大系统的BIBO稳定性

本文首先给出了一类大系统有界输入有界输出（ＢＩＢＯ）稳定化的一种分散控制方案。其可稳定化的条件仅仅是其子系统一致完全可控。然后考虑了每个子系统含有非线性摄动的大系统鲁棒稳定化问题，其摄动的允许界通过局部状态反馈获得，最后应用获得的结果到线性单系统，改进了Ｗｕ等人的一些近期结果。     

Decentralized global robust stabilization of a class of interconnected minimum-phase nonlinear systems

This paper focuses on a class of large-scale interconnected minimum-phase nonlinear systems with parameter uncertainty and nonlinear interconnections. The uncertain parameters are allowed to be time-varying and enter the systems nonlinearly. The interconnections are bounded by nonlinear functions of states. The problem we address is to design a decentralized robust controller such that the closed-loop large-scale interconnected nonlinear system is globally asymptotically stable for all admissible uncertain parameters and interconnections. It is shown that decentralized global robust stabilization of the system can be achieved using a control law obtained by a recursive design method together with an appropriate Lyapunov function.     

Stabilization of large-scale systems via observer–controller compensators: frequency domain approach

This paper is concerned with the stabilization or large-scale systems via an observer–controller compensator. The overall system is considered as a decentralized form containing many linear time-invariant multivariable subsystems. Using both the M-matrix property and analysis of the input-output stability, a new stability criterion for large-scale systems controlled by observer–controller compensators is derived. Finally, based on this stability criterion, a design algorithm is proposed for finding a stabilizing observer–controller compensator for large-scale systems.     

Decentralized robust stabilization for large-scale feedforward non-linear systems

In this paper, we consider the decentralized robust stabilization problem for large-scale feedforward non-linear systems, which possess an upper-triangular structure, while in the decentralized control area the commonly studied large-scale feedback non-linear systems possess a lower-triangular structure. Our decentralized robust stabilizer for each subsystem takes a nested saturation feedback, with the saturation levels satisfying a set of equations and inequalities. Global asymptotic stability of the closed-loop large-scale system has been proved, and a simulation example is given.     

Decentralized robust control of multiple static var compensators via Hamiltonian function method

Using the energy-based Hamiltonian function method, this paper investigates the decentralized robust nonlinear control of multiple static var compensators (SVCs) in multimachine multiload power systems. First, the uncertain nonlinear differential algebraic equation model is constructed for the power system. Then, the dissipative Hamiltonian realization of the system is completed by means of variable transformation and prefeedback control. Finally, based on the obtained dissipative Hamiltonian realization, a decentralized robust nonlinear controller is put forward. The proposed controller can effectively utilize the internal structure and the energy balance property of the power system. Simulation results verify the effectiveness of the control scheme.     

Stabilisation using a stable controller and robust stability and performance

A class of strictly proper multi-input multi-output (MIMO) causal linear time invariant (LTI) systems with a detectable and stabilisable realisation in a proposed observer-controller scheme, is considered. This class is characterised by the rank of the observability matrix in closed loop. The considered scheme is based on an ?_∞ pre-compensator and on an ?_∞ dual post-compensator stabilising a full actuation full information plant and on pseudo inverses of the input and of the output matrices. The pre-compensator and post-compensator are of reduced complexity and belong to the family of all stabilising controllers. The separation principle is satisfied and necessary and sufficient stability conditions are presented for the overall system getting a stable ?_∞ controller. An algebraic approach and a state space approach are used to find this stability condition. The estimated error is zero in stationary state. Also, the control parameters allow the stationary state error and the complementary sensitivity function in high frequencies to approach zero asymptotically. So, robust stability and performance are achieved. A compromise exists between the stability of the compensators and the robust performance objective. The results are illustrated on a mechanical system.     

前馈广义分散控制系统的真镇定

讨论了前馈广义分散控制系统的真镇定问题,给出了前馈广义分散控制系统能被贫 散正常动态补偿器真镇定的充要条件,即该系统不存在不稳定的分散有穷固定模和分散脉冲 固定模,为真镇定广义系统的分散正常动态补偿器的设计奠定了基础.     

鲁棒观测器-控制器的设计*

本文讨论了多变量系统参数摄动下鲁棒观测器-控制器的设计方法,并给出了带观测器-控制器闭环系统的鲁棒稳定条件。     

Decentralized robust control for a class of large-scale interconnected systems with uncertainties

The design problem of decentralized robust controllers is considered for a class of large-scale systems. The system considered in this paper is composed of interconnected subsystems with time-varying uncertainties. For such large-scale uncertain systems, we give a simple und new method whereby we can derive the sufficient conditions for asymptotically stabilizing the overall system using decentralized feedback robust controllers. An illustrative example is given to demonstrate the design procedure of the decentralized feedback robust controllers, in the light of the method developed in this paper.     

Parametrization of nonlinear stabilizing controllers: theobserver-controller configuration

The paper uses the author's (1996) previous results to develop the parametrization of nonlinear stabilizing observer-controller compensators of a given nonlinear system. The configuration described permits a simple parametrization of stabilizing controllers using coprime factorisation techniques     

Robust decentralized model reference adaptive control of discrete-time interconnected systems

A robust decentralized model reference adaptive controller is proposed for a class of large-scale systems composed of several interconnected subsystems and described by state space equations. We have formulated a local adaptive controller for each subsystem using only local information such that the state of this subsystem tracks the corresponding state of a reference model. The content of the paper is limited to interconnected subsystems which are described by linear, deterministic, single-input single-output and discrete-time models with unknown and/or slowly time-varying parameters. Sufficient conditions, formulated by utilizing Lyapunov theory, are given for the overall system to be stabilizable by decentralized state feedback adaptive control laws. The results are illustrated by a numerical example.     

State estimation of large-scale systems

This paper addresses the problem of the robustness of a Luenberger observer applied to a given large-scale system to obtain the state estimation from the viewpoint of decentralized observation. While the large-scale system suffers parametric perturbations, a robust stability criterion for decentralized state estimation and control is derived. If saturating actuators are employed to drive the large-scale system, a new stability criterion is also given for the stabilization of large-scale systems by decentralized Luenberger observer-based constrained control. Finally, the results from several simulations are provided for illustration.     

Application of matrix perturbation theory in robust control of large-scale systems

The aim of this paper is to develop new results for robust centralized and decentralized control of large-scale systems using matrix perturbation theory. A new robustness measure is proposed which is more appropriate for large-scale systems than the existing measures. The use of this new index allows for an evaluation of system eigenvalue sensitivity to perturbations without calculating the eigenvectors and the condition number of the modal matrix. In addition, a novel robust decentralized controller design method is proposed to assign the closed-loop eigenvalues of the large-scale system in a desired region. This method is based on eigenstructure assignment of isolated subsystems. The assignment of overall closed-loop poles in the desired region is guaranteed provided that certain sufficient conditions for the isolated subsystems are satisfied. Simulation results are given to show the efficiency of the new methods.     

Decentralized global disturbance attenuation for a class of large-scale uncertain nonlinear systems

This paper studies the problem of global robust disturbance attenuation via decentralized state feedback for a class of large-scale nonlinear systems with parameter and interconnection uncertainties. The parameter uncertainty is from a compact set and the uncertain interconnections are bounded by higher-order polynomials of state variables. The problem that we address is to design a robust decentralized controller such that the closed-loop large-scale nonlinear system is input-to-state stable and the L₂ gain from the disturbance input to the controlled output is below a prescribed value for all admissible uncertain parameters and interconnections. A Lyapunov-based recursive design approach is developed to construct the decentralized controller explicitly. As a special case, the problem of almost disturbance decoupling via decentralized state feedback is also solved.     

不确定广义大系统分散鲁棒H∞保性能控制

针对一类状态矩阵和控制矩阵存在参数不确定的广义大系统,研究其分散鲁棒H∞保性能控制问题,系统中不确定项具有数值界,可不满足匹配条件.基于广义系统的有界实引理,应用线性矩阵不等式(LMI)方法,给出了不确定广义大系统存在分散鲁棒H∞保件能控制器的一个LMI条件,并用这个线性矩阵不等式系统的可行解提供了一组分散鲁棒H∞保性能控制律的参数化表示,最后用例子说明该方法的应用.     

Decentralized state-feedback stabilization and robust control of uncertain large-scale systems with integrally constrained interconnections

This paper is concerned with a problem of stabilization and robust control design for interconnected uncertain systems. A new class of uncertain large-scale systems is considered in which interconnections between subsystems as well as uncertainties in each subsystem are described by integral quadratic constraints. The problem is to design a set of local (decentralized) controllers which stabilize the overall system and guarantee robust disturbance attenuation in the presence of the uncertainty in interconnections between subsystems as well as in each subsystem. The paper presents necessary and sufficient conditions for the existence of such a controller. The proposed design is based on recent absolute stabilization and minimax optimal control results and employs solutions of a set of game-type Riccati algebraic equations arising in H_∞ control.     

一类扩展结构大系统的分散有限时间鲁棒关联镇定

研究一类扩展结构大系统分散有限时间鲁棒关联镇定问题. 扩展结构大系统是在原结构系统上增加新子系统而构成的, 在原系统分散控制律确定不变的情况下, 设计新加入子系统的鲁棒分散控制律, 使扩展后的系统仍能保持有限时间关联稳定. 利用LMI 方法推导此类系统基于状态反馈和输出反馈的分散有限时间关联镇定的充分条件, 并给出扩展子系统的相应控制器的设计方法. 最后通过仿真实验表明了所提出方法的可行性和有效性.

     

Intelligent Robust Tracking Control for a Class of Uncertain Strict-Feedback Nonlinear Systems

This paper addresses the problem of designing robust tracking controls for a large class of strict-feedback nonlinear systems involving plant uncertainties and external disturbances. The input and virtual input weighting matrices are perturbed by bounded time-varying uncertainties. An adaptive fuzzy-based (or neural-network-based) dynamic feedback tracking controller will be developed such that all the states and signals of the closed-loop system are bounded and the trajectory tracking error should be as small as possible. First, the adaptive approximators with linearly parameterized models are designed, and a partitioned procedure with respect to the developed adaptive approximators is proposed such that the implementation of the fuzzy (or neural network) basis functions depends only on the state variables but does not depend on the tuning approximation parameters. Furthermore, we extend to design the nonlinearly parameterized adaptive approximators. Consequently, the intelligent robust tracking control schemes developed in this paper possess the properties of computational simplicity and easy implementation. Finally, simulation examples are presented to demonstrate the effectiveness of the proposed control algorithms.