具有零动态仿射非线性系统控制Lyapunov函数的构造

研究具有零动态仿射非线性系统控制Lyapunov函数的构造问题.提出通过求解一个Lyapunov方程获得可线性化部分的二次型控制Lyapunov函数.由可线性部分的控制Lyapunov函数和零动态部分的Lyapunov函数,通过构造一个正定函数,得到了整个系统的控制Lyapunov函数,且设计了可半全局镇定整个闭环系统的控制律.仿真实例说明了所提出方法的有效性.     

基于鲁棒控制Lyapunov 函数的非线性预测控制

针对一类约束不确定性非线性仿射系统,提出一种可保证闭环系统鲁棒镇定的非线性模型预测控制算法.利用鲁棒控制Lyapunov函数得到改进的Sontag公式,并以此为基础,构造一种计算有效的单自由度鲁棒预测控制器.以Matlab语言为仿真工具,对一开环不稳定振荡器进行了仿真研究,结果表明,利用该控制算法得到的闭环系统不仅渐近稳定于原点,而且所得控制量和系统状态都满足系统约束,从而验证了控制算法的有效性.     

基于量化依赖Lyapunov函数的有界丢包网络控制系统的保成本控制

研究了一类具有有界丢包的网络控制系统（Networked control systems,NCSs）的保成本控制问题,提出了一种包含量化反馈的网络控制系统数学模型,该模型将系统的镇定问题转化为镇定一系列子系统的鲁棒控制问题.在对网络控制系统的分析中,区别于常用的二次型Lyapunov函数,本文采用了一种新的且能够降低保守性的量化依赖Lyapunov函数方法.基于本文的Lyapunov函数,得到了充分考虑丢包过程的保成本控制器的设计方法.仿真算例验证了所给出方法的有效性.     

具有状态和控制滞后的线性时变时滞系统的输出反馈镇定

研究具有状态和控制滞后的线性时变时滞系统的静态输出反馈镇定,其设计过程只需解一个特殊的代数Ｒｉｃｃａｔｉ方程。并且指出,系统的动态输出反馈镇定问题可等价为广义系统的静态输出反馈镇定问题。最后通过实例论证了本方法的有效性。     

带有未知参数的惯性轮摆系统的自适应控制

针对带有未知参数的惯性轮摆系统,提出了一种自适应控制律设计方法。首先利用坐标变换将惯性轮摆系统的动力学模型转化为级联系统的形式。然后,针对系统参数未知的问题,在已有的惯性轮摆系统反馈控制律的基础上,利用控制器迭代设计思想,设计了惯性轮摆系统的自适应控制律,并利用李雅普诺夫稳定性理论证明了所得自适应控制律可以使得带有未知参数的惯性轮摆系统保持在摆杆垂直向上的平衡状态。最后以一个实际的惯性轮摆系统为例,采用该系统的物理参数进行仿真,分析了不同自适应参数下惯性轮摆系统各状态的收敛速度及摆起和稳定时间。仿真结果验证了所设计自适应控制器能够使惯性轮摆系统从垂直向下的平衡位置摆起并稳定在垂直向上的平衡位置。     

一类线性切换系统的鲁棒状态反馈镇定

考虑一类标称系统存在共同Lyapunov函数的切换系统的鲁棒镇定问题。在不确定性不满足匹配条件下,设计出鲁棒状态反馈控制器,并在给定的切换策略下,确保闭环系统在其平衡点处渐近稳定。仿真结果表明所设计控制器是有效的。     

结构不确定性线性多变量系统鲁棒控制*

本文回顾了结构不确定性线性多变量系统鲁棒控制的分析与设计中,过去与近来对系统稳定鲁棒和性能优化方面的进展。无论对于频域描述研究的方法,还是对于时域描述研究的结果,本文均加以讨论与评价。本文还着重讨论了很有前途的结构不确定性线性多变量系统鲁棒控制的H~∞与μ方法,并探讨了将来的研究方向。     

基于障碍Lyapunov 函数的输出有界全局收敛鲁棒控制

为了克服基于障碍Lyapunov函数反演控制方法在输出约束控制中约束变量收敛区间小和要求模型精确已知的缺陷,提出一种输出有界且全局收敛的鲁棒控制策略。将收敛区间扩展到全局,并使输出保持在约束区间内;同时消除了由未知干扰和模型不确定性引起的稳态误差,放宽了对指令信号连续可导的限制。应用于电动舵机位置伺服控制的仿真结果表明,舵面能够全局稳定且摆幅有界,稳态无静差,动态响应快,抗扰动能力强。     

多重线性单输入系统的同时镇定

本文研究了多重单输入系统的同时状态反馈镇定问题，证明了r 1个单输入系统的同时镇空问题等价于r个系统用一个Hurwitz反馈向量同时镇定的问题，并对2个系统的情况给出了一个设计的例子。     

关于正切换系统的共同线性copositive Lyapunov函数

研究了正线性系统的共同线性copositive Lyapunov函数。首先,基于几何性质给出了关于一对二阶正线性系统的定理的另一种证明。通过新的证明方法,把结果推广到有限个二阶正线性系统的情况.然后对三阶情况给出了一个结果。最后,对高阶的正线性系统给出了一些结果。     

Asymptotic feedback stabilization: A sufficient condition for the existence of control Lyapunov functions

In this paper we study the feedback stabilization problem for a wide class of nonlinear systems that are affine in the control. We offer sufficient conditions for the existence of ‘Control Lyapunov functions’ that according to [3,23] and [28–30] guarantee stabilization at a specified equilibrium by means of a feedback law, which is smooth except possibly at the equilibrium. We note that the results of the paper present a local nature.     

同时镇定一族带有不确定参数的多输入非线性系统

Simultaneous stabilization for a collection of multi-input nonlinear systems with uncertain parameters is dealt with in this paper. A systematic method for obtaining a control Lyapunov function (CLF) is presented by solving the Lyapunov equation. A sufficient condition that a quadratic CLF is a common CLF for these systems is acquired. A continuous state feedback is designed to simultaneously stabilize these systems. Finally, the effectiveness of the proposed scheme is illustrated by a simulation example.     

Stabilization via dynamic output feedback for systems with output nonlinearities

The problem of asmptotically stabilizing a class of systems by means of continuous output feedback is considered. These systems are characterized by nonlinear terms, depending only on the ouputs. It is shown that for these systems stabilization via continuous state-feedback plus stabilization via output injection imply stabilization via continuous dynamic output-feedback. This generalizes a well-knwon result for linear systems.     

Parametric quadratic stabilizability of uncertain nonlinear systems

The objective of this paper is to introduce the notion of parametric quadratic stabilizability (PQ-stabilizability) of nonlinear control systems

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. When we consider nonlinear systems, reference inputs and disturbances may alter dynamics in an essential way by moving the equilibrium to a new location, or destroying it altogether. For this reason, when we consider quadratic stabilizability (Q-stabilizability) of nonlinear systems, we need to combine the two concepts of parametric stability and Q-stabilizability, and consider PQ-stabilizability. When nonlinear function φ belongs to a subclass of passive functions, it is shown that the necessary and sufficient condition for quadratic stabilizability (Q-stabilizability) of linear systems via dynamic state feedback, which was derived by Zhou and Khargonekar, is also a necessary and sufficient condition for that of nonlinear systems considered in this paper. Moreover, when nonlinear function φ belongs to a subclass of incresing functions and when ΔB = 0, it shown that the necessary and sufficient condition for Q-stabilizability of linear systems via static state feedback, which was derrived by Petersen, is also a necessary and sufficient condition for that of nonlinear systems considered in this paper.     

Stabilization of Nonlinear Systems with Filtered Lyapunov Functions and Feedback Passivation

In this paper a generalized class of filtered Lyapunov functions is introduced, which are Lyapunov functions with time‐varying parameters satisfying certain differential equations. Filtered Lyapunov functions have the same stability properties as Lyapunov functions. Tools are given for designing composite filtered Lyapunov functions for cascaded systems. These functions are used to design globally stabilizing dynamic feedback laws for block‐feedforward systems with stabilizable linear approximation.     

Further remarks on strict input-to-state stable Lyapunov functions for time-varying systems

We study the stability properties of a class of time-varying non-linear systems. We assume that non-strict input-to-state stable (ISS) Lyapunov functions for our systems are given and posit a mild persistency of excitation condition on our given Lyapunov functions which guarantee the existence of strict ISS Lyapunov functions for our systems. Next, we provide simple direct constructions of explicit strict ISS Lyapunov functions for our systems by applying an integral smoothing method. We illustrate our constructions using a tracking problem for a rotating rigid body.