一类切换模糊时滞系统的状态反馈控制

针对切换模糊时滞系统,根据平行分布补偿算法,设计了模糊状态反馈控制器.使用切换技术及单Lyapunov函数和多Lyapunov函数方法,给出了这一类切换模糊时滞系统渐近稳定的充分条件及切换律.仿真结果表明了方法的有效性.     

一类切换模糊时滞组合系统的分散镇定

提出了切换模糊时滞组合系统模型,并研究了状态和互联项具有时滞情况下的分散镇定问题.当每个互联子系统中的每个切换子系统具有有限个备选的状态反馈控制器,且单一控制器均不能保证系统稳定的情况下,利用多Lyapunov函数方法给出了时滞相关的矩阵不等式条件和分散切换律设计方法,使系统在所提出的分散切换律和分散控制器下渐近稳定.仿真结果表明了所提出方法的有效性.     

一类离散切换模糊系统的稳定性

针对离散模糊系统,提出一类离散切换模糊系统的稳定性问题.使用切换技术及单Lyapunov函数、多Lyapunov函数方法构造出连续状态反馈控制器,使得相应的闭环系统渐近稳定,同时设计可以实现系统全局渐近稳定的切换律.模型中的每个切换系统的子系统是离散模糊系统,取常用的平行分布补偿PDC控制器,主要条件以凸组合和矩阵不等式的形式给出,具有较强的可解性.计算机仿真结果表明设计方法的可行性与有效性.     

一类带有时滞的不确定广义系统的切换渐近稳定性

研究了一类带有时滞的切换不确定广义系统的鲁棒渐近稳定问题. 利用Lyapunov稳定性定理和线性矩阵不等式(Linear matrix inequality, LMI)工具, 采用多Lyapunov函数技术, 在设定的切换律下, 得到切换不确定广义时滞系统鲁棒渐近稳定的时滞相关充分条件. 进一步, 建立了一个具有线性矩阵不等式约束的凸优化问题, 利用Matlab软件中的LMI工具箱求解, 得到保证切换广义系统鲁棒渐近稳定的最大可允许时滞上界. 最后示例表明了该方法的有效性.     

时滞切换系统稳定性分析与镇定—Lyapunov函数方法

利用Lyapunov函数方法克服“相空间”与“事件空间”之间的不一致,以考虑时滞切换系统稳定性的分析与综合.其一,对将多Lyapunov函数方法推广至时滞情形,由此给出子系统稳定性准则及切换序列的约束条件,使整个系统是指数稳定的.其二,对于不稳定的时滞子系统,提出了保证观测误差在任意切换作用下指数衰减的观测器设计方法,并构造出基于估计状态的切换序列,使状态变量指数收敛.     

具有状态时滞的离散时间切换系统的H∞ 滤波器设计: 依赖状态的切换方法

讨论一类时滞离散时间切换系统的H∞滤波器的设计问题.首先,当所有子系统都稳定时,基于切换Lyapunov函数和Finsler引理,得到了滤波误差系统渐近稳定且具有指定的H∞性能指标的充分条件,即使切换系统的每个子系统均不稳定,通过利用多Lyapunov函数方法和依赖状态的切换技术仍能保证切换系统稳定;然后,设计了H∞滤波器,并得到滤波误差系统满足指定的H∞性能指标的充分条件;最后,通过数值算例验证了所提出方法的有效性.     

一类时滞切换系统的鲁棒控制器设计

研究了一类具有外部干扰的线性时滞切换系统的鲁棒控制器的设计问题.利用完备性和Lyapunov函数方法设计出状态反馈的鲁棒控制器,并设计出切换策略,证明了闭环系统在给定的切换策略下在其平衡点处的渐近稳定性.仿真结果验证了结论的有效性.     

一类不确定切换模糊时滞系统的保性能控制

针对一类存在时滞的不确定切换模糊系统,研究系统的保性能控制问题.利用平行分布补偿算法(PDC)给出保性能控制器的设计方法,利用单Lyapunov函数方法和多Lyapunov函数方法,给出不确定切换模糊时滞系统保性能控制器存在的充分条件和切换律设计.使得闭环系统对所有允许的不确定,在所设计的控制器和切换律下实现保性能控制.仿真结果表明方法的有效性.     

时滞切换系统的时滞依赖稳定

首先利用多Lyapunov 函数方法, 分析常时滞切换系统的时滞依赖稳定性, 并给出此系统时滞依赖稳定的充分条件及切换律的设计; 然后运用共同Lyapunov 函数方法, 研究一类时变时滞切换系统的时滞依赖稳定性, 也给出此系统时滞依赖稳定的充分条件及切换律的设计. 所得结果均可用线性矩阵不等式方法求解. 最后通过仿真验证了结论的正确有效性.     

一类区间时变时滞T-S模糊系统的鲁棒控制

针对一类区同时变时滞T-S模糊系统,研究了其时滞相关渐近稳定性以及控制器设计问题.基于Lyapunov稳定性理论和线性矩阵不等式(LMI)工具,并结合自由权矩阵方法,设计一个包含时滞区间均值在内的新Lyapunov-Krasovskii泛函,给出了改进的时滞T-S模糊系统渐近稳定的时滞相关准则.同时,根据并行分布补偿算法,给出了带有记忆的状态反馈模糊控制器的设计方法.最后,实例仿真表明了方法的有效性.     

Robust control for a class of uncertain switched fuzzy systems

A model of uncertain switched fuzzy systems whose subsystems are uncertain fuzzy systems is presented. Robust controllers for a class of switched fuzzy systems are designed by using the Lyapunov function method. Stability conditions for global asymptotic stability are developed and a switching strategy is proposed. An example shows the effectiveness of the method.     

基于观测器的网络切换模糊时滞系统鲁棒控制

针对带有随机时变时滞的非线性网络切换系统稳定控制问题进行研究,在系统状态不可测且存在不确定性的情况下,采用T-S模型将非线性网络切换系统建模为网络切换模糊系统。然后,采用平均驻留时间法（ADT）,设计出基于观测器的控制器及系统切换律,并给出网络切换模糊系统指数稳定的平均驻留时间条件。结合李雅普诺夫（LKF）方法给出时滞相关的网络切换模糊系统指数稳定的矩阵不等式条件。最后通过MATLAB数值仿真验证了该设计方法的有效性和优越性。     

基于分段多项式李雅普诺夫函数的模糊系统的稳定性分析

本文采用最大型分段多项式李雅普诺夫函数研究了多项式模糊系统的闭环稳定性问题.首先,本文设计了与分段李雅普诺夫函数对应的切换模糊控制器,提出了多项式模糊模型稳定的平方和条件,同时证明了最大型分段多项式李雅普诺夫函数在函数切换点的稳定性.然后,设计了相应的路径跟踪优化算法,对本文非凸的稳定条件进行迭代求解.最后,通过两个算例进行仿真与比较,说明并验证了本文所提出结论的可行有效性.     

基于模糊双线性模型的连续搅拌反应釜滑模控制

主要对连续搅拌反应釜系统(CSTR)的滑模控制问题进行研究;该系统的模型可由Takagi-Sugeno (T-S)模糊双线性模型进行描述,基于该模糊双线性模型,给出滑模控制方法;在之前学者的研究成果上对线性滑模面进行改进,构造积分滑模面,由此设计出的等效控制量与切换控制量,可以保证系统的控制精度;通过对其进行稳定性研究,得到全局稳定的充分条件,并求出滑模面的控制器参数;同时,构造7条模糊规则,采用模糊化方法对切换增益项进行模糊推理,使整体控制量平滑化,也避免系统状态出现抖振现象,实现实际可操作性;最后,连续搅拌反应釜的仿真验证了控制方法的有效性.     

Exponential stability and robust H∞ control of a class of discrete-time switched non-linear systems with time-varying delays via T-S fuzzy model

This paper deals with stability and robust H_∞ control of discrete-time switched non-linear systems with time-varying delays. The T-S fuzzy models are utilised to represent each sub-non-linear system. Thus, with two level functions, namely, crisp switching functions and local fuzzy weighting functions, we introduce a discrete-time switched fuzzy systems, which inherently contain the features of the switched hybrid systems and T-S fuzzy systems. Piecewise fuzzy weighting-dependent Lyapunov–Krasovskii functionals (PFLKFs) and average dwell-time approach are utilised in this paper for the exponentially stability analysis and controller design, and with free fuzzy weighting matrix scheme, switching control laws are obtained such that H_∞ performance is satisfied. The conditions of stability and the control laws are given in the form of linear matrix inequalities (LMIs) that are numerically feasible. The state decay estimate is explicitly given. A numerical example and the control of delayed single link robot arm with uncertain part are given to demonstrate the efficiency of the proposed method.     

Dynamic switching based fuzzy control strategy for a class of distributed parameter system

In this work, a dynamic switching based fuzzy controller combined with spectral method is proposed to control a class of nonlinear distributed parameter systems (DPSs). Spectral method can transform infinite-dimensional DPS into finite ordinary differential equations (ODEs). A dynamic switching based fuzzy controller is constructed to track reference values for the multi-inputs multi-outputs (MIMO) ODEs. Only a traditional fuzzy logic system (FLS) and a rule base are used in the controller, and membership functions (MFs) for different ODEs are adjusted by scaling factors. Analytical models of the dynamic switching based fuzzy controller are deduced to design the scaling factors and analyze stability of the control system. In order to obtain a good control performance, particle swarm optimization (PSO) is adopted to design the scaling factors. Moreover, stability of fuzzy control system is analyzed by using the analytical models, definition of the stability and Lyapunov stability theory. Finally, a nonlinear rod catalytic reaction process is used as an illustrated example for demonstration. The simulation results show that performance of proposed dynamic switching based fuzzy control strategy is better than a multi-variable fuzzy logic controller.     

Adaptive fuzzy output-feedback fault-tolerant tracking control of a class of uncertain nonlinear switched systems

ABSTRACT

This paper considers the output-feedback fault-tolerant tracking control problem for a class of uncertain nonlinear switched systems with nonlinear faults and strict-feedback form, where the faults which are nonaffine occur on the actuator. As a kind of specialised function approximating tool, fuzzy logic systems (FLSs), are employed to approximate the unknown smooth nonlinear functions. A switched fuzzy observer is designed to address the problem of unmeasurable states, filtered signals are used to address algebraic loop problem and the average dwell time (ADT) method is further utilised to prove the stability of the resulting closed-loop systems under a type of slowly switching signals. Based on the backstepping recursive design technique and Lyapunov function method, an adaptive fuzzy output-feedback control scheme is developed. The developed control method can ensure all the signals are semi-globally uniformly ultimately bounded (SGUUB) and the system output tracks the reference signal tightly even if unknown fault occurs. A simulation carried on an example demonstrates the validity of the obtained control scheme.     

基于新型切换模糊系统的控制方法研究

提出一类新型的切换模糊系统,即以聚类型模糊集合为基础的切换模糊系统.模糊模型的前件采用聚类型模糊集合和隶属度函数的形式.在研究中,首先讨论聚类型模糊集合的切换模糊系统形式和机理;然后,使用多Lyapunov函数给出离散切换模糊系统在满足最小驻留时间切换策略下的指数稳定性条件,并设计出切换律;最后,通过仿真实例验证所提出方法的有效性.