一类切换广义时滞系统的时滞相关稳定性准则

针对一类切换广义时滞系统的稳定性问题进行了研究．提出了一种新的研究切换广义时滞系统的多Lyapunov泛函,利用Lyapunov稳定性理论和线性矩阵不等式工具,通过引入适当的自由权矩阵,在设定的切换律下,得到了基于严格线性矩阵不等式表示的切换广义时滞系统的时滞相关稳定性条件．进一步通过建立一个具有线性矩阵不等式约束的凸...     

线性时滞系统对时滞参数的自适应控制

针对实际中线性时滞系统的时滞常数往往不能精确已知的缺点,对具有状态滞后的线性时滞系统提出一种对时滞常数的自适应控制方案,其控制器存在的充分条件由一个线性矩阵不等式（LMI）的形式给出,并对整个闭环系统的稳定性进行了分析。     

广义系统的时滞依赖静态输出反馈控制

针对一类不确定线性广义时滞系统,给出了静态输出反馈控制器的设计方法.首先基于标称广义时滞系统的稳定条件,以受限线性矩阵不等式形式,给出闭环广义时滞系统正则、无脉冲且渐近稳定的充分条件,同时利用受限矩阵不等式的可行解给出静态输出反馈控制律的一个参数化表示;其次,利用矩阵的正交补,把求受限线性矩阵不等式的可行解问题转化为求严格线性矩阵不等式(LMIs)的可行解;最后应用数值实例说明了所给方法的有效性和正确性.     

一类时滞矩形广义系统的镇定

为研究时滞矩形广义系统的镇定问题,首先引入时滞动态补偿器对系统进行反馈补偿,然后构建一个合适的Lyapunov-Krasovskii泛函,并选取先进的积分不等式来处理泛函导数的积分项,进而获得了以严格线性矩阵不等式(LMI)表示的时滞矩形广义系统的镇定条件。在此基础上,利用迭代线性矩阵不等式的算法计算动态补偿器和反馈增益的参数矩阵。最后,通过数值算例验证了方法的有效性和优越性。     

时滞系统时滞相关型稳定性准则

针对常数时滞线性系统的稳定性问题,基于一个适当形式的Lyapunov-Krasovskii泛函,通过利用一个积分不等式,采用时滞分解方法,以线性矩阵不等式的形式给出了时滞系统的时滞相关型稳定性准则.与现有的时滞相关型稳定性结果相比较,所得到的结果具有保守性更好,结构更加简单,且不合有任何多余的矩阵变量等特点,并从理论上进行了严格的证明,解决了现有的稳定性结果绝大多数只是从数值例子说明其有效性的问题.示例说明了所得结果的有效性.     

奇异时滞系统对时滞参数的自适应控制

针对一类状态时滞奇异系统,研究状态反馈控制器的设计问题。基于Lyapunov稳定性理论和线性矩阵不等式（LMI）工具,当时滞常数精确已知时,设计带有记忆的状态反馈控制器,使得相应的闭环系统渐近稳定;当时滞常数不能精确已知时,通过求解相应的线性矩阵不等式,得到满足设计要求的对时滞参数的自适应控制器,使得时滞系统镇定。最后,仿真实例表明此方法的有效性。     

不确定离散时滞系统的状态时滞反馈保性能控制器的设计

对一类同时具有状态时滞和输入时滞的不确定离散时滞系统,提出保性能状态时滞反馈控制律的设计问题。结合一个二次型性能指标,基于Lyapunov函数和线性矩阵不等式处理方法,推出状态时滞反馈保性能控制律存在的条件,并用线性矩阵不等式的可行解给出保性能控制律的构造方法。最后给出一个仿真例子证明该方法的有效性。     

线性时滞系统依赖于时滞的H~∞状态反馈控制

对具有纯滞后输入的线性时滞系统 ,在系统的状态时滞与控制输入时滞不同时 ,研究了依赖时滞的 H∞ 状态反馈控制器设计问题 ,其控制器存在的充分条件由一个线性矩阵不等式 (L MI)的形式给出 ,并给出了相应的 H∞ 控制器的综合设计方法     

一类不确定时滞系统的非线性H_∞控制

利用Lyapunov稳定性定理和线性矩阵不等式工具,讨论了一类不确定时滞系统的非线性H∞控制问题.设计的非线性H控制器可由线性矩阵不等式的解给出.进一步,建立一个具有线性矩阵不等式约束的凸优化问题,得到了不确定时滞系统的最优状态反馈H控制律,仿真示例表明了该方法的可行性.     

时滞依赖网络控制系统的量化控制:分段时滞法

为了减小时滞依赖系统分析的保守性,获得较大的时滞上界,也为了减小网络中的数据传输率,本文提出了一种具有量化的网络控制系统的新的分析方法:时滞分段法.将时滞落于某一段小区间看做一种情形,针对每种不同情形利用不同的自由权矩阵,并利用矩阵函数的凸性,得到了新的时滞依赖的稳定性条件.通过求解若干组线性矩阵不等式可得时滞上界和量...     

一种模糊系统稳定性的分析方法

针对T-S型模糊系统进行局部稳定性分析．首先指出模糊系统全局渐近稳定充分条件的不足，证明了此条件不是必要条件；然后将模糊集合的隶属度函数代入模糊系统表达式，得到一个特殊的非线性离散系统，从系统分析的区域、判定稳定的条件及稳定范围3方面确定稳定区域；最后对不稳定的系统给出了不稳定判据．仿真实例证明了这种方法的有效性．该方法对系统稳定点附近局部稳定性的判定有着很强的实用价值．     

时滞不确定随机系统基于参数依赖Lyapunov函数的稳定条件

针对一类具有凸多面体参数不确定性的时滞随机系统, 研究了其鲁棒稳定性问题. 通过引入适当的加权矩阵变量来寻找Leibniz-Newton公式各项之间的关系, 从而直接地处理系统中的时滞状态项, 避免了常规的应用Leibniz-Newton公式来进行模型变换的间接方法所带来的较大保守性. 采用参数依赖Lyapunov函数方法, 推导了此类系统鲁棒稳定的时滞相关的充分条件. 本文所得条件为线性矩阵不等式形式, 便于借助于内点算法进行求解. 仿真实例证明了本文所提出的稳定条件具有较低的保守性.     

A robust stabilization problem of fuzzy control systems and itsapplication to backing up control of a truck-trailer

A robust stabilization problem for fuzzy systems is discussed in accordance with the definition of stability in the sense of Lyapunov. We consider two design problems: nonrobust controller design and robust controller design. The former is a design problem for fuzzy systems with no premise parameter uncertainty. The latter is a design problem for fuzzy systems with premise parameter uncertainty. To realize two design problems, we derive four stability conditions from a basic stability condition proposed by Tanaka and Sugeno: nonrobust condition, weak nonrobust condition, robust condition, and weak robust condition. We introduce concept of robust stability for fuzzy control systems with premise parameter uncertainty from the weak robust condition. To introduce robust stability, admissible region and variation region, which correspond to stability margin in the ordinary control theory, are defined. Furthermore, we develop a control system for backing up a computer simulated truck-trailer which is nonlinear and unstable. By approximating the truck-trailer by a fuzzy system with premise parameter uncertainty and by using concept of robust stability, we design a fuzzy controller which guarantees stability of the control system under a condition. The simulation results show that the designed fuzzy controller smoothly achieves backing up control of the truck-trailer from all initial positions     

Stability analysis of a class of non-linear distributed parameter systems—tubular chemical reactors†

A sufficient condition for local stability of the spatially discretized model of a class of non-linear distributed parameter systems is derived using the circle criterion for stability and bounded-input, bounded-output stability. As a physical system the catalytic packed-bed tubular reactor is taken to illustrate the application of the theorem to process control systems. The stability condition in the large derived from non-linear system equations is compared with the stability condition in the small derived from linearized system equations. Interpretations of the result are given in terms of physical variables.     

A note on asymptotic behaviour in linear discrete systems

A necessary and sufficient condition for uniform exponential stability in linear discrete systems is given. This condition is the analogue of one used to study asymptotic behaviour in linear differential systems. However, in the continuous time case, it has been shown that this condition implies an asymptotic stability property which is weaker than uniform exponential stability.     

A test for stability robustness of linear time‐varying systems utilizing the linear time‐invariant ν‐gap metric

A stability robustness test is developed for internally stable, nominal, linear time‐invariant (LTI) feedback systems subject to structured, linear time‐varying uncertainty. There exists (in the literature) a necessary and sufficient structured small gain condition that determines robust stability in such cases. In this paper, the structured small gain theorem is utilized to formulate a (sufficient) stability robustness condition in a scaled LTI ν‐gap metric framework. The scaled LTI ν‐gap metric stability condition is shown to be computable via linear matrix inequality techniques, similar to the structured small gain condition. Apart from a comparison with a generalized robust stability margin as the final part of the stability test, however, the solution algorithm implemented to test the scaled LTI ν‐gap metric stability robustness condition is shown to be independent of knowledge about the controller transfer function (as opposed to the LMI feasibility problem associated with the scaled small gain condition which is dependent on knowledge about the controller). Thus, given a nominal plant and a structured uncertainty set, the stability robustness condition presented in this paper provides a single constraint on a controller (in terms of a large enough generalized robust stability margin) that (sufficiently) guarantees to stabilize all plants in the uncertainty set. Copyright © 2008 John Wiley & Sons, Ltd.     

On the stability of neural networks with arbitrary weights

Dynamical properties of a general neural network are discussed. A condition for the neural activation dynamics being stable is derived. The stability condition does not put any symmetry restriction on the weights. The transitions from stable to non-stable dynamics are analysed and their analogy to phase transitions in statistical mechanics discussed. In general, the network dynamics can violate the stability condition. To avoid that happening, a method is introduced which makes the dynamics adaptive such that the stability condition is sustained. Relations to some previous works on stability are discussed.     

不确定多重状态时滞离散系统的LMI鲁棒稳定条件

研究了具有多重状态时滞的凸多面体不确定离散系统的鲁棒稳定性分析问题．基于参数依赖的李亚普诺夫稳定性和线性矩阵不等式推导出使得时滞鲁棒稳定系统鲁棒稳定的充分条件．应用此条件，通过测试一组线性矩阵不等式的可解性即可达到判定系统的鲁棒稳定性的目的．因为使用了参数依赖的李亚普诺夫稳定性思想，此鲁棒稳定条件比基于二次稳定概念的稳定条件的保守性更小．算例验证了结果．     

非线性系统有限时间稳定的一个新的充分条件

研究了一类非线性系统的有限时间稳定性．通过函数构造和变量替换的方法,给出一个新的非线性系统有限时间稳定的充分条件．该条件与现有结果相比,具有更少的保守牲．进一步,将所得的结果推广到不确定性非线性系统,通过构造Lyapunov函数方法,给出系统有限时间稳定的充分条件．仿真例子表明了所得结论的有效性．