时变非线性不确定系统H∞鲁棒模型预测控制

针对输入受限的时变不确定非线性系统,提出一种H∞鲁棒模型预测控制策略。假设线性化系统矩阵一致有界,将非凸的无穷时域优化问题转化为带有单个线性矩阵不等式(LMI)约束的凸优化问题,降低控制量求解难度。结合滚动优化原理与H∞控制方法在线极小化性能指标,使得闭环系统满足控制性能和约束。在LMI框架下给出H∞NMPC的求解方法及其鲁棒稳定性充分条件。仿真实验对比验证了该策略的有效性。     

具有时延和丢包的NCS鲁棒H∞控制

针对一类含有不确定参数的网络控制系统(NCS),研究网络中存在时延与丢包情况下的鲁棒?∞控制问题.构造一个新的Lyapunov-Krasovskii泛函,并基于改进的Wirtinger不等式推导出闭环NCS渐近稳定且满足?∞性能的充分条件,该条件能得到比已有文献保守性更小的结果.给出线性锥补算法以实现次优鲁棒?∞控制器增益的求解.最后通过多个数值实例验证了所提出方法的有效性.     

不确定性时滞系统H∞鲁棒保性能控制

在Riccati不等式的基础上,给出鲁棒保性能H∞不确定性时滞系统的定义.然后以性能指标上界最小为优化命题设计状态反馈控制器,使得闭环系统不仅对容许的参数不确定性以及时变时滞保持渐近稳定,而且具有给定H∞干扰衰减度以及保性能上界最优.数值实例及仿真结果表明了该方法的有效性和可行性.     

不确定线性时变时滞系统的鲁棒H∞ 滤波

研究一类不确定线性连续时滞系统的改进鲁棒H∞滤波问题.采用时滞分解方法,构造一种新的Lyapunov-Krasovskii泛函,并基于一种积分不等式讨论了确定性系统的H∞性能分析问题.然后,借助于线性化技术,以线性矩阵不等式(LMI)的形式给出了滤波器存在的充分条件,并将确定性系统滤波器设计方法扩展到凸多面体不确定性情形.最后通过仿真算例说明了该方法的有效性.     

基于参数依赖滚动时域H∞控制的高超声速飞行器控制

针对输入受限的高超声速飞行器强耦合、强非线性以及严重不确定性的特点,提出一种参数依赖滚动时域?∞控制(PD-RHHC)的方法.首先在考虑控制输入约束的条件下,引入参数依赖Lyapunov函数和松弛因子并提出了基于LMI优化的PD-RHHC;然后采用函数替换方法,结合张量积模型转换方法实现高超声速飞行器(HSV)纵向非线性弹性模型的LPV描述,并将PD-RHHC应用到高超声速飞行器纵向控制中,以实现HSV在大飞行包线内的机动飞行;最后通过仿真实验验证了所提出算法的有效性.     

不确定多智能体互联动态系统分布式鲁棒H∞协同控制

研究一类具有时延和切换拓扑的不确定多智能体互联系统的分布式协同控制问题,提出一类分布式鲁棒H∞协同控制器.该控制器能够在满足期望的H∞性能指标的前提下,使得所有智能体鲁棒地跟踪虚拟Leader.针对所提出的分布式H∞协同控制器,借助Lyapunov-Krasovskii泛函,利用线性矩阵不等式,推导出一系列充分(必要)条件,并且在通信拓扑连通的前提条件下,给出整个闭环系统的稳定性证明.仿真实例表明了所提出方法的有效性.     

参数不确定性奇异系统的鲁棒H∞控制

利用线性矩阵不等式,通过引入广义二次可镇定且具有H∞性能指标的概念,得到了在状态反馈作用下,参数不确定性奇异系统鲁棒H∞控制律的存在条件.所得的状态反馈控制律保证闭环系统正则、无脉冲、稳定且满足给定的H∞性能指标.     

一类具有范数有界的非线性不确定性时滞系统的鲁棒H∞控制器设计

研究一类具有有界范数非线性不确定性的线性时滞系统的鲁棒Ｈ∞控制，提出一种鲁棒Ｈ∞控制器的设计方法。该控制器不仅能鲁棒镇定原不确定系统，还能保证闭环系统一定的Ｈ∞性能。     

基于不完全转移率的连续Markov 跳变奇异系统的H∞ 控制

研究一类不完全转移率信息的Markov跳变奇异系统的H∞控制问题,提出连续Markov跳变奇异系统的新型有界实引理,并将其推广到不完全转移率条件.进一步设计H∞状态反馈控制器,使得闭环系统在转移率部分未知的条件下随机可容许,且满足H∞性能H.所得结论涵盖了奇异矩阵模态依赖情形,且表示为严格线性矩阵不等式形式,利于工程实现.最后,通过仿真算例表明了所提出方法的有效性和优越性.     

具有结构不确定性系统的鲁棒H∞控制*

本文研究具有结构不确定系统的鲁棒Ｈ∞状态反馈控制问题，这个问题的解涉及到一个代数Ｒｉｃｃａｔｉ方程，通过分析，这个问题的解与一个辅助的线性时不变系统的Ｈ∞状态反馈控制问题的解是等价的，把这一结果求解具有结构不确定性系统的鲁棒Ｈ∞动态输出反馈控制问题，很方便地给出只需求解两个代数Ｒｉｃｃａｔｉ方程的鲁棒Ｈ∞动态输出反馈控制问题的解。     

网络化多胞型系统的变增益H∞ 控制

研究参数变化速率有界的网络化多胞型系统的变增益H_∞ 控制问题. 采用时滞状态增广方法处理状态传输时延, 得到切换多胞型系统模型; 考虑参数变化速率约束与参数传输时延影响, 给出对当前参数、次刻参数和时滞参数三元组的多胞描述方法; 进而基于参数依赖切换Lyapunov 函数方法给出变增益H_∞ 控制器的LMI 设计准则. 该方法将已有结果推广至包含网络传输时延的情形, 具有较低的保守性. 仿真实例表明了所提出方法的有效性.     

H∞ control of dead-time systems based on a transformation

This paper presents a transformation that makes all the robust control problems of dead-time systems able to be solved similarly as in the finite-dimensional situations. With trade-off of the performance, some advantages obtained are: (i) the controller has a quite simple and transparent structure; (ii) there are no any additional hidden modes in the Smith predictor and, hence, there is no additional hidden possibility to destabilize the system; (iii) it can be applied to systems with long dead-time without any difficulty. Hence, the practical significance is obvious.     

A mixed H2/H∞ adaptive tracking control for constrained non-holonomic systems

In this study, a PID type controller incorporating an adaptive control scheme for the mixed H₂/H_∞ tracking performance is developed for constrained non-holonomic mechanical systems under unknown or uncertain plant parameters and external disturbances. By virtue of the skew-symmetric property of the non-holonomic mechanical systems and an adequate choice of a state variable transformation, sufficient conditions are developed for the adaptive mixed H₂/H_∞ tracking control problems in terms of a pair of coupled algebraic equations instead of a pair of coupled non-linear differential equations. The coupled algebraic equations can be solved analytically.     

Networked H∞ control of linear systems with state quantization

This paper addresses the problem of H_∞ controller design for linear systems over digital communication networks. A new model is proposed to describe both the network conditions and the state quantization of the networked control systems in a unified framework. From this model, a quantized state feedback strategy is developed for global and asymptotical stabilization of the networked control systems. The same H_∞ disturbance attenuation level as that in the case without quantization is achieved. Numerical examples are given to demonstrate the effectiveness of the proposed method.     

New delay-dependent non-fragile H∞ observer-based control for continuous time-delay systems

The problem of the delay-dependent non-fragile H_∞ observer-based control for a class of continuous time-delay systems is investigated in this paper. The additive gain variations under consideration are contained in both the controller gain and obhsiunserver gain. Delay-dependent criteria are derived to guarantee the stability of the non-fragile H_∞ observer-based control system using the Lyapunov functional approach. The controller and observer gains are given from the LMI feasible solutions. Based on the result of this paper, the constraint of matrix equality is not necessary for designing the non-fragile H_∞ observer-based controls. Computer software Matlab can be applied to solve all the proposed results. Finally, a numerical example is illustrated to show the improvement of this paper.     

Delay-dependent robust H∞ control for uncertain systems with a state-delay

A robust H_∞ control for uncertain linear systems with a state-delay is described. Systems with norm-bounded parameter uncertainties are considered and linear memoryless state feedback controllers are obtained. Firstly, a delay-dependent bounded real lemma for systems with a state-delay is presented in terms of linear matrix inequalities (LMIs). By taking a new Lyapunov-Krasovsii functional, neither model transformation nor bounding for cross terms is required to obtain delay-dependent results. Secondly, based on the bounded real lemma obtained, delay-dependent condition for the existence of robust H_∞ control is presented in terms of nonlinear matrix inequalities. In order to solve these nonlinear matrix inequalities, an iterative algorithm involving convex optimization is proposed. Numerical examples show that the proposed methods are much less conservative than existing results.     

A parametric optimization approach to H∞ and H2 strong stabilization

This paper presents an approach for designing stable MIMO H_∞ and H₂ controllers by directly computing the norm-constrained stable transfer matrices Q in the H_∞ and H₂ suboptimal controller parameterizations. This is done by first converting the H₂ and H_∞ strong stabilization problems into some nonlinear unconstrained optimization problems through explicit parameterization of the norm-constrained Q's for any fixed order. Then, a two-stage numerical search is carried out by using a combination of a genetic algorithm and a quasi-Newton algorithm in order to reach an optimal solution. The effectiveness of the proposed algorithms is illustrated through some benchmark numerical examples.