一类不确定非线性系统的鲁棒自适应控制

针对一类输入带有一定的不确定性的非线性系统 ,设计了一种鲁棒自适应控制器。该控制器作用与系统 ,能保证闭环系统信号的全局有界性 ,又能使闭环系统输出任意小。     

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.     

指定圆形极点配置区域输出无偏的输出反馈协方差控制器设计

系统输出无偏性及稳态状态协方差是随机系统的两个重要稳态性能指标，系统的动态品质主要决定于系统的闭环极点位置。本文给出的输出反馈协方差控制器能确保系统：１）闭环极点位于指定圆形配置区域；２）稳态协方差满足既定的上限约束；３）稳态输出无偏。     

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.     

基于反馈线性化同步伺服电机鲁棒跟踪控制

为了保证具有不确定非线性的PM同步伺服电机驱动系统的稳定性,确保闭环系统的输出准确跟踪期望输出并减少不确定项对该驱动系统的影响,利用Lyapunov稳定性理论,设计了一种基于反馈线性化的鲁棒跟踪控制器,并作了相应的仿真研究。仿真结果表明,该控制器不仅确保闭环系统的输出按指数规律跟踪期望输出,而且保证闭环系统状态的一致最终有界。该控制器设计简单,易于实现,具有很好的实用性。     

基于输出反馈的鲁棒容错D-稳定性分析

研究线性不确定系统基于输出反馈的鲁棒容错控制问题.基于连续型执行器故障模式,利用线性矩阵不等式LMI,给出了系统基于输出反馈的鲁棒容错D-稳定的充分条件,并把控制器的设计方法归结为求解一族线性矩阵不等式组.与常规的方法相比,给出的控制器不仅保证闭环系统对执行器故障具有完整性,并且使闭环系统的极点配置在指定区域D中.通过仿真示例表明,无论执行器发生故障与否,得到的基于输出反馈的鲁棒容错控制器均保证闭环系统是D-稳定的,从而验证了所提出设计方法的有效性.     

磁耦合谐振无线电能传输系统的输出鲁棒控制

磁耦合谐振无线电能传输系统的负载和谐振参数会因为受到外界环境的影响而发生变化, 系统工作频率发生随机漂移, 导致模型参数存在不确定性. 针对参数不确定下的输出鲁棒控制问题, 本文基于H_∞控制理论, 应用Matlab鲁棒控制工具箱设计H_∞控制器, 并基于结构奇异值法分析了闭环系统的鲁棒稳定性与鲁棒性能. 结果表明, 在H_∞控制器的作用下, 实现了闭环摄动系统的输出鲁棒控制, 并为此类高阶非线性不确定闭环系统提供了一种通用的控制器设计方法.     

Buck三电平变换器的PWM滑模控制

针对Buck三电平变换器飞跨电容电压闭环与输出电压闭环相互耦合的问题,利用解耦控制技术分别独立地设计控制器对两个闭环进行控制。其中,为了降低对参数变化和负载扰动的敏感性,设计基于PWM的滑模变结构控制器对输出电压进行控制。仿真试验结果表明,与传统PWM控制器相比,该方法在保持对飞跨电容电压进行有效控制的同时能减小输出电压的超调量,缩短调节时间。     

基于H∞理论的关联大系统分散鲁棒控制

基于H∞理论提出了关联大系统分散鲁棒控制的一种新的设计方法.得到的控制器不但 使闭环系统渐近稳定,而且能使闭环系统从扰动输入到被控输出的传递矩阵的H∞范数小于 某个给定的扰动变小常数,并对系统参数的不确定性具有鲁棒性.     

具有极点约束的输出反馈完整性控制器设计

基于LMI理论，给出了线性连续时不变系统具有极点约束的输出反馈完整性控制器存在的充分条件，并在此基础上提出一种输出反馈完整性控制器的设计方法。使得当传感器或执行器发生故障时。闭环系统渐近稳定，且闭环极点位于左半复平面的指定区域。数值示例说明了该方法的有效性。     

Robust Output Feedback Consensus of High-order Multi-agent Systems with Nonlinear Uncertainties

In this paper, the output feedback consensus problem of high-order multi-agent systems with nonlinear uncertainties is researched by the robust control method. By the dimensional extension of the observation matrix, the consensus control problem is transformed into a stability problem. Then the robust controller is designed by combining the nominal controller and the robust compensator. The nominal controller can obtain desired nominal performance based on the output informations. The robust compensator, which relys on robust signal compensation technology, is order to suppress the nonlinear uncertainties. According to the proposed method, output consensus error can be guaranteed as small as desired. Finally, simulation results are given to illustrate the effectiveness of this control method.     

一类不确定非线性系统的指数鲁棒输出跟踪

研究一类不确定非线性系统的鲁棒输出跟踪控制问题。应用输入／输出反馈线性化法和李亚普诺夫方法,提出一种基于不确定项上界的连续型鲁棒输出跟踪控制器设计方法。该控制器不仅可确保闭环系统的状态一致最终有界,使系统输出按指数规律跟踪期望输出,而且计算简单,更易实现。仿真结果证明了该方法的可行性与有效性。     

Robust control for nonlinear systems with unknown perturbations using simplified robust right coprime factorisation

This article is concerned with operator-based robust control for nonlinear feedback system with unknown perturbations with simplified robust right coprime factorisation method. By the designed simplified robust controllers, the Bezout identity for the nominal nonlinear system and the perturbed nonlinear system are guaranteed to be simply satisfied, which means that not only the nonlinear system with nominal plant but also that with perturbed plant can be stabilised. Moreover, the plant output can be guaranteed to asymptotically track the reference output. The effectiveness of the proposed design scheme is verified by the simulation results.     

A gradient flow approach to on-line robust pole assignment for synthesizing output feedback control systems

Pole assignment is a basic design method for synthesis of feedback control systems. In this paper, a gradient flow approach is presented for robust pole assignment in synthesizing output feedback control systems. The proposed approach is shown to be capable of synthesizing linear output feedback control systems via on-line robust pole assignment. Convergence of the gradient flow can be guaranteed. Moreover, with appropriate design parameters the gradient flow converges exponentially to an optimal solution to the robust pole assignment problem and the closed-loop control system based on the gradient flow is globally exponentially stable. These desired properties make it possible to apply the proposed approach to slowly time-varying linear control systems. Simulation results are shown to demonstrate the effectiveness and advantages of the proposed approach.     

控制可重构飞机多变量鲁棒控制器设计

控制可重构飞机要求其基本飞行控制系统对舵面部分缺损故障具有强的鲁棒特性,在故障发生后保证飞机的稳定性,提供听时间进行故障的检测和隔离,为控制系统重构提供条件,本文采用高速采样ＰＩ控制器设计输出反馈跟随系统,给出了控制器的设计方法,并分析了它对于控制舵面部分缺损故障的鲁棒特性,仿真结果表明,这种控制器具有好的鲁棒特性。     

Discrete-time certainty equivalence output feedback: allowing discontinuous control laws including those from model predictive control

We present certainty equivalence output feedback results for discrete-time nonlinear systems that employ possibly discontinuous control laws in the feedback loop. Coupling assumptions of nominal robustness with uniform observability or detectability assumptions, we assert nominally robust stability for output feedback closed loops. We further show that model predictive control (MPC) can be used to generate a feedback control law that is robustly globally asymptotically stabilizing when used in a certainty equivalence output feedback closed loop. Allowing for discontinuous feedback control laws is important for systems employing MPC, since the method can, and sometimes necessarily does, result in discontinuous control laws.     

基于LMI的输出反馈鲁棒完整性控制器设计

完整性是容错控制的一个重要研究方向,不确定系统的鲁棒完整性研究具有很强的实际意义.本文基于[0,σ]故障模型和线性矩阵不等式(LMI)方法,提出了参数不确定系统的输出反馈鲁棒完整性控制器存在的充分条件,通过求解两个矩阵不等式获得控制器,使闭环系统在传感器发生故障时仍然保持二次稳定,并对参数不确定性具有鲁棒性.数值示例说明了该方法的有效性.     

Robust‐decentralized tracking control for a class of uncertain MIMO nonlinear systems with time‐varying delays

A new control design method based on signal compensation is proposed for a class of uncertain multi‐input multi‐output (MIMO) nonlinear systems in block‐triangular form with nonlinear uncertainties, unknown virtual control coefficients, strongly coupled interconnections, time‐varying delays, and external disturbances. By this method, the controller design is performed in a backstepping manner. At each step of backstepping procedure, a nominal virtual controller is first designed to get desired output tracking for the nominal disturbance‐free subsystem, and then a robust virtual compensator is designed to restrain the effect of the uncertainties, delays involved in the subsystem, and the couplings among the subsystems. The designed controller is linear and time‐invariant, so the explosion of complexity in the control law is avoid. It is proved that robust stability and robust practical tracking property of the closed‐loop system can be ensured, and the tracking errors can be made as small as desired. Copyright © 2013 John Wiley & Sons, Ltd.     

Robust output tracking of nonlinear systems with mismatched uncertainties

The problem of robust output tracking for a class of uncertain nonlinear systems which do not satisfy the conventional matching condition is considered. The main assumption on the uncertainty is that the triangularity condition is satisfied. Based on backstepping method and input/output linearization approach, we propose a class of non-adaptive state feedback controllers which can guarantee exponential stability of the tracking error for the uncertain nonlinear systems first. Next, adaptive control laws are developed so that no prior knowledge of the bounds on the uncertainties is required. By updating these upper bounds, we design a class of adaptive robust controllers. It is shown that under the proposed adaptive robust control the tracking error of the controlled system converges to zero as time approaches infinity.     

Robust control of multivariable critical systems

Based on the method of inequalities and H _∞-optimization method, this paper develops an approach to robust control design of multivariable critical systems with external and internal uncertainties. In this approach the formulation of the robust control design of these systems is expressed by a set of inequalities which includes output performance criteria in the time domain and a robust performance criterion in the frequency domain of the system. Some relationships between an input space, a modelling error space, a controller, output performance and robust performance are established by inequalities for SISO and MIMO critical systems so that the robust control design problem of these systems is largely simplified.