广义双线性系统的输出变结构控制

首次利用广义Lyapunov函数方法针对不确定广义双线性系统的输出变结构控制问题进行研究.首先,选取设计了带有滑动模动态补偿器的切换函数,保证了系统在准切换流形上的渐近稳定性.其次,在不确定参数和扰动范数有界的条件下,设计了变结构控制器,使得在控制下闭环系统在有限时间内实现滑模运动.最后,通过数值算例说明了设计方法的合理性和有效性.     

基于扰动补偿趋近律的非匹配离散广义准滑模控制

研究了非匹配不确定离散广义系统准滑模控制策略的综合问题.给出了具有前级状态向量的动态切换函数,使得系统能够在切换带内稳定.设计了两种带有扰动补偿的离散广义趋近律,消除了常规滑模控制策略中不确定项必须有界的限制,且不必满足匹配条件.给出了系统准滑动模态保持逐步穿越切换面的必要条件,减小了准滑动模态切换带的带宽.所设计的滑模控制器在有限时间内可达切换面,削弱了系统抖振,有效地改善了系统动态品质.最后,数值算例验证了该控制策略的可行性.     

卫星姿态跟踪的间接自适应模糊预测控制

对含模型不确定性和未知干扰的卫星姿态系统提出了具有间接自适应模糊补偿的广义预测跟踪控制方法. 首先基于卫星姿态动力学模型设计了非线性广义预测控制律, 再利用自适应模糊系统逼近预测控制律中的模型不确定项, 使得所得到的预测控制算法可实施.证明了当卫星姿态模型中不确定项满足一定条件时, 所设计的控制律可使卫星姿态跟踪误差收敛到原点的小邻域内,并仿真结果验证了所提出方法的有效性.     

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.     

多时滞线性切换系统的稳定性及其反馈镇定

研究了具有多时滞线性切换系统的稳定性及其反馈镇定问题,利用完备性条件、矩阵分解与二次Lyapunov泛函,给出了多时滞切换系统渐近稳定的充分条件和切换律设计方法.在此基础上,研究了这类系统的镇定控制问题,设计了保证系统时滞独立渐近镇定的控制器.     

时滞切换中立系统的稳定性

针对一类带有分布时滞的切换中立控制系统,研究具渐近稳定性问题.利用Lyapunov函数法给出了在任意切换律条件下系统渐近稳定的充分条件.     

广义不确定系统的终端滑模控制

本文研究了线性广义不确定系统在满足匹配条件下的终端滑模控制的综合设计问题.利用变结构控制方法设计切换函数和终端滑模控制器,获得了在终端滑模控制下,闭环系统的模态在有限时间内到达平衡点的重要结果.克服了传统的变结构控制方法只能保证闭环系统的模态在平衡点渐近稳定,不能实现有限时间到达平衡点的缺点.举例说明了设计方法的合理性和有效性.     

一类不确定离散混杂系统的稳定性

基于切换Lyapunov函数描述了在离散时间下一类不确定的离散混杂系统的L2增益分析以及控制合成问题.运用Lyapunov函数理论以及线性矩阵不等式,给出了一类不确定离散切换系统在任意切换律下的稳定性条件,并构造了反馈控制律使系统达到干扰衰减及内稳定性.     

具外部扰动的变时滞不确定奇异系统的滑动模态控制

研究了含有多个变时滞的不确定奇异系统的滑动模态问题.该系统相比文献中已研究的系统更为复杂,具有多个变时滞,且分别含有匹配和不匹配的外部扰动项.通过对系统进行等价分解化为两个子系统,对分解后的系统进行切换函数的设计,再通过定义Lyapunov函数得到使得系统的滑模运动渐近稳定的充分条件.由此证明了所设计的滑模控制率能够保证状态轨迹在优先时间内被驱动到指定的切换面上且保持运动.设计过程简单,且结果以线性矩阵不等式呈现,相比文献中已有的结论更易于实现.最后通过例子验证结论的正确性.     

高维空间中连接双曲鞍点的异宿环的稳定性

本文考虑任意有限维空间连接两个双曲鞍点的非扭曲异宿环的稳定性问题.在可定义Poincar′e映射的条件下,给出了异宿环在其部分邻域内是渐近稳定的判据,将3维系统鞍点异宿环的稳定性结果推广到了m+n+2维空间中的非扭曲的2-鞍点异宿环,其中m 0,n 0.通过在两个鞍点充分小邻域内,给出系统在适当的线性变换下的第一个规范型,接着采用将局部稳定流形和不稳定流形拉直的变换建立了第二个规范型.然后,在鞍点P1,P2的小邻域内适当选取两个异宿轨道的横截面,并分别分两部分来构造流映射.在鞍点P1,P2的小邻域内,本质上我们利用线性近似系统的流来构造奇异流映射的主部,而在鞍点的邻域外的异宿轨道的小管状邻域内,则用近似于一个非奇异矩阵的微分同胚来获得正则流映射.将四者复合即得到定义于P1小邻域内某横截面上的Poincar′e映射.最后,我们通过技巧性地估计向量的模,给出了在横截面上Poincar′e映射的初始点与首次回归点离异宿轨道与横截面交点的距离之比,由此得到关于非扭曲2-点异宿环的非常简洁的稳定性判据.     

输入通道有干扰多变量MRAC系统全局稳定化控制

对具有未建模动态且输入通道存在干扰的动态不确定多输入多输出(MIMO)模型参考自适应控制(MRAC) 系统，仅应用系统的输入输出量测数据给出了一种变结构模型跟踪控制器设计机制.通过辅 助信号和带有记忆功能的正规化信号,并适当选择控制器参数, 所提出的变结构控制 (VSC)能保证闭环系统的全局稳定性,且跟踪误差可调整到任意小.     

Finite time control of a class of nonlinear switched systems in spite of unknown parameters and input saturation

This article is devoted to the problem of robust stabilization of uncertain nonlinear switched systems with canonical structure. It is assumed that the constant parameters of the subsystems are unknown and cannot be adopted in the controller design. In addition, the dynamics of the subsystems are perturbed via modeling errors and external disturbances. The effects of unknown actuator saturation are compensated via proper adaptive control signals. The derived controller is based on the terminal sliding mode theory and does not need any prior knowledge about the bounds of the lumped uncertain terms. It is proved that once the system states reach the prescribed sliding manifold in a finite time interval, the whole system becomes insensitive to both the lumped uncertainties and the switching dynamics of the system. The common assumption of having known quadratic Lyapunov functions for the subsystems is relaxed and the derived adaptive approach does not force any limitation on the switching signal of the system. Subsequently, non-conservative conditions are provided to guarantee the global finite time bounded stability of the equilibrium state for the overall uncertain nonlinear switched system under arbitrary switching signals. A numerical computer simulation demonstrates the robust performance of the proposed controller.     

输入通道有干扰多变量MRAC系统的全局稳定化控制

对具有未建模动态并且输入通道存在干扰的动态不确定多输入多输出(MIMO)模型参考自适应控制(MRAC)系统,应用输出反馈给出了一种变结构模型跟踪控制器设计．系统的已建模部分有大于1的任意相对阶且已建模部分阶的上界是未知的．通过引入辅助信号和带有记忆功能的正规化信号,以及适当选择控制器参数,保证了闭环系统的全局稳定性,且跟踪误差可调整到任意小．     

Dynamic soft variable structure control of singular systems

The dynamic soft variable structure control (VSC) of singular systems is discussed in this paper. The definition of soft VSC and the design of its controller modes are given. The stability of singular systems with the dynamic soft VSC is proposed. The dynamic soft variable structure controller is designed, and the concrete algorithm on the dynamic soft VSC is given. The dynamic soft VSC of singular systems which was developed for the purpose of intentionally precluding chattering, achieving high regulation rates and shortening settling times enhanced the dynamic quality of the systems. It is illustrated the feasibility and validity of the proposed strategy by a simulation example, and an outlook on its auspicious further development is presented.     

Design of a robust nonlinear controller for a synchronous generator connected to an infinite bus

This article presents a new design of robust finite‐time controller which replaces the traditional automatic voltage regulator for excitation control of the third‐order model synchronous generator connected to an infinite bus. The effects of system uncertainties and external noises are fully taken into account. Then a single input robust controller is proposed to regulate the system states to reach the origin in a given finite time. The designed robust finite‐time excitation controller can refine the system behaviors in convergence and robustness against model uncertainties and external disturbances. The robustness and finite‐time stability of the closed‐loop system are analytically proved using the finite‐time control idea and Lyapunov stability theorem. The suitability and robustness of the designed controller are shown in contrast with two other strong nonlinear control strategies. The main advantages of the proposed controller are as follows: a) robustness against system uncertainties and external noises; b) convergence to the equilibrium point in a given finite time; and c) the use of a single control input. © 2015 Wiley Periodicals, Inc. Complexity 21: 203–213, 2016     

Control and stability analysis of a turbocharged Diesel engine using singular perturbation methods

The control of the air path of a diesel engine with a variable geometry turbocharger and exhaust gas recirculation can be improved significantly by nonlinear methods. The control objective is to supply an amount of fresh air by the compressor and to achieve a desired pressure in the intake manifold in the neighborhood of an operating point of the engine. The mathematical model of the air path is split into a slow and a fast part. For the proposed controller, asymptotic stability of the closed loop system in the sense of Lyapunov is guaranteed by the use of singular perturbation methods. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Robust decentralized adaptive control for uncertain large-scale delayed systems with input nonlinearities

The paper is concerned with the problem of robust stabilization for uncertain large-scale time-varying delayed systems with input nonlinearities. Based on the sliding mode control, a memoryless decentralized adaptive sliding mode controller (DASMC) is developed. The proposed controller ensures the occurrence of the sliding manifold of the composite system even subjected to input nonlinearity. It shows that the uncertain nonlinear large-scale system also possesses the property of insensitivity to uncertainties and disturbances as a linear system does. A numerical example is given to verify the validity of the developed memoryless DASMC.     

自适应模糊变结构控制的研究

本文主要研究一类具有未知常数控制增益的非线性系统的自适应模糊控制问题,提出了一种能够利用专家的语言信息和数字信息的自适应模糊变结构控制器的设计方案。通过理论分析,证明了模糊变结构控制系统是全局稳定的,跟踪误差可收敛到零的一个邻域内