一类不确定离散系统的严格正实分析和设计

考虑了一类不确定离散多变量系统严格正实分析和控制问题,其中不确定参数具有非负性.分析了系统鲁棒稳定且严格正实的条件,讨论了状态反馈、输出反馈使闭环系统鲁棒稳定且严格正实的问题.将不确定系统的鲁棒严格正实分析和设计转化为确定系统的严格正实分析和控制,得到了系统鲁棒稳定且严格正实的充分必要条件.最后给出了鲁棒严格正实控制问题的可解条件及控制器的综合方法.     

离散广义系统的鲁棒严格正实控制

研究确定的以及具有范数有界不确定性的离散广义系统的严格正实分析和控制问题,首先给出了确定离散广义系统状态反馈扩展严格正实控制器的存在条件和设计方法;然后利用线性矩阵不等式分析了不确定离散广义系统广义二次稳定且扩展严格正实的条件,讨论了状态反馈使闭环系统广义二次稳定且扩展严格正实问题,给出了状态反馈鲁棒扩展严格正实控制器的综合方法;最后通过数值算例说明了所提出方法的有效性．     

多变量反馈控制系统的完整性分析

以线性时不变多输入多输出反馈控制系统为研究对象，建立了基于ｋ个传感器和ｎ个执行器失效的故障系统数学模型，并提出了仍能保证系统稳定性的控制器必须满足的条件，从而为设计具有容错能力的控制系统提供了理论依据。     

广义系统正实反馈控制的一种新方法

研究了广义连续系统的扩展严格正实的控制问题.首先,利用与原系统等价的增广系统和矩阵分解,给出了广义系统正则,无脉冲,稳定且扩展严格正实的一个新的充分必要条件.并且此条件是便于Matlab求解的严格线性矩阵不等式形式.其次,基于此定理和线性矩阵不等式的性质,给出了保证闭环系统是正则,无脉冲,稳定且ESPR的控制器设计方法.最后通过2个数值算例说明了所提出方法的有效性和可行性.     

广义系统输出反馈严格正实控制器设计

研究连续广义系统的正实控制问题。目的是设计静态输出反馈和动态输出反馈严格正实控制器使得闭环系统容许且扩展严格正实。基于广义系统严格正实引理，利用线性矩阵不等式和广义代数Riccati不等式，给出了广义系统静态输出反馈和动态输出反馈严格正实控制器存在的充要条件及设计方法。对动态输出反馈情形，给出了一个数值算例说明控制器设计方法的有效性及可行性。     

独立摄动参数不确定线性系统的正实控制

考虑了一类范数有界参数不确定线性系统的鲁棒正实性分析和设计问题,其中参数不确定性是独立摄动的．通过构造增广系统将不确定系统的鲁棒正实分析和控制问题转化为确定系统的情形,给出了鲁棒正实分析问题的线性矩阵不等式解法,导出了输出反馈控制器的存在条件．所得结论将范数有界参数不确定系统的鲁棒正实分析和控制的现有结果推进了一步．     

具有多线性相关系数扰动的有理函数的严格正实不变性判据及其应用

传递函数的严格正实不变性分析,由于它在绝对稳定性分析中的重要作用,引起了人们的 重视.该文考虑在多线性相关系数摄动下,有理函数族的严格正实不变性的判别问题.利用 严格正实函数所具有的相位条件和映射定理.证明了在参数空间中判别该有理函数族保持严 格正实不变性的顶点检验条件,并将这一结果应用于带参数不确定性的鲁里叶系统的绝对稳 定性分析中.     

连续和离散系统的鲁棒严格正实性*

本文提出了一种统一的鲁棒严格正实性判定准则，既适用于连续系统，又适用于离散系统，在此准则的基础上，形成了鲁棒严格正实滤波器和补偿器的设计方法，当考虑的系统是线性参数摄动系统或由若干个独立线性参数摄动系统串联成的，则本文给出的是端点结果。     

鲁棒严格正实镇定的顶点结果

本文主要研究了区间系统的鲁棒严格正实镇定问题。文中首先给出了系统严格正实镇定的充分条件。然后分析了该条件的可计算性并对一类区间分母系统获得了采用一阶控制器时鲁棒严格正实镇定的顶点结果，使得控制器设计大为简化。     

Controller synthesis for switched positive linear systems by output feedback

The output-feedback controller synthesis issue for a class of continuous-time switched linear systems via average dwell time switching with constrained controls and output is addressed. First, we focus on the output-feedback stabilisation by decomposing control gain matrix. Second, the stabilisation problem with sign-restricted controls while imposing positivity and stability on closed-loop system is solved, then the results extend to asymmetrically bounded controls and constrained outputs. All the derived conditions are formulated as linear programming. Finally, numerical examples are given to show the applicability of the proposed methods.     

Static output feedback control for positive linear continuous‐time systems

This paper studies the problem of designing the static output feedback controller for the positive linear continuous‐time systems. On the basis of a system augmentation approach, a novel characterization on the stable condition of the closed‐loop system is firstly established. Then, a necessary and sufficient condition is given to ensure the existence of the desired static output feedback controller, and an iterative linear matrix inequality algorithm is presented to compute the feedback gain matrix. Finally, a numerical example is provided to illustrate the effectiveness of the proposed method. Copyright © 2012 John Wiley & Sons, Ltd.     

不确定时延输出反馈网络化系统保性能控制

研究了一类具有不确定时延的动态输出反馈网络控制系统的保性能控制问题．针对小于等于一个采样周期的不确定时延,利用Lyapunov理论和线性矩阵不等式方法,推导出了动态输出反馈网络控制系统保性能控制律存在的条件,给出了动态输出反馈保性能控制律设计方法．利用LMI工具箱中的目标函数最小化工具,可以求得该类系统优化的保性能控制律参数和优化的性能指标,从而获得该系统的保性能控制律．给出的仿真算例说明了设计方法是有效的所得结果是可行的．     

Output feedback variable structure control of uncertain linear systems in the presence of actuator dynamics

A new output feedback variable structure control scheme is developed based on a novel passivity idea. This scheme may practically stabilize a class of higher‐relative‐degree uncertain linear systems, and realize output tracking and disturbance attenuation as well. The controller is composed of linear filters and a single relay, without employing real‐time exact differentiators. Under this framework, we also explain how actuator dynamics affect the closed loop behavior. A simulation example shows the simplicity and efficiency of this method. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Constrained control for uncertain discrete-time linear systems

In this paper the problem of stabilizing uncertain linear discrete-time systems under state and control linear constraints is studied. Many formulations of this problem have been given in the literature. Here we consider the case of finding a linear state feedback control law making a given polytope in the state space positively invariant while the control remains bounded within prefixed values under the effect of all the uncertainty sequences belonging to a given polytope in the perturbations space. A necessary and sufficient condition for the existence of a solution of this problem is first given. This condition leads to a set of linear constraints which can be solved using linear programming tecniques by defining an appropriate objective function. A worked example shows the effectiveness of the proposed algorithm. © 1998 John Wiley & Sons, Ltd.     

Robustness analysis of linear parameter varying systems using integral quadratic constraints

A general approach is presented to analyze the worst case input/output gain for an interconnection of a linear parameter varying (LPV) system and an uncertain or nonlinear element. The LPV system is described by state matrices that have an arbitrary, that is not necessarily rational, dependence on the parameters. The input/output behavior of the nonlinear/uncertain block is described by an integral quadratic constraint (IQC). A dissipation inequality is proposed to compute an upper bound for this gain. This worst‐case gain condition can be formulated as a semidefinite program and efficiently solved using available optimization software. Moreover, it is shown that this new condition is a generalization of the well‐known bounded real lemma type result for LPV systems. The results contained in this paper complement known results that apply IQCs for analysis of LPV systems whose state matrices have a rational dependence on the parameters. The effectiveness of the proposed method is demonstrated on simple numerical examples. Copyright © 2014 John Wiley & Sons, Ltd.     

基于神经网络MIMO非线性系统自适应输出反馈控制

针对一类具有对象不确定和外部干扰的MIMO(多输入多输出)非线性系统提出了自适应鲁棒输出跟踪控制方案.使用了高斯径向基神经网络自适应补偿对象非线性,高增益观测器被用来估计不能直接测量的输出导数.此方法所设计的控制器不仅保证闭环系统稳定,而且所有状态有界以及跟踪误差一致终值有界.仿真结果充分表明了该方案的有效性和可行性.     

Dual approaches to strictly positive real controller synthesis with a performance using linear matrix inequalities

The synthesis of controllers that minimize a performance index subject to a strictly positive real (SPR) constraint is considered. Two controller synthesis methods are presented that are then combined into an iterative algorithm. Each method synthesizes optimal SPR controllers by posing a convex optimization problem where constraints are enforced via linear matrix inequalities. Additionally, each method fixes the controller state‐feedback gain matrix and finds an observer gain matrix such that an upper bound on the closed‐loop ‐norm is minimized and the controller is SPR. The first method retools the standard ‐optimal control problem by using a common Lyapunov matrix variable to satisfy both the criteria and the SPR constraint. The second method overcomes bilinear matrix inequality issues associated with the performance and the SPR constraint by employing a completing the square method and an overbounding technique. Both synthesis methods are used within an iterative scheme to find optimal SPR controllers in a sequential manner. Comparison of our synthesis methods to existing methods in the literature is presented. Copyright © 2012 John Wiley & Sons, Ltd.