非线性扰动不确定时滞系统时滞相关鲁棒观测器设计

研究一类具有非线性扰动的不确定时滞系统的时滞相关鲁棒稳定性及其基于观测器 的时滞相关鲁棒控制问题.将线性矩阵不等式(LMI,1inear matrix inequality)与数值不等式 (AVI,algebraic value inequality)方法相结合给出了开环系统渐近稳定及其指数稳定的时滞相 关条件.并设计了系统的观测器,给出了该系统基于观测器的时滞相关可镇定条件.     

不确定时滞系统的稳定条件

利用比较定理、矩阵范数和矩阵测度的有关性质,提出了简单不确定时滞系统及对称组合不确定时滞系统的稳定条件.指出若带有时滞的系统稳定,则去掉时滞时系统一定稳定.在组合系统的情况下给出了时滞相关型的稳定条件.所研究对象的不确定矩阵的范数有一定限制.     

具有饱和执行器的时滞广义系统的鲁棒控制

利用李亚普诺夫方法研究了时滞广义系统、不确定广义系统和不确定时滞广义系统的鲁棒镇定问题.首先设计了时滞广义系统的具有饱和执行器的控制律,并给出其闭环系统渐近稳定的充分条件.对不确定项是范数有界的不确定广义系统,给出其控制器的设计方法和闭环系统渐近稳定的充分条件.在此基础上,进一步给出了不确定时滞广义线性系统的镇定条件.最后,给出了一个数值算例来说明方法的有效性.     

离散广义时滞系统的时滞依赖稳定性分析

讨论离散广义时滞系统的稳定性问题. 在不使用系统分解和等价转换的情况下, 利用线性矩阵不等式方法, 给出保证系统正则、因果和稳定的时滞依赖条件. 与已有的方法相比, 本文的方法更加充分地利用时滞的信息, 因此所得结果具有较小的保守性. 数值例子说明本文结果的有效性.     

一类结构不确定性的离散时滞大系统的分散镇定

研究了一类离散时滞大系统的时滞相关鲁棒分散镇定问题, 系统的不确定与标称系统具有结构相似性. 通过构造性的差分格式, 将时滞相关鲁棒分散镇定控制器的存在条件转化为一列线性矩阵不等式的可行解问题. 提出了控制时滞及控制器的时滞鲁棒性概念, 在获得分散镇定控制器的同时给出了鲁棒时滞上界的求解, 因此比现有文献的结果更具有实际应用价值.     

线性不确定时滞系统的时滞依赖鲁棒镇定方法研究

研究一类同时存在状态和控制滞后的线性不确定时滞系统的鲁棒镇定问题。系统的不确定项参数时为未知但范数有界,其滞后项也时时变的。对此,给出一个使得系统鲁棒稳定的无记忆状态反馈控制律,所得结果与时滞相关,且相应的结果以线性矩阵不等式的形式给出。     

时滞切换系统的时滞依赖稳定

首先利用多Lyapunov 函数方法, 分析常时滞切换系统的时滞依赖稳定性, 并给出此系统时滞依赖稳定的充分条件及切换律的设计; 然后运用共同Lyapunov 函数方法, 研究一类时变时滞切换系统的时滞依赖稳定性, 也给出此系统时滞依赖稳定的充分条件及切换律的设计. 所得结果均可用线性矩阵不等式方法求解. 最后通过仿真验证了结论的正确有效性.     

不确定奇异时滞系统的时滞相关型鲁棒∞弹性控制

讨论了不确定奇异时滞系统的时滞相关型鲁棒弹性控制器设计问题.在一个关于标称奇异时滞系统的新的时滞相关型稳定性判据的基础上给出了一种新的有界实引理(BRL:bounded real lemma);基于此给出了时滞相关型鲁棒弹性控制器存在的充分性条件,最后通过数值算例说明本文结果的有效性.     

时滞相关型离散时变时滞奇异系统的鲁棒镇定

讨论含参数不确定的离散时变时滞奇异系统的时滞相关的鲁棒状态反馈稳定化问题. 在一系列等价变换下, 阐述了其和一个不确定正常线性离散时变时滞系统的鲁棒状态反馈稳定化问题的等价关系;利用矩阵不等式方法, 给出一个对所有容许的不确定, 使得闭环系统正则、因果且稳定的时滞相关鲁棒状态反馈稳定化控制器存在的充分条件以及无记忆状态反馈控制器的一个解.     

时滞项可微系统的时滞依赖的稳定性条件

本文研究了带有可微时滞项连续系统的稳定性问题. 通过利用时滞项导数的信息, 给出了改进的时滞系统渐近稳定性条件. 与已有的做法不同, 即便是时滞项导数的上界大于等于 1 时这个上界仍可被利用. 文中证明了所得结果比已有结果的保守性小. 同时, 由于涉及较少的决策变量, 计算复杂度也大为降低. 数例进一步说明了所得结果的有效性和少保守性.     

时变时滞神经网络系统的时滞依赖的鲁棒稳定性准则

基于Lyapunov稳定性理论和线性矩阵不等式技术,针对一类带有范数有界不确定性的时变时滞神经网络系统,给出时滞依赖的鲁棒稳定性准则.系统稳定的充分条件是在激励函数满足一类更为通用的条件下得到的,即激励函数不必是单调可微的,并且消除对时变时滞导数的限制.所给的准则可用Matlab中的线性矩阵不等式控制工具箱进行验证.仿真结果进一步证明结论的有效性.     

时滞大系统的Robust稳定性

在本文中考虑了由非线性扰动子系统组成的时滞大系统的鲁棒稳定性问题，利用Ｌｙａｐｕｎｏｖ稳定性准则，对角占优矩阵的方法和结合矩阵Ｒｉｃｃａｔｉ方程，获得了系统指数稳定的充分判据，本文的结果改进并推广了文（４，６）的结果。     

String stability of infinite-dimension stochastic interconnected large-scale systems with time-varying delay

The exponential string stability for a class of nonlinear interconnected large-scale systems with time-varying delay is analysed by using the box theory and constructing a vector Lyapunov function. Under the assumption that the time delay is bounded and continuous, a criterion for exponential string stability of the systems is obtained by analysing the stability of differential inequalities with time-varying delay. The large-scale system is exponential string stable when the conditions associating with the coefficient matrices of the system and the solutions of the Lyapunov equations, interconnected with the system, are satisfied. Since it is independent of the delays and simplifies the calculation, the criterion is easy to apply.     

多区域时滞电力系统稳定判据的优化

在大规模互联电力系统进行全网动态分析与控制的过程中,通信时滞的存在易导致动力系统产生控制设备失效、系统性能恶化及失稳等现象.而现有时滞系统稳定判据的研究多基于Lyapunov分析方法,研究过程中需采用不等式放缩及构造Lyapunov泛函,使得稳定判据具有较高保守性,增加了系统的控制成本.针对这一问题,本文以多区域时滞电力系统为研究对象,通过引入Wirtinger不等式优化稳定判据推导过程和构造新的Lyapunov泛函两种方式,降低系统稳定判据的保守性.最后,利用典型的二阶时滞系统和两区域负荷频率控制系统,验证了本文算法的正确性和有效性.     

H-infinity control for networked control systems （NCS） with time-varying delays

1Introduction Ina networkedcontrol system(NCS),a communicationnetwork connects sensors,actuators and controllers.AnNCS has many advantages over the point_to_pointcommunication of traditional control systems:fast and easymaintenance,low cost,greater flexibility,etc.Therefore,NCSs are increasingly being usedfor industrial control in avariety of fields[1,2].On the other hand,control loopsonthe communication network are closedin an NCS.Thetime delays that occur when information is transmitte…     

New results on robust H-infinity control for discrete-time systems with interval time-varying delays

This paper deals with delay-dependent robust H-infinity control for uncertain discrete-time systems with interval time-varying delay. By using a new Lyapunov functional and the convex combination method, a new delay-dependent stability criterion is established. Some redundant variable matrices are removed in the new conditions, which makes the obtained results more efficient. Then, an iterative algorithm based on the cone complementarity Linearization method is proposed to obtain the delay-dependent robust H-infinity controller. Numerical examples are given to show the effectiveness of the proposed method.     

Robust stability and stabilization of discrete singular systems with interval time-varying delay and linear fractional uncertainty

The robust stability and robust stabilization problems for discrete singular systems with interval time-varying delay and linear fractional uncertainty are discussed. A new delay-dependent criterion is established for the nominal discrete singular delay systems to be regular, causal and stable by employing the linear matrix inequality (LMI) approach. It is shown that the newly proposed criterion can provide less conservative results than some existing ones. Then, with this criterion, the problems of robust stability and robust stabilization for uncertain discrete singular delay systems are solved, and the delay-dependent LMI conditions are obtained. Finally, numerical examples are given to illustrate the e?ectiveness of the proposed approach.     

一类多延时多变量网络控制系统的建模及稳定性

针对一类多延时多变量网络控制系统（NCS）,讨论其建模和稳定性问题．首先假设传感器采用时间驱动、控制器和执行器采用事件驱动,建立了系统在连续时域~MIMO数学模型;然后根据Lyapunov稳定性原理和Razumikhin定理,构造系统的Lyapunov函数,并分析系统的渐近稳定性,进而得到了系统稳定的时延参数和稳定性条件;最后通过仿真实例验证了该类网络控制系统的稳定判据．     

H-infinity control for networked control systems (NCS) with time-varying delays

This paper discusses H-infin it y state feedback control for a networked control system with time-varying delays.Based on the free-weighing matri x method,a delay-dependent stability criterion satisfying a prescribed H-infini ty norm bound is presented for an NCS with unknown,time-varying and bounded del ays.And then,the criterion is transformed into suffici ent conditions based on linear matrix inequalities f or H-infinity control.The conditions thus obtained a re also used to design an H-infinity state feed back controller.This design method is further extend ed to solve the design problem of robust H-infin ity state feedback control.A numerical example demo nstrates the validity of the method.     

Novel delay‐derivative‐dependent stability criteria using new bounding techniques

This paper studies the stability of linear systems with interval time‐varying delays. By constructing a new Lyapunov–Krasovskii functional, two delay‐derivative‐dependent stability criteria are formulated by incorporating with two different bounding techniques to estimate some integral terms appearing in the derivative of the Lyapunov–Krasovskii functional. The first stability criterion is derived by using a generalized integral inequality, and the second stability criterion is obtained by employing a reciprocally convex approach. When applying these two stability criteria to check the stability of a linear system with an interval time‐varying delay, it is shown through some numerical examples that the first stability criterion can provide a larger upper bound of the time‐varying delay than the second stability criterion. Copyright © 2012 John Wiley & Sons, Ltd.