非线性微分-代数系统的输出反馈镇定:基于线性采样控制

对满足指数1和线性增长条件的非线性微分-代数系统,本文证明其采样输出反馈镇 定控制问题可解.首先,给出一个线性显式非初始化状态观测器设计;然后,构造出线性的采样输出 反馈控制器,使得整个闭环系统渐近稳定.仿真结果表明了所提控制方法的有效性.     

一类非线性系统的自适应时延观测器设计

利用输出差分及滑模方法研究一类非线性系统的自适应时延状态观测器设计问题. 首先将系统输出的微分及高阶微分用输出和其延迟测量值的差商来表示, 然后在此基础上构造了一种时延状态观测器, 估计误差的影响可由滑模项来消除. 在系统满足线性参数化的条件下给出了一种自适应时延状态观测器设计. 最后给出仿真研究说明设计方法的有效性.     

具有非匹配扰动的非线性变参数系统模型参考跟踪控制

本文研究了一类含有非匹配扰动的非线性变参数系统的跟踪控制问题.首先,设计非线性扰动观测器用于估计系统所受到的未知扰动.其次,在前馈–反馈跟踪控制器中引入扰动补偿控制项,提出一种基于扰动观测器的跟踪控制策略.利用依赖于状态和时变参数的线性矩阵不等式,导出保证闭环系统输入–状态稳定的充分条件,进而运用平方和凸优化技术解析地构造出扰动观测器和跟踪控制器.通过理论证明,所设计的控制策略能够实现非线性变参数系统输出对参考模型输出的跟踪,消除输出通道中非匹配扰动的影响.最后,由数值仿真例子验证了所提方法的有效性.     

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.     

带传输滞后的离散系统的观测器及输出动态反馈

针对带输出传输滞后的线性离散系统,讨论了其状态观测器设计问题.利用滞后输出信息,给出了状态观测器的设计方法,并得到状态观测器存在的充要条件,进而设计出基于观测器的输出动态反馈控制器,证明了闭环系统满足极点分离原理.数值仿真验证了所提出方法的有效性.     

一类非线性时变系统基于观测器的反馈稳定化

1　引言目前,有关非线性系统的状态反馈控制已取得了许多引人注目的研究结果,其中状态可测是此控制方法中的一个必不可少的假设.在实际中,许多系统的状态是部分可测或不完全可测,故构造观测器,并用估计状态实现反馈控制是一个非常有意义的研究工作.本文研究了一类仿射非线性时变系统基于状态观测器的输出反馈稳定控制问题.首先设计了系统的状态观测器,然后综合控制器和观测器得到了非线性输出反馈控制器,并证明了反馈后闭环系统的指数稳定性.研究结果表明,系统的控制器与观测器可以分离独立进行设计.2　系统的描述及预备知识考虑下列非线性…     

基于迭代学习的线性不确定重复系统间歇性故障估计

针对一类带有不确定参数项的线性重复系统间歇性故障估计问题, 本文提出一种基于迭代学习的故障估计算法.该算法通过设计基于迭代学习的故障估计器和状态观测器, 构造李雅普诺夫方程和优化函数证明该算法的鲁棒性和收敛性, 并通过线性矩阵不等式, 求解出算法中的观测器增益矩阵和迭代学习参数矩阵.区别于其他观测器方法, 本文中的方法利用上一次基于迭代学习观测器输出和系统实际输出产生的残差信号, 对本次的故障信号进行跟踪估计, 从而准确地估计出故障的幅值和形状.仿真结果说明了该算法的有效性和准确性.     

采用观测器的双线性系统最优跟踪控制器设计

研究一类参考输入由外系统描述的双线性系统的最优输出跟踪控制问题.利用逐次逼近的方法,首先构造一族非齐次线性两点边值问题序列将原非线性两点边值问题解耦;然后迭代求解伴随向量的序列,得到由状态向量的线性解析函数和以伴随向量的极限形式给出的非线性部分的补偿项组成的最优输出跟踪控制律.通过构造降维观测器重构外系统的状态,解决了最优输出跟踪控制律的物理可实现问题仿真结果表明了该方法的有效性.     

中立型非线性不确定时滞系统的控制器设计

研究了一类中立型非线性不确定时滞系统的稳定性分析和状态观测器设计问题,系统包含状态时滞和非线性不确定性,基于Lyapunov稳定性理论,给出了该类时滞系统在非线性不确定性满足增益有界的条件下状态观测器存在的充分条件,并通过线性矩阵不等式(LMI)方法构造得出基于状态观测器的动态输出反馈控制器,最后给出一个数值算例验证了本文结果的有效性.     

带线性输出的一般非线性系统的观测器设计

一般非线性系统的观测器设计一直是控制理论研究的重点.本文针对一类带线性输出的一般非线性系统的观测器设计问题,通过微分中值定理,给出了观测器的一般形式.然后利用构造“观测器Lyapunov函数”,提出了一种较为宽松的一般非线性系统观测器设计方法,并证明其渐进稳定性.针对两个典型的一般非线性系统和双线性系统的分析说明了所给算法是可行的.最后,通过对一个单摆系统的观测器构造方法可以看出该算法是简单的且是易于实现的.     

Global sampled-data output feedback control for a class of feedforward nonlinear systems

This paper investigates the problem of global output feedback stabilization for a class of feedforward nonlinear systems via linear sampled-data control. To solve the problem, we first construct a linear sampled-data observer and controller. Then, a scaling gain is introduced into the proposed observer and controller. Finally, we use the sampled-data output feedback domination approach to find the explicit formula for choosing the scaling gain and the sampling period which renders the closed-loop system globally asymptotically stable. A simulation example is given to demonstrate the effectiveness of the proposed design procedure.     

Model recovery anti-windup for output saturated SISO linear closed loops

We define model recovery anti-windup for SISO linear control systems with output saturation. We address the problem by relying on a hybrid modification of the linear closed loop which employs a suitable logic variable to activate/deactivate various components of a control scheme. The scheme relies on a finite-time observation law, an open-loop observer and an open-loop input generator which is capable of driving the plant output within the saturation limits. Then the control scheme is based on suitable (hybrid) resetting laws allowing the controller to operate on the artificial output signal generated by the open-loop observer when the actual plant output is outside the saturation limits. Unlike existing results, not only we prove uniform global asymptotic stability of the closed loop, but we also prove the local preservation and global recovery properties, typical of model recovery anti-windup paradigms. We also illustrate the proposed technique on an example study.     

Cooperative output regulation of heterogeneous multi-agent systems based on passivity

This paper investigates the problem of cooperative output regulation of heterogeneous linear multi-agent systems. A passive framework is presented for the stabilisation analysis of cooperative output regulation, which can overcome the difficulty caused by the fact that the global dynamics of heterogeneous multi-agent systems depends on the global communication structure. An adaptive distributed observer is proposed to estimate the state of the exosystem, and the proposed distributed observer is independent of any global information of the communication graph. Based on passivity design and adaptive distributed observer, both a distributed state feedback and a distributed output feedback protocol are designed for output synchronisation of heterogeneous multi-agent systems. The gain matrices of the distributed protocols and observers are obtained by a Riccati equation design approach. Furthermore, sufficient local conditions for solving the problem of cooperative output regulation of heterogeneous multi-agent systems are presented. Finally, numerical simulation results are given to illustrate the effectiveness of the proposed distributed control schemes.     

Open‐Loop Functional Observer and State Feedback for Linear Systems Using Multirate Output Sampling

In this paper, the problem of estimating a linear functional of the state vector is considered in order to implement a feedback control law for discrete‐time linear multivariable systems. The proposed method is based on multirate sampling of the plant output. We give necessary and sufficient conditions for the existence of the functional observer, and propose a functional observer with the minimal number of output samples. In this work, the control law is implemented using the output samples, thus this methodology is more practical than state based techniques. A numerical example is considered to illustrate the procedure and highlight the advantages of the proposed method.     

Dynamic observer-based control for fractional-order uncertain linear systems

This paper addresses the problem of dynamic observer-based control for fractional-order linear uncertain systems. By constructing a new linearising change of variables, the conditions for designing the observer and controller gains are obtained in terms of solutions to a set of linear matrix inequalities (LMIs) even in the presence of uncertainties in system, input and output matrices simultaneously. Meanwhile, owing to having additional degrees of freedom in the designed observer structure, the proposed methods have no equality constraint, which is needed by using Luenberger-type observer. Numerical examples are given to illustrate the benefits and the effectiveness of the proposed method.     

Output feedback model predictive control for LPV systems based on quasi-min–max algorithm

This paper proposes a robust output feedback model predictive control (MPC) scheme for linear parameter varying (LPV) systems based on a quasi-min–max algorithm. This approach involves an off-line design of a robust state observer for LPV systems using linear matrix inequality (LMI) and an on-line robust output feedback MPC algorithm using the estimated state. The proposed MPC method for LPV systems is applicable for a variety of systems with constraints and guarantees the robust stability of the output feedback systems. A numerical example for an LPV system subject to input constraints is given to demonstrate its effectiveness.     

基于自适应分布式滤波观测器的多智能体系统编队控制

本文考虑了全局指令系统输出信息受到信道扰动情况下线性多智能体系统的编队控制问题.首先,基于协作式输出调节理论框架对线性多智能体系统的编队控制问题进行数学建模.其次,针对受到信道扰动的全局指令系统输出信息,提出了一类基于受扰输出的自适应分布式滤波观测器,在降低网络信息交换量的同时消除扰动的影响.最后,设计了输出反馈确定等价控制律,解决了线性多智能体系统的分布式编队控制问题.给出了数值仿真结果检验控制性能.     

Semi-global sampled-data output feedback disturbance rejection control for a class of uncertain nonlinear systems

This paper investigates the semi-global output feedback disturbance rejection control problem for a class of uncertain nonlinear systems with additive disturbances using linear sampled-data control. Aiming to reject the adverse effects caused by the uncertainties and unknown nonlinear perturbations which may not satisfy the strict feedback or feedforward structure, a new generalised discrete-time extended state observer is proposed to estimate the disturbance at sampling points. An output feedback disturbance rejection control law is then constructed in a sampled-data form which facilitates digital implementations. By selecting adequate control gains and a sufficiently small sampling period to restrain the state growth under a zero-order-hold input, the semi-global asymptotic stability of the hybrid closed-loop system and the disturbance rejection ability are proved. Both numerical example and an application of a single-link robot arm system demonstrate the feasibility and efficacy of the proposed method.     

Flatness-based linear output feedback control for disturbance rejection and tracking tasks on a Chua's circuit

A linear output feedback controller is developed for trajectory tracking problems defined on a modified version of Chua's circuit. The circuit modification considers the introduction of a flat input, i.e. a suitable external control input channel guided by (a) the induction of the flatness property on a measurable output signal of the circuit and (b) the physical viability of the control input. A linear active disturbance rejection control based on a high-gain linear disturbance observer, is implemented on a laboratory prototype. We show that the state-dependent disturbance can be approximately, but arbitrarily closely, estimated through a linear high-gain observer, called a generalised proportional integral (GPI) observer, which contains a linear combination of a sufficient number of extra iterated integrals of the output estimation error. Experimental results are presented in the output reference trajectory tracking of a signal generated by an unrelated chaotic system of the Lorenz type. Laboratory experiments illustrate the proposed linear methodology for effectively controlling chaos.