不确定Lurie时滞系统绝对稳定性分析

研究了不确定Lurie时滞系统的绝对稳定问题。通过构造适当的Lyapunov泛函、引入一些自由权矩阵和充分考虑时滞导数的上限信息,得到了基于LMIs(线性矩阵不等式)形式的时滞相关绝对稳定性新准则,两个数值例子验证了所得结论的有效性和更弱保守性。     

时滞不确定Lurie系统的鲁棒绝对稳定性准则

研究一类具有时变时滞的范敷有界结构不确定性Lurie控制系统的鲁棒绝对稳定性问题.利用Lyapunov-Krasovskii泛函方法,分别给出系统在无限扇形及有限扇形角内绝对稳定的时滞相关充分条件,所给的判定条件是线性矩阵不等式(LMI)形式的,可以很方便地运用Matlab工具葙求解.两个数值实例表明,本文所给条件是有...     

具有饱和执行器的不确定时滞系统的鲁棒稳定性

本文研究了一类具有饱和执行器的不确定时滞系统的鲁棒镇定问题，所考虑的系统具有时变未知有界的不确定参数和状态滞后，基于系统的线性矩阵不等式给出了系统可鲁棒镇定的判据以及鲁棒无记忆状态反馈控制规律。     

一类时滞系统的绝对稳定性问题研究

基于线性矩阵不等式处理方法,研究了一类具有扇形非线性关联的时滞系统绝对稳定性问题.导出了用一个线性矩阵不等式系统的可行性表示的绝对稳定性滞后依赖型条件,进而,通过求解一组线性矩阵不等式,给出使得闭环系统绝对稳定的无记忆状态反馈控制律设计方法,最后用例子验证了文中提出的结果.     

时滞系统的鲁棒稳定性分析

本文研究了具有时滞的线性不确定系统的鲁棒稳定性问题。利用矢量不等式的方法和Lyapunov稳定性原理，给出了不确定时滞系统鲁棒稳定的充分条件，最后以挠性航天器为例验证方法的有效性。     

一类不确定时滞系统的时滞依赖型鲁棒控制器设计

本文研究了一类状态和控制同时存在滞后的不确定线性系统时滞依赖型鲁棒镇定２，针对所有容许的时变未知但有界的不确定性，得到了一种新的确保系统可鲁棒镇定的充分条件和相应的鲁棒镇定控制器设计方法，所得到的结果与时滞相关的，并且以线性矩阵不等式（ＬＭＩ）形式给出。     

一类不确定线性时滞系统的输出反馈鲁棒镇定

研究一类不确定线性时滞系统的输出反馈鲁棒镇定问题,其中不确定性不必满足匹配条件。以二次Lyapunov泛函保证系统的渐近稳定性,利用线性矩阵不等式给出了系统可以利用动态输出反馈鲁棒镇定的充分条件。当此条件成立时,基于线性矩阵不等式的解构造了全阶动态输出反馈镇定控制器。     

线性不确定时滞系统的鲁棒指数稳定性

针对带有时变有界的不确定参数和状态时滞的线性不确定时滞系统,研究其时滞依赖型具有指定收敛率的鲁棒指数稳定性问题。通过应用Lyapunov-Krasovskii稳定性定理方法,合理建立Krasovskii泛函,利用线性矩阵不等式方法导出了系统鲁棒指数稳定且具有指定收敛率的判据。所得结论采用线性矩阵不等式表示,与时滞参数的导数无关,克服了通常所得结论与时滞导数有关,且要求时滞参数导数小于常数1的限制。应用实例证明了设计方案切实可行。     

不确定时滞系统基于观测器的鲁棒控制器设计

研究了不确定线性时滞系统的状态观测器和基于观测器的鲁棒控制器设计问题，其中不确定性是时变的，通过构造增广系统，利用线性矩阵不等式方法，获得了该不确定系统存在状态观测器和基于观测器的鲁棒控制器的充分条件，同时给出了相应的状态观测器和基于观测器的鲁棒控制器，所给示例说明了本文方法的设计步骤和有效性。     

参数不确定系统的鲁棒灵敏度设计

应用Schur补公式讨论了参数不确定系统的灵敏度问题,给出了灵敏度的设计方法,指出灵敏度设计不同于扰动抑制的设计,求解灵敏度应首先求解一个输出注入问题。最后用算例说明了该方法的有效性。     

Robust absolute stability criteria for uncertain Lur'e systems of neutral type

This paper is concerned with robust absolute stability of uncertain Lur'e systems of neutral type. Some delay‐dependent stability criteria are obtained and formulated in the form of linear matrix inequalities. The criteria cover some existing results as their special cases. Neither model transformation nor bounding technique for cross terms is involved through derivation of the stability criteria. Numerical examples show the effectiveness of the criteria. Copyright © 2007 John Wiley & Sons, Ltd.     

不确定广义时滞系统的鲁棒稳定方法研究

研究一类带有时滞不确定广义系统的鲁棒渐近稳定问题．利用Lyapunov稳定性定理和线性矩阵不等式工具,得到了广义系统正则、鲁棒渐近稳定的时滞相关充分条件．为了降低所得结果的保守性,避免了采用系统模型变换和利用矩阵不等式方法．进一步,建立一个具有线性矩阵不等式约束的凸优化问题,利用Matlab软件中的LMI工具箱求解,得到保证广义系统鲁棒渐近稳定的最大可允许时滞上界．仿真示例表明了该方法的有效性．     

线性时滞系统的时滞相关鲁棒控制

讨论了同时具有输入时滞与状态时滞的线性系统的时滞相关鲁棒控制问题.将矩阵分解思想应用于线性时滞系统的控制综合,借助于积分不等式,利用Lyapunov_Krasovskii泛函方法,得到了系统经无记忆状态反馈后可镇定的、基于LMI的时滞相关条件.既不要对原系统进行模型变换,也不要对交叉项进行界定.最后的实例说明了本文方法的有效性.     

Improved robust stability criteria and design of robust stabilizing controller for uncertain linear time‐delay systems

In this paper, an improved linear matrix inequality (LMI)‐based robust delay‐dependent stability test is introduced to ensure a larger upper bound for time‐varying delays affecting the state vector of an uncertain continuous‐time system with norm‐bounded‐type uncertainties. A quasi‐full‐size Lyapunov–Krasovskii functional is chosen and free‐weighting matrix approach is employed. Less restrictive sufficient conditions are derived for robust stability of time‐varying delay systems with norm‐bounded‐type uncertainties. Moreover, the investigation of the stabilization problem with memoryless state‐feedback control is presented such that the stabilizability criteria are obtained in terms of matrix inequalities, which can be solved via utilizing a cone complementarity minimization algorithm. Finally, the problem of output feedback stabilization for square systems is also taken into consideration. The output feedback stabilizability criteria are derived in the form of linear matrix inequalities, which are convex and can be easily solved using interior point algorithms. A plenty of numerical examples are presented indicating that the proposed stability and stabilization methods effectively improve the existing results. Copyright © 2006 John Wiley & Sons, Ltd.     

On relationship between quadratic and robust stability of uncertain systems

A game theoretic approach is introduced to analyse the relationship between the quadratic and robust stability of systems with structured uncertainties. Necessary and sufficient condition for the equivalence of these two types of stability is presented. The distance between quadratic and robust stability is bounded when this condition is not satisfied. This gives new insight into the mechanism of the quadratic stability. Checking this necessary and sufficient condition and calculating the error bound are formulated as a convex optimization problem. The results developed in this paper are illustrated by several numerical examples. Copyright © 1999 John Wiley & Sons, Ltd.     

不确定时滞系统鲁棒镇定新方法

针对一类同时具有状态和控制滞后的不确定时滞系统,提出了一种新的时滞依赖型鲁棒镇定设计方法.通过引入一种新的线性状态变换,分离出时滞依赖因子,采用Lyapunov-Krasovskii泛函方法,导出了不确定时滞系统可鲁棒镇定的时滞依赖型的新判据,所得结论以线性矩阵不等式组的解的形式表示.仿真结果表明所得结论较之已有结果更为简单,具有更小保守性,且有更广泛的应用范围,不仅可以解决小时滞问题,也可用于解决大时滞问题.     

New strategy for robust stability analysis of discrete-time uncertain systems

In this paper, a new robust stability analysis approach is developed for uncertain discrete-time linear time-invariant systems with polytopic or affine parameter-dependent uncertainty models. The proposed approach is based on a combination of a branch-and-bound like strategy with linear matrix inequality (LMI) based analysis formulations. Two sufficient conditions are considered, one for the robust stability of the uncertain system and other one for the contrary situation. If both sufficient conditions fail to characterize the polytope, then it is iteratively subdivided into subpolytopes until some one proves to be unstable or all ones are verified to be robustly stable. The polytope subdivision is implemented by means of a specially developed simplex subdivision algorithm. Exhaustive numerical tests prove the efficiency of the proposed approach when compared with the most recent LMI-based formulations.     

LMI stability conditions for uncertain rational nonlinear systems

This paper presents LMI conditions for local, regional, and global robust asymptotic stability of rational uncertain nonlinear systems. The uncertainties are modeled as real time varying parameters with magnitude and rate of variation bounded by given polytopes and the system vector field is a rational function of the states and uncertain parameters. Sufficient LMI conditions for asymptotic stability of the origin are given through a rational Lyapunov function of the states and uncertain parameters. The case where the time derivative of the Lyapunov function is negative semidefinite is also considered and connections with the well known LaSalle's invariance conditions are established. In regional stability problems, an algorithm to maximize the estimate of the region of attraction is proposed. The algorithm consists of maximizing the estimate for a given target region of initial states. The size and shape of the target region are recursively modified in the directions where the estimate can be enlarged. The target region can be taken as a polytope (convex set) or union of polytopes (non‐convex set). The estimates of the region of attraction are robust with respect to the uncertain parameters and their rate of change. The case of global and orthant stability problems are also considered. Connections with some results found in sum of squares based methods and other related methods found in the literature are established. The LMIs in this paper are obtained by using the Finsler's Lemma and the notion of annihilators. The LMIs are characterized by affine functions of the state and uncertain parameters, and they are tested at the vertices of a polytopic region. It is also shown that, with some additional conservatism, the use of the vertices can be avoided by modifying the LMIs with the S‐Procedure. Several numerical examples found in the literature are used to compare the results and illustrate the advantages of the proposed method. Copyright © 2013 John Wiley & Sons, Ltd.