LMI approach for absolute stability of general neutral type Lurie indirect control systems

This paper deals with the problem of the absolute stability for general neutral type Lurie indirect control systems by Lyapunov method and linear matrix inequality (LMI) technique. Delay_dependent sufficient conditions for the absolute stability are derived and expressed as the feasibility problem of LMI, which can be easily solved by Matlab Toolbox. Finally, some examples are provide to demonstrate the effectiveness of proposed method.     

中立型一般Lurie系统绝对稳定的时滞相关准则

研究了具有时滞的中立型一般Lurie系统的绝对稳定性问题.利用Lyapunov方法给 出了系统在无限扇形角内绝对稳定的时滞相关准则,所给的判定条件是线性矩阵不等式(LMI) 形式的,可以很方便地运用Matlab工具箱求解.一个应用的例子表明与现有的一些准则相比, 本文所给的条件具有较小的保守性.     

一类时滞系统的绝对稳定性问题研究

基于线性矩阵不等式处理方法,研究了一类具有扇形非线性关联的时滞系统绝对稳 定性问题.导出了用一个线性矩阵不等式系统的可行性表示的绝对稳定性滞后依赖型条件,进 而,通过求解一组线性矩阵不等式,给出使得闭环系统绝对稳定的无记忆状态反馈控制律设计 方法,最后用例子验证了文中提出的结果.     

多时变状态和控制时滞系统的绝对稳定性

研究了具有多时变状态和控制时滞的Lurie控制系统基于线性矩阵不等式(LMI)的绝对稳定性条件.首先,构造了关于Lyapunov泛函中正定矩阵和积分项系数等自由参数的LMI,获得了系统时滞无关绝对稳定条件.进一步引入自由权矩阵来表示牛顿-莱布尼兹公式中各项的相互关系,得到了系统绝对稳定的时滞相关条件.最后,通过一个实例阐述了本文方法的有效性和相比已有结果的优越性.     

基于LMI的非线性摄动系统鲁棒绝对稳定性判据

讨论了前馈通道同时存在对象和控制器的范数摄动,而反馈通道存在扇区非线性的摄 动系统的稳定性问题.基于H∞理论和LMI方法,得到了一组由线性矩阵不等式表达的充分性 条件,建立了判断非线性摄动系统鲁棒绝对稳定性的新判据.     

Influence maximization with limit cost in social network

Social networking service (SNS) applications are changing the way information spreads in online communities. As real social relationships are projected into SNS applications, word of mouth has been an important factor in the information spreading processes of those applications. By assuming each user needs a cost to accept some specific information, this paper studies the initial "seed user" selection strategy to maximize information spreading in a social network with a cost budget. The main contributions of this paper are: 1) proposing a graphic SEIR model (gSEIR) by extending the epidemic compartmental model to simulate the dynamic information spreading process between individuals in the social network; 2) proposing a formal definition for the influence maximization problem with limit cost (IMLC) in social networks, and proving that this problem can be transformed to the weighted set-cover problem (WSCP) and thus is NP-Complete; 3) providing four different greedy algorithms to solve the IMLC problem; 4) proposing a heuristic algorithm based on the method of Lagrange multipliers (HILR) for the same problem; 5) providing two parts of experiments to test the proposed models and algorithms in this paper. In the first part, we verify that gSEIR can generate similar macro-behavior as an SIR model for the information spreading process in an online community by combining the micro-behaviors of all the users in that community, and that gSEIR can also simulate the dynamic change process of the statuses of all the individuals in the corresponding social networks during the information spreading process. In the second part, by applying the simulation result from gSEIR as the prediction of information spreading in the given social network, we test the effectiveness and efficiency of all provided algorithms to solve the influence maximization problem with cost limit. The result show that the heuristic algorithm HILR is the best for the IMLC problem.     

Improved Robust Stability Criteria for Time‐Delay Lur'e System

This paper deals with the problem of the robustly absolute stability for neutral‐type Lur'e systems with mixed time‐varying delay. By combining the piecewise analysis theory with the reciprocally convex method and Wirtinger‐based inequality technology, some new delay‐dependent stability criteria are proposed via a modified Lyapunov‐Krasovskii functional (LKF) approach. The stability conditions can be solved by using standard linear matrix inequality (LMI) convex optimization solvers. The criteria are less conservative than some previous ones. Three numerical examples are presented to show the effectiveness of the proposed approach.     

时滞不确定Lurie系统的鲁棒绝对稳定性准则

研究一类具有时变时滞的范敷有界结构不确定性Lurie控制系统的鲁棒绝对稳定性问题.利用Lyapunov-Krasovskii泛函方法,分别给出系统在无限扇形及有限扇形角内绝对稳定的时滞相关充分条件,所给的判定条件是线性矩阵不等式(LMI)形式的,可以很方便地运用Matlab工具葙求解.两个数值实例表明,本文所给条件是有...     

一类Takagi-Sugeno模糊离散广义系统的稳定性判据

利用Lyapunov方法,研究了一类Takagi-Sugeno(T-S)模糊离散广义系统的稳定性问题．给出了该系统一致正则、因果和稳定的充分条件,并把此条件用线性矩阵不等式(LMI)表示．通过矩阵分解把广义系统的非严格矩阵不等式约束转化成严格的矩阵不等式约束,从而可以用LMI工具箱一次判定系统的稳定性,算例说明所给方法使用方便．     

具有时变时滞的Lurie系统绝对稳定性的时滞相关条件

Some delay-dependent absolute stability criteria for Lurie control systems with time-varying delay are derived, in which some free-weighting matrices are used to express the relationships between the terms in the Leibniz-Newton formula. These criteria are based on linear matrix inequality(LMI) such that the upper bound of time-delay guaranteeing the absolute stability and the free-weighting matrices can be obtained through the solutions of the LMI. Moreover, the Lyapunov functional constructed by the solutions of these LMIs is adopted to guarantee the absolute stability of the systems. Finally, some examples are provided to demonstrate the effectiveness of the proposed methods.     

Delay-dependent Conditions for Absolute Stability of Lurie Control Systems with Time-varying Delay

Some delay-dependent absolute stability criteria for Lurie control systems with time- varying delay are derived,in which some free-weighting matrices are used to express the relation- ships between the terms in the Leibniz-Newton formula.These criteria are based on linear matrix inequality(LMI) such that the upper bound of time-delay guaranteeing the absolute stability and the free-weighting matrices can be obtained through the solutions of the LMI.Moreover,the Lyapunov functional constructed by the solutions of these LMIs is adopted to guarantee the absolute stability of the systems.Finally,some examples are provided to demonstrate the effectiveness of the proposed methods.     

Lur'e Lyapunov functions and absolute stability criteria for Lur'e systems with multiple nonlinearities

In this paper, the absolute stability problem of Lur'e systems with multiple nonlinearities is investigated. Popov‐type absolute stability criteria are surveyed and classified by distinguishing the Lur'e Lyapunov function upon which the criteria are based. A modified Lur'e Lyapunov function is presented. Some necessary and sufficient conditions for the existence of the Lyapynov function to guarantee the absolute stability of Lur'e systems are derived. By these conditions, LMI‐based stability criteria are presented. The obtained criteria are expected to be less conservative than the existing ones. Finally, numerical examples are given to illustrate the advantages and effectiveness of our results. Copyright © 2006 John Wiley & Sons, Ltd.     

具有多状态和控制时滞的控制系统的绝对稳定性分析

基于线性矩阵不等式方法, 对具有多个状态和控制的时变时滞的Lurie型控制系统的稳定性进行分析, 得到了系统绝对稳定的几个充分条件, 这些条件用线性矩阵不等式表示, 具有较低的保守性. 最后通过一个实例验证了所得条件的保守性较以往结果的保守性小.     

不确定时滞Lur'e型控制系统与时滞相关的绝对稳定性

研究了一类参数不确定的具有多个时滞的Lur'e型控制系统与时滞相关绝对稳定性问 题.通过将原系统变换为等价的奇异系统,利用Moon不等式放大向量积,构造出一个新的 Lyapunov-Krasovskii泛函.并由此基于线性矩阵不等式,得到了系统与时滞相关绝对稳定的充分条 件.这些充分条件无须预调任何参数矩阵,可以直接运用Matlab软件中LMI工具箱求解.数值例 子表明,与现有结果相比,本文结果较大地改进了保证不确定时滞Lur'e型控制系统绝对稳定的 时滞界.     

不确定时滞Lur''''e型控制系统与时滞相关的绝对稳定性(英文)

研究了一类参数不确定的具有多个时滞的Lur'e型控制系统与时滞相关绝对稳定性问题.通过将原系统变换为等价的奇异系统,利用Moon不等式放大向量积,构造出一个新的Lya-punov-Krasovskii泛函.并由此基于线性矩阵不等式,得到了系统与时滞相关绝对稳定的充分条件.这些充分条件无须预调任何参数矩阵,可以直接运用Matlab软件中LMI工具箱求解.数值例子表明,与现有结果相比,本文结果较大地改进了保证不确定时滞Lur'e型控制系统绝对稳定的时滞界.     

Cellular Neural Networks for Gray Image Noise Cancellation Based on a Hybrid Linear Matrix Inequality and Particle Swarm Optimization Approach

This paper describes a technique for gray image noise cancellation. This method employs linear matrix inequality (LMI) and particle swarm optimization (PSO) based on cellular neural networks (CNN).We use two images that one is desired image and the other is corrupted to find the CNN template. The Lyapunov stability theorem is employed to derive the criterion for uniqueness and global asymptotic stability of the CNN equilibrium point. The current study characterizes the template design problem as a standard LMI problem and the optimization parameters of the templates are carried out by PSO. Finally, the examples are given to illustrate the effectiveness of the proposed method.     

不确定时滞Lurie型控制系统与时滞相关的绝对稳定性

研究了一类参数不确定的具有多个时滞的Lur′e型控制系统与时滞相关绝对稳定性问题.通过将原系统变换为等价的奇异系统,利用Moon不等式放大向量积,构造出一个新的Lyapunov-Krasovskii泛函.并由此基于线性矩阵不等式,得到了系统与时滞相关绝对稳定的充分条件.这些充分条件无须预调任何参数矩阵,可以直接运用Matlab软件中LMI工具箱求解.数值例子表明,与现有结果相比,本文结果较大地改进了保证不确定时滞Lur′e型控制系统绝对稳定的时滞界.     

LMI optimization approach to robust decentralized controller design

A new approach for design of robust decentralized controllers for continuous linear time‐invariant systems is proposed using linear matrix inequalities (LMIs). The proposed method is based on closed‐loop diagonal dominance. Sufficient conditions for closed‐loop stability and closed‐loop block‐diagonal dominance are obtained. Satisfying the obtained conditions is formulated as an optimization problem with a system of LMI constraints. By adding an extra LMI constraint to the system of LMI constraints in the optimization problem, the robust control is addressed as well. Accordingly, the decentralized robust control problem for a multivariable system is reduced to an optimization problem for a system of LMI constraints to be feasible. An example is given to show the effectiveness of the proposed method. Copyright © 2010 John Wiley & Sons, Ltd.     

基于比较原理的非线性组合系统的输出反馈镇定

综合运用比较原理和LMI方法，通过构造一比较系统，将原组合系统的稳定性问题转化为维数较低的比较系统的稳定性问题，并利用M矩阵特性导出了比较系统稳定的一个充分条件．为了求取输出反馈增益，建立了等价稳定条件的QLMI表示形式．这一方法的特点是使大系统的稳定控制器设计的复杂度保持在子系统一级的水平上．数值实例说明了所提出算法在实际工程应用中的可行性和有效性．     

一类结构不确定采样系统的鲁棒控制

针对一类结构不确定性线性采样系统，在时域中用Lyapunov方法研究采样系统的鲁棒控制及最优鲁棒控制，给出了系统鲁棒稳定的充分条件以及相应的鲁棒控制律，控制律的求取借助于求解一类线性矩阵不等式（LMI），或求解满足特定线性不等式条件下的优化问题，算例结果表明，采样周期是一个关键性的设计参数。