基于LMIs方法-不确定性随机分布型时滞Markov跳变系统的鲁棒镇定

研究了一类具有不确定性Markov跳变参数的线性分布型时滞系统.考虑了具不确定性、Markov跳变参数、及分布型时滞系统的鲁棒均方稳定性问题.设计了系统的鲁棒状态反馈镇定控制器.采用了Grownwall Bellman不等式,基于线性矩阵不等式(LMIs)方法,给出了鲁棒稳定性的LMI时滞依赖的代数判据,从而降低了判据的保守性.同时得到了相应的离散时滞情形下的结果.     

一类线性时滞系统的时滞依赖稳定性研究

针对一类带有参数不确定性的线性时滞系统,研究其时滞依赖稳定性问题。采用改进的Lyapunov-Krasovskii泛函方法给出了线性时滞系统基于线性矩阵不等式的时滞依赖稳定的充分条件,在定理的证明中结合牛顿公式改进了一系列二次型积分不等式,从而有效降低了定理保守性。最后给出2个计算实例,通过与现有方法的比较可以看出本文方法的更加有效,且得到的最大时滞具有更小的保守性。     

一种时滞相关非脆弱模糊控制器的设计

研究了一类带有时变时滞的离散模糊双线性系统的时滞相关非脆弱控制问题。引入自由权值矩阵并定义一种新型的Lyapunov函数,在控制器存在加性不确定的情况下,得到了保守性小的时滞相关渐近稳定的充分条件。通过附加矩阵,将所得到的稳定条件转换为线性矩阵不等式(linear matrix inequality, LMI)形式,非脆弱控制器可由LMI的解得到。数例仿真验证了该方法的有效性。     

一类非线性不确定时滞系统的时滞相关鲁棒H∞控制

针对一类具有状态非线性不确定性的时滞系统,基于适当形式的Lyapunov泛函和Lyapunov稳定性理论,利用线性矩阵不等式(LMI)方法,讨论了时滞相关型鲁棒H∞状态反馈控制器设计问题.在非线性不确定性满足增益有界条件下,得到了该类时滞系统依赖于时滞的满足鲁棒H∞性能的一个充分条件,且控制器存在的充分条件由线性矩阵不等式组(LMIs)的形式给出,可以通过求解一个线性矩阵不等式组获得鲁棒H∞控制器.最后给出一个具体算例说明了该方法的有效性.     

不确定线性时滞系统时滞相关状态反馈鲁棒镇定

利用Lyapunov-Krasovskii泛函方法,基于积分不等式,讨论了不确定线性时变时滞系统时滞相关状态反馈鲁棒镇定问题。采用线性化处理技术将非线性矩阵不等式（nonlinear matrix inequality, NLMI）转化为线性矩阵不等式（linear matrix inequality, LMI）,获得的鲁棒镇定准则只有一个易于选择的待定参数,避免了参数选择不当带来的保守性,数值例子说明本文方法的有效性。     

一类非线性中立型时滞系统的稳定性判据

考虑了一类具有非线性扰动的中立型时滞系统的鲁棒稳定性问题.系统状态的时滞是时变的.基于增广Lyapunov-Krasovskii泛函和自由权矩阵的方法,推导出保证系统在非线性扰动作用下渐近稳定的时滞依赖条件.所得到的判据以线性矩阵不等式的形式给出.由于在估计Lyapunov泛函导数上界的过程中既没有进行模型变换,也没有引入不等式放缩技术,所以得到的结果有较小的保守性.最后,通过一个数值算例验证了所提方法的有效性以及较已有工作的改进.     

区间时滞相关不确定奇异系统的鲁棒稳定性和镇定性

研究区间时滞相关的不确定时变时滞奇异系统的鲁棒稳定性和镇定性问题,不确定参数假设是范数有界的。充分利用时滞的下界信息构造Lyapunov函数,用严格的矩阵不等式给出系统对所有的容许不确定满足正则、无脉冲、稳定的新判据。基于这个判据,设计状态反馈控制器使得系统鲁棒稳定。数值例子说明所得结果具有更小的保守性。     

两类不确定奇异时滞系统鲁棒稳定的相关型判据

研究了不确定奇异时滞系统的鲁棒稳定性问题。首先以线性矩阵不等式的形式给出了奇异时滞系统正则,无脉冲模且零解渐近稳定的一种新的时滞相关型判据。通过引入新的参数避免了利用不等式处理交叉项,从而使该判据具有较小的保守性。最后,利用研究结果,给出了两类不确定奇异时滞系统新的时滞相关型鲁棒稳定性判据。     

基于时滞分割法的Markov随机切换系统指数稳定性

研究了时变时滞满足h₁≤d(t)≤h₂的Itô型随机Markov切换系统的区间时滞相关指数稳定性。基于时滞分割的思想,建立了新颖的Lyapunov-Krasovskii泛函,并引入一些改进的积分等式,以线性矩阵不等式的形式给出了低保守性的区间时滞相关指数稳定条件。最后用几个数值算例说明该结论的有效性及其较低的保守性。     

Stability and guaranteed cost control for uncertain time-delay Lur''''e systems

The problem of delay-dependent stability and guaranteed cost control （GCC） for a class of uncertain time-delay Lur＇e systems are studied. By using an improved integral inequality,a less conservative delay-dependent stability criterion is formulated as the feasibility problem of the linear matrix inequality （LMI）. The criterion is proved theoretically to be less conservative than some existing results for linear time-delay systems. Because of the fact that the matrices in the LMI-based stability criteria usually have different dimensions, different structures, and different variables, the conservatism analysis of the criteria is difficult. This study brings about a new insight into the comparison of conservatism among different stability criteria, which are expressed in certain LMI forms. The existence of the guaranteed cost controller is given in terms of matrix inequalities. The condition can be solved by using an iterative procedure and does not need any parameter tuning. A numerical example is given to illustrate the effectiveness of the proposed method.     

Improved stability criteria for uncertain linear systems with interval time-varying delay

This paper deals with the robust stability analysis of dynamic systems with interval timevarying delay and uncertainties. The innovation of the method includes employment of a tighter integral inequality and construction of an appropriate type of Lyapunov functional. The stability criteria derived from this method have less conservatism than some existing ones. Numerical examples are given to illustrate the effectiveness of the proposed method.     

Mean-square exponential stability for stochastic time-varying delay systems with Markovian jumping parameters: a delay decomposition approach

The mean-square exponential stability problem is investigated for a class of stochastic time-varying delay systems with Markovian jumping parameters.By decomposing the delay interval into multiple equidistant subintervals,a new delay-dependent and decay-rate-dependent criterion is presented based on constructing a novel Lyapunov functional and employing stochastic analysis technique.Besides,the decay rate has no conventional constraint and can be selected according to different practical conditions.Finally,two numerical examples are provided to show that the obtained result has less conservatism than some existing ones in the literature.     

区间变时滞不确定系统鲁棒稳定性分析

研究了一类线性区间变时滞不确定系统鲁棒稳定性问题。基于新型的时滞分割法和交互式凸组合技术,借助于构造包含四重积分项的新Lyapunov Krasovskii泛函,并利用新的积分不等式界定方法给出了线性矩阵不等式形式的时滞相关稳定性判据。与已有文献相比,该判据扩大了保证系统稳定的最大时滞上界范围,在降低结论的保守性和提高计算效率两者间达到了一个很好的平衡。最后通过3个具有代表性的数值例子对比验证了该方法在降低结论保守性方面的优越性。     

New results on the robust stability analysis of neural networks with discrete and distributed time delays

Delay-dependent robust stability of cellular neural networks with time-varying discrete and distributed time-varying delays is considered. Based on Lyapunov stability theory and the linear matrix inequality （LMIs） technique, delay-dependent stability criteria are derived in terms of LMIs avoiding bounding certain cross terms, which often leads to conservatism. The effectiveness of the proposed stability criteria and the improvement over the existing results are illustrated in the numerical examples.     

Stability of singular networked control systems with control constraint

Based on bounded network-induced time-delay, the networked control system is modeled as a linear time-variant singular system. Using the Lyapunov theory and the linear matrix inequality approach, the criteria for delay-independent stability and delay-dependent stability of singular networked control systems are derived and transformed to a feasibility problem of linear matrix inequality formulation, which can be solved by the Matlab LMI toolbox, and the feasible solutions provide the maximum allowable delay bound that makes the system stable. A numerical example is provided, which shows that the analysis method is valid and the stability criteria are feasible.     

Delay differential equations under nonlinear impulsive control and applications to neural network models

In this paper,a class of delay differential equations with nonlinear impulsive control is discussed.Based on the nonsmooth analysis,criteria of stability are obtained for delay differential equations with nonlinear impulses control under certain conditions.These criteria can be applied to some neural network models.At the end of the paper,two examples are provided to illustrate the feasibility and effectiveness of the proposed results.     

具有变时滞的线性系统的时滞相关稳定性

具有时滞的控制系统是工程实践中经常遇到的一类重要的非线性控制系统。根据微分方程理论和矩阵指数特性，提出了具有不确定性的时滞控制系统与时滞相关和与时滞无关稳定的充分性判据，并给出系统衰减速率的估计方法。该方法仅需假定时滞有界，因而其结论适用于变时滞的系统。同时还给出了应用实例，并与相关成果进行了比较，计算结果表明了该方法的有效性。     

Improved delay-dependent stability criteria for systems with interval delay

This paper deals with the problem of stability for systems with delay varying in an interval.A new Lyapunov functional,which makes use of the information of both the lower and upper bounds of the interval time-varying delay,is proposed to derive some new stability criteria.Furthermore,the relationship of the time-varying delay and its lower bound and upper bound is taken into account.As a result,some less conservative delay-dependent stability criteria are obtained without ignoring any useful information in the derivative of Lyapunov functional,which are established in the forms of linear matrix inequalities.Numerical examples are provided to show that the obtained results are better than existing ones.     

Delay-dependent exponential stability of impulsive stochastic systems with time-varying delay

The problem of delay-dependent exponential stability is investigated for impulsive stochastic systems with time-varying delay.Although the exponential stability of impulsive stochastic delay systems has been discussed by several authors,few works have been done on delay-dependent exponential stability of impulsive stochastic delay systems.Firstly,the Lyapunov-Krasovskii functional method combing the free-weighting matrix approach is applied to investigate this problem.Some delay-dependent mean square exponential stability criteria are derived in terms of linear matrix inequalities.In particular,the estimate of the exponential convergence rate is also provided,which depends on system parameters and impulsive effects.The obtained results show that the system will stable if the impulses’ frequency and amplitude are suitably related to the increase or decrease of the continuous flows,and impulses may be used as controllers to stabilize the underlying stochastic system.Numerical examples are given to show the effectiveness of the results.