T-S模糊系统输出直接反馈控制器设计

讨论了T-S模糊系统输出直接反馈控制器的稳定性分析和设计方法。为了减小稳定性分析的保守性和难度,充分利用模糊规则前件变量模糊隶属度函数的结构信息,对前件变量采用标准模糊分划的T-S模糊系统输出直接反馈控制器进行了研究,获得了稳定性条件。在稳定性分析的基础上,采用平行分布补偿法(PDC)和线性矩阵不等式方法(LMI),研究了输出直接反馈控制器的设计。通过对一个非线性质量块-弹簧-阻尼器系统输出反馈控制器的设计和计算机仿真,验证了方法的有效性。     

大型不确定前馈型系统的分散鲁棒镇定

研究了大型不确定前馈型系统的鲁棒分散镇定问题。因为系统具有前馈型结构,采用自下而上的迭代分析方法,同时注意运用互联非线性系统有界性和稳定性判据。将设计任务转化为镇定底层子系统和其他子系统的标称部分,并可以明确构造简单的饱和控制律。该方法利用系统的结构特性,不太依赖李雅普诺夫函数,也不需要通常的LMI技巧。仿真说明该方法的有效性。     

Robust H∞ control for uncertain stochastic saturating systems with time delays

The robust H∞ control problem for uncertain stochastic time-delay systems containing nonlinear actuators is considered. The uncertainties in the systems are assumed to satisfy specific match condition. The time delays exitst in state as well as control input. The new stochastic robust stabilization criterion and a sufficient condition for the existence of stochastic robust stabilizing control law are derived. The delay-independent memoryless robust H∞ controllers are constructed to stabilize the given systems in terms of a group of linear matrix inequalities. A numerical simulation example is presented to show that the proposed approach is valid.     

非线性时变系统的部分指数稳定性分析

讨论了非线性时变系统平凡解的部分指数稳定性和全局部分指数稳定性。分别利用数量与向量Lyapunov函数并结合数量与向量比较原理,得到了保证系统平凡解部分指数稳定和全局部分指数稳定的一系列充分条件。作为特殊情形,对于一类定常拟线性系统,在一定的条件下,若其对应的线性系统的平凡解是部分渐近稳定的,利用二次型Lyapunov函数得到了保证拟线性系统的平凡解是全局部分指数稳定的一个代数判据,这些结果在实际应用中具有一定的指导意义。最后用两个数值例子对所得主要结果加以阐明。     

基于LMI的连续时间模糊大系统的分散镇定

讨论了连续时间模糊大系统的分散镇定问题。整个模糊大系统由m个相互关联的T-S子模糊系统组成。基于李亚普诺夫稳定性理论及大系统分散控制理论,将单个模糊系统的稳定性条件推广到关联模糊大系统的情形,给出了保证该模糊大系统闭环渐近稳定的分散化并行分布补偿(decentralizedparalleldistributedcompensation,DPDC)控制器的设计方法。这些分散控制器的存在条件均以LMI的形式出现,因此可通过Matlab的LMI工具箱有效地对其进行求解。仿真例子说明了所提方法的有效性。     

Delay-dependent stability and stabilization of a class of linear switched time-varying delay systems

The stability and stabilization of a class of linear switched time-varying delay systems are investigated. A piecewise quadratic Lyapunov function (PWQLF) is constructed and is used to obtain the stability conditions based on the linear matrix inequalities (LMIs). The stabilizing controller for this class of system is then designed and the solution of the desired controller can be obtained by a cone complementary linearization algorithm. Numerical examples are provided to illustrate the less conservativeness of the new stability and the validity of the controller design procedures.     

Stabilization of coupled pde-ode systems with spatially varying coefficient

The paper is concerned with the stabilization of a class of coupled PDE-ODE systems with spatially varying coefficient, via state-feedback or output-feedback. The system is more general than that of the related literature due to the presence of the spatially varying coefficient which makes the problem more difficult to solve. By infinite-dimensional backstepping method, both state-feedback and output-feedback stabilizing controllers are explicitly constructed, which guarantee that the closed-loop system is exponentially stable in the sense of certain norm. It is worthwhile pointing out that, in the case of output-feedback, by appropriately choosing the state observer gains, the severe restriction on the ODE sub-system in the existing results is completely removed. A simulation example is presented to illustrate the effectiveness of the proposed method.     

关于一类线性时不变切换系统的脉冲控制

针对一类线性时不变脉冲切换系统,利用Lyapunov函数导出了一种有效的控制方法.首先,建立了这类系统在任意切换率下稳定与渐近稳定的充分条件;然后,给出了这类系统在设定的切换率下指数稳定的判别准则;最后,给出了一个数值例子及仿真来阐明结论的正确性.     

新分段分数阶混沌系统的同步控制

通过改变修正的Lorenz-Stenflo (modified Lorenz-Stenflo, MLS)混沌系统的分段函数项,得到了一个新的四维分段混沌系统。新系统较MLS混沌系统具有更低的分数阶维数,在3.44阶时仍具有混沌特性。根据分数阶系统的线性稳定性理论和非线性反馈控制方法,提出了新分数阶系统的状态同步方法。通过理论推导,得到了两个混沌系统的同步稳定条件。控制器能够自适应地根据误差大小调节反馈系数,缩短同步时间。最后对3.6阶的分数阶系统进行了同步仿真实验,仿真结果验证了改进算法能够加快同步速度。     

基于自适应同步的超混沌Chen系统的参数识别

为了研究超混沌Chen系统的完全同步及未知参数的识别及优化问题,利用两个线性控制器实现参数匹配的两个超混沌Chen系统的完全同步,研究了参数未知的超混沌Chen系统的参数辨识及优化问题,基于Lyapunov稳定性理论,解析地获得同步控制器和参数观测器表达式,其中的控制器个数低于系统维数。研究结果表明:当两个超混沌系统达到完全同步后,驱动系统的5个未知参数被准确识别。该方法在驱动系统的参数发生跃变的情况下也是有效的。     

Decentralized robust stabilization of discrete-time fuzzy large-scale systems with parametric uncertainties: a LMI method

1. INTRODUCTION Large-scale dynamic system theory has been intensi- vely studied during the past decade[1～3], but for fuzzy large-scale systems, namely large-scale systems comp- osed of a series of fuzzy subsystems, has been seldom done in literature. In Ref.[4], decentralized stabiliz- ation problem of fuzzy large-scale systems composed of a series of fuzzy subsystems was considered. Sufficient conditions for asymptotic stability of the fuzzy large-scale system and design methods of dec…     

连续多时滞系统的保成本H∞容错控制

针对状态具有多个时滞的线性连续系统,基于Lyapunov稳定性理论和线性矩阵不等式方法,研究了在执行器发生故障的情况下,连续多时滞系统的保成本H_∞容错控制问题。首先,在无外部扰动时,得到了系统存在容错控制器的一个充分条件|其次,得到了系统存在保成本容错控制器的一个充分条件|最后,在有外部扰动时,得到了系统存在H_∞容错控制器的一个充分条件。进一步,得到了系统存在保成本H_∞容错控制器的一个充分条件以及该控制器的设计方法。仿真结果证明了该方法的正确性和有效性。     

Stability analysis of decentralized adaptive backstepping control systems with actuator failures

In this paper, the authors analyze the stability of a class of interconnected systems with subsystem unmodeled dynamics and dynamic interactions employing decentralized adaptive controllers designed by Wen, Zhou, and Wang (2008) in the presence of actuator failures. It will be shown that the global stability of the remaining closed-loop system is still ensured and the outputs are also regulated to zero when some subsystems break down.     

Design of saturated controllers for linear singular systems

1.INTRODUCTION Singularsystemsaredynamicalsystemswhosebehav iorsaregovernedbybothdifferentialequationsand algebraicequations.Suchsystemariseinelectrical networks,powersystems,large scalesysem,optimal controlproblems,somepopulationgrowthmodels andsoon.Theproblemofcontrollerdesignforsin gularsystemshasbeenrecentlyresearchedbymany authors[1～3].Theseresearcheswellnearastationary operatingpointwhenitisregulatedbyPID,LQ,or otherlinearcontrollers.Thecontrollawcanbecho sensuchthattheconstra…     

时延通信网络的新型指数稳定跟踪控制器设计

针对一个具有单瓶颈和多用户的高速通信网络,提出了一个新的指数稳定跟踪控制器的设计方法。将闭环数据率控制系统描述为一个连续时间时变时滞系统,基于线性矩阵不等式(LMI)技术和Lyapunov方法给出了闭环系统时滞依赖的指数稳定充分条件。导出了状态反馈控制器的设计方法,使得实际网络带宽分配率和实际队列长度在该控制器的作用下分别以指数速度跟踪上给定的参考值,从而有效降低了数据包丢失率,提高了网络利用率。通过在闭环系统指数稳定条件的导出过程中引入自由变量的方法使得得到的时滞依赖条件具有更小的保守性,并且闭环系统具有更快的指数稳定跟踪速度。仿真算例验证了本文方法的有效性和优越性.     

Robust Feedback Controller for Exponential Stability of Nonlinear Systems with Mismatched Uncertainties

The robust stabilization of nonlinear systems with mismatched uncertainties is investigated. Based on the stability of the nominal system, a new approach to synthesizing a class of continuous state feedback controllers for uncertain nonlinear dynamical systems is proposed. By such feedback controllers, the exponential stability of uncertain nonlinear dynamical systems can be guaranteed. The approach can give a clear insight to system analysis. An illustrative example is given to demonstrate the utilization of the approach developed. Simulation results show that the method presented is practical and effective.     

New Bezout Identity and Parameterizationof All Properly Stabilizing NormalControllers for Singular Systems

1IntroductionWeconsiderthefollowinglineartime-invariantsquaresillglllarsystem:wherexER",,ueR",yER'.ThematrixEmaybesingularwitllrallkE<7t.TOguarallteethatsystem(1.1)hasauniquesolution,wehereafterassumethatitisregular,l.e.,sEC,det(sE--A)gi0.whenE=I,system(1.1)isdegeneratedilltoanorlualone.Forsimplicity,(E,A,B,C,D)isusedtodellotesystem(1.1)and(A,B,C,D)isusedtodenotea11ormalsystem(In,A,B,C,D).TheInatrixDisoftentermeddirectcontrolfeedthrough(DCF).Inthelastseveralyears,considerableatte…     

Partial stability of a class of large-scale systems with partiallystable isolated subsystems

1.INTRODUCTION Partialstability(i.e.stabilitywithrespecttopartof thesystem’sstatevariables)playsanimportantrole instudyingofcontroltheoryanditsapplica tions[1～8],becausethestabilityofahigher order equationsisjustequivalenttothatofpartialstate variablesofacorrespondingsystemsoftheequations.Forsomeproblems,onemaybeinterestedonlyin somevariables,andinmethodologyitisverydifficult tosolveonceandforalltheproblemsabouthigher di mensionalsystems.Forexample,inmultispecies populationinteractionswh…     

Resilient predictive control for a class of uncertain time-delay systems

In practice, gain perturbations of controllers which are caused by actuator degradation and other reasons often lead to performance degradation. They are capable of violating the closed-loop stability. For a system with constrained inputs, the actual controllers might exceed their limits because of gain perturbations. By the reason, this article considers the problem of resilient predictive control for a class of uncertain time-delay systems. By describing the gain perturbation as a time-varying uncertainty, the sufficient conditions to ensure the closedloop stability and the input constraints are derived. Additionally, an approach to design the resilient predictive controllers is presented in terms of LMI. Finally, the simulation shows that the proposed approach is very effective.     

On PID Control Theory for Nonaffine Uncertain Stochastic Systems

PID(proportional-integral-derivative) control is recognized to be the most widely and successfully employed control strategy by far. However, there are limited theoretical investigations explaining the rationale why PID can work so well when dealing with nonlinear uncertain systems.This paper continues the previous researches towards establishing a theoretical foundation of PID control, by studying the regulation problem of PID control for nonaffine uncertain nonlinear stochastic systems. To be ...