不确定离散时滞系统具有H_∞干扰抑制的保成本控制

针对一类用矩阵凸多面体形式表示的不确定线性离散时滞系统 ,提出一种通过无记忆状态反馈实现的具有 H∞ 干扰抑制的保成本控制。当对象存在不确定性以及外部干扰统计特性未知时 ,该控制器能保证闭环系统稳定和一定的线性二次型性能指标上界 ,同时具有 H∞ 范数下的干扰抑制作用。基于L yapunov稳定性理论 ,控制器设计可转化为线性矩阵不等式的可解性问题。数值仿真表明 ,该控制器实际是对最优保成本上界和干扰抑制能力的一种折衷     

不确定离散时间系统的H2/ H∞最优保性能控制

针对具有两个不同被调输出的一类不确定离散时间系统,研究其H2/H∞状态反馈保性能控制问题,基于线性矩阵不等式处理方法。推导出存在H2/H∞保性能控制律的充分必要条件,并用一个线性矩阵不等式的可行解给出了所有保性能控制律的参数化表示,进而通过建立和求解一个凸优化问题,给出了H2/H∞最优保性能控制律设计方法,最后通过一个例子说明了所提出方法的有效性。     

具有H∞干扰抑制的中立型系统保成本控制

针对一类范数有界时变非线性不确定性的中立型系统,将其转化为时滞广义系统.利用时滞广义系统的相关理论、Lyapunov-Krasovskii稳定性定理和线性矩阵不等式方法,通过无记忆状态反馈实现了具有H∞干扰抑制的保成本控制,并给出了具有H∞干扰抑制的中立型系统保成本控制器存在的充分条件及相应的干扰抑制保成本指标.控制器的设计使得闭环系统鲁棒稳定,具有给定H∞干扰衰减度同时使给定的干扰抑制保成本指标最优.所得结论等价于一组线性矩阵不等式（LMI）的可解性问题.最后给出算例以验证设计方法的有效性.     

不确定离散时滞系统的时滞相关保性能控制

针对一类范数有界不确定离散状态时滞系统,研究了系统时滞相关保性能控制问题.通过在李亚普诺夫函数的前向差分中引入零项式和松弛变量,得到了改进的系统保性能控制律存在的时滞相关条件.针对控制律存在的时滞相关条件不是用严格线性矩阵不等式表示的情况,得到了一个改进的求解非凸可行性问题的迭代算法.通过两个数值例子表明所得结论能得到更小的性能指标上界.     

基于观测器的线性中立时滞系统的H ∞控制

研究一类中立时滞系统基于观测器的鲁棒H∞控制问题．首先讨论了相应的标称系统的稳定性准则，然后通过LMI方法给出了基于观测器的无记忆镇定控制器存在的充分条件及相应的设计方案，最后通过一个数值例子的仿真表明所提出的设计方法是有效而可用的．     

一类线性串联时滞不确定系统的鲁棒H∞控制

本文讨论一类具有串联结构的线性不确定系统的鲁棒Ｈ∞控制器,此类系统除状态及控制输入具有滞后特性外,其状态的时滞常数也不相同。文中考虑用分段状态方程描述受控对象,分别设计相应的鲁棒Ｈ∞控制器,并证明了分段设计方法能保证整体系统在Ｈ∞范数界约束下二次型稳定。     

不确定离散时滞系统的保性能控制

针对一类具有范数有界不确定性和状态滞后的离散时间线性系统,结合一个二次型性能指标,采用线性矩阵不等式方法,提出了无记忆状态反馈保性能控制律的存在条件,并利用一个线性矩阵不等式的解给出了保性能控制律的一个参数化表示.     

时变不确定奇异时滞系统的时滞相关H∞控制

研究一类含有时变时滞的不确定奇异系统的H∞控制问题,采用Lyapunov泛函方法和线性矩阵不等式（LMI）工具,给出闭环系统正则、渐近稳定且具有范数界的时滞相关充分条件;通过求解相应的线性矩阵不等式,得到奇异系统的H∞控制律。与已有结论相比,该方法无需模型变换。数值算例说明该方法的有效性。     

不确定时滞系统的保成本控制

针对一类具有时变参数不确定性的时滞系统，结合二次型成本函数研究该系统的保成本控制问题，提出了通过求解参数Ｒｉｃｃａｔｉ矩阵方程正定解的保成本状态反馈控制的设计方法 。     

时变不确定离散时滞系统的H∞鲁棒控制

研究了一类线性不确定离散时滞系统的H∞鲁棒控制问题,其时变不确定项是范数有界的,但无需满足匹配条件.基于线性矩阵不等式(LMI)方法,得到了可H∞鲁棒镇定的一个充分条件.通过求解一个特定的线性矩阵不等式,即可获得H∞状态反馈控制器.具体算例说明了该方法的有效性.     

Robust H∞ control for discrete-time polytopic uncertain systems with linear fractional vertices

The robust H∞ control problem for discrete-time uncertain systems is investigated in this paper. The uncertain systems are modelled as a polytopic type with linear fractional uncertainty in the vertices. A new linear matrix inequality (LMI) characterization of the H∞ performance for discrete systems is given by introducing a matrix slack variable which decouples the matrix of a Lyapunov function candidate and the parametric matrices of the system. This feature enables one to derive sufficient conditions for discrete uncertain systems by using parameter-dependent Lyapunov functions with less conservativeness. Based on the result, H∞ performance analysis and controller design are carried out. A numerical example is included to demonstrate the effectiveness of the proposed results.     

Guaranteed cost repetitive control for uncertain discrete-time systems

This paper considers the problem of guaranteed cost repetitive control for uncertain discrete-time systems. The uncertainty in the system is assumed to be norm-bounded and time-varying. The objective is to develop a novel design method for the repetitive control systems by introducing a robust output feedback controller so that the closed-loop system is quadratically stable and a certain bound of performance index is guaranteed for all admissible uncertainties. Necessary and sufficient conditions for the existence of such controllers are derived in terms of linear matrix inequality (LMI). A suboptimal guaranteed cost controller is obtained by solving an optimization problem with LMI constraints. Finally, a simulation example is provided to illustrate the validity of the proposed method.     

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.     

Guaranteed cost control of discrete-time uncertain systems with both state and input delays

The paper proposes a guaranteed cost feedback control for discrete-time uncertain systems with both state and input delays. The delays are assumed to be time-varying and bounded. In addition to norm-bounded parametric uncertainties, the class of admissible uncertainties and nonlinearities of the system comprehend several types of uncertainties frequently investigated in the literature. Using some recent developments, new sufficient conditions for the existence of the guaranteed cost control are given by bilinear matrix inequalities. Numerical examples illustrate the effectiveness of the proposed method.     

不确定离散时间马尔可夫切换时滞系统的保成本控制

研究了一类不确定具有模式依赖时滞马尔可夫切换系统的保成本控制问题.首先将系统变换为等价的奇异系统,并对等价的奇异系统,构造出一个新型随机Lyapunov泛函.然后运用此Lyapunov泛函,基于线性矩阵不等式,得到了无记忆状态反馈保成本控制器存在的与时滞相关的充分条件.举例结果表明,与现有方法相比,用本文方法可以使成本指标取得较小的成本上界.     

Guaranteed cost stabilization for a class of uncertain discrete-time systems

A technique to design stabilizing state feedback controllers is presented for a class of linear discrete-time systems subject to possibly time-varying uncertainties that affect the system and input matrices. The controller design procedure is based on the solution of one of three modified algebraic Riccati matrix equations. Stability considerations rely on the second method of Lyapunov. To evaluate the system's performance degradation due to uncertainly, an upper bound (guaranteed cost) is derived for the cost of the controlled uncertain system with respect to a designer-chosen quadratic cost function. An example adapted from the literature is used to illustrate the method.     

不确定时延网络控制系统的保性能控制

在工程实际网络控制系统中,不仅要求系统能够保持稳定,还要系统具有一定的性能指标,采用状态反馈控制是一种非常有效的控制方式。针对一类线性不确定时延网络控制系统,研究了在有记忆状态反馈控制器下的保性能控制问题。利用Lyapunov函数和线性矩阵不等式的方法,给出了网络控制系统保性能控制律存在的条件和相应的状态反馈控制器的设计方法。最后,通过Matlab数值仿真算例验证了该方法的有效性和正确性。     

Guaranteed cost control for multi-inventory systems with uncertain demand

In this paper we consider the problem of controlling a multi-inventory system in the presence of uncertain demand. The demand is unknown but bounded in an assigned compact set. The control input is assumed to be also constrained in a compact set. We consider an integral cost function of the buffer levels and we face the problem of minimizing the worst-case cost. We show that the optimal cost of a suitable auxiliary problem with no uncertainties is always an upper bound for the original problem. In the special case of minimum-time control, this upper bound is tight, namely its optimal cost is equal to the worst-case cost for the original system. Furthermore, the result is constructive, since the optimal control law can be explicitly computed.     

Set-membership filtering for polytopic uncertain discrete-time systems

In this paper, a set-membership filtering problem is considered for systems with polytopic uncertainty. A recursive algorithm for calculating an ellipsoid which always contains the state is developed. In the prediction step, a predicted state ellipsoid is determined; in the update step, a state estimation ellipsoid is computed by combining the predicted state ellipsoid and the set of states compatible with the measurement equation. A smallest possible estimate set is calculated recursively by solving the semi-definite programming problems. Hence, the proposed set-membership filter relies on a two-step prediction–correction structure, which is similar to the Kalman filter. Simulation results are provided to demonstrate the effectiveness of the proposed method.     

Guaranteed cost control for saturated uncertain linear systems

In this paper, we discuss the problem of guaranteed cost control for uncertain linear systems subject to actuator saturation. Based on the quadratic and non-quadratic Lyapunov functions, sufficient conditions for the robust stability and performance are derived. Moreover, all the conditions can be expressed as linear matrix inequalities （LMIs） or bilinear matrix inequalities （BMIs） in terms of the feedback gain. Thus, the static controller can be effectively synthesized via convex optimization. A numerical example illustrates the effectiveness of the method.