一类多输入多输出网络控制系统的稳定性分析

研究了具有分布时延、有界输入的多输入多输出网络控制系统的建模和稳定性问题.基于线性时不变对象,建立了系统的数学模型.利用李雅普诺夫第2方法和线性矩阵不等式描述,分析了系统的渐近稳定性,导出了与时延相关的系统渐近稳定判据,同时得到了系统稳定运行的最大允许时延.系统渐近稳定的最大允许时延可用MatlabLMI工具箱从稳定判据获得.仿真算例表明稳定判据是可行的.     

具有有界输入的网络控制系统时延独立稳定性

基于有界时延、无数据包丢失、传感器时钟驱动、执行器事件驱动,文章提出了用一个特定的实值函数来调节动态输出反馈控制器的输出以确保控制对象输入有界的方法,建立了具有分布时延、有界输入、动态输出反馈网络控制系统的非线性数学模型.用李雅普诺夫第二方法和线性矩阵不等式描述分析了系统的渐近稳定性,并推导出与时延无关的系统渐近稳定的充分条件.最后MATLAB仿真算例说明：稳定判据是可行的,有界输入的控制方法是有效的.     

关于Sontag-Type控制的注记

基于控制李雅普诺夫函数的Sontag-Type控制是仿射系统鲁棒镇定中的重要控制律.首先揭示该控制律本质上是一种变结构控制且闭环的切换面总可达,受此启发并为了相对容易地构造控制李雅普诺夫函数,运用零状态可检测概念定义弱控制李雅普诺夫函数,并证明了基于弱控制李雅普诺夫函数的Sontag-Type控制的优化镇定性.文中还证明,在温和条件下,基于弱控制李雅普诺夫函数的Sontag＿Type控制为仿射系统的输入到状态镇定控制.     

一类不确定切换系统的鲁棒状态反馈镇定

研究了一类扰动项不满足匹配条件的不确定切换系统的鲁棒镇定问题.在每个子系统均不能镇定的情况下,利用完备性条件和多李雅普诺夫函数方法,分别得到了不确定切换系统可镇定的充分条件.状态矩阵和控制输入矩阵同时带有时变、未知且有界的不确定性,基于凸组合技术和LMI方法,设计出鲁棒状态反馈控制器及相应的切换策略,使得闭环系统在其平衡点处是渐近稳定的.最后仿真结果表明所设计的控制器及切换策略的正确有效性.     

线性系统的事件触发输出反馈有限时间有界控制

本文研究了线性系统的事件触发输出反馈有限时间有界控制问题. 与渐近稳定只定性地要求系统在采样间隔 有界不同, 有限时间有界需要估计系统轨迹的上界以保证满足动态系统的定量要求. 本文基于类李雅普诺夫函数给出了 保证闭环系统的有限时间有界性和避免芝诺现象的充分条件. 这些充分条件可以转化为线性矩阵不等式, 便于验证和实 际应用. 此外, 为了节约资源, 提出了一种可变参数的事件触发规则, 提高了设计灵活性. 仿真结果验证了本文的主要结 论.     

输入饱和及输出受限的纯反馈非线性系统控制

针对具有输入饱和和输出受限的纯反馈非线性系统,设计了神经网络自适应控制器.首先利用隐函数定理和中值定理将非仿射形式的纯反馈非线性系统转换成有显式输入的非线性系统,基于李雅普诺夫第二方法以及反推法并采用障碍型李雅普诺夫函数进行控制器的设计,最后通过稳定性分析证明了闭环控制系统是半全局一致最终有界的,利用仿真例子验证了控制...     

模糊CMAC神经网络用于MIMO非线性系统的反馈线性化

针对一类多输入多输出（ＭＩＭＯ）连续时间非线性系统,应用模糊ＣＭＡＣ神经网络,给出一种状态反馈控制器,用于使状态反馈可线笥化的未知的非线性动态系统儿得要求的患 很弱的假设条件下,应用李雅普诺夫稳定性理论严格地证明了闭环系统内的所有信号为一致最终有界（ＵＵＢ）。     

具有非线性滞后关联的随机大系统的分散镇定

本文通过利用李雅普诺夫函数和李雅普诺夫矩阵方程的性质，对具有非线性滞后关联的一类随机大系统建立了分散鲁棒镇定的判据，所得闭环随机大系统的和稳定性不依赖于任意实数滞后，并对不确定系数矩阵和随机扰动强度具有鲁棒性。     

具有有界控制输入线性多变量系统的渐近稳定性

基于连续时间系统向量比较定理,本文针对状态反馈控制器,带有观测器的状态反馈控制器和动态输出反馈控制器三种情况给出了控制输入有界时控制系统闭环渐近稳定性判据。     

一类非线性耗散系统的逆最优控制

首先研究一类单输入非仿射非线性系统的逆最优控制问题, 其代价泛函为非线性-非二次型, 设计出一族参数化的状态反馈逆最优控制器;然后讨论当该系统为耗散系统时, 在供给率为二次型的耗散性理论框架下,给出使系统渐近稳定的李雅普诺夫函数和镇定控制律, 并通过适当选取代价泛函中的参数,使得李雅普诺夫函数也是最优值函数,进而揭示出耗散系统在线性输出反馈意义下稳定性与最优性之间的等价关系.     

Asymptotic Stability and Finite‐Time Stability of Networked Control Systems: Analysis and Synthesis

This paper focuses on the problems of asymptotic stability and finite‐time stability (FTS) analysis, along with the state feedback controller design for networked control systems (NCSs) with consideration of both network‐induced delay and packet dropout. The closed‐loop NCS is modeled as a discrete‐time linear system with a time‐varying, bounded state delay. Sufficient conditions for the asymptotic stability and the FTS of the closed‐loop NCS are provided, respectively. Based on the stability analysis results, a mixed controller design method, which guarantees the asymptotic stability of the closed‐loop NCS in the usual case and the FTS of the closed‐loop NCS in the unusual case (that is, in some particular time intervals, large state delay occurs), is presented. A numerical example is provided to illustrate the effectiveness of the proposed mixed controller design method.     

广义双线性系统的参考模型变结构控制

变结构控制是自动控制理论的重要研究分支,首次对广义双线性系统的参考模型变结构控制进行研究.利用广义Lyapunov方法研究广义双线性系统的参考模型变结构控制,通过引入滑动模态补偿器,选取适当的切换流形设计其变结构控制,以保证其闭环系统的渐近稳定,实现滑动模运动,举例说明设计方法的合理性和有效性.     

Dynamical Output Feedback Stabilization Of Mimo Bilinear Systems With Undamped Natural Response

This paper considers the globally asymptotic stabilization problem of multi‐input multi‐output bilinear systems with undamped natural response. Under the conditions for asymptotic stabilization by static state feedback control and system detectability, two output dynamic feedback controllers with saturation bounded control are constructed. The global asymptotic stability of the closed‐loop system is verified by Lyapunov stability theory and LaSalle's Lemma. An example is given to demonstrate the obtained results.     

A Reset‐Time Dependent Approach for Stability Analysis of Nonlinear Reset Control Systems

A reset mechanism in controller can affect the stability property of a closed loop control system. In a simple word, there are stable reset control systems with unstable base‐systems and also unstable reset systems with stable base‐systems. The Lyapunov stability theory is a strong tool to investigate the stability of a nonlinear system. In this paper, based on the well‐known Lyapunov stability concept, some stability conditions for nonlinear reset control systems are addressed. These conditions are dependent on the reset‐times and hence the reset‐time intervals are explicitly emerged in the stability conditions. Some applications of these results are used in numerical examples to show the effectiveness of the proposed approach.     

变时滞不确定组合系统基于观测器的鲁棒镇定

研究一类孤立子系统中状态及控制输入均含有时变时滞,且互联项也含有时变时滞的不确定组合系统基于状态观测器的鲁棒控制问题.基于一组线性矩阵不等式（LMIs）解的存在性,并依据Razumikhin-type理论和Lyapunov稳定性理论,给出了保证系统可鲁棒分散镇定的充分条件及相应控制器的设计方法.分散控制器可通过求解一组LMIs得到.最后,利用一个数值例子验证了所给设计方法的有效性.     

Nonlinear–nonquadratic optimal and inverse optimal control for stochastic dynamical systems

In this paper, we develop a unified framework to address the problem of optimal nonlinear analysis and feedback control for nonlinear stochastic dynamical systems. Specifically, we provide a simplified and tutorial framework for stochastic optimal control and focus on connections between stochastic Lyapunov theory and stochastic Hamilton–Jacobi–Bellman theory. In particular, we show that asymptotic stability in probability of the closed‐loop nonlinear system is guaranteed by means of a Lyapunov function that can clearly be seen to be the solution to the steady‐state form of the stochastic Hamilton–Jacobi–Bellman equation and, hence, guaranteeing both stochastic stability and optimality. In addition, we develop optimal feedback controllers for affine nonlinear systems using an inverse optimality framework tailored to the stochastic stabilization problem. These results are then used to provide extensions of the nonlinear feedback controllers obtained in the literature that minimize general polynomial and multilinear performance criteria. Copyright © 2017 John Wiley & Sons, Ltd.     

A riccati equation approach to the stabilization of uncertain linear systems

This paper presents a method for designing a feedback control law to stabilize a class of uncertain linear systems. The systems under consideration contain uncertain parameters whose values are known only to within a given compact bounding set. Furthermore, these uncertain parameters may be time-varying. The method used to establish asymptotic stability of the closed loop system (obtained when the feedback control is applied) involves the use of a quadratic Lyapunov function. The main contribution of this paper involves the development of a computationally feasible algorithm for the construction of a suitable quadratic Lyapunov function. Once the Lyapunov function has been obtained, it is used to construct the stabilizing feedback control law. The fundamental idea behind the algorithm presented involves constructing an upper bound for the Lyapunov derivative corresponding to the closed loop system. This upper bound is a quadratic form. By using this upper bounding procedure, a suitable Lyapunov function can be found by solving a certain matrix Riccati equation. Another major contribution of this paper is the identification of classes of systems for which the success of the algorithm is both necessary and sufficient for the existence of a suitable quadratic Lyapunov function.     

Conditions for stabilizability of linear switched systems

This paper investigates some conditions that can provide stabilizability for linear switched systems with polytopic uncertainties via their closed loop linear quadratic state feedback regulator. The closed loop switched systems can stabilize unstable open loop systems or stable open loop systems but in which there is no solution for a common Lyapunov matrix. For continuous time switched linear systems, we show that if there exists solution in an associated Riccati equation for the closed loop systems sharing one common Lyapunov matrix, the switched linear systems are stable. For the discrete time switched systems, we derive a Linear Matrix Inequality (LMI) to calculate a common Lyapunov matrix and solution for the stable closed loop feedback systems. These closed loop linear quadratic state feedback regulators guarantee the global asymptotical stability for any switched linear systems with any switching signal sequence.     

Improved delay‐dependent stabilization of time‐delay systems with actuator saturation

This paper addresses the controller synthesis problem of linear time‐delay systems subjected to saturating control. Delay‐dependent regional stabilization criteria are derived based on Lyapunov–Krasovskii approach by using both the polytopic or dead‐zone representation of the saturation function. The main contribution of the paper lies in developing less conservative convex criterion in terms of LMIs to obtain superior results. On the basis of the derived stabilization criterion, an optimization problem is defined to compute the stabilizing state feedback gains with an aim to maximize the stabilizing region while guaranteeing the asymptotic stability of the closed‐loop system. Considering three numerical examples, an assessment of the polytopic and dead‐zone nonlinearity approaches is made. Copyright © 2012 John Wiley & Sons, Ltd.     

Adaptive robust control of uncertain systems with state and input delay

In this paper, adaptive robust control of uncertain systems with multiple time delays in states and input is considered. It is assumed that the parameter uncertainties are time varying norm-bounded whose bounds are unknown but their functional properties are known. To overcome the effect of input delay on the closed loop system stability, new Lyapunov Krasovskii functional will be introduced. It is shown that the proposed adaptive robust controller guarantees globally uniformly exponentially convergence of all system solutions to a ball with any certain convergence rate. Moreover, if there is no disturbance in the system, asymptotic stability of the closed loop system will be established. The proposed design condition is formulated in terms of linear matrix inequality (LMI) which can be easily solved by LMI Toolbox in Matlab. Finally, an illustrative example is included to show the effectiveness of results developed in this paper.