Lienard方程解的渐近性态

讨论了Liemrd方程解的振荡性和有界性及极限环的存在性和不存在性.给出了几个存在奇闭轨和正(负)半轨趋向原点或无穷的充分条件,改进和补充了文(1)等的有关结果.     

Gain scheduling control of nonlinear singularly perturbed time-varying systems with derivative information

In this paper, we analyse the ultimate boundedness of nonlinear singularly perturbed time-varying systems and propose a control law using gain scheduling where the slow state and the exogenous signals are used as scheduling variables. In our control scheme, we have some flexibility in selecting the slow manifold of the system. Moreover, the derivative information can be properly engaged to manipulate the size of ultimate bound in tracking error of the controlled system.     

二阶具分布时滞的泛函微分方程解的有界性

本文讨论二阶具分布时滞的泛函微分方程,利用不等式的估计得到了解的有界性比较定理。同时还运用李雅普诺夫泛函方法,给出一类二阶具分布时滞的泛函微分方程的有界性判别法则。     

H∞ sliding mode control of discrete switched systems with time-varying delays

The finite-time boundedness issue for a class of discrete switched systems with time-varying delays is investigated via sliding mode control (SMC) approach. By employing the Lyapunov functional and average dwell time method, new sufficient conditions are derived to guarantee the finite-time boundedness of the dynamic system in the novel sliding surface. By solving an optimization problem, the sliding mode controller is synthesized such that the discrete reaching condition is satisfied and the chattering is reduced. A simulation example tests the feasibility of the provided SMC scheme.     

矩阵测度及泛函微分方程关于部分变元的一致最终有界性

本文利用矩阵测度研究了拟线性泛函微分方程关于部分变元的一致最终有界性。通过借助一个推广的拟线性泛函微分方程解的估计，我们得到了一类较广泛的关于部分变元为一致最终有界的充分条件。     

一类差分方程的动力学

本文研究了一类差分方程解的全局稳定性、周期特征及有界性.     

收敛自由空间到序列空间lp（1〈p〈∞）无穷矩阵变换集的有界性

研究了从收敛自由空间到序列空间lp（1〈p〈∞）的无穷矩阵变换有界集的特征．给出从一般的收敛自由空间到序列空间lp（1〈p〈∞）的无穷矩阵变换的一般形式,并进一步指出完全收敛自由空间无穷矩阵变换的一般表达式具有简捷的形式．     

基于Petri网分解技术的自动化物流系统建模分析*

针对西安科技大学自动化物流系统的任务规划,提出了一种基于变迁指标和库所指标融合的Petri网分解方法。采用Petri网理论对该物流系统建立模型,给出定义,在此基础上采用提出的Petri网分解方法得到融合了T网和S网特性的最小子网。通过分析该最小子网,得出Petri网模型的活性和有界性,据此推断出物流系统的任务规划合理有效。该方法大大减少了直接分析子网或原Petri网模型的计算量,可避免全局或局部死锁,为系统良好运行提供了依据。     

On the boundedness of the set of stabilizing controllers

This paper shows that the set of rational, strictly proper, robustly stabilizing controllers for single‐input single‐output linear‐time invariant plants will form a bounded (can even be empty) set in the controller parameter space if and only if the order of the stabilizing controller cannot be reduced any further; if the set of proper stabilizing controllers of order r is not empty and the set of strictly proper controllers of order r is bounded, then r is the minimal order of stabilization. The paper also extends this result to characterize the set of controllers that guarantee some pre‐specified performance specifications. In particular, it is shown here that the minimal order of a controller that guarantees specified performance is l iff (1) there is a controller of order l guaranteeing the specified performance and (2) the set of strictly proper, robustly stabilizing controllers of order l and guaranteeing the performance is bounded. Moreover, if the order of the controller is increased, the set of higher‐order controllers which satisfies the specified performance will necessarily be unbounded. This characterization is provided for performance specifications, such as gain margin and robust stability, which require a one‐parameter family of real polynomials to be Hurwitz, where the parameter is in a closed interval. Other performance specifications, such as phase margin and ℋ︁_∞ norm, can be reduced to the problem of determining a set of stabilizing controllers that renders a family of complex polynomials Hurwitz. The characterization of the set of controllers for the stabilization of complex polynomials is provided and is used to show the boundedness properties for the set of controllers that guarantee a given phase margin or an upper bound on the ℋ︁_∞ norm. Copyright © 2007 John Wiley & Sons, Ltd.