A Riccati equation approach to the design of stabilizing controllers and observers for a class of uncertain linear systems

This paper presents a procedure for designing a full state observer and feedback control law which will stabilize a given uncertain linear system. The uncertain linear systems under consideration are described by state equations which depend on uncertain parameters. These uncertain parameters may be time varying. Their values, however, are constrained to lie within known compact bounding sets. The design procedure involves solving two algebraic Riccati equations. A feature of the design procedure presented is the fact that it reduces to the standard LQG design procedure if the system contains no uncertain parameters.     

一类不确定动态时滞系统的无记忆鲁棒镇定控制

针对状态和控制均存在滞后,同时具有未知且有界的一类时变不确定线性时滞系统,提出了一种无记忆鲁棒镇定控制器设计算法.给出了闭环系统二次稳定的充分条件,并利用一等价线性时不变系统的H∞标准问题综合方法来构造出所需的线性状态反馈控制律,即可通过求解一代数Riccati型方程来求得控制律静态增益阵,从而保证了解的存在性和可解性.     

Eigenvalue assignment via uncertain state feedback controllers

In this paper, we propose a method for eigenvalue assignment using linear control systems containing uncertain elements. Uncertain systems are systems described by state equations which depend on uncertain parameters. In this paper, uncertainty is modeled with interval numbers. The proposed method assigns prescribed eigenvalues to a state feedback control system. Also, we introduce two interval operations to be used in our method use them. Some numerical experiments are presented to illustrate the effectiveness of the proposed method.     

Stabilization of a class of uncertain time-delay systems containing saturating actuators

The delay-dependent robust stabilization problem for a class of uncertain linear timedelay systems containing saturating actuator is considered in this paper. The uncertain time-delay systems under consideration are described by state differential equations with time-varying unknown-but-bounded uncertain parameters and delayed state. The delay is assumed to be constant bounded but unknown. New robust stability criteria and a sufficient condition for the existence of memoryless robust stabilizing control law are derived. The results depend on the size of the delay and are given in terms of several linear matrix inequalities (LMIs). A numerical example is presented to illustrate the obtained results.     

Delay-dependent robust stabilization of uncertain systems withmultiple state delays

This paper deals with the problem of robust stabilization for uncertain systems with multiple state delays. The parameter uncertainties are time-varying and unknown but are norm-bounded, and the delays are time-varying. A new method for achieving robust stabilization is presented for a class of uncertain time-delay systems via linear memoryless state feedback control. The results depend on the size of the delays and are given in terms of several linear matrix inequalities     

线性不确定时滞系统指定衰减度鲁棒镇定

研究了一类线性不确定时滞系统时滞依赖型具有指定衰减度的无记忆状态反馈鲁棒镇定问题.所考虑的线性不确定时滞系统含有时变未知但有界的不确定参数和状态滞后.通过应用Razumikhin定理和Lyapunov定理,导出了系统鲁棒稳定且具有指定衰减度的判据和具有指定衰减度的无记忆状态反馈鲁棒镇定控制律存在的充分条件及相应的控制器设计方法.所得时滞相关的结果用一组线性矩阵不等式(LMI)表示.     

带饱和执行器的不确定时滞系统的鲁棒控制

研究了一类具有饱和执行器约束的不确定时滞系统时滞依赖型无记忆鲁棒控制问题.所考虑的时滞系统包括时变未知但有界的不确定参数以及状态和控制的时滞项.文中应用了Lyapunov定理以及线性矩阵不等式(LMI)方法来研究该系统的分析和综合问题,导出了一个新的鲁棒可镇定判据和相应的无记忆鲁棒镇定控制律设计方法.所得的基于一组LMIs的结果是与时滞相关的.     

不确定多状态滞后系统时滞相关鲁棒稳定与镇定

针对具有范数有界参数不稳定性的多态性滞后系统,本文提出了与系统时滞相关的鲁棒稳定性判据,并给出了一种无记忆的时滞相关的鲁棒稳定控制率的设计方法,本文的结果与系统的时滞大小有关,并采用ＬＭＩ描述。     

带饱和执行器的不确定时滞系统的 鲁棒控制

研究了一类具有饱和执行器约束的不确定时滞系统时滞依赖型无记忆鲁棒控制问题 .所考虑的时滞系统包括时变未知但有界的不确定参数以及状态和控制的时滞项 .文中应用了 Lyapunov定理以及线性矩阵不等式 ( LMI)方法来研究该系统的分析和综合问题 ,导出了一个新的鲁棒可镇定判据和相应的无记忆鲁棒镇定控制律设计方法 .所得的基于一组LMIs的结果是与时滞相关的     

基于观测器的时滞系统鲁棒控制器的设计

研究了一类不确定时滞系统基于观测器的鲁棒镇定问题,系统的不确定性时变未知且范数有界,目的是设计状态观测器和线性无记忆观测状态反馈控制器,使其能够镇定一类状态和控制输入不确定性时滞系统。基于Lyapunov稳定性理论,采用线形矩阵不等式这一有效工具,给出了系统基于观测状态反馈鲁棒镇定的充分条件,并且利用线形矩阵不等式的解构造了使得系统鲁棒稳定的基于观测状态反馈控制器,所得结果与时滞相关,从而相对减弱了控制器设计的保守性。数值算例表明了所提出的设计方法的有效性。     

Quadratic stabilizability of uncertain linear systems: Existence of a nonlinear stabilizing control does not imply existence of a linear stabilizing control

This note is concerned with the problem of stabilizing an uncertain linear system via state feedback control. An uncertain system which admits a stabilizing state feedback control and some associated quadratic Lyapunov function is said to be quadratically stabilizable. In a number of recent papers, conditions are given under which quadratic stabilizability via nonlinear control implies quadratic stabilizability via linear control. These papers restrict the manner in which the uncertain parameters are permitted to enter structurally into the state equation in order to establish this result. This note presents an example which shows that this implication is not true for more general uncertain linear systems. To this end, we describe an uncertain linear system which is quadratically stabilizable via nonlinear control but not quadratically stabilizable via linear control.     

参数不确定统一混沌系统鲁棒最优控制

针对含有参数不确定性的统一混沌系统,基于鲁棒最优控制理论,提出了一种简单的线性状态反馈控制策略.该策略给出了系统渐进稳定的充分条件,并可以通过求解线性矩阵不等式(LMI),快速有效地求得系统反馈的控制增益,利用Lyapunov方法证明了闭环系统的稳定性.仿真结果验证了所提出的控制策略的有效性.     

A stabilization algorithm for a class of uncertain linear systems

This paper presents an algorithm for the stabilization of a class of uncertain linear systems. The uncertain systems under consideration are described by state equations which depend on time-varying unknown-but-bounded uncertain parameters. The construction of the stabilizing controller involves solving a certain algebraic Riccati equation. Furthermore, the solution to this Riccati equation defines a quadratic Lyapunov function which is used to establish the stability of the closed-loop system. This leads to a notion of ‘quadratic stabilizability’. It is shown that the stabilization procedure will succeed if and only if the given uncertain linear system is quadratically stabilizable.The paper also deals with a notion of ‘overbounding’ for uncertain linear systems. This procedure enables the stabilization algorithm to be applied to a larger class of uncertain linear systems. Also included in the paper are results which indicate the degree of conservativeness introduced by this overbounding process.     

基于观测器的动态时滞系统鲁棒控制器的设计

在状态不能由输出直接得到的情况下，通过解两个Ｒｉｃｃａｔｉ方程，对不满足匹配条件的不确定线性时滞系统进行镇定。设计了一个“有记忆型”控制器。结果表明，如果状态方程的不确定参数值限定在已知有界紧集内，则可用得到的观测器与反馈控制律对系统进行镇定。     

On robust state derivative feedback control for uncertain polytopic systems with uncertain sampling period and network-induced delay

This paper addresses the state derivative feedback control problem for uncertain polytopic systems subject to an uncertain sampling period and network-induced delay. The distinctive contribution relies on the direct design of a robust state derivative feedback controller employing an augmented discretized model derived in terms of the state derivative feedback such that network-induced delay and uncertain sampling periods can be incorporated from the original continuous-time state-space representation into the discretized model. Two augmented models are provided to handle longer input time delays, as well as delays less or equal to the sampling period. In this work, all the uncertain parameters are modeled as a polytopic form whose resulting discrete-time model has matrices with polynomial dependence on the uncertain parameters and an additive norm-bounded term featuring the discretization residual error. Moreover, synthesis conditions are derived using a set of linear matrix inequalities (LMI) to solve the stabilization problem for this class of systems under different input time delays. Finally, numerical simulations are carried out to evaluate the effectiveness of the proposed method.     

Parameter and state estimation for uncertain linear systems by multiple observers

A parameter and state estimation problem is considered for uncertain linear time-invariant systems. Under a certain condition, it is shown that the state of the system can be asymptotically described by a linear combination of state estimates generated by suitable multiple observers, where the weights of the linear combination are the parameters to be estimated. Using this property, a computation method is proposed for simultaneous estimation of the parameters and the state from the output data of the plant and multiple observers.     

Guaranteed cost control of uncertain nonlinear systems via polynomial lyapunov functions

In this paper, we consider the problem of guaranteed cost control for a class of uncertain nonlinear systems. We derive linear matrix inequality conditions for the regional robust stability and performance problems based on Lyapunov functions which are polynomial functions of the state and uncertain parameters. The performance index is calculated over a set of initial conditions. Also, we discuss the synthesis problem for a class of affine control systems. Numerical examples illustrate our method.     

连续搅拌反应釜的自适应输出反馈控制及参数整定

针对一类连续搅拌反应釜(CSTR),提出了基于扩张状态观测器和反步法的自适应控制方法,并结合连续动作强化学习器(CARLA)进行控制器参数整定.将CSTR视为包含不确定函数的非严格反馈非线性系统,利用扩张状态观测器对系统中的状态变量实时估计,并对不确定函数在线逼近,将系统补偿为线性二阶积分串联系统,为其设计反步法控制器.通过李雅普诺夫稳定性定理对系统稳定性进行分析,证明了闭环系统中所有信号均有界.最后,针对大量控制器参数难以人工整定的问题,设计CARLA算法快速搜索控制器参数最优值,提升了控制品质.仿真实验进一步验证了该方法的有效性.     

Uncertainty decomposition of quantum networks in SLH framework

This paper presents a systematic method to decompose uncertain linear quantum input‐output networks into uncertain and nominal subnetworks, when uncertainties are defined in SLH representation. To this aim, two decomposition theorems are stated, which show how an uncertain quantum network can be decomposed into nominal and uncertain subnetworks in cascaded connection and how uncertainties can be translated from SLH parameters into state‐space parameters. As a potential application of the proposed decomposition scheme, robust stability analysis of uncertain quantum networks is briefly introduced. The proposed uncertainty decomposition theorems take account of uncertainties in all three parameters of a quantum network and bridge the gap between SLH modeling and state‐space robust analysis theory for linear quantum networks.     

一类具有非线性饱和执行器的不确定时滞系统鲁棒控制

研究一类具有非线笥饱和执行器朱确定线性时滞系统的鲁棒性镇定问题。所考虑的不确定时滞系统具有时变未知且有界的不确定参数和状态时滞。提出了新的鲁棒可镇定判据和相应的鲁棒无记忆状态反馈控制器设计方法。数值仿真例子说明了所提出方法的有效性。