区间时滞相关不确定奇异系统的鲁棒稳定性和镇定性

研究区间时滞相关的不确定时变时滞奇异系统的鲁棒稳定性和镇定性问题,不确定参数假设是范数有界的。充分利用时滞的下界信息构造Lyapunov函数,用严格的矩阵不等式给出系统对所有的容许不确定满足正则、无脉冲、稳定的新判据。基于这个判据,设计状态反馈控制器使得系统鲁棒稳定。数值例子说明所得结果具有更小的保守性。     

Stability analysis and stabilization for discrete-time singular delay systems

Stability analysis and stabilization for discrete-time singular delay systems are addressed,respectively.Firstly,a sufficient condition for regularity,causality and stability for discrete-time singular delay systems is derived.Then,by applying the skill of matrix theory,the state feedback controller is designed to guarantee the closed-loop discrete-time singular delay systems to be regular,casual and stable.Finally,numerical examples are given to demonstrate the effectiveness of the proposed method.     

两类不确定奇异时滞系统鲁棒稳定的相关型判据

研究了不确定奇异时滞系统的鲁棒稳定性问题。首先以线性矩阵不等式的形式给出了奇异时滞系统正则,无脉冲模且零解渐近稳定的一种新的时滞相关型判据。通过引入新的参数避免了利用不等式处理交叉项,从而使该判据具有较小的保守性。最后,利用研究结果,给出了两类不确定奇异时滞系统新的时滞相关型鲁棒稳定性判据。     

Robust stability analysis of uncertain discrete-time systems with state delay

The sufficient conditions of stability for uncertain discrete-time systems with state delay have been proposed by some researchers in the past few years, yet these results may be conservative in application. The stability analysis of these systems is discussed, and the necessary and sufficient condition of stability is derived by method other than constructing Lyapunov function and solving Riccati inequality. The root locations of system characteristic polynomial, which is obtained by augmentation approach and Laplace expansion, determine the stability of uncertain discrete-time systems with state delay, the system is stable if and only if all roots lie within the unit circle. In order to analyze robust stability of system characteristic polynomial effectively, Kharitonov theorem and edge theorem are applied. Example shows the practicability of these methods.     

Delay-dependent state feedback robust stabilization for uncertain singular time-delay systems

The problem of robust stabilization for uncertain singular time-delay systems is studied.First,a new delay-dependent asymptotic stability criteria for normal singular time-delay systems is given,which is less conservative.Using this result,the problem of state feedback robust stabilization for uncertain singular time-delay systems is discussed.Finally,two examples are given to illustrate the effectiveness of the results.     

T-S模糊时滞系统的鲁棒无源控制

基于Lyapunov稳定性理论,时具有参数不确定性的T-S模糊时滞系统的鲁棒稳定性和无源性进行了研究.具有参数不确定性的T-S模糊模型可以任意精度近似连续非线性不确定系统.假设系统中的参数不确定性是范数有界的.运用Lyapunov稳定性理论给出了鲁棒无源控制器存在的充分条件.通过解一组线性矩阵不等式(LMIs),可直接获得鲁棒无源控制器.所设计的鲁棒无源控制器能够保证对于T-S模糊时滞系统中所有的参数不确定性,闭环系统都是鲁棒稳定的并且是严格无源的.并且,通过求解带有约束条件的线性矩阵不等式问题,可以设计出具有最大耗散率的鲁棒无源控制器.数值例子验证了所提出设计方法的有效性.     

不确定切换组合大系统的鲁棒分散控制

考虑了一类不确定切换组合大系统的鲁棒分散状态反馈镇定问题。利用单李雅普诺夫函数方法,得到了不确定切换组合大系统鲁棒可稳的充分条件。在互相关联的低维子系统的状态矩阵和控制输入矩阵同时带有未知、时变但有界的不确定性、各自的单个子系统均不能被镇定的情况下,基于凸组合技术和线性矩阵不等式方法,设计出分散状态反馈控制器及相应的分散切换策略,使得闭环系统渐近稳定。仿真结果表明所设计方法的正确有效性。     

不确定离散广义系统的保成本控制

针对一类具有范数有界时变参数不确定性的离散广义系统和二次成本函数,研究保成本控制律的设计问题。利用李雅普诺夫稳定性理论,得到了不仅使得闭环系统鲁棒二次稳定,而且闭环成本函数不超过某个确定上界的保成本控制存在的充分必要条件,并通过求解一个里卡蒂不等式给出了最优控制律的设计方法,最后通过数值例子说明方法的可行性。     

广义离散时变系统的Lyapunov稳定性

对于一类广义离散时变系统,通过Lyapunov方程的建立,给出了系统因果且渐近稳定的充分必要条件。接着利用Lyapunov不等式进一步研究了系统的稳定性问题,同时给出了系统因果且渐近稳定的另一个充分必要条件,该方法使得判断系统的稳定性更为方便。最后,给出了应用上述方法的具体步骤,通过举例说明了所得结果的正确性。     

On delay-dependent robust stability for uncertain neutral systems

1.INTRODUCTION Time delaysarefrequentlyencounteredinvariousengi neeringsystems,includingaircraftstabilization,nuclear reactors,populationdynamicsmodels[1].Theirexistence isoftenthesourceofinstabilityinmanycontrolsystems.Stabilitycriteriafortime delaysystemscanbeclassified intotwocategories.Thestabilitycriteriathatincludein formationonthesizeofdelaysarereferredtoasdelay de pendentcriteria[2～18]andthecriteriaapplicabletoanar bitrarysizeofdelaysarereferredtoasdelay independent criteria[19～…     

Delay-dependent stability and stabilization of a class of linear switched time-varying delay systems

The stability and stabilization of a class of linear switched time-varying delay systems are investigated. A piecewise quadratic Lyapunov function (PWQLF) is constructed and is used to obtain the stability conditions based on the linear matrix inequalities (LMIs). The stabilizing controller for this class of system is then designed and the solution of the desired controller can be obtained by a cone complementary linearization algorithm. Numerical examples are provided to illustrate the less conservativeness of the new stability and the validity of the controller design procedures.     

不确定广义离散系统的鲁棒H-infinity控制

研究E矩阵,确定其它系数矩阵都存在满足范数有界条件的参数不确定性广义离散线性系统的鲁棒H∞控制问题。利用线性矩阵不等式方法,导出广义离散线性系统正则、因果、稳定且传递函数满足给定的范数界的等价条件。在此基础上,可以将广义不确定离散线性系统的状态反馈鲁棒H∞控制问题和输出反馈鲁棒H∞控制问题,分别转化为辅助广义确定性离散线性系统的状态反馈H∞控制问题和输出反馈H∞控制问题。     

基于LMI的不确定时滞切换广义系统的保成本控制

研究了一类具有状态时滞不确定性的切换广义系统在任意切换策略下的二次稳定保成本控制问题。利用线性矩阵不等式(linear matrix inequality, LMI)技术,给出了状态反馈保成本控制器存在的充分条件,使得所研究的时滞不确定切换广义系统是可行的,并满足相应的性能指标。进一步将保成本控制器的设计问题转化为线性矩阵不等式的可行解问题。数值仿真算例说明了该方法的有效性。     

New criteria on delayed state feedback stabilization for stochastic systems with time-varying delay

The problems of robust exponential stability in mean square and delayed state feedback stabilization for uncertain stochastic systems with time-varying delay are studied.By using Jensen’s integral inequality and combining with the free weighting matrix approach,new delay-dependent stability conditions and delayed state feedback stabilization criteria are obtained in terms of linear matrix inequalities.Meanwhile,the proposed delayed state feedback stabilization criteria are more convenient in application than the existing ones since fewer tuning parameters are involved.Numerical examples are given to illustrate the effectiveness of the proposed methods.     

Delay-dependent state feedback robust stabilization for uncertain singular time-delay systems

The problem of robust stabilization for uncertain singular time-delay systems is studied. First, a new delay-dependent asymptotic stability criteria for normal singular time-delay systems is given, which is less conservative. Using this result, the problem of state feedback robust stabilization for uncertain singular time-delay systems is discussed, Finally, two examples are given to illustrate the effectiveness of the results.     

Robust passive control for discrete-time T-S fuzzy systems with delays

This article deals with the robust stability analysis and passivity of uncertain discrete-time Takagi-Sugeno (T-S) fuzzy systems with time delays. The T-S fuzzy model with parametric uncertainties can approximate nonlinear uncertain systems at any precision. A sufficient condition on the existence of robust passive controller is established based on the Lyapunov stability theory. With the help of linear matrix inequality (LMI) method, robust passive controllers are designed so that the closed-loop system is robust stable and strictly passive.  urthermore, a convex optimization problem with LMI constraints is formulated to design robust passive controllers with the maximum dissipation rate. A numerical example illustrates the validity of the proposed method.     

不确定离散广义线性系统的保性能最优控制

对一类具有范数有界时不变参数不确定性的广义离散时间线性系统和一个二次型性能指标,研究了其最优保性能状态反馈控制律的设计问题。通过采用线性矩阵不等式方法,导出了存在保性能控制律的一个充分条件,进而证明了该条件可化为一个线性矩阵不等式的可解性问题,并用这组线性矩阵不等式的可行解给出了保性能控制律的一个参数化表示。在此基础上,通过建立并求解一个凸优化问题,给出了最优保性能控制律的设计方法,最后用例子说明了该方法的应用。     

区间离散广义系统输出反馈鲁棒H∞控制

讨论了区间离散广义系统的静态输出反馈鲁棒H∞控制问题,在给出区间离散广义系统的等价描述之后,基于系统参数矩阵不等式,得到了问题可解的充分条件,并给出了输出反馈控制器显式表示,所得控制器保证闭环系统是容许的,且满足给定的H∞性能指标,数值例子说明了该方法的可行性。     

Adaptive NN stabilization for stochastic systems with discrete and distributed time-varying delays

A new adaptive neural network(NN) output-feedback stabilization controller is investigated for a class of uncertain stochastic nonlinear strict-feedback systems with discrete and distributed time-varying delays and unknown nonlinear functions in both drift and diffusion terms.First,an extensional stability notion and the related criterion are introduced.Then,a nonlinear observer to estimate the unmeasurable states is designed,and a systematic backstepping procedure to design an adaptive NN output-feedback controller is proposed such that the closed-loop system is stable in probability.The effectiveness of the proposed control scheme is demonstrated via a numerical example.     

奇异不确定性多时滞系统的二次稳定性与H∞控制

针对奇异不确定性多时滞系统,研究了其二次稳定性及H∞状态反馈控制器的设计.假定其中的不确定性是范数有界的,通过构造改进的Lyapunov泛函,给出了其二次稳定性及H∞状态反馈控制器存在的条件.仅通过求解相应的线性矩阵不等式(linear matrix inequality,LMI)就可得到鲁棒H∞控制器,设计的控制器对所有容许的不确定性不仅使得相应的闭环系统渐进稳定,也能保证闭环系统满足一定的H∞性能指标,达到抑制干扰的效果.最后,用数值算例及仿真验证了所给方法的有效性.