一阶伪线性系统的模型参考输出跟踪控制

针对伪线性系统的模型参考输出跟踪问题,设计伪线性系统的模型参考跟踪策略.控制器分为两部分,其一为反馈镇定控制器,保证闭环系统是渐近稳定的;另一为前馈补偿控制器,通过求解基于控制器存在条件建立的方程组得到控制器的参量矩阵,使得闭环系统的输出渐近跟踪参考系统的输出,且当系统中存在时变系数时方法仍是有效的,控制器中保有部分自由度可以进一步利用,以提高具体控制任务所需的系统性能.数值仿真验证了所提出方法的有效性.     

一类线性时变系统的输出反馈控制

基于线性时不变系统能控能观标准型变换及非线性系统高增益观测器方法,本文研究了一类线性时变系统 的输出反馈控制问题. 通过引入时变的状态变量坐标变换,分别设计了线性时变系统的状态反馈控制器、状态观测器以及基于 状态观测器的输出反馈控制器. 进一步地,本文分别证明了观测器动态误差是渐近收敛于零的,而状态反馈控制器以及输出反馈控制器可以 保证闭环系统的渐近稳定性.     

Robust input-output energy decoupling for uncertain singular systems

1 Introduction During recent years, singular systems have at- tracted the interest of a number of researchers due to the fact that they appear more naturally in the study of naturally occurring systems than regular systems (state-space systems), e.g. in economic, circuit, and boundary control systems, and chemical processes[1～3]. Many contributions have been made to the study of these systems, and a great number of results on the theory of regular systems have been generalized to the area of …     

An efficient LMI approach for the quadratic stabilisation of a class of linear,uncertain, time-varying systems

The purpose of this article is to provide a numerically efficient method for the quadratic stabilisation of a class of linear, discrete-time, uncertain, time-varying systems. The considered class of systems is characterised by an interval time-varying (ITV) matrix and constant sensor and actuator matrices. It is required to find a linear time-invariant (LTI) static output feedback controller yielding a quadratically stable closed-loop system independently of the parameter variation rate. The solvability conditions are stated in terms of linear matrix inequalities (LMIs). The set of LMIs includes the stability conditions for the feedback connection of a unique suitably defined extreme plant with an LTI output controller and the positivity of a closed-loop extremal matrix. A consequent noticeable feature of the article is that the total number of LMIs is independent of the number of uncertain parameters. This greatly enhances the numerical efficiency of the design procedure.     

Robust H∞ control for uncertain discrete-time systems with time-varying delays via exponential output feedback controllers

This paper considers the problem of robust H_∞ control for uncertain discrete systems with time-varying delays. The system under consideration is subject to time-varying norm-bounded parameter uncertainties in both the state and measured output matrices. Attention is focused on the design of a full-order exponential stable dynamic output feedback controller which guarantees the exponential stability of the closed-loop system and reduces the effect of the disturbance input on the controlled output to a prescribed level for all admissible uncertainties. In terms of a linear matrix inequality (LMI), a sufficient condition for the solvability of this problem is presented, which is dependent on the size of the delay. When this LMI is feasible, the explicit expression of the desired output feedback controller is also given. Finally, an example is provided to demonstrate the effectiveness of the proposed approach.     

Fuzzy guaranteed cost control for nonlinear systems with time-varying delay

This paper focuses on the problem of guaranteed cost control for Takagi-Sugeno (T-S) fuzzy systems with time-varying delayed state. A linear quadratic cost function is considered as a performance index of the closed-loop fuzzy system. Then, the guaranteed cost control of the closed-loop fuzzy system is discussed, and the sufficient conditions are provided for the construction of a guaranteed cost controller via state feedback and observer-based output feedback. When these conditions, which are given in terms of the feasibility of linear matrix inequalities (LMIs), are satisfied, the designed state feedback controller and observer-based controller gain matrices can be obtained via a convex optimization problem. Two illustrative examples are provided to demonstrate the effectiveness of the approaches proposed in this paper.     

A dynamic observer for a synchronous machine†

The closed-loop optimal control law obtained for a linear time-invariant system always requires the entire state vector to be available for direct measurement. It is seldom that all the state variables of a physical system are available for measurement. A compatible dynamic observer of the Luenberger type is designed to reconstruct the entire state vector for a synchronous machine-infinite bus system. The performance of the system with the observer cascaded to the optimal controller is compared with the performance of the system when all the state variables are available for feedback. The transfer matrix relating the output and input is derived.     

Markov跳变系统的输出反馈鲁棒预测控制

对离散时间Markov跳变系统, 当系统状态不完全可测时, 研究了一类基于输出反馈的鲁棒模型预测控制问题. 所研究系统为准线性参数时变的, 考虑在当前时刻系统的时变参数是已知的, 将来时刻未知的情况. 综合考虑系统存在多胞不确定性和有界噪声等因素, 通过运用线性矩阵不等式方法及变量变换思想, 将无穷时域性能指标的最小最大鲁棒预测控制问题转化为具有线性矩阵不等式约束的凸优化问题, 得到了系统的输出反馈控制律. 引入二次有界概念, 在满足输入输出约束的情况下, 保证闭环系统的随机稳定性. 数值算例验证了方法的有效性.     

随机型不确定中立时滞系统的鲁棒H∞控制

研究了一类具有不确定性的随机性中立时滞系统的鲁棒H∞状态反馈控制器的设计问题.假设时滞是已知的,且时滞同时出现在状态变量和控制变量中,利用线性矩阵不等式方法,给出了状态反馈控制器存在的时滞依赖的充分条件,保证了对于所有的参数不确定性,闭环系统是指数均方稳定的,且从干扰输入到被控输出的影响小于一个指定的性能指标.仿真算例验证了该方法的可行性.     

具有方差和极点约束的不确定系统鲁棒H∞输出反馈控制

针对一类具有范数有界不确定性的连续系统和二次矩阵不等式区域,考虑系统具有方差和区域极点约束的输出反馈控制器设计问题．为此首先导出闭环系统区域稳定的充分必要条件．然后用线性矩阵不等式方法给出输出反馈控制器存在的一个充分条件．在此充分条件下闭环系统是鲁棒区域稳定的且具有H∞性能以及当干扰为白噪声信号时其稳态状态方差有限．接下来用矩阵分解方法给出输出反馈控制器增益矩阵的求解过程．最后通过一个仿真实例说明本文所提出的控制器设计方法的有效性．     

具有方差和极点约束的不确定系统鲁棒H∞输出反馈控制

针对一类具有范数有界不确定性的连续系统和二次矩阵不等式区域, 考虑系统具有方差和区域极点约束 的输出反馈控制器设计问题. 为此首先导出闭环系统区域稳定的充分必要条件. 然后用线性矩阵不等式方法给出输出反馈控制器存在的一个充分条件. 在此充分条件下闭环系统是鲁棒区域稳定的且具有H-infinity性能以及当干扰为白噪声信号时其稳态状态方差有限. 接下来用矩阵分解方法给出输出反馈控制器增益矩阵的求解过程. 最后通过一个仿真实例说明本文所提出的控制器设计方法的有效性.     

Constrained robust model predictive control via parameter-dependent dynamic output feedback

This paper considers output feedback robust model predictive control for the quasi-linear parameter varying (quasi-LPV) system with bounded disturbance. The so-called quasi-LPV means that the varying parameters of the linear system are known at the current time, but unknown in the future. The control law is parameterized as a parameter-dependent dynamic output feedback, and the closed-loop stability is specified by the notion of quadratic boundedness. An iterative algorithm is proposed for the on-line synthesis of the control law via convex optimization. A numerical example is given to illustrate the effectiveness of the controller.     

动态输出反馈鲁棒模型预测控制

研究了具有多包不确定性和有界噪声的系统的动态输出反馈鲁棒模型预测控制的综合方法.系统为准线性参数时变的,即系统时变参数在当前时刻精确已知,但在将来时刻未知.采用二次有界概念刻画扩展闭环系统的稳定性.本文主要创新在于提出了一种辅助优化方法,从而为下个采样时刻的主优化问题提供可靠的真实状态的界.通过连续搅拌釜式反应器控制系统验证了该方法的有效性.     

一类具有连续分布时滞的分布参数系统的反馈控制

针对一类同时具有变时滞和连续分布时滞的分布参数系统的状态反馈控制问题进行了研究,通过选择适当的Lyapunov-Krasovskii函数,采用线性矩阵不等式(LMI)方法,得到了变时滞闭环系统渐近稳定的一个充分条件.设计了无记忆的状态反馈控制器,使得在一个正定矩阵存在的条件下,闭环系统是可镇定的,从而得到了常时滞分布参数系统可镇定的一个推论.最后,通过一个数值仿真例子说明了所给出设计方法的可行性和有效性.     

Adaptive stabilization of a class of nonlinear systems with unstable internal dynamics

This note considers global stabilization of a class of uncertain nonlinear output feedback systems with unstable internal dynamics. The coefficients which characterize the internal dynamics are allowed to be functions of system output, and the uncertainty of the system is characterized by an unknown constant parameter vector. The key step in the proposed control design is to estimate the internal state variables and impose control over them. The control design is presented first for systems without unknown parameters, and then for the systems with unknown parameters using adaptive control techniques.     

时变参数不确定离散时间系统的预见控制

基于具有参数依赖的Lyapunov函数方法及LMI技巧,研究一类时变参数不确定离散时间系统的预见跟踪控制问题.首先,采用预见控制理论中误差系统的方法,引入两个与状态变量和输入变量有关的辅助信号,构造出包含未来目标值信号和干扰信号的信息的扩大误差系统,将原系统的预见跟踪问题转化为扩大误差系统的镇定问题;然后,针对扩大误差系统,考虑输出反馈时,通过改造输出方程融合可预见信号的未来信息.研究表明,通过求解LMI,即可确定静态输出反馈预见控制器增益矩阵的参数矩阵.数值仿真表明了结果的有效性.     

Discretization and event triggered digital output feedback control of LPV systems

This paper investigates the problem of discretization and digital output feedback control design for continuous-time linear parameter-varying (LPV) systems subject to a time-varying networked-induced delay. The proposed discretization procedure converts a continuous-time LPV system into an equivalent discrete-time LPV system based on an extension of the Taylor series expansion and using an event-based sampling. The scheduling parameters are continuously measured and modeled as piecewise constant. A new transmission of the measured output to the controller is triggered by significant changes in the parameters, yielding time-varying transmission intervals. The obtained discretized model has matrices with polynomial dependence on the time-varying parameters and an additive norm-bounded term representing the discretization residual error. A two step strategy based on linear matrix inequality conditions is then proposed to synthesize a digital static scheduled output feedback control law that stabilizes both the discretized and the LPV model. The conditions can also be used to provide robust (i.e., independent of the scheduling parameter) static output feedback controllers. The viability of the proposed design method is illustrated through numerical examples.     

多组时滞大型控制系统的镇定

给出了由无时滞线性定常闭孤立控制子系统的渐近稳定性推出多组时滞线性定常闭环大型控制系统的渐近稳定性的充分条件，并说明了所得结果可以推广到多组时滞线性时变闭环大型控制系统与多组时滞线中立型定常（或时变）闭环大型控制系统，所得结果改进了前人的结果，通过参数镇定域的比较知，可使参数镇定域扩大为原来的６倍。     

Anti-windup design of uncertain discrete-time Markovian jump systems with partially known transition probabilities and saturating actuator

This paper carries out a study on the design of anti-windup gains for uncertain discrete-time Markovian jump systems subject to both actuator saturation and partially known transition probabilities. The parameter uncertainties appearing in both the state and input matrices are assumed to be time-varying and norm-bounded. Under the assumption that a set of linear dynamic output feedback controllers have been designed to stabilise the Markovian jump system in the absence of actuator saturation, anti-windup compensation gains are designed for maximising the domain of attraction of the closed-loop system with actuator saturation. Then, by solving a convex optimisation problem with constraints of a set of linear matrix inequalities, the anti-windup compensation gains are obtained. A simulation example is provided to illustrate the effectiveness of the proposed technique.