques, the stability criteria for the uncertain delayed genetic networks are established in the form of LMIs, which can be readily verified by using standard numerical software. An important feature of the results reported here is that all the stability conditions are dependent on the upper and lower bounds of the delays, which is made possible by using up-to-date techniques for achieving delay dependence. Another feature of the results lies in that a novel Lyapunov functional dependent on the uncertain parameters is utilized, which renders the results to be potentially less conservative than those obtained via a fixed Lyapunov functional for the entire uncertainty domain. A genetic network example is employed to illustrate the applicability and usefulness of the developed theoretical results.
143 citations
01 Apr 2008
TL;DR: A new criterion of exponential stability is derived and then formulated in terms of a linear matrix inequality, which proves to be much less conservative than the most recent result, and the conservatism can be notably reduced as the fractioning goes thinner.
Abstract: In this correspondence, the problem of exponential stability for neural networks with time delay is investigated. By introducing a novel Lyapunov-Krasovskii functional with the idea of delay fractioning, a new criterion of exponential stability is derived and then formulated in terms of a linear matrix inequality. This new criterion proves to be much less conservative than the most recent result, and the conservatism can be notably reduced as the fractioning goes thinner. An example is provided to demonstrate the advantage of the proposed result.
127 citations
TL;DR: A new criterion of asymptotic stability is derived in terms of a linear matrix inequality (LMI), which can be efficiently solved via standard numerical software and proves to be less conservative than most of the existing results.
TL;DR: The polynomially parameter-dependent idea is utilized to solve the robust H infin filtering problem, with new linear matrix inequality conditions obtained for the existence of admissible filters based on homogeneous polynomial parameter- dependent matrices of arbitrary degree.
Abstract: This paper is concerned with the problem of robust H infin filtering for linear continuous-time systems with polytopic parameter uncertainties and time-varying delay in the state. We utilize the polynomially parameter-dependent idea to solve the robust H infin filtering problem, with new linear matrix inequality conditions obtained for the existence of admissible filters. These conditions are developed based on homogeneous polynomially parameter-dependent matrices of arbitrary degree. The delay-dependence and polynomial parameter-dependence guarantee the proposed approach to be potentially less conservative, which is shown via a numerical example.
TL;DR: In this article, a structured polynomial parameter-dependent approach is proposed for robust H 2 filtering of linear uncertain systems, where the focus is on designing a robust filter such that the filtering error system is robustly asymptotically stable and has a guaranteed estimation error variance for the entire uncertainty domain.
TL;DR: In this article, a new control strategy is proposed, which integrates both the command input shaping and the sliding mode output feedback control (SMOFC) techniques, where the input shaper is designed for the reference model and implemented outside of the feedback loop.
Abstract: In this paper, the vibration reduction problem is investigated for a flexible spacecraft during attitude maneuvering. A new control strategy is proposed, which integrates both the command input shaping and the sliding mode output feedback control (SMOFC) techniques. Specifically, the input shaper is designed for the reference model and implemented outside of the feedback loop in order to achieve the exact elimination of the residual vibration by modifying the existing command. The feedback controller, on the other hand, is designed based on the SMOFC such that the closed-loop system behaves like the reference model with input shaper, where the residual vibrations are eliminated in the presence of parametric uncertainties and external disturbances. An attractive feature of this SMOFC algorithm is that the parametric uncertainties or external disturbances of the system do not need to satisfy the so-called matching conditions or invariance conditions provided that certain bounds are known. In addition, a smoothed hyperbolic tangent function is introduced to eliminate the chattering phenomenon. Compared with the conventional methods, the proposed scheme guarantees not only the stability of the closed-loop system, but also the good performance as well as the robustness. Simulation results for the spacecraft model show that the precise attitudes control and vibration suppression are successfully achieved.
TL;DR: A Lyapunov-Krasovskii method underlies the LMI-based mixed H2/Hinfinity output-feedback control design using some free weighting matrices and simulation results illustrate the effectiveness of the proposed methodology.
Abstract: A mixed H 2 / H ∞ output-feedback control design methodology is presented in this paper for second-order neutral linear systems with time-varying state and input delays. Delay-dependent sufficient conditions for the design of a desired control are given in terms of linear matrix inequalities (LMIs). A controller, which guarantees asymptotic stability and a mixed H 2 / H ∞ performance for the closed-loop system of the second-order neutral linear system, is then developed directly instead of coupling the model to a first-order neutral system. A Lyapunov–Krasovskii method underlies the LMI-based mixed H 2 / H ∞ output-feedback control design using some free weighting matrices. The simulation results illustrate the effectiveness of the proposed methodology.
TL;DR: A new asymptotic stability criterion for neural networks with multiple successive delay components is derived by constructing a new Lyapunov functional and using advanced techniques for achieving delay dependence.
TL;DR: A linear matrix inequality (LMI) approach is developed to establish sufficient conditions for the existence of admissible state estimators, which guarantee the estimation error to be globally exponentially stable in the presence of time-varying delays.
TL;DR: In this article, the authors considered the problem of sliding mode control of two-dimensional (2D) discrete systems in the Roesser model and proposed two different controller design procedures, which can be easily implemented by using standard numerical software.
Abstract: The study is concerned with the problem of sliding mode control of two-dimensional (2D) discrete systems. Given a 2D system in Roesser model, attention is focused on the design of sliding mode controllers, which guarantee the resultant closed-loop systems to be asymptotically stable. This problem is solved by using two different methods: model transformation method and Choi's 1997 method. In terms of linear matrix inequality, sufficient conditions are formulated for the existence of linear switching surfaces guaranteeing asymptotic stability of the reduced-order equivalent sliding mode dynamics. Based on this, the problem of controller synthesis is investigated, with two different controller design procedures proposed, which can be easily implemented by using standard numerical software. A numerical example is provided to illustrate the effectiveness of the proposed controller design methods.
TL;DR: In this paper, a delay-dependent exponential stability condition is established for stochastic time-delay systems based on the delay fractioning approach, which can greatly reduce conservativeness compared with the existing results.
Abstract: The problem of concern here is the stability analysis for stochastic systems with a time delay in the state. By employing a novel Lyapunov–Krasovskii functional, a new delay-dependent exponential stability condition is established for such stochastic time-delay systems. Based on the delay fractioning approach, the developed method can greatly reduce conservativeness compared with the existing results. Numerical examples are provided to show the advantage of the proposed techniques.
TL;DR: The polynomially parameter-dependent approach is developed to solve the addressed filtering problem, with a new linear matrix inequality condition obtained for the existence of desired Hinfin filters.
Abstract: This paper presents a new approach to the design of robust filters for uncertain 2-D systems described by the Fornasini-Marchesini (FM) model. The polynomially parameter-dependent approach is developed to solve the addressed filtering problem, with a new linear matrix inequality condition obtained for the existence of desired Hinfin filters. An example is given to show the reduced conservatism of the proposed method.
TL;DR: This paper revisits the problem of synchronization stability for general complex dynamical networks with coupling delays with a new delay-dependent criterion derived by introducing a new kind of Lyapunov–Krasovskii functional formulated in terms of a linear matrix inequality, which can be readily solved via standard software.
Abstract: This paper revisits the problem of synchronization stability for general complex dynamical networks with coupling delays. A new delay-dependent criterion is derived by introducing a new kind of Lyapunov-Krasovskii functional and is formulated in terms of a linear matrix inequality, which can be readily solved via standard software. This new criterion based on a delay fractioning approach is proved to be much less conservative and the conservatism could be notably reduced by thinning the delay fractioning. Furthermore, the resulting criterion is further extended to the synchronization stability analysis of complex dynamical networks with time-varying structured uncertainties. Two numerical examples are provided to show the effectiveness and advantage of the proposed results.
TL;DR: In this article, the authors investigated the problem of robust filtering for a class of uncertain nonlinear discrete-time systems with multiple state delays, where the parameter uncertainties appearing in all the system matrices reside in a polytope, and the nonlinearities entering into both the state and measurement equations satisfy global Lipschitz conditions.
Abstract: This paper investigates the problem of robust filtering for a class of uncertain nonlinear discrete-time systems with multiple state delays. It is assumed that the parameter uncertainties appearing in all the system matrices reside in a polytope, and that the nonlinearities entering into both the state and measurement equations satisfy global Lipschitz conditions. Attention is focused on the design of robust full-order and reduced-order filters guaranteeing a prescribed noise attenuation level in an H∞ or l2-l∞ sense with respect to all energy-bounded noise disturbances for all admissible uncertainties and time delays. Both delay-dependent and independent approaches are developed by using linear matrix inequality (LMI) techniques, which are applicable to systems either with or without a priori information on the size of delays.
TL;DR: In this article, robust stability conditions for linear discrete-time systems with polytopic parameter uncertainties and time-varying delay in the state are presented, derived by defining parameter-dependent Lyapunov functions, which are not only dependent on the maximum and minimum delay bounds, but also dependent on uncertain parameters.
Abstract: This paper presents several new robust stability conditions for linear discrete-time systems with polytopic parameter uncertainties and time-varying delay in the state These stability criteria, derived by defining parameter-dependent Lyapunov functions, are not only dependent on the maximum and minimum delay bounds, but also dependent on uncertain parameters in the sense that different Lyapunov functions are used for the entire uncertainty domain It is established, theoretically, that these robust stability criteria for the nominal and constant-delay case encompass some existing result as their special case The delay-dependent and parameter-dependent nature of these results guarantees the proposed robust stability criteria to be potentially less conservative
TL;DR: In this article, the authors present a new model to characterize the state-feedback control systems with signal transmission after-effects, which deals with the transmission aftereffects from sensor to controller and from controller to actuator separately.
Abstract: In many practical systems, the physical plant, controller, sensor, and actuator are difficult to be located at the same place, and thus signals are required to be transmitted from one place to another. One immediate problem arising from such situations is that signals may exhibit after-effect phenomena during their transmission. In this paper, we present a new model to characterize the state-feedback control systems with signal transmission after-effects, which deals with the transmission after-effects from sensor to controller and from controller to actuator separately. Analysis and synthesis results based on this new model are established by using a Lyapunov-Krasovskii approach. Numerical simulations are provided to illustrate the usefulness of the theoretical results. Copyright (c) 2007 John Wiley & Sons, Ltd.
25 Jun 2008
TL;DR: In this paper, an improved delay-range-dependent stability condition for linear systems with an interval time-varying delay was proposed, which satisfies h 1lesd(t)lesh2.
Abstract: This paper proposes an improved delay-range-dependent stability condition for linear systems with an interval time-varying delay, which satisfies h1lesd(t)lesh2. The improvement is achieved by representing d(t) as h1+h(t) with 0lesh(t)lesh2-h1, and then constructing a novel Lyapunov-Krasovskii functional with the idea of partitioning the constant time delay. It is illustrated via a numerical example that the proposed result is much less conservative than those available in the literature.
01 Dec 2008
TL;DR: A robust state feedback controller is designed such that the closed-loop system is stochastically stable in the mean square and preserves a guaranteed Hinfin performance.
Abstract: The paper considers the problem of synchronization for dynamical systems with unreliable communication links which are modeled as stochastic dropouts. A robust state feedback controller is designed such that the closed-loop system is stochastically stable in the mean square and preserves a guaranteed Hinfin performance. A numerical example is provided to show the effectiveness of the proposed results.
02 Jul 2008
TL;DR: In this paper, the authors investigated the problem of robust sampled-data Hinfin control for active vehicle suspension systems and proposed an input delay approach to transform a continuous-time system with a delay in the state.
Abstract: This paper investigates the problem of robust sampled-data Hinfin control for active vehicle suspension systems. By using an input delay approach, the active vehicle suspension system with sampling measurements is transformed into a continuous-time system with a delay in the state. The transformed system contains possibly non-differentiable time-varying state delay. The controller design is cast into a convex optimization problem with LMI constraints. A quarter-car model with active suspension system is considered and the effectiveness of the proposed approach is illustrated by a realistic design example.
TL;DR: In this paper, the robust H2 filtering problem was revisited for discrete-time systems with parameter uncertainties, where the focus was on designing a robust filter such that the filtering error system is robustly asymptotically stable and has a guaranteed estimation error variance for the entire uncertainty domain.
TL;DR: In this article, the problem of exponential stabilization of linear systems with time-varying sampling is studied, where the sampling rate varies from sample to sample with the given probability, and a new exponential stability criterion is derived for the sampled-data system by using the Lyapunov functional approach.
01 Dec 2008
TL;DR: In this article, the problem of synchronization stability analysis for complex dynamical networks with coupling delays, both continuous and discrete cases are considered, with the method of delay partitioning, less conservative criteria are derived in the form of linear matrix inequalities (LMIs).
Abstract: This paper focuses on the problem of synchronization stability analysis for complex dynamical networks with coupling delays, both continuous and discrete cases are considered. With the method of delay partitioning, less conservative criteria are derived in the form of linear matrix inequalities (LMIs). Numerical examples are provided to show the effectiveness of the proposed results.