Robust reliability method for non-fragile guaranteed cost control of parametric uncertain systems

The problem of non-fragile guaranteed cost control of uncertain systems is studied from a new point of view of reliability against uncertainties. An efficient robust reliability method for the analysis and design of non-fragile guaranteed cost controller of parametric uncertain systems is presented systematically. By the method, a robust reliability measure of an uncertain control system satisfying required robust performance can be obtained, and the robustness bounds of uncertain parameters such that the control cost of a system is guaranteed can be provided. The optimal non-fragile guaranteed cost controller obtained in the paper may possess optimal guaranteed cost performance satisfying the precondition that the system is robustly reliable with respect to uncertainties occurring in both the controlled plant and controller gain. The presented formulations are in the framework of linear matrix inequality and thus can be carried out conveniently. The presented method provides an essential basis for the tradeoff between reliability and control cost in controller design of uncertain systems. Two numerical examples are provided to demonstrate the efficiency and feasibility of the presented method. It is shown that the coordination and simultaneous realization of the system performance, control cost, and robust reliability in control design of uncertain systems are significant.     

不确定时滞系统的模糊保成本控制

研究一类用T－S模糊模型描述的不确定时滞系统的鲁棒保成本控制问题，提出了系统存在保成本控制律的充分条件，基于LMI给出了系统设计状态反馈模糊保成本控制器的新方法，仿真结果证明了该方法的有效性。     

不确定非线性系统的鲁棒耗散性与保性能控制

考虑了不确定仿射非线性系统的鲁棒耗散性与保性能控制问题,不确定性范数有界,不满足匹配条件.基于HJI不等式,设计了状态反馈控制器.当扰动存在时,控制器能使系统达到耗散,当扰动为零时,所设计的控制器使系统对于给定的性能函数具有上界,最后研究了不确定线性系统的保性能与耗散性控制情形.     

Robust guaranteed cost control for uncertain stochastic systems with multiple decision makers

The guaranteed cost control (GCC) problem for uncertain stochastic systems with N decision makers is investigated. It is noteworthy that the necessary conditions, which are determined from Karush-Kuhn-Tucker (KKT) conditions, for the existence of a guaranteed cost controller have been derived on the basis of the solutions of cross-coupled stochastic algebraic Riccati equations (CSAREs). It is shown that if CSAREs have an optimal solution, then the closed-loop system is exponentially mean square stable (EMSS) and has a cost bound. In order to simplify computations and attain a global optimum, the linear matrix inequality (LMI) technique is also considered. Finally, a numerical example for a practical megawatt-frequency control problem shows that the proposed methods can help in attaining an adequate cost bound. Furthermore, the features of these methods are characterized.     

Robust guaranteed cost control of uncertain fuzzy systems under time-varying sampling

In practice, the system is often modeled as a continuous-time fuzzy system, while the control input is applied only at discrete instants. This system is called a sampled-data control system. In this paper, robust guaranteed cost control for uncertain sampled-data fuzzy systems is discussed. A guaranteed cost control where a quadratic cost function is bounded by a certain scalar, not only stabilizes a system but also considers a control performance. A typical sampled-data control is the zero-order input, which can be represented as a piecewise-continuous delay. Here we take a delay system approach to the sampled-data guaranteed cost control problem. The closed-loop system with a sampled-data state feedback controller becomes a system with time-varying delay. First, guaranteed cost control performance conditions for the closed-loop system are given in terms of linear matrix inequalities (LMIs). Such conditions are derived by using Leibniz–Newton formula and free weighting matrix method for fuzzy systems under the assumption that sampling time is not greater than some prescribed scalar. Then, a design method of robust guaranteed cost state feedback controller for uncertain sampled-data fuzzy systems is proposed. Examples are given to illustrate our robust sampled-data guaranteed cost control design.     

不确定性时滞系统H∞鲁棒保性能控制

在Riccati不等式的基础上,给出鲁棒保性能H∞不确定性时滞系统的定义.然后以性能指标上界最小为优化命题设计状态反馈控制器,使得闭环系统不仅对容许的参数不确定性以及时变时滞保持渐近稳定,而且具有给定H∞干扰衰减度以及保性能上界最优.数值实例及仿真结果表明了该方法的有效性和可行性.     

时滞不确定采样控制系统的鲁棒稳定性

本文给出了一种可定量分析采样控制系统的时滞鲁棒稳定性的方法.因为采样系统的对象是连续时间的,所以对象中的时滞也应该是按连续时间来处理.文中指出,一个整数倍时滞是稳定的采样系统,可能会因为有并不很大的连续时间时滞而失稳.定义了一个新的变量w(t),用来描述这个不确定连续时间时滞带来的动特性.将w(t)的反馈回路分成与时滞无关和有关的两个部分,并提出了一种用频率响应来确定是否存在由不确定时滞引起的周期解的方法.用修正z-变换法和仿真验证了这个由图解解析所求得的解.本方法既可用于采样系统,也可用于一般的连续时间系统.     

不确定多时滞系统非脆弱鲁棒保代价控制

针对一类含有多时滞的不确定线性系统，在控制器增益存在乘性和加性两种摄动形式时分别设计了非脆弱具有鲁棒性能的保代价控制器．利用构造的Lyapunov函数和线性矩阵不等式，证明并给出了非脆弱鲁棒保代价状态反馈控制问题有解的充分条件，仅通过求解相应的线性矩阵不等式就可得到非脆弱鲁棒保代价控制器．所设计的控制器不仅使闭环系统具有鲁棒性，能满足所给的的鲁棒保代价性能指标，而且当控制器增益参数变化时，系统性能指标同样能够满足要求．该系统对环境参数的变化具有更好的适应能力。     

不确定系统的网络化保性能控制

本文针对控制网络中存在着随机传输时延和数据包丢失的现象,考虑了网络化控制系统的状态反馈保性能控制器设计问题.首先采用时滞相关方法并引入自由权矩阵,给出了基于矩阵不等式的网络化二次型保性能控制器存在的充分条件,然后基于该充分条件获得了基于线性矩阵不等式的控制器设计方法,相应的网络化保性能控制律可以通过求解线性矩阵不等式来构造,并采用锥互补线性化算法给出了网络化次优保性能控制器的设计方法.最后数值示例演示了所得控制器设计结果的应用方法和有效性,并通过仿真比较了传统保性能控制器和网络化保性能控制器在网络化控制系统中的控制性能.     

具有结构不确定性的时滞系统的最优非脆弱保性能控制

对一类具有结构不确定性的线性时滞系统的最优非脆弱保性能控制问题进行了研究.以线性矩阵不等式的形式给出了设计非脆弱保性能控制律的一个充分条件.然后给出了在使性能指标上界最小的意义下,最优非脆弱保性能控制律的设计算法.最后用例子演示了方法的有效性.     

Delay-dependent robust and non-fragile guaranteed cost control for uncertain singular systems with time-varying state and input delays

This paper considers the design problems of a delay-dependent robust and non-fragile guaranteed cost controller for singular systems with parameter uncertainties and time-varying delays in state and control input. The designed controller, under the possibility of feedback gain variations, can guarantee that a closed-loop system is regular, impulse-free, stable, an upper bound of guaranteed cost function, and non-fragility in spite of parameter uncertainties, time-varying delays, and controller fragility. The existence condition of the controller, the controller’s design method, the upper bound of guaranteed cost function, and the measure of non-fragility in the controller are proposed using the linear matrix inequality (LMI) technique. Finally, numerical examples are given to illustrate the effectiveness and less conservatism of the proposed design method. Recommended by Editorial Board member Guang-Hong Yang under the direction of Editor Young Il Lee. Jong-Hae Kim received the B.S., M.S., and Ph.D. degrees in Electronics from Kyungpook National University in 1993, 1995, and 1998, respectively. He was with STRC at Kyungpook National University from Nov. 1998 to Feb. 2002. He has been with Sun Moon University since March, 2002. His research interests focus on robust control, signal processing, and industrial application systems.     

带不确定时滞的中立型系统之鲁棒非脆弱保性能控制

针对一类动态不确定时滞中立型系统,研究了非脆弱鲁棒保性能控制器设计问题.考虑的中立型系统和状态反馈控制器均具有不确定性.在适当的假设下利用Lyapunov稳定性方法,以线性矩阵不等式的形式,给出了使该动态时滞不确定中立型系统二次稳定及非脆弱鲁棒保性能状态反馈控制器存在的充分条件.通过求解相应的线性矩阵不等式就可得到系统的非脆弱鲁棒保性能控制器,同时也能保证二次性能函数不超过一个确定的界.最后,用数值仿真验证了所给方法的可行性.     

Adaptive guaranteed cost control of systems with uncertain parameters

Guaranteed cost control is a method of synthesizing a closed-loop system in which the controlled plant has large parameter uncertainty. This paper gives the basic theoretical development of guaranteed cost control, and shows how it can be incorporated into an adaptive system. The uncertainty in system parameters is reduced first by either: 1) on-line measurement and evaluation, or 2) prior knowledge on the parametric dependence of a certain easily measured situation parameter. Guaranteed cost control is then used to take up the residual uncertainty. It is shown that the uncertainty in system parameters can be taken care of by an additional term in the Riccati equation. A Fortran program for computing the guaranteed cost matrix and control law is developed and applied to an airframe control problem with large parameter variations.     

结构不确定离散系统的最优非脆弱保成本控制

讨论了一类不确定线性离散系统的最优非脆弱保成本控制问题.考虑的系统和状态反馈控制器均具有时变的结构化的不确定性.基于线性矩阵不等式的方法,给出了存在和设计非脆弱保成本控制律的一个充分条件,以及在使二次成本函数上界最小意义下,最优非脆弱保成本控制律的凸优化设计方法.并用数值例子说明该方法降低了成本函数上界的保守性.     

不确定时变时滞切换广义系统的鲁棒H∞ 保性能控制

利用公共 Lyapunov 泛函方法和凸组合技术研究了一类不确定时变时滞切换广义系统的鲁棒 ∞保性能控制和状态反馈镇定问题.在设定的切换规则下,给出了基于线性矩阵不等式表示的鲁棒 ∞保性能控制器存在的充分条件,保证了系统具有鲁棒 ∞干扰抑制水平 及状态反馈可切换镇定的同时满足保性能指标.最后的仿真示例验证了该方法的有效性.     

基于T-S模型的非线性时滞系统非脆弱保性能模糊控制

针对一类用T-S模糊模型描述的非线性时滞系统,采用状态反馈的并行分布补偿方法,研究其保守性较小的非脆弱保性能模糊控制问题,使闭环系统在控制器存在加性摄动的情况下,其闭环性能指标值低于确定的上界.利用线性矩阵不等式处理方法,导出了非脆弱保性能模糊控制律的存在条件,通过建立和求解一个线性矩阵不等式问题,给出了非脆弱保性能模糊控制律的设计方法.仿真结果表明了所提出方法的有效性.     

Minimax guaranteed cost control of uncertain non-linear systems

In this paper, a guaranteed cost control for non-linear uncertain systems is developed. The relationship between the idea of guaranteed cost control and dissipative feedback is first discussed which have been independently studied in the literature on robust control. It turns out that the two approaches are equivalent, and both presume the existence of a storage function (a Lyapunov function candidate) which guarantees the stability of the closed-loop system. The idea of guaranteed cost control is then applied to solve the robust control problem for non-linear systems with both drift vector field and input vector field uncertainties. Necessary and sufficient conditions are given for the solvability of this problem in terms of certain Hamilton-Jacobi Isaac's inequalities. The robustness properties of the controllers are also discussed. Finally, a passivity-based approach to the synthesis of guaranteed cost controllers is discussed.     

不确定离散时滞系统的动态输出反馈鲁棒保性能控制

研究不确定离散时滞系统的动态输出反馈保性能控制问题, 通过引入动态输出反馈补偿器, 采用线性矩阵不等式的方法, 导出了系统存在保性能控制律的充分条件. 数值算例说明了其有效性.     

Robust guaranteed cost control for continuous-time uncertain Markov switching singular systems with mode-dependent time delays

Neural Computing and Applications - The guaranteed cost control problem for mode-dependent time-delay Markov switching singular systems with norm-bounded uncertain parameters is discussed. Based on...