一类随机非线性系统的全局有限时间状态反馈镇定

研究一类连续但非光滑的随机非线性系统的全局有限时间状态反馈镇定控制问题.通过增加幂次积分器技术和四次Lyapunov函数的构造,系统地给出了系统状态反馈有限时间镇定控制器的设计方法.基于引入的随机非线性系统有限时间稳定的判定准则,可以证明闭环系统的有限时间稳定性.仿真结果进一步验证了所设计控制器的有效性.     

分数阶微分中立型系统的有限时间镇定性及有界性（英文）

讨论了一类分数阶微分中立型系统的有限时间状态反馈镇定性及有界性问题.利用Gronwall不等式,获得了使得系统有限时间状态反馈镇定及有限时间有界的充分性条件.     

一类非线性不确定系统的全局指数镇定

研究一类非线性不确定系统的全局指数镇定问题.提出了连续反馈控制器的设计方法,并给出一类非线性不确定系统全局指数镇定的充分条件.如果充分条件得到满足,证明了提出的连续反馈控制使得闭环系统是全局指数稳定的.实例表明了所得结果的有效性.     

一类随机系统的有限时间镇定

讨论随机系统的有限时间镇定问题.首先提出了随机系统有限时间稳定的概念;其次证明了随机系统有限时间稳定的Lyapunov定理;然后,讨论了一类随机系统的镇定问题.     

不确定Lur'e系统的鲁棒脉冲饱和镇定

对一类参数不确定的Lur'e系统,提出了具有饱和执行器的脉冲镇定问题.将饱和非线性项表示为有限个线性函数的凸组合,运用与脉冲时间序列关联的时变Lyapunov函数,建立了具有饱和脉冲输入的不确定Lur'e系统指数稳定性的判据,并获得了零解吸引域的估计.然后,基于线性矩阵不等式,给出了脉冲饱和控制器存在的条件,同时给出了求解最大吸引域估计的凸优化问题.最后,数值实例验证了所提出方法的有效性.     

分数阶微分中立型系统的有限时间镇定性及有界性

讨论了一类分数阶微分中立型系统的有限时间状态反馈镇定性及有界性问题.利用Gronwall 不等式, 获得了使得系统有限时间状态反馈镇定及有限时间有界的充分性条件.     

具有随机时延的模糊不确定网络控制系统的指数镇定

研究了一类非线性不确定网络系统的指数镇定问题.根据网络诱导时延在不同区间上取值,引入满足Bernoulli分布的随机变量,建立新的非线性网络系统模型.利用Lyapunov稳定性理论,以线性矩阵不等式形式给出系统均方指数镇定条件和模糊控制器设计策略.仿真算例说明了方法的有效性.     

不确定系统的鲁棒严格正实镇定问题

本文考虑的鲁棒严格正实镇定问题是指如何设计一固定控制器不仅能在单位反馈下鲁棒镇定一个不确定系统,而且还能使其闭环系统传递函数是鲁棒严格正实的.本文内容包括:1.建立不确定系统的鲁棒严格正实镇定准则,2.给出控制器的综合方法,3.简介其结果在非线性控制系统鲁棒渐近超稳定方面的应用.     

具有非线性扰动的不确定随机时变时滞系统的鲁棒镇定

本文研究了具有非线性扰动的不确定随机时变时滞系统的鲁棒镇定的问题.构造了适当的Lyapunov-Krasovskii泛函并利用自由权矩阵方法,借助于线性矩阵不等式(LMI)技术,设计了一个无记忆状态反馈控制器,并获得了不确定随机时变时滞系统的时滞依赖鲁棒镇定判据.数值例子及其仿真曲线表明所提出的理论结果是有效的.     

具有非线性扰动的不确定多个变时滞系统的有记忆非脆弱状态反馈控制（英文）

本文研究不确定非线性多时滞系统的非脆弱鲁棒镇定问题.状态和输入矩阵中的参数不确定性假设是范数有界.延迟是未知的,但随时间变化范围是已知的.对所有容许的参数不确定性,非脆弱鲁棒镇定问题是设计一个记忆脆弱的状态反馈控制器使得闭环系统是鲁棒稳定.利用Lyapunov泛函和自由权矩阵方法,以线性矩阵不等式(LMI)的的形式,得到时滞依赖充分镇定判据.数值例子说明所提出的理论结果的有效性.     

Finite‐time stability and boundedness of switched nonlinear time‐delay systems under state‐dependent switching

This article investigates the finite‐time stability, stabilization, and boundedness problems for switched nonlinear systems with time‐delay. Unlike the existing average dwell‐time technique based on time‐dependent switching strategy, largest region function strategy, that is, state‐dependent switching control strategy is adopted to design the switching signal, which does not require the switching instants to be given in advance. Some sufficient conditions which guarantee finite‐time stable, stabilization, and boundedness of switched nonlinear systems with time‐delay are presented in terms of linear matrix inequalities. Detail proofs are given using multiple Lyapunov‐like functions. A numerical example is given to illustrate the effectiveness of the proposed methods. © 2014 Wiley Periodicals, Inc. Complexity 21: 267–275, 2015     

Stabilization of nonlinear switched systems using control Lyapunov functions

In this paper, we study the stabilization of general nonlinear switched systems by using control Lyapunov functions. The concept of control Lyapunov function for nonlinear control systems is generalized to switched control systems. The first part of our contribution provides a necessary and sufficient condition of stabilization. The main idea is to use a common control Lyapunov function; this is achieved with the converse Lyapunov theorem dedicated to switched systems. In the second part, an explicit construction of a common control Lyapunov function is addressed with respect to a finite family of switched systems. The approach uses a family of control Lyapunov functions attached to the subsystems.     

Exponential stabilization using sliding mode control for singular systems with time-varying delays and nonlinear perturbations

This paper considers a sliding mode control (SMC) of singular systems. The systems under consideration involve nonlinear perturbations and time-varying delays. The aim of this paper is to design a sliding mode controller such that the nonlinear singular system is exponentially stable and its trajectory can be driven onto the sliding surface in finite time. By using the Lyapunov–Krasovskii functional and some specified matrices, conditions on exponential stabilization are obtained in the form of strict linear matrix inequalities (LMIs). A numerical example is given to illustrate the effectiveness of the proposed main results. All these results are expected to be of use in the study of singular time-varying delay systems with nonlinear perturbations.     

Stability and stabilization of a class of nonlinear impulsive hybrid systems based on FSM with MDADT

The issue of stability and stabilization for a class of nonlinear impulsive hybrid systems based on finite state machine (FSM) with mode-dependent average dwell time (MDADT) is investigated in this paper. The concepts of global asymptotic stability and global exponential stability are extended for the systems, and the multiple Lyapunov functions (MLFs) are constructed to prove the sufficient conditions of global asymptotic stability and global exponential stability, respectively. Furthermore, the method of stabilization is also given for the hybrid systems. The application of MLFs and MDADT leads to a reduction of conservativeness in contrast with classical Lyapunov function. Finally, a numerical example is given to show the feasibility and effectiveness of the proposed approach.     

Some results on the internal finite‐time stabilization of vibrating strings with interior mass

In this paper, the problem of internal finite‐time stabilization for 1‐D coupled wave equations with interior point mass is handled. The nonlinear stabilizing feedback law leads, in closed‐loop, to nonlinear evolution equations where Kato theory is used to prove the well‐posedness. In addition, it is showed that in some cases, the solution of this hybrid system is constant in finite‐time if we use Neumann boundary conditions. This result can be improved (in complete finite‐time stability sense) if we change the above feedback.     

一类非线性系统的局部镇定

研究一类非线性系统的局部状态反馈镇定问题．基于中心流形理论,给出一类非线性系统渐近镇定的充分条件,并设计出镇定系统的反馈控制律．文中利用具有齐次导数的Lyapunov函数方法,特别研究了一类平面非线性系统及具有二重零特征值的一类非线性系统的渐近镇定问题,给出了系统镇定的若干充分条件,并构造出控制律．文中的例表明了所得结果的有效性．     

Robust stabilization of delayed nonholonomic systems with strong nonlinear drifts

This paper presents a control strategy for stabilization of nonholonomic control systems with strongly nonlinear uncertainties and time delay. By applying a novel Lyapunov functional, discontinuous transformation and dynamic feedback approach, robust nonlinear state feedback switching controllers are designed, which can guarantee the stabilization of closed loop systems. The proposed method proves to be effective by a simulation example.     

Robust Stability and Stabilization of a Class of Nonlinear Itô-Type Stochastic Systems via Linear Matrix Inequalities

This article presents a new approach to robust quadratic stabilization of nonlinear stochastic systems. The linear rate vector of a stochastic system is perturbed by a nonlinear function, and this nonlinear function satisfies a quadratic constraint. Our objective is to show how linear constant feedback laws can be formulated to stabilize this type of stochastic systems and, at the same time maximize the bounds on this nonlinear perturbing function which the system can tolerate without becoming unstable. The new formulation provides a suitable setting for robust stabilization of nonlinear stochastic systems where the underlying deterministic systems satisfy the generalized matching conditions. Our sufficient conditions are written in matrix forms, which are determined by solving linear matrix inequalities (LMIs), which have significant computational advantage over any other existing techniques. Examples are given to demonstrate the results.     

Space-time localization in problems with free boundaries for a nonlinear second-order equation

For thermal and diffusion processes in active media described by nonlinear evolution equations, we study the phenomena of space localization and stabilization for finite time.