Robust Input-Output Energy Decoupling for Uncertain Singular Systems

This paper addresses the robust input-output energy decoupling problem for uncertain singular systems in which all parameter matrices except E exist as time-varying uncertainties. By means of linear matrix inequalities (LMIs), sufficient conditions are derived for the existence of linear state feedback and input transformation control laws, such that the resulting closed-loop uncertain singular system is generalized quadratically stable and the energy of every input controls mainly the energy of a corresponding output, and influences the energy of other outputs as weakly as possible. Keywords Uncertain singular systems - generalized quadratical stability - input-output energy decoupling - linear matrix inequality (LMI) Xin-Zhuang Dong graduated from the Institute of Information Engineering of People’s Liberation Army, China, in 1994. She received the M. S. degree from the Institute of Electronic Technology of People’s Liberation Army, in 1998 and the Ph.D. degree from Northeastern University, China, in 2004. She is currently a post-doctoral fellow at the Key Laboratory of Systems and Control, CAS.Her research interests include singular and nonlinear systems, especially the control of singular systems such as H ∞ control, passive control and dissipative control. Qing-Ling Zhang received the Ph.D. degree from Northeastern University, China, in 1995. He is currently a professor with the Institute of Systems Science, Northeastern University. His research interests include singular systems, fuzzy systems, decentralized control, and H 2/H ∞ control.

Robust H_∞ control for a class of nonlinear singular system with uncertain parameters

The static output feedback H∞ control is explored for a class of nonlinear singular system with norm-bounded uncertainty. On certain suppose, the zero solution asymptotically stability is analyzed by means of Lyapunov function and Lyapunov stability theory. Based on which, a sufficient condition is presented such that the system is zero solution asymptotically stable and has H∞ norm constraint γ. Then, the static output feedback H∞ controller is designed to guarantee the resulting closed-loop system has the same performance. Finally, an example proves the effectiveness of the conclusion.

GUARANTEED COST CONTROL OF CONTINUOUS-TIME UNCERTAIN SINGULAR SYSTEM WITH BOTH STATE AND INPUT DELAYS

The guaranteed cost control problem for a continuous-time uncertain singular system with state and control delays, and a given quadratic cost function is studied in this paper. Sufficient conditions for the existence of the guaranteed cost controller are derived based on the linear inequality (LMI) approach. A parameterized characterization of the guaranteed cost laws is given in terms of the feasible solutions to a certain LMI, and the cost function of guaranteed cost controller exists an upper bound.

Decentralized robust guaranteed cost control for a class of interconnected singular large-scale systems with time-delay and parameter uncertainty

The decentralized robust guaranteed cost control problem is studied for a class of interconnected singular large-scale systems with time-delay and norm-bounded time-invariant parameter uncertainty under a given quadratic cost performance function. The problem that is addressed in this study is to design a decentralized robust guaranteed cost state feedback controller such that the closed-loop system is not only regular, impulse-free and stable, but also guarantees an adequate level of performance for all admissible uncertainties. A sufficient condition for the existence of the decentralized robust guaranteed cost state feedback controllers is proposed in terms of a linear matrix inequality （LMI） via LMI approach. When this condition is feasible, the desired state feedback decentralized robust guaranteed cost controller gain matrices can be obtained. Finally, an illustrative example is provided to demonstrate the effectiveness of the proposed approach.

Delay-dependent robust control for uncertain discrete singular systems with time-varying delay

The design problem of delay-dependent robust control for uncertain discrete singular systems with time-varying delay is addressed in this paper. The uncertainty is assumed to be norm-bounded. By establishing a finite sum inequality based on quadratic terms, a new delay-dependent robust stability condition is derived and expressed in terms of linear matrix inequalities (LMIs). A suitable robust state feedback control law is presented, which guarantees that the resultant closed-loop system is regular, causal and stable for all admissible uncertainties. Numerical examples are given to demonstrate the applicability of the proposed method.

Robust Admissibility and Stabilization of Uncertain Singular Fractional-Order Linear Time-Invariant Systems

This paper addresses the robust admissibility problem in singular fractional-order continuous time systems. It is based on new admissibility conditions of singular fractional-order systems expressed in a set of strict linear matrix inequalities(LMIs). Then, a static output feedback controller is designed for the uncertain closed-loop system to be admissible. Numerical examples are given to illustrate the proposed methods.

Mixed L_1/H-infinity control for uncertain linear singular systems

The mixed L1/H-infinity control problem for a class of uncertain linear singular systems is considered using a matrix inequality approach. The purpose is to design a state feedback control law such that the resultant closed-loop system is regular, impulse-free, stable and satisfies some given mixed L1/H-infinity performance. A sufficient condition for the existence of such control law is given in terms of a set of matrix inequalities by the introduction of inescapable set and ＊-norm. When these matrix inequalities are feasible, an explicit expression of the desired state feedback control law is given. A numerical example is used to demonstrate the applicability of the proposed approach.

STABILITY OF SINGULAR UNCERTAIN DIFFERENTIAL SYSTEMS WITH MULTIPLE TIME-VARYING DELAYS

The stability of singular uncertain differential systems with multiple time-varying delays is discussed, and many results on this are obtained.

DELAY-DEPENDENT ROBUST STABILITY CRITERIA FOR UNCERTAIN SINGULAR NEUTRAL DIFFERENTIAL SYSTEMS WITH TIME-VARYING AND DISTRIBUTED DELAYS

The problem of delay-dependent robust stability for uncertain linear singular neutral systems with time-varying and distributed delays is investigated. The uncertainties under consideration are norm bounded,and possibly time varying. Some new stability criteria,which are simpler and less conservative than existing results,are derived based on a new class of Lyapunov-Krasovskii functionals combined with the descriptor model transformation and the decomposition technique of coeffcient matrix and formulated in...

具有不确定转移速率的广义马尔可夫跳变系统的耗散模糊控制

研究了具有不确定转移速率的广义马尔可夫跳变系统的耗散模糊控制问题.首先,建立了一个新的李雅普诺夫函数,进而得到了能够保证系统随机可容许并且具有给定耗散性能指标α的有界实引理.利用时滞分割方法和新的不等式去处理函数,从而在一定程度上减少了结论的保守性.其次,基于这些因素,得到了可以利用严格的线性矩阵不等式求解的期望控制器的显式表达式.在设计控制器的过程中,将不确定转移速率分为两种情况,进而得到了两种不同情况下的线性矩阵不等式.最后,一些数值算例反映出本文方法具有较小的保守性和有效性.

不确定多时滞奇异系统鲁棒H_∞降维滤波器的设计

讨论了一类同时具有不确定性和多时滞的奇异系统鲁棒H∞降维滤波器的设计问题.目的是对于所容许的不确定性和多时滞,设计一个比原系统维数低的确定维数的稳定线性滤波器,使得滤波误差动态系统是渐进稳定并满足给定的H∞性能要求.该问题有解的充分条件是0≤ETY,rankX≤^n,Π1<0,Π2<0;并且当这些条件满足时,以参数显式化的形式给出了所求的鲁棒H∞降维滤波器.所有这些结果都只利用了原始系统的矩阵而没有分解,这就使得设计过程简便、直接.最后用数值算例验证了结论的可行性和有效性.

参数不确定广义时滞系统的保性能控制

针对状态时滞的参数不确定性广义系统,讨论了它的保性能控制问题。目的是对状态时滞的参数不确定广义系统,提出它的时滞无关保性能鲁棒控制器的一个设计方法。首先给出了广义时滞系统正则、脉冲自由且稳定的严格线性矩阵不等式表示的时滞无关充分条件;然后采用线性矩阵不等式方法,给出参数不确定性广义时滞系统的时滞无关保性能控制问题可解的一个严格线性矩阵不等式表示的充分条件,在此条件可解时,给出了时滞无关保性能鲁棒控制器表达式,以及相应的可保性能指标。最后给出了所提出方法的应用。

时变不确定广义系统的鲁棒无源控制

研究了除E外其余系数矩阵均含有范数有界时变不确定性的广义系统的鲁棒无源控制器设计问题.利用线性矩阵不等式方法,首先给出自治系统广义二次稳定且无源的充分条件;然后给出状态反馈鲁棒无源控制器的存在条件并用线性矩阵不等式的解构造了相应的控制器;随后以矩阵不等式的形式得到了动态输出反馈鲁棒无源控制器的存在条件,同时利用矩阵不等式的解给出相应控制器的设计方法;最后举例说明了所提出方法的可行性.

不确定非线性广义系统的鲁棒控制与保性能控制

研究了不确定非线性结构扰动的广义系统的鲁棒控制和保性能控制问题,该不确定性为时间、状态函数且满足Lipschitz条件的。目的是分别设计系统的鲁棒控制器和保性能控制器。应用线性矩阵不等式方法,分别给出了系统的鲁棒控制器和保性能控制器存在的充分条件;并在这些条件可解时,分别给出了鲁棒控制器和保性能控制器的表达式。最后用例子说明了所给方法的应用。

一类参数不确定广义时滞系统的H_∞保性能鲁棒控制

针对一类状态时滞的参数不确定性广义系统,讨论了它的保性能控制问题.目的是对状态时滞的参数不确定广义系统,提出它的时滞无关保性能鲁棒控制器的一个设计方法.首先给出了广义时滞系统正则、脉冲自由且稳定的严格线性矩阵不等式表示的时滞无关充分条件;然后采用线性矩阵不等式方法,给出参数不确定性广义时滞系统的时滞无关保性能控制问题可解的一个严格线性矩阵不等式表示的充分条件,在此条件可解时,给出了时滞无关保性能鲁棒控制器表达式,以及相应的可保性能指标.最后给出了所提出方法的应用.

不确定离散广义系统的鲁棒无源控制

将严格无源的概念引入到离散广义系统中 ,研究了具有未知定常不确定参数的离散广义系统在有界外部输入作用下的鲁棒无源控制问题 ;利用线性矩阵不等式 ,给出了不确定离散广义系统广义二次稳定且从外部输入到被调输出之间是严格无源的 ,并在此基础上给出存在状态反馈控制器 ,使得闭环系统广义二次稳定且从外部输入到被调输出之间是严格无源 ,同时给出相应的依赖于矩阵不等式的解的控制器构造 ;数值算例说明了结论的有效性。

多时滞不确定广义系统的非脆弱H_∞保成本控制

对一类具有结构不确定性的线性多时滞广义系统,结合了一个二次性能指标,研究其非脆弱H∞保成本控制律的设计问题.基于Lyapunov稳定性理论证明其系统的稳定性.利用线性矩阵不等式(LMI)方法,分别对控制器增益具有加法式摄动和乘法式摄动两种情形加以讨论,得到非脆弱保成本控制律设计的一个充分条件.该控制器能保证闭环系统稳定和一定的线性二次性能指标上界,同时具有H∞范数下的干扰抑制作用.最后,针对加法和乘法两种摄动的情况,用数值例子进一步说明本文所给方法的有效性.

一类不确定线性奇异系统的有限时间控制问题

讨论了一类同时带有时变参数不确定性和外部干扰的线性奇异系统的有限时间控制问题 ,找到了问题可解的充分条件 ,并给出了状态反馈控制器的设计方法 .这些条件可以归结为基于线性矩阵不等式 (LMI)的可解性问题 .

不确定奇异时滞系统的保性能控制

利用线性矩阵不等式方法 ,讨论不确定性奇异时滞系统的保性能控制问题 ,给出了问题可解的一个充分条件和保性能鲁棒控制器的设计 ,以及相应的可保性能指标。

基于神经网络的时滞广义系统鲁棒H_∞控制

针对神经网络模型自身的结构特点,研究了当系统存在扰动时的鲁棒H∞控制问题。将神经网络和控制理论相结合,利用线性矩阵不等式方法和神经网络良好的逼近能力,对一类时滞广义系统设计了鲁棒H∞控制器,并给出了H∞反馈控制器存在的充分条件。使得在一定条件下,闭环系统渐近稳定且从扰动到控制输出的传递函数的H∞范数不超过某个确定的上界。所得结论可化为标准的线性矩阵不等式(LMI)求解,该方法具有一定的实际意义和可行性,算例也验证了其有效性。