线性时变系统有限时间稳定性的数值判定算法

针对系统的初值和系统的状态均限定在多面体集合的情形,本文从数值计算角度研究了连续线性时变(linear time-varying, LTV)系统有限时间稳定性(finite-time stability, FTS)的判定问题.首先,通过求解特定的函数优化问题,给出了该类系统有限时间稳定的充分必要条件.然后,利用所得充分必要条件以及特定函数的Lipschitz连续性质,从数值计算角度给出了判定该类系统有限时间稳定性的充分条件.进一步,基于所得充分条件,将特定的函数优化问题转化为相应的线性规划,提出了一种判定该类系统有限时间稳定性的数值算法.最后,给出的4个数值算例说明了本文算法的正确性和有效性,以及相比已有结果的优越性.     

分数阶时变切换系统有限时间异步控制

针对一类时变切换系统,当考虑子系统具有分数阶(Fractional Order)特性时,提出了一种基于模型依赖平均驻留时间方法的有限时间稳定性条件及异步切换控制策略.借助Caputo分数阶导数引理和切换Lyapunov函数,利用矩阵不等式技术提出了分数阶时变切换系统有限时间稳定的充分条件.将有限时间稳定的结果进一步推广到有限时间有界的情形,利用平均驻留时间思想提出了分数阶时变切换系统有限时间有界的充分条件,基于该条件设计了系统的异步切换控制器.所给出的设计方法将系统异步切换控制问题转化为矩阵不等式组的求解问题.通过数值仿真验证了所提控制方法的有效性.     

线性时变系统的稳定性

本文介绍线性时变系统方程解的估计问题。根据系统方程系数矩阵Ａ，给出一种方法找出方程解的上边界和下边界。而这种方法与方程的精确解是完全一致的。然后建立线性时变系统稳定性判据。     

线性随机系统有限时间H∞ 控制

讨论一类具有时变、有限能量外部扰动的线性随机系统有限时间H∞控制问题．首先,给出了线性随机系统有限时间如控制问题的定义;然后,通过构造Lyapunov-Krasovskii函数,并结合线性矩阵不等式,给出了随机系统有限时间如控制器有解的充分条件;进一步,将该问题简化为具有线性矩阵不等式约束的优化问题,并给出了相应的求解算法;最后,通过数值算例表明了该设计方法的有效性．     

连续时间线性脉冲系统的有限时间滤波

研究了连续时间线性脉冲系统的有限时间滤波问题。一方面给出了滤波误差系统有限时间稳定和满足性能要求的充分条件,并且给出了滤波器的设计方法。另一方面为了避免设计方法中出现的耦合问题,给出了另外两个结论。最后通过数值算例表明了结论的可行性和有效性。     

线性时变系统的区间稳定性与鲁棒稳定性

本文应用向量比较定理研究线性时变系统的区间稳定性和具非线性时变摄动的线性时变系统的鲁棒稳定性，所得的新结果包含文献的一些主要结果作为特例，本文的研究方法说明向量比较方法是分析区间稳定性和鲁棒稳定性的一种自然而有力的工具。     

离散线性时变系统鲁棒稳定性分析

运用矩阵范数方法和分析技巧，研究离散线性时变系统在结构扰动和外加扰动情形下的鲁棒稳定性问题，获得了一组新的充分性定理和便于应用的代数判据。     

一类线性离散时间系统有限时间控制问题

讨论一类具有时变、有限能量外部扰动的线性离散时间系统的有限时间控制问题.首先研究问题可解的充分条件,并讨论了状态反馈控制器存在的条件,这些条件可归结为基于线性矩阵不等式(LMI)的可解性问题;然后给出状态反馈控制器和输出反馈控制器的具体设计;最后通过仿真验证了该方案的有效性.     

连续时间时变参数系统的指数稳定性和Lp指数稳定性

本文给出具有慢时变参数的连续时间线性齐次系统指数稳定的一个一般性条件，并给出具有随机时变参数的连续时间线性齐次系统Ｌｐ指数稳定的一个充分条件。这些结果可用来分析带有未建模动态，确定性噪声或随机噪声及慢时变参数的自适应控制系统的稳定性问题。     

时变时滞连续切换奇异系统的一致有限时间稳定分析

讨论一类含有时变时滞的连续时间切换奇异系统的一致有限时间稳定、有限时间有界和状态反馈镇定问题. 在给定任意的切换规则下, 运用多Lyapunov 函数和平均驻留时间方法设计使得闭环系统一致有限时间稳定和有限时间有界的状态反馈控制器, 同时给出基于线性矩阵不等式表示的控制器存在的充分条件. 最后通过数值算例表明了所提出方法的合理性和有效性.

     

Improved stability criteria for linear time-varying systems on time scales

ABSTRACT

In this paper, asymptotic stability problems of linear time-varying (LTV) systems on time scales are considered based on a less conservative Lyapunov inequality, whose right side is not required to be necessarily negative. It is shown that the Lyapunov inequality covers not only the corresponding trivial (continuous and discrete) ones but also nontrivial ones. Based on this inequality, some necessary and sufficient conditions for asymptotic stability, exponential stability, uniformly exponential stability of LTV systems on time scales are obtained. An example about nontrivial systems is given for illustrating the effectiveness of the proposed results.     

不确定广义线性时变系统的鲁棒稳定和二次稳定

针对不确定广义线性时变系统,采用矩阵不等式的分析方法,提出不确定广义线性时变系统鲁棒稳定和二次稳定的概念.建立该类系统的矩阵不等式,将该类系统的鲁棒控制问题转化为求解矩阵不等式问题,得到该类系统鲁棒稳定和二次稳定的充分必要条件,并给出一种状态反馈鲁棒镇定控制器的设计方法.最后,通过数值算例表明了所提出方法的可行性.     

一类区间时变时滞系统的稳定性分析

针对一类区间时变时滞系统的稳定性问题,进行了全局渐近稳定性分析.通过引入时滞分段方法和构建恰当的Lyapunov-Krasovskii泛函,得到了新的区间时滞相关稳定性判定准则.该准则以线性矩阵不等式形式给出,便于利用LMI工具箱对系统的稳定性进行判定.新准则具有较少的保守性,并且在一定范围内保守性随着时滞分段增多而减少,即时滞分段越多,保守性越少.数值仿真算结果例表明了新准则所具有的有效性和较少的保守性.     

Finite‐time stability of switched positive linear systems

This brief paper addresses the finite‐time stability problem of switched positive linear systems. First, the concept of finite‐time stability is extended to positive linear systems and switched positive linear systems. Then, by using the state transition matrix of the system and copositive Lyapunov function, we present a necessary and sufficient condition and a sufficient condition for finite‐time stability of positive linear systems. Furthermore, two sufficient conditions for finite‐time stability of switched positive linear systems are given by using the common copositive Lyapunov function and multiple copositive Lyapunov functions, a class of switching signals with average dwell time is designed to stabilize the system, and a computational method for vector functions used to construct the Lyapunov function of systems is proposed. Finally, a concrete application is provided to demonstrate the effectiveness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.     

Input-output finite-time stability of time-varying linear singular systems

This paper studies the input-output finite-time stabilization problem for time-varying linear singular systems. The output and the input refer to the controlled output and the disturbance input,respectively.Two classes of disturbance inputs are considered,which belong to L-two and L-infinity.Sufficient conditions are firstly provided which guarantee the input-output finite-time stability.Based on this,state feedback controllers are designed such that the resultant closed-loop systems are input-output finite-time stable.The conditions are presented in terms of differential linear matrix inequalities.Finally,an example is presented to show the validity of the proposed results.     

Sufficient conditions for stability of linear time-varying systems

In this paper we consider sufficient conditions for the exponential stability of linear time-varying systems of the form . Stability guaranteeing upper bounds for different measures of parameter variations are derived.     

A delay-range-partition approach to analyse stability of linear systems with time-varying delays

In this paper, the stability analysis of linear systems with an interval time-varying delay is investigated. First, augmented Lyapunov–Krasovskii functionals are constructed, which include more information of the delay's range and the delay's derivative. Second, two improved integral inequalities, which are less conservative than Jensen's integral inequalities, and delay-range-partition approach are utilised to estimate the upper bounds of the derivatives of the augmented Lyapunov–Krasovskii functionals. Then, less conservative stability criteria are proposed no matter whether the lower bound of delay is zero or not. Finally, to illustrate the effectiveness of the stability criteria proposed in this paper, two numerical examples are given and their results are compared with the existing results.     

Less conservative delay-dependent stability criteria for linear systems with interval time-varying delays

This article provides new delay-dependent stability criteria for linear systems with interval time-varying delays. With a new Lyapunov–Krasovskii functional constructed, a tighter upper bound of its derivative is estimated. The resulting criterion has an advantage over some existing ones in the literature due to the fact that it involves fewer matrix variables and is less conservative, which is established theoretically. Two numerical examples are given to demonstrate the reduced conservatism of the proposed results.     

Finite-time stability and stabilisation of singular discrete-time linear positive systems with time-varying delay

ABSTRACT

In this paper, the problem of finite-time stability and stabilisation for positive singular discrete-time linear systems with time-varying delay is investigated. We first present novel delay-dependent sufficient conditions for positivity and finite-time stability of the unforced systems. We then apply the obtained results to solve finite-time stabilisation problem of the considered systems. The sufficient conditions for the positivity and finite-time stabilisable of such systems are formulated in terms of a standard linear programming (LP) problem. Numerical examples are provided to illustrate the effectiveness and advantages of our results.