一类不确定离散切换模糊时滞系统的鲁棒非脆弱控制

针对一类不确定离散切换模糊时滞系统,研究了在控制器增益存在摄动情况下的稳定性问题.利用切换技术和多Lyapunov函数方法,并以矩阵不等式形式给出了非脆弱状态反馈控制器存在的充分条件和切换律设计.最后通过数值仿真算例验证了设计方法的有效性和可行性.     

Adaptive fuzzy observer backstepping control for a class of uncertain nonlinear systems with unknown time-delay

In this paper, a new adaptive fuzzy backstepping control approach is developed for a class of nonlinear systems with unknown time-delay and unmeasured states. Using fuzzy logic systems to approximate the unknown nonlinear functions, a fuzzy state observer is designed for estimating the unmeasured states. On the basis of the state observer and applying the backstepping technique, an adaptive fuzzy observer control approach is developed. The main features of the proposed adaptive fuzzy control approach not only guarantees that all the signals of the closed-loop system are semiglobally uniformly ultimately bounded, but also contain less adaptation parameters to be updated on-line. Finally, simulation results are provided to show the effectiveness of the proposed approach.     

Adaptive neural control for strict-feedback stochastic nonlinear systems with time-delay

The problem of robust stabilization is investigated for strict-feedback stochastic nonlinear time-delay systems via adaptive neural network approach. Neural networks are used to model the unknown packaged functions, then the adaptive neural control law is constructed by a novel Lyapunov-Krasovskii functional and backstepping. It is shown that all the variables in the closed-loop system are semi-globally stochastic bounded, and the state variables converge into a small neighborhood in the sense of probability.     

模糊时滞系统的输出反馈控制及其稳定性分析

利用模糊T－S模型对一类不确定非线性时滞系统进行建模，在此基础上，提出了模糊不确定时滞系统的状态反馈控制及其输出反馈控制的设计，并给出了模糊闭环系统渐近稳定的充分条件，基于李亚普诺夫函数和线性矩阵不等式方法，证明了模糊系统的渐近稳定性。     

Robust energy-to-peak filter design for stochastic time-delay systems

This paper considers the robust energy-to-peak filtering problem for uncertain stochastic time-delay systems. The stochastic uncertainties appear in both the dynamic and the measurement equations and the state delay is assumed to be time-varying. Attention is focused on the design of full-order and reduced-order filters guaranteeing a prescribed energy-to-peak performance for the filtering error system. Sufficient conditions are formulated in terms of linear matrix inequalities (LMIs), and the corresponding filter design is cast into a convex optimization problem which can be efficiently handled by using standard numerical algorithms. In addition, the results obtained are further extended to more general cases where the system matrices also contain uncertain parameters. The most frequently used ways of dealing with parameter uncertainties, including polytopic and norm-bounded characterizations, have been taken into consideration, with convex optimization problems obtained for the design of desired robust energy-to-peak filters.     

Adaptive fuzzy tracking control of nonlinear time-delay systems with unknown virtual control coefficients

In this paper, a novel adaptive fuzzy control scheme is proposed for a class of uncertain single-input and single-output (SISO) nonlinear time-delay systems with the lower triangular form. Fuzzy logic systems are used to approximate unknown nonlinear functions, then the adaptive fuzzy tracking controller is constructed by combining Lyapunov-Krasovskii functionals and the backstepping approach. The proposed controller guarantees uniform ultimate boundedness of all the signals in the closed-loop system, while the tracking error converges to a small neighborhood of the origin. An advantage of the proposed control scheme lies in that the number of adaptive parameters is not more than the order of the systems under consideration. Finally, simulation studies are given to demonstrate the effectiveness of the proposed design scheme.     

具有控制时滞的离散系统的无抖振滑模控制

研究含时滞的线性离散系统的变结构控制问题. 首先将之简化为不含时滞项的线性离散系统. 然后对简化系统提出一种新的无抖振滑动模态控制算法. 该算法使滑模控制分为两个阶段,当系统轨迹在滑模某邻域以外时, 利用传统的到达控制律使系统状态轨迹单调趋近滑模面; 当系统轨迹进入该邻域内, 无抖振控制律使其轨迹一步到达滑模面. 该控制律有效地削除了由离散系统解轨迹的不连续性产生的抖振现象. 仿真结果表明了这种方法的有效性.     

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.     

随机不确定时滞系统的鲁棒H∞控制

本文研究了随机不确定时滞系统的鲁棒稳定性与鲁棒H∞控制问题,系统的不确性具有凸多面体形式.利用线性矩阵不等式方法,通过依赖于参数的Lyapunov函数,得到了此类系统鲁棒随机镇定的充分条件.在此基础上,又给出了H∞状态反馈控制器的设计.     

A novel approach to output feedback control of fuzzy stochastic systems

This paper investigates the problem of Hankel-norm output feedback controller design for a class of T–S fuzzy stochastic systems. The full-order output feedback controller design technique with the Hankel-norm performance is proposed by the fuzzy-basis-dependent Lyapunov function approach and the conversion on the Hankel-norm controller parameters. Sufficient conditions are established to design the controllers such that the resulting closed-loop system is stochastically stable and satisfies a prescribed performance. The desired output feedback controller can be obtained by solving a convex optimization problem, which can be efficiently solved by standard numerical algorithms. Finally, a Henon map system is used to illustrate the effectiveness of the proposed techniques.     

双时滞不确定离散系统的满意容错控制

为了满足工业实际中要求容错控制策略不仅保证故障模式下系统的稳定,同时还须满足一定的性能指标或约束条件的要求,针对同时具有状态和控制时滞的不确定离散时滞系统,在一般执行器故障模式下,研究了基于状态反馈的H∞满意容错控制问题,并用仿真示例验证方法的有效性。     

一类时滞广义非线性系统H_∞可靠跟踪控制

讨论一类Lipschitz时滞非线性广义系统的H∞可靠跟踪控制问题.分别给出了执行器失效和传感器失效两种模型下可靠控制器存在的充分条件,使得闭环系统正则无脉冲并且指数稳定,同时系统输出跟踪预先给定的可测参考模型的输出,且满足H∞性能指标,并利用线性矩阵不等式技巧给出了可靠控制器的设计方法.最后给出了一个数值例子,说明了本文所给出方法的有效性.     

一类非线性时滞输出反馈系统的自适应控制

针对一类参数化非线性时滞输出反馈系统,提出了一种无记忆自适应跟踪控制器的设计方案.采用时滞滤波器估计系统状态,用Domination处理非线性时滞项,应用Backstepping技术设计控制器和参数自适应律.放宽了对时滞项的要求.通过构建一个Lyapunov＿Krasoviskii泛函,证明了闭环系统的稳定性,实现了对目标轨线的渐近跟踪,保证了所有信号一致有界.实例仿真说明了该方案的可行性.     

Nonfragile control for a class of uncertain switching fuzzy time-delay systems

A sufficient condition for the existence of nonfragile state-feedback controllers and a switching law for a class of uncertain switching fuzzy time-delay systems are proposed based on the multiple Lyapunov functions technique, under the assumption that the controller gain to be designed has variations. The corresponding results are all formulated in terms of linear matrix inequalities (LMIs). Simulation results show the effectiveness of the design method.     

一类模糊时滞系统指定衰减度的鲁棒控制

研究了一类非线性时滞系统基于模糊T-S模型的鲁棒镇定问题,所考虑的不确定时滞系统含有时变未知但有界的状态时滞,首先利用Razumikhin定理和Lyapunov定理,得出了由模糊T-S模型描述的非线性时滞系统鲁棒稳定且具有指定衰减度的判据,其次得到了具有指定衰减度的无记忆状态反馈控制律存在的充分条件及相应的控制器设计方法,该条件被进一步等价地转化为一个线性矩阵不等式的可解性问题,所设计的控制器确保了闭环系统具有指定衰减度鲁棒稳定。     

Adaptive state feedback control for time-delay stochastic nonlinear systems based on dynamic gain method

This paper studies the adaptive state feedback control for p normal form time-delay stochastic nonlinear systems with unknown parameters by dynamic gain technique. The power order restriction is completely removed and tracking problem is further studied. Through the inductive design method, the virtual controllers are constructed in each step, and the corresponding dynamic gain is introduced to eliminate residual terms generated by the differential operator of Lyapunov–Krasovskii functional in the subsequent step, which is used to deal with the time-delay terms. The unknown parameters are addressed by the modified tuning function method. Based on the constructed adaptive controller, the boundedness of the tracking error and other state variables can be guaranteed. Especially, if the reference signal is zero, the state variables can converge to equilibrium almost surely. Finally, simulation results are presented to illustrate the effectiveness of the proposed method.     

一类状态时滞广义串级控制系统的H∞镇定

针对一类具有状态时滞的广义串级控制系统,研究其H∞控制问题.考虑到当非零扰动作用于系统时采用静态反馈控制对于被控对象的输出具有不足性,从而将串级控制应用于具有状态时滞的广义系统中,并且建立了闭环广义串级控制系统新的模型.提出的方法着重在于串级控制在广义系统中的应用.利用线性矩阵不等式方法得到了相应系统正则、无脉冲和稳定的条件,并进一步利用得到的条件给出了相应的H∞稳定控制器设计方法.最后通过仿真实例说明了所提方法的有效性.     

非参数不确定时滞系统的重复控制

针对非参数不确定时滞系统,给出能够实现跟踪误差本身沿整个周期完全跟踪的重复控制器设计．针对系统不确定特性的界函数已知和未知两种情形,分别分析闭环系统的稳定性与收敛性．控制器中学习部分采用完全饱和形式,使得参数估计囿于一预先给定的范围内．该控制律可保证闭环系统内所有信号有界以及跟踪误差本身趋于零．数值仿真表明算法的有效性．     

一类不确定模糊动态时滞系统保成本控制

针对一类不确定非线性动态时滞系统，利用模相T—S模型，通过状态反馈对保成本控制问题进行研究。应用线性矩阵不等式给出模糊闭环系统渐近稳定的充分条件，保证了所有允许的不确定闭环系统是稳定的，而且对于一个给定的二次型成本函数，舱保证闭环成本不超过某个界。仿真结果表明所提出的控制方法是有效的。     

基于LM I 的一类非线性时滞关联大系统的分散模糊控制

针对一类采用Takagi—Sugeno模糊模型描述的非线性时滞关联大系统，研究其分散模糊状态反馈控制器设计问题；利用Lyapunov稳定性分析理论和线性矩阵不等式等工具，得到了闭环系统的可镇定条件和相应的分散模糊状态反馈控制器；在此基础上，通过求解具有线性矩阵不等式组约束的凸优化问题，给出了具有较小反馈增益的分散模糊控制器设计方法。