Bresse系统的内部时滞控制器的设计

研究具有内部分布时滞控制的Bresse系统镇定问题.目标是设计反馈控制器使得闭环系统指数稳定.不同于以前的控制器设计方法,文章采用系统反馈等价方法,通过设计目标系统,应用系统等价方法寻找反馈控制律.利用具有奇异积核的积分变换,实现了当前控制系统与目标系统的等价.所应用的方法克服了通常反馈控制闭环系统的稳定性分析的困难.     

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.     

一类大型互联非线性系统的鲁棒分散控制

本文对带有界扰动的一类大型互联非线性系统进行了分散状态反馈控制设计,通过子系统状态的线性变换,得到分散状态反馈控制律.当状态反馈控制律作用于该系统时,无扰动的闭环系统是渐近稳定的.当扰动较小时,系统的状态能够收敛到原点的一个小邻域内.     

带有界扰动的一类大型互联非线性系统的鲁棒分散输出反馈设计

本文对带有界扰动的一类大型互联非线性系统进行了分散输出反馈控制设计,通过子系统状态的线性变换,得到分散输出反馈控制律.当输出反馈控制律作用于该系统时,系统的状态能够收敛到原点的一个小邻域内.     

基于均方指数稳定的随机时延网络系统的输出反馈控制

研究了随机时延网络系统的输出反馈控制问题.通过把网络诱导时延和数据丢包看做满足区间Bernoulli分布的等价时延,建立了随机时延网络系统模型.基于随机系统稳定性理论,以线性矩阵不等式形式给出了系统均方指数稳定条件和输出反馈控制器设计方法.仿真结果说明了该方法的有效性.     

有效证券市场上证券价格长期波动控制系统的反馈控制

探讨有效证券市场上证券价格长期波动控制系统的反馈控制问题,建立了有效市场条件下证券价格长期波动的控制系统模型.根据系统完全能达的条件,讨论了以股市政策为单控制输入配置极点的问题和以上市公司政策为单控制输入配置极点的问题;根据系统非完全能达的条件,探讨了上市公司不发展时的镇定问题和股市宏观上不调控时的镇定问题.设计了一个降维状态观测器,用以估计证券的内在价值.选择使上市公司均衡增长时对应的证券平均内在价值作为目标值,设计线性多变量调节器,使所得到的闭环系统渐近稳定,且系统的输出跟踪该目标值.通过反馈控制以改善控制系统的内部结构特征和性能,达到人们对证券市场进行调控的预期目的.     

基于动态面技术的随机非线性关联系统的输出反馈控制

针对一类参数不确定且含有未知关联项的随机非线性关联系统,提出了一种自适应输出反馈控制方案.该方案利用K滤波器估计不可量测的系统状态,将动态面技术与输出反馈控制相结合,避免了传统后推设计过程中对虚拟控制律反复求导出现的"复杂性膨胀"问题,设计的自适应动态面控制器可以确保闭环系统中的所有信号在概率意义下半全局一致终结有界,且跟踪误差收敛到一个小的残差集内.     

输入带有时滞的随机前馈非线性系统的全局状态反馈控制

研究了一类输入带有时滞的随机前馈非线性系统的全局状态反馈控制问题.通过使用齐次占优思想和选取合适的Lyapunov-Krasovskii泛函,独立于时滞的状态反馈控制器被显式的构造出来使得闭环系统是依概率全局渐近稳定的.仿真例子验证了所提设计方法的有效性.     

一类非线性微分-代数系统的状态/输出反馈镇定

针对一类可能含有非Lipschitz连续性非线性项的非线性微分-代数系统的状态/输出反馈镇定问题进行研究.首先,利用反步法给出了一种状态反馈控制器的递归设计方法.其次,在非线性项和代数约束满足适当的假设条件下,基于输出反馈占优技术得到了一种输出反馈控制器的设计方法.虽然所给出的两种控制器仅依赖于微分系统的状态,但均能够保证闭环系统的状态是渐近稳定的.仿真结果验证了所提出的两种控制方法的有效性.     

基于观测器的模糊时滞系统的指数稳定控制

研究一类模糊时滞系统的指数稳定和基于观测器的模糊控制问题.在系统状态未知的情况下,通过设计系统的模糊观测器利用矩阵不等式分析的方法给出了系统指数稳定条件和基于观测器的动态输出反馈控制器设计方案.仿真结果说明了所提方法的有效性.     

一类KKT系统的结构敏度分析

本文讨论一类KKT系统的敏度分析，这类KKT系统产生于用有限元方法离散Stokes方程，有结构特性．首先给出了最佳向后扰动界，接下来定义了偏条件数并导出了表达式．最后给出了新的扰动界．     

MEAN-SQUARE STABILITY OF NONLINEAR SYSTEMS WITH TIME-VARYING,RANDOM DELAY

A class of nonlinear systems with a time-varying delay is considered.The delay is modeled by a continuous-time Markov process with a finite number of states. Systems of this type may arise in real-time control applications. Employing a “delay-averaging” approach we demonstrate how certain mean-square stochastic stability conditions can be derived in terms of transition functions of the Markov process and stability properties of a system with a constant delay.     

A CLASS OF NEW NONCONFORMING FINITE ELEMENTS

A class of new nine-parameter nonconforming finite elements with convergent prop-erties are constructed in terms of the approach of interpolation methods in this paper. All of those finite elements can be viewed as the generalization of Zienkiewicz's finite element by dis-lurbing its parameters.     

Finite-time stability analysis of fractional order time-delay systems: Gronwall’s approach

In this paper, a stability test procedure is proposed for linear nonhomogeneous fractional order systems with a pure time delay. Some basic results from the area of finite time and practical stability are extended to linear, continuous, fractional order time-delay systems given in state-space form. Sufficient conditions of this kind of stability are derived for particular class of fractional time-delay systems. A numerical example is given to illustrate the validity of the proposed procedure.     

Varieties of Birkhoff Systems Part I

A Birkhoff system is an algebra that has two binary operations ? and + , with each being commutative, associative, and idempotent, and together satisfying x?(x + y) = x+(x?y). Examples of Birkhoff systems include lattices, and quasilattices, with the latter being the regularization of the variety of lattices. A number of papers have explored the bottom part of the lattice of subvarieties of Birkhoff systems, in particular the role of meet and join distributive Birkhoff systems. Our purpose in this note is to further explore the lattice of subvarieties of Birkhoff systems. A primary tool is consideration of splittings and finite bichains, Birkhoff systems whose join and meet reducts are both chains. We produce an infinite family of subvarieties of Birkhoff systems generated by finite splitting bichains, and describe the poset of these subvarieties. Consideration of these splitting varieties also allows us to considerably extend knowledge of the lower part of the lattice of subvarieties of Birkhoff systems     

一类含参数的分块对称矩阵的正定性及应用

首先给出一种判断分块对称矩阵正定的方法,提供了确定一组尽可能小的参数,使一类含参数的分块对称矩阵正定的简单算法,然后,将其结果用于研究线性定常大系统的分散镇定性,得到了一类可分散镇定的线性大系统,并给出了相应的分散镇定算法,同文献中提供的方法相比,该算法不仅扩大了所考虑的系统范围,而且不会引起过高的反馈增益,同时还简单易算。     

LONG-TIME BEHAVIOR OF FINITE DIFFERENCE SOLUTIONS OF A NONLINEAR SCHRODINGER EQUATION WITH WEAKLY DAMPED

1. IntroductionThe nonlinear schr~r equation with weakly dampedwhere t = N, o > 0, together with appropriate boUndary and hatal condition, is ared inmany physical fields. The echtence of an attractor is one of the most boortant ~eristiCSfor a dissipative system. The long-tabs dynamics is completely determined by the attractorof the system. J.M. Ghidaglia[1] studied the lOng-the behavior of the nonlineaz Sequation (1.1) and proved the eAstence of a compact global attractor A in H'(n) which…     

Explicit formulas for Hankel norm approximations of infinite-dimensional systems

Recently Hankel norm approximation for finite dimensional systems has been studied extensively, both for continuous time systems and discrete time systems. One of the approaches is to combine the work of J.A. Ball and J.W. Helton with results on Wiener-Hopf factorization to produce explicit formulas for the solutions. This has been done by J.A. Ball and A.C.M. Ran for the finite-dimensional case and for a class of infinite-dimensional systems by A.C.M. Ran. Here we show that this approach can be extended to a much larger class of infinite-dimensional systems; those with an exponentially stable semigroup and unbounded input and output operators which satisfy a smoothness condition. This class is larger than the nuclear class for which this problem was solved by K. Glover, R.F. Curtain and J.R. Partington by an approximation approach.     

Geometries over Universal Left Conjugacy Closed Quasifields

A class of examples of loops with universal left conjugacy property defined in the Canadian Journal of Mathematics (Vol. 46 (1994), pp. 1027--1056) is provided by proving that finite André systems have universal left conjugacy closed multiplicative loops. Then quasifields, in which the multiplicative loop has this property are characterized geometrically.     

一类具有零动态不确定非线性系统的有限时间镇定问题

研究了一类带有零动态不确定非线性系统的有限时间镇定问题.基于有限时间稳定的Lyapunov理论和反推技术给出了一个状态反馈控制器的设计步骤,解决了这类不确定非线性系统的有限时间镇定问题.