不确定线性内互联大系统的分散鲁棒H∞控制

讨论含有界不确定性的线性内互联大系统,通过分散状态反馈和分散动态输出反馈的鲁棒Ｈ∞控制问题,首先给出一个重要引理,然后基于有界实引理分别导出放动态输出反馈的分散鲁棒Ｈ∞控制问题有解的充分必要条件,该条件及其问题的求解等价地转化成一个线性矩阵不等式和双线性矩阵不等式的求解。     

Static output feedback controller design for fuzzy systems: An ILMI approach

This paper examines the problem of static output feedback control of a Takagi-Sugeno (TS) fuzzy system. The existence of a static output feedback control law is given in terms of the solvability of bilinear matrix inequalities. An iterative algorithm based on the linear matrix inequality is proposed to compute the static output feedback gain. To reduce the conservatism of the design, the structural information of the membership function of the fuzzy rules is incorporated. Numerical examples are used to illustrate the validity of the methods.     

L1 synthesis of a static output controller for positive systems by LMI iteration

An approach to find a static output feedback gain that makes the feedback system positive and minimizes the L₁ gain is proposed. The problem of finding a static output feedback gain has 3 aspects: stabilizing the system, making the system positive, and then minimizing the L₁ gain. Each subproblem is described by bilinear matrix inequality with respect to the feedback gain and the Lyapunov matrix or vector. Linear matrix inequality (LMI) that is sufficient to satisfy bilinear matrix inequality is derived using a convex‐concave decomposition, and the feedback gain sequence is calculated by an iterative solution of LMI. The sequence of the upper bounds on the design parameter is guaranteed to be monotonically nonincreasing for each algorithm. Similarly, 2 other LMIs are derived for each subproblem using another convex‐concave decomposition and PK iteration. The effectiveness of these algorithms is illustrated via several numerical examples.     

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.     

模糊不确定时滞系统的静态输出的反馈镇定:迭代线性矩阵不等式方法

对一类不确定非线性时滞系统利用模糊T＿S模型进行建模,研究了静态输出反馈镇定问题.用矩阵不等式的形式给出了模糊T＿S不确定时滞系统可通过静态输出反馈镇定的充分条件.并将矩阵不等式的条件转化为迭代线性矩阵不等式(ILMI),并给出相应的算法.     

Static Output Feedback Stabilization: An ILMI Approach

In this note, the static output feedback stabilization problem is addressed using the linear matrix inequality technique. A necessary and sufficient condition for static output feedback stabilizability for linear time-invariant systems is derived in the form of a matrix inequality. The extension of the result to H_∞ control is studied. An iterative LMI (ILMI) algorithm is proposed to compute the feedback gain. Numerical examples are employed to demonstrate the effectiveness and the convergence of the algorithm.     

参数不确定广义大系统的保性能分散控制

对一类范数有界时不变参数不确定的连续广义大系统和一个二次型性能指标,研究了其保性能分散控制问题.目的是设计一状态反馈分散控制器,使得对所有容许的不确定性,闭环系统不仅是鲁棒稳定的,而且性能指标有一上界.应用线性矩阵不等式方法,给出了一个用线性矩阵不等式表达的保性能分散控制器存在的充分条件;在此条件可解时,给出了保性能分散控制律的表达式.最后,举例说明了该方法的应用.     

连续不确定模糊系统的静态输出反馈控制

对于一类状态矩阵、输入矩阵和扰动输入矩阵中均含有不确定项的连续T-S模糊系统,研究其静态输出反馈控制问题.用矩阵不等式的形式给出了该模糊系统可通过静态输出反馈控制稳定的充分条件,并将矩阵不等式的条件转化为迭代线性矩阵不等式,同时给出了相应的迭代算法.最后用数值仿真例子说明了该算法的有效性和收敛性.     

基于LMI的大型互联线性系统的分散有限时间镇定

借助于有限时间稳定性的定义,针对大型互联线性系统,引入了分散有限时间镇定的概念.对一类大型互联线性系统进行分散状态反馈和分散动态输出反馈控制器设计,利用线性矩阵不等式(LMI)的方法提出一个充分条件,当反馈控制律作用于该系统时,闭环系统是有限时间稳定的.仿真算例说明了所得结论的可行性和有效性.     

具有次优保性能滑动模态的静态输出反馈滑模控制

针对一类不确定系统,提出了一种具有次优保性能滑模面的静态输出反馈滑模控制方法.首先将滑模面的设计问题等价为一个对称矩阵的求解问题,基于等效控制法,推导了保性能滑模面存在的充分条件.然后基于迭代线性矩阵不等式(iterative linear matrix inequality,ILMI)方法,给出了次优保性能线性滑模面的求解算法,最后基于线性矩阵不等式(linearmatrix inequality,LMI)方法,设计了输出反馈滑模控制器,使得闭环系统渐近稳定且切换函数能在有限时间内到达零.该方法首次实现了输出反馈滑模面的优化,且具有保守性小、无需对被控系统模型进行坐标变换的优点.仿真结果验证了本文方法的优越性.     

轧辊偏心的H∞输出反馈鲁棒重复控制

针对轧辊偏心问题,用线性矩阵不等式(LMI)方法设计了用于轧辊偏心补偿控制的H∞输出反馈鲁棒重复控制器,首先引入动态输出反馈来保证闭环系统的鲁棒稳定性,把重复控制器设计问题转化为H∞动态反馈控制器的设计问题,采用变量替换法将非线性矩阵不等式转化为线性矩阵不等式并对其求解进而得到控制器参数.另外在采用上述控制器保证系统鲁棒稳定性的同时,通过在重复控制器中引入一个前向系数进一步改善和提高系统的动态性能与稳态控制精度.理论证明与仿真研究表明当系统对象参数存在摄动时,这种控制器仍能有效地补偿轧辊偏心对产品质量的影响.     

基于BMI方法的扇形极点配置输出反馈控制

研究一类线性系统在有界静态输出反馈下的区域极点配置问题, 给出了问题可解的双线性矩阵不等式(Bilinear matrix inequality, BMI)条件. 利用摄动线性化方法给出了求解期望输出反馈的迭代线性矩阵不等式(Linear matrix inequality, LMI)算法, 并用算例说明了所提算法的有效性.     

Optimization of static output feedback using substitutive LMI formulation

This note proposes a new design tool for optimizing static output feedback using a linear matrix inequality (LMI) formula called substitutive LMI. A matrix inequality derived from static output feedback is not usually linear. Adding a positive definite term including auxiliary variables, the matrix inequality is transformed into an LMI with respect to the positive definite matrix and the static output feedback gain. An iterative calculation algorithm is given to solve the substitutive LMI. In this note, designs of the static output feedback gain are shown in the frame of H/sub /spl infin// and H/sub 2/ syntheses. A numerical example is shown to demonstrate the effectiveness of the proposed technique.     

基于静态输出反馈控制器的主动队列管理

利用李亚普诺夫函数对线性时滞系统的鲁棒稳定性进行了证明．给出了一种基于线性矩阵不等式（LMI）的参数判定依据,设计出了一种实现主动队列管理的静态输出反馈控制器（SOFC）．仿真结果表明,这种控制器具有良好的控制性能,并且在变化的网络环境下具有较强的鲁棒性．     

基于线性矩阵不等式的不确定关联系统的分散鲁棒镇定

应用线性矩阵不等式（LMI）方法研究不确定性关联大系统的分散便棒镇定问题。系统中不稳定项具有数值界,可不满足匹配条件。基于不确定项的表达形式,给出了其可分散状态反馈镇定的充分条件,即一组LMIs有解。在此基础上,通过求第一凸优化问题,提出了具有较小反馈增益的分散稳定化状态反馈控制律的设计方法。仿真示例说明了该方法的有效性和优越性。     

具有干扰输入的大型互联线性系统的分散有限时间镇定

借助于大型互联线性系统有限时间稳定性的定义,对具有干扰输入的大型互联线性系统引入了分散有限时间镇定的概念,并对一类具有干扰输入的大型互联不确定线性系统进行了分散状态反馈和分散动态输出反馈控制器设计,利用线性矩阵不等式（LMI）方法,提出了一个充分条件.当反馈控制律作用于该系统时,闭环系统是有限时间稳定的.     

变时滞不确定关联系统的分散鲁棒无记忆控制

针对一类不确定项具有数值界的变时滞不确定关联系统,主要运用线性矩阵不等式（LMI）方法对其分散鲁棒无记忆控制问题进行了研究,首先,通过构建适当形式的Lyapunov泛函数,运用LMI方法与矢量不等式方法,提出了以一组LMIs有解作为系统可分散鲁棒无记忆控制的充分条件,并给出了系统在此条件下的控制律,然后,将求解一个具有LMIs约束的凸优化问题作为设计尽可能小反馈增益的分散鲁棒无记忆控制律的系统化方法,从而可以得到更符合实际的满意的分散无记忆控制律。     

基于输出反馈的不确定连续系统的鲁棒预测控制

运用线性矩阵不等式方法,研究一类基于输出反馈的线性连续时间范数有界参数不确定系统的鲁棒预测控制问题．基于变量变换的思想,将无限时域“最小—最大”优化问题转化为线性规划问题,得出分段连续的输出反馈控制律,并给出了控制律存在的充分条件,证明了优化问题在初始时刻的可行解保证闭环系统渐近稳定．仿真实例验证了此方法的有效性．     

Static output feedback stabilization with prescribed degree ofstability

The problem of finding a static output feedback matrix is restated. The new formulation replaces the solution of a set of inversely coupled Lyapunov inequalities with the simultaneous solution to an algebraic Riccati inequality and a Lyapunov inequality. An algorithm is developed based on the restated problem. Unlike previous algorithms, the algorithm is noniterative in linear matrix inequality (LMI) solutions. The algorithm may be used to prescribe a given degree of stability, while keeping the static output feedback gain small. Use of the algorithm is demonstrated via an example     

Simultaneous linear-quadratic optimal control design via static output feedback

In this paper, the problem of designing a fixed static output feedback control law which minimizes an upper bound on linear quadratic (LQ) performance measures for r distinct MIMO plants is addressed using linear matrix inequality (LMI) technique. An iterative LMI algorithm is proposed to obtain the solution. Examples are used to demonstrate its effectiveness. Copyright ©1999 John Wiley & Sons, Ltd.