同时镇定：逆LQ方法

本文使用逆ＬＱ方法了同时镇定问题,首先得到了ｒ个正则ＭＩＭＯ对象可静态输出反馈同时定的充要条件,然后给出了状态反馈问题同时镇定的一种解,这些条件均以一组耦合Ｒｉｃｃａｔｉ方程和Ｒｉｃｃａｔｉ不等式的形式给出,本语文证明,任一同时镇定反馈增益均可描述为一组具有合适交叉项的耦合ＬＱ控制问题的解。     

基于结构L yapunov 矩阵的静态输出反馈镇定

线性时不变系统的静态输出反馈控制可行性等价于两个耦合的线性矩阵不等式解的存在性问题,这导致了一个非线性最优化问题,是无法直接求解的．针对线性时不变系统(LTI),深入研究这两个矩阵不等式的关系,通过构造一个结构Lyapunov矩阵,给出了一个问题有解的充分条件,并在此基础上提出一个静态输出反馈镇定算法．利用线性矩阵不等式(LMI)方法,可直接求解出相应的输出反馈增益．数值实例证明了该方法的有效性．     

基于谱技术的随机系统的区间输出反馈镇定控制

基于谱技术研究了线性随机系统的区间稳定性与镇定控制问题.首先给出了保证随机系统区间稳定的充分性判据,该判据可确保随机系统的谱全部位于左半复平面的某一带状区域内;然后,利用矩阵的奇异值分解给出了静态输出反馈镇定控制器的设计方法,并将其归结为一组线性矩阵不等式（LMIs）的求解问题;最后,数值仿真验证了所得结论的正确性.     

严格正则多输入多输出对象同时镇定

使用逆LQ方法讨论了r个严格正则多输入多输出对象的同时镇定问题,基于矩阵不等式方法得到了静态输出反馈可同时镇定的充要条件,本文证明,r个对象静态输出反馈同时镇定等价于r个耦合LQ控制问题的解.然后,基于迭代线性矩阵不等式技术给出了一种迭代求解方法,并给出了算例.     

最小阶输出反馈镇定控制器设计*

本文首先基于逆ＬＱＧ方法得到了静态输出反馈可镇定的一种充要条件,并进一步给出了固定输出反馈可镇定的充要条件和控制器的设计方法,基于此给了一种最小阶镇定控制器的设计方法,这些条件的形式简单,判断其可镇定性和设计镇定控制器仅需解几个相应的矩阵不等式。     

抵御执行器故障的H∞静态输出反馈可靠控制

针对线性系统,考虑连续增益故障模型,研究了具有执行器故障的H∞静态输出反馈可靠控制问题。首先,在执行器无故障的前提下,给出H∞性能指标存在的充分条件,进而得出系统的静态输出反馈控制率。然后,基于执行器故障,重新设计静态输出反馈控制器,利用求解线性矩阵不等式的方法,完成静态输出反馈可靠控制器的设计。由此可靠控制器构成的闭环系统,使得当执行器发生故障时,也可使闭环系统的保持渐近稳定。最后的数值仿真验证了本文结果的有效性和可行性。     

Static output feedback control of positive linear systems with output time delays

ABSTRACT

In this paper, we discuss a new problem of static output feedback controllers design for positive systems with delayed output measurements. When delayed output measurements are exclusively used as feedback control signals, previous control design methods for positive systems relying on the so-called delay-independent positivity and stability conditions are unable to synthesise a stable static output feedback controller for positive systems. A new method based on delay-dependent positivity and stability conditions is proposed in this paper to tackle this issue. We show that the synthesis of static output feedback controllers for positive systems under the effect of delayed output measurements is feasible under the newly proposed design method. Numerical examples are given to demonstrate the effectiveness of the new result.     

传感器失效下不确定离散时滞系统的静态输出反馈鲁棒可靠保成本控制

针对一类参数不确定离散时滞系统,研究了当传感器发生增益故障情况下的静态输出反馈保成本可靠控制器设计问题.系统中的参数不确定性满足广义匹配条件,传感器元件具有部分输出增益故障.根据Lyapunov稳定性理论和线性矩阵不等式(LMI)方法,分别给出了含有时滞记忆和无时滞静态输出反馈保成本鲁棒可靠控制律的存在条件.通过求解由一组线性矩阵不等式所表示的凸优化问题可以得到使得闭环保成本上界最小的鲁棒可靠控制器.最后通过仿真示例说明所提出方法的正确性.     

H2 CONTROLLER DESIGN FOR NETWORKED CONTROL SYSTEMS

This paper deals with the problem of designing an H₂ controller for a networked control system (NCS) with communication delays from the sensor to the controller and/or from the controller to the plant. Our objective is to design a robust controller that will not only stabilize the system but also achieve a sub‐opti‐ mal H₂ performance in the face of possible communication delays. Both the state feedback control and output feedback control are considered. The feedback control problem for the original system is first converted to a static output feedback control problem. A recursive linear matrix inequality (LMI) algorithm is then presented to compute a state or output feedback H₂ controller for the system. Our approach allows a fixed order controller. Numerical examples are given to demonstrate the effectiveness of the proposed approach.     

Design of robust output-feedback repetitive controller for class of linear systems with uncertainties

Repetitive control, which adds a human-like learning capability to a control system, is widely used in many fields. This paper deals with the problem of designing a robust repetitive-control system based on output feedback for a class of plants with time-varying structured uncertainties. A continuous-discrete two-dimensional hybrid model is established that accurately describes the features of repetitive control so as to enable independent adjustment of the control and learning actions. A sufficient conditi...     

Robust <Emphasis Type="Italic">H</Emphasis><Subscript>∞</Subscript> static output feedback control of discrete-time switched polytopic linear systems with average dwell-time

This paper investigates the problem of robust exponential H _∞ static output feedback controller design for a class of discrete-time switched linear systems with polytopic-type time-varying parametric uncertainties. The objective is to design a switched static output feedback controller guaranteeing the exponential stability of the resulting closed-loop system with a minimized exponential H _∞ performance under average dwell-time switching scheme. Based on a parameter-dependent discontinuous switched Lyapunov function combined with Finsler’s lemma and Dualization lemma, some novel conditions for exponential H _∞ performance analysis are first proposed and in turn the static output feedback controller designs are developed. It is shown that the controller gains can be obtained by solving a set of linear matrix inequalities (LMIs), which are numerically efficient with commercially available software. Finally, a simulation example is provided to illustrate the effectiveness of the proposed approaches.     

受控正系统的弹性静态输出反馈鲁棒H∞控制

首先,利用线性矩阵不等式(LMI)及有界实引理,借助一个小的标量,得到了受控正系统弹性静态输出反馈鲁棒H∞控制的一个充分条件,使得控制器参数与未知参数分开,从而更有利于弹性静态输出反馈控制器的设计.然后,基于此条件,针对控制矩阵的一种特殊情形给出了一个推论,并得到了更一般的受控正系统弹性静态输出反馈鲁棒H∞控制的充分条件,其中的控制器增益矩阵均可根据锥补线性化技巧来进行求解.最后,利用数值仿真表明了结论的有效性.     

Mixture inventory model with back orders and lost sales for variable lead time demand with the mixtures of normal distribution

In recent papers by Ben-Daya and Raouf and by Ouyang et al. a continuous review inventory model is presented in which they considered both the lead time and the order quantity as decision variables. When the demands of the different customers do not have identical lead times, then we cannot use only a distribution (such as Ouyang et al. who used a normal distribution) to describe the demand of the lead time. Hence, we have extended the model of Ouyang et al. by considering the mixtures of normal distribution (see the book by Everitt and Hand). In addition, we also still assume that shortages are allowed. Moreover, the total amount of stock-out is considered as a mixture of back orders and lost sales during the stock-out period. Moreover, we also develop an algorithmic procedure to find the optimal order quantity and optimal lead time; the effects of parameters are also studied.     

基于LMI不确定离散随机系统输出反馈保性能控制

针对一类范数有界不确定离散随机系统,研究了具有输出反馈控制器的保性能控制,由此得到闭环系统的二次型性能指标上界的一般形式;然后应用LMI凸优化技术,推导出使闭环系统渐近稳定的最优保性能控制器的设计方法;最后通过仿真算例验证了所提出算法的可行性和有效性.     

New characterisations of positive realness and static output feedback control of discrete-time systems

This article is concerned with the problems of positive real analysis and control synthesis for discrete-time systems. New linear matrix inequality (LMI) characterisations of positive realness are derived, which enable one to check the positive realness by using parameter-dependent Lyapunov function. The relationship between the proposed characterisations and the existing ones are clarified, which shows that our new results are of less conservatism for characterising the positive realness of discrete-time systems with polytopic uncertainty. In addition, sufficient conditions for static output feedback positive real controller design are given in terms of solutions to a set of linear matrix inequalities. Numerical examples are included for illustration.