离散滞后广义系统稳定性的定量估计

利用Lyapunov方法讨论离散滞后广义系统，并给出了该系统的零解一致稳定区域和渐近稳定区域的大小估计，当初始扰动是在稳定区域时，离散滞后广义系统的初始值问题的解一致稳定，当初始扰动是在渐近稳定区域时，离散滞后广义系统的台值问题的解趋于零，所举的仿真例子描述了该方法的应用。     

线性离散周期奇异系统的可解性与渐近稳定性

讨论了线性离散周期奇异系统初值问题的可解性和渐近稳定性问题.首先分析总结了线性离散变系数奇异系统可解性及其广义状态解的一般概念.在此基础上,定义了线性离散变系数奇异系统的一致渐近稳定性,并通过增加系统维数把线性离散周期奇异系统转化为线性定常奇异系统,从而得到了线性离散周期奇异系统可解和一致渐近稳定的充要条件.     

不确定时变线性系统的鲁棒一致渐近稳定的扰动界

不确定时变线性系统的鲁棒一致渐近稳定的扰动界奚宏生（中国科学技术大学自动化系合肥２３００２６）关键词不确定时变线性系统，鲁棒一致渐近稳定，奇异值．ｌ引言在文献［１—３］中利用状态空间方法研究了结构不确定定常线性系统参数扰动的稳定区域．本文利用时变矩阵...     

非线性离散广义系统的输出反馈H∞控制

主要对非线性离散广义系统的输出反馈H∞控制器的设计问题进行讨论,首先利用广义Lyapunov函数和线性矩阵不等式,对系统的零解E-渐近稳定性问题进行分析,在此条件基础上给出系统零解E-渐近稳定且具有H∞范数约束的充分条件,然后设计系统的输出反馈H∞控制器,使得闭环系统具有同样的性能。     

滞后广义系统的状态反馈H∞控制

研究了一类状态方程和输出方程均带有时滞的滞后广义系统的H ∞控制问题.利用线性矩阵不等式,首先给出滞后广义系统零解渐近稳定且具有H ∞范数约束的充分条件,进而分别设计无记忆和有记忆状态反馈控制律,保证闭环系统具有上述性能,同时基于线性矩阵不等式的解得到了相应控制器构造方法.最后给出一个数值算例说明文中结论的有效性.     

滞后广义系统的状态反馈H∞控制

研究了一类状态方程和输出方程均带有时滞的滞后广义系统的H_∞控制问题.利用线性矩阵不等式,首先给出滞后广义系统零解渐近稳定且具有H_∞范数约束的充分条件,进而分别设计无记忆和有记忆状态反馈控制律,保证闭环系统具有上述性能,同时基于线性矩阵不等式的解得到了相应控制器构造方法.最后给出一个数值算例说明文中结论的有效性.     

多滞后时变区间动力系统的稳定性和衰减率

研究了多滞后时变区间动力系统的渐近稳定性和α指数稳定性,给出了其一致渐近稳定 和α指数稳定的充分条件,推广和改进了文[1-4]的工作.     

具有时滞和时变系数的离散多智能体系统的一致性

研究一类具有时滞和时变系数的离散多智能体系统的一致性问题. 首先, 通过构造合适的控制协议, 并以第一个智能体的位移作为参考状态, 将原系统的一致性问题转化为误差系统中零解的渐近稳定性问题; 然后, 运用矩阵范数理论研究误差系统零解的渐近稳定性, 导出使多智能体系统实现一致的充分条件; 最后, 通过数值模拟验证了该判据的正确性和有效性.

     

离散广义系统稳定性分析与控制的Lyapunov方法

利用Lyapunov方法,研究离散广义系统稳定性分析与控制问题.得到了离散广义 系统正则、具有因果关系且渐近稳定的等价条件;还给出了相关的鲁棒稳定性分析与镇定方 法.     

一类含扰动的非线性切换系统稳定性分析

首先在非零扰动情况下,利用平均滞留时间的方法给出保证切换系统一致有界或一致终极有界的条件以及最终边界.当切换系统中含有不稳定子系统时,证明了当切换规则满足一定条件时,仍可保证切换系统是有界的.然后在零扰动情况下,给出了扰动非线性切换系统稳定的充分条件.最后通过仿真算例说明了所得结果的有效性.     

具输入饱和因子的广义系统的镇定

广义系统的镇定问题是广义系统理论的基本问题之一.为了研究具输入饱和因子 的广义系统的镇定,首先利用代数方法,借助大系统分解原理,对具输入饱和因子的广义系统 进行综合,给出闭环系统渐近稳定的判别条件.其次,给出了闭环系统E一渐近稳定的概念,利 用广义Lyapunov函数方法,研究具输入饱和因子的广义系统,提出了合适的反馈控制,得到 了具输入饱和因子的广义系统E一渐近稳定的判别定理.     

Asymptotic stability in probability of singular stochastic systems with Markovian switchings

This paper investigates the problem of asymptotic stability in probability for singular stochastic systems with Markovian switchings. A stochastic Lyapunov theorem on asymptotic stability in probability for the considered systems is provided. Also, we show that the original system has the same stability property as its difference‐algebraic form based on singular value decomposition. By utilizing the earlier results, a sufficient condition is obtained in terms of linear matrix inequalities, which is easy to check by using standard software. Copyright © 2017 John Wiley & Sons, Ltd.     

Kalman滤波的局部渐近稳定性和渐近最优性*

本文用现代时间序列分析方法和非递推状态估计理论，对完全可观、非完全可控系统，提出了稳态Ｋａｌｍａｎ预报器局部渐近稳定性和最优性概念，揭示了两者的关系；证明了这类系统的Ｋａｌｍａｎ预报器总是局部渐近最优和渐近稳定的；提出了构造最大局部渐近最优域的新方法，并给出了几何解释，推广和发展了经典Ｋａｌｍａｎ滤波稳定性理论，一个算例及其仿真结果说明了所提出的结果的有效性。     

String stability of interconnected systems

Introduces the notion of string stability of a countably infinite interconnection of a class of nonlinear systems. Intuitively, string stability implies uniform boundedness of all the states of the interconnected system for all time if the initial states of the interconnected system are uniformly bounded. It is well known that the input output gain of all the subsystems less than unity guarantees that the interconnected system is input-output stable. The authors derive sufficient (“weak coupling”) conditions which guarantee the asymptotic string stability of a class of interconnected systems. Under the same “weak coupling” conditions, string-stable interconnected systems remain string stable in the presence of small structural/singular perturbations. In the presence of parameter mismatch, these “weak coupling” conditions ensure that the states of all the subsystems are all uniformly bounded when a gradient-based parameter adaptation law is used and that the states of all the systems go to zero asymptotically     

Asymptotic stability in probability and stabilization for a class of discrete‐time stochastic systems

This paper investigates asymptotic stability in probability and stabilization designs of discrete‐time stochastic systems with state‐dependent noise perturbations. Our work begins with a lemma on a special discrete‐time stochastic system for which almost all of its sample paths starting from a nonzero initial value will never reach the origin subsequently. This motivates us to deal with the asymptotic stability in probability of discrete‐time stochastic systems. A stochastic Lyapunov theorem on asymptotic stability in probability is proved by means of the convergence theorem of supermartingale. An example is given to show the difference between asymptotic stability in probability and almost surely asymptotic stability. Based on the stochastic Lyapunov theorem, the problem of asymptotic stabilization for discrete‐time stochastic control systems is considered. Some sufficient conditions are proposed and applied for constructing asymptotically stable feedback controllers. Copyright © 2014 John Wiley & Sons, Ltd.     

Further results on the robust stability of linear systems with a single time delay

For linear systems with a single time-varying delay time, we propose a method to characterize how large the deviation of the delay time can be compared to the nominal zero value, such that the system still preserves its asymptotic stability. Both cases of linear time-delay systems with and without uncertainties are considered. The criteria developed are seen to give less conservative results in simulation examples.     

Trajectory tracking control for robot manipulators using only position measurements

In the paper, the trajectory tracking control problem is investigated for robotic manipulators which are not equipped with the tachometers. Our contribution consists in establishing uniform asymptotic stability in closed-loop system by using the dynamic position-feedback controller with feedforward. Using Lyapunov vector function and comparison principle, we construct the non-linear controller with variable gain matrices and first-order linear dynamic compensator such that the origin of the closed-loop system is uniformly asymptotically stable. The controller is shown to be robust with respect to parameters incertainties. We illustrate the utility of our result by simulation tests with reference to a two-link planar elbow robot manipulator.     

Optimal singular control for nonlinear semistabilisation

The singular optimal control problem for asymptotic stabilisation has been extensively studied in the literature. In this paper, the optimal singular control problem is extended to address a weaker version of closed-loop stability, namely, semistability, which is of paramount importance for consensus control of network dynamical systems. Three approaches are presented to address the nonlinear semistable singular control problem. Namely, a singular perturbation method is presented to construct a state-feedback singular controller that guarantees closed-loop semistability for nonlinear systems. In this approach, we show that for a non-negative cost-to-go function the minimum cost of a nonlinear semistabilising singular controller is lower than the minimum cost of a singular controller that guarantees asymptotic stability of the closed-loop system. In the second approach, we solve the nonlinear semistable singular control problem by using the cost-to-go function to cancel the singularities in the corresponding Hamilton–Jacobi–Bellman equation. For this case, we show that the minimum value of the singular performance measure is zero. Finally, we provide a framework based on the concepts of state-feedback linearisation and feedback equivalence to solve the singular control problem for semistabilisation of nonlinear dynamical systems. For this approach, we also show that the minimum value of the singular performance measure is zero. Three numerical examples are presented to demonstrate the efficacy of the proposed singular semistabilisation frameworks.     

On the conditions of exponential stability in active disturbance rejection control based on singular perturbation analysis

Stability of active disturbance rejection control (ADRC) is analysed in the presence of unknown, nonlinear, and time-varying dynamics. In the framework of singular perturbations, the closed-loop error dynamics are semi-decoupled into a relatively slow subsystem (the feedback loop) and a relatively fast subsystem (the extended state observer), respectively. It is shown, analytically and geometrically, that there exists a unique exponential stable solution if the size of the initial observer error is sufficiently small, i.e. in the same order of the inverse of the observer bandwidth. The process of developing the uniformly asymptotic solution of the system reveals the condition on the stability of the ADRC and the relationship between the rate of change in the total disturbance and the size of the estimation error. The differentiability of the total disturbance is the only assumption made.     

仿射非线性奇异系统的反馈控制与稳定化

研究非线性奇异系统的反馈稳定化问题，首先给出仿射非线性奇异系统反馈稳定化的概念；然后利用零动态算法构造的局部坐标变换给出仿射非线性奇异系统的一种标准型，并将其用于研究仿射非线性奇异系统的反馈控制和系统稳定化问题；最后证明了对于正则仿射非线性奇异系统，当其零动态渐近稳定时，该系统可通过反馈控制实现系统的稳定化。