连续不确定模糊系统的静态输出反馈控制

对于一类状态矩阵、输入矩阵和扰动输入矩阵中均含有不确定项的连续T-S模糊系统,研究其静态输出反馈控制问题.用矩阵不等式的形式给出了该模糊系统可通过静态输出反馈控制稳定的充分条件,并将矩阵不等式的条件转化为迭代线性矩阵不等式,同时给出了相应的迭代算法.最后用数值仿真例子说明了该算法的有效性和收敛性.     

LMI-based robust iterative learning controller design for discrete linear uncertain systems

This paper addresses the design problem of robust iterative learning controllers for a class of linear discrete-time systems with norm-bounded parameter uncertainties. An iterative learning algorithm with current cycle feedback is proposed to achieve both robust convergence and robust stability. The synthesis problem of the proposed iterative learmng control （ILC） system is reformulated as a γ-suboptimal H-infinity control problem via the linear fractional transformation （LFT）. A sufficient condition for the convergence of the ILC algorithm is presented in terms of linear matrix inequalities （LMIs）. Furthermore, the linear wansfer operators of the ILC algorithm with high convergence speed are obtained by using existing convex optimization techniques. The simulation results demonstrate the effectiveness of the proposed method.     

H∞ approach to monotonically convergent ILC for uncertain time-varying delay systems

This paper deals with iterative learning control (ILC) design for uncertain time-delay systems. Monotonic convergence of the resulting ILC process is studied, and a sufficient condition within an H_∞-based framework is developed. It is shown that under this framework, delay-dependent conditions can be obtained in terms of linear matrix inequalities (LMIs), together with formulas for gain matrices design. A numerical example is provided to illustrate the effectiveness of the robust H_∞-based approach to ILC designed via LMIs.     

Design of robust output-feedback repetitive controller for class of linear systems with uncertainties

Repetitive control, which adds a human-like learning capability to a control system, is widely used in many fields. This paper deals with the problem of designing a robust repetitive-control system based on output feedback for a class of plants with time-varying structured uncertainties. A continuous-discrete two-dimensional hybrid model is established that accurately describes the features of repetitive control so as to enable independent adjustment of the control and learning actions. A sufficient conditi...     

线性定常时滞系统的鲁棒控制

在建立线性定常时滞系统模型的基础上,给出了时滞系统是独立鲁棒稳定的条件,并利用Lyapunov理论给予一些定理的证明,同时设计出了使闭环系统时滞独立鲁棒稳定的状态反馈控制器（即时滞独立鲁棒镇定问题）,最后给出的一个数值例子中用Matlab编程求出了符合条件的正定矩阵和控制律,从算例结果验证了所得出的结论。     

Feedback min–max model predictive control using robust one-step sets

A solution to the infinite-horizon min–max model predictive control (MPC) problem of constrained polytopic systems has recently been defined in terms of a sequence of free control moves over a fixed horizon and a state feedback law in the terminal region using a time-varying terminal cost. The advantage of this formulation is the enlargement of the admissible set of initial states without sacrificing local optimality, but this comes at the expense of higher computational complexity. This article, by means of a counterexample, shows that the robust feasibility and stability properties of such algorithms are not, in general, guaranteed when more than one control move is adopted. For this reason, this work presents a novel formulation of min–max MPC based on the concept of within-horizon feedback and robust contractive set theory that ensures robust stability for any choice of the control horizon. A parameter-dependent feedback extension is also proposed and analysed. The effectiveness of the algorithms is demonstrated with two numerical examples.     

具有控制约束的网络控制系统的鲁棒H_∞控制

针对具有控制约束的网络控制系统(Networked Control Systems,NCS)的特点,建立了具有外部扰动的网络控制系统模型,对其H∞性能加以分析和研究,并验证所取得的理论成果.假设具有控制约束的网络控制系统的H∞控制器与执行器均为事件驱动,传感器为时间驱动,且网络诱导时延小于传感器的采样周期,然后将此类网络控制系统的广义被控对象建模为一类线性离散系统,运用Lyapunov函数和线性矩阵不等式(LMI),导出闭环系统渐近稳定且满足给定H∞性能指标的充分条件,并给出了控制器的具体求法.得到了系统的H∞控制器存在条件及具体方法,通过设计该控制器,使具有外部扰动的网络控制系统的性能有很大的改善,通过Matlab仿真证明该控制器行之有效.     

一类非仿射系统的鲁棒控制

考虑汽车转向控制中出现的微分包含系统的控制问题。首先用一非仿射不确定系统来描述这一微分包含系统，基于耗散理论分析了这一类非仿射不确定系统的鲁棒控制问题。并针对该非线性系统的有界性，给定系统鲁棒稳定的充分条件是满足一线性矩阵不等式，最后给出了一个仿真计算实例以验证算法的有效性。     

多输入/多输出系统动态矩阵控制鲁棒稳定性

研究了基于脉冲响应模型的动态矩阵预测控制(DMC)算法,针对多输入、多输出(MIMO)系统脉冲响应模型的特点,利用脉冲响应系数误差矩阵范数平方和定义预测模型的模型误差,以线性矩阵不等式(LMI)的形式提出了DMC闭环鲁棒稳定充要条件,将DMC算法闭环稳定问题转换为一类线性矩阵不等式的可解问题.并且研究了模型误差与闭环系统稳定性之间的关系,给出了保证系统稳定条件下模型误差界的求取方法,通过求解一个线性矩阵不等式约束的凸优化问题得到保证闭环系统稳定的误差界.最后,利用算例对本文方法的有效性进行了验证.     

一类带调节因子的状态反馈控制设计

讨论了线性时滞系统带调节因子的状态反馈控制问题. 减小调节因子时, 所允许的时滞范围将得到扩大. 时滞固定时, 不同的调节因子导致不同的反馈增益, 从而可以通过选取合适的调节因子来优化闭环系统的动态性能. 通过设计调节因子的自适应律, 并将其引入到反馈增益存在的条件中, 得到了实时变化的反馈增益. 与用固定反馈增益所取得的控制效果相比较, 本文方法具有更弱的保守性, 且系统的动态性能更优. 仿真示例验证了本文方法的有效性.     

直接多模型自适应控制器设计——LMI方法

本文将线性矩阵不等式(LMI)方法引入直接多模型自适应控制, 将直接多模型控制器的设计过程转化为求解线性矩阵不等式的可行解问题,同时给出在不同不确定参数范围内的多个状态反馈控制器,并由此构成直接多模型自适应控制器．同时将直接多模型自适应控制推广到多输入多输出被控对象的设定值跟踪问题,并给出稳定性分析结果．     

迭代学习控制在线性时变系统终端控制问题中的应用研究

An iterative learning control algorithm based on shifted Legendre orthogonal polynomials is proposed to address the terminal control problem of linear time-varying systems. First, the method parameterizes a linear time-varying system by using shifted Legendre polynomials approximation. Then, an approximated model for the linear time-varying system is deduced by employing the orthogonality relations and boundary values of shifted Legendre polynomials. Based on the model, the shifted Legendre polynomials coefficients of control function are iteratively adjusted by an optimal iterative learning law derived. The algorithm presented can avoid solving the state transfer matrix of linear time-varying systems. Simulation results illustrate the effectiveness of the proposed method.