比例时滞线性系统的反馈镇定

研究了比例时滞线性系统的反馈镇定问题．利用标准反馈控制与时滞反馈控制实现系统不稳定平衡点的镇定．构造合适的李亚普诺夫泛函，得出了闭环系统稳定的几个充分条件．通过实例说明了方法的有效性．     

输出反馈实现一类带不确定输入动态非线性系统的鲁棒几乎干扰解耦

研究一类带不确定输入动态非线性系统的输出反馈干扰抑制问题并基于观测器给出了输出反馈控制器 构造性的设计方法.所设计的控制器具有对可允许不确定动态的鲁棒性.不仅在L₂增益意义上抑制了干扰对输出 的影响,同时在ISS镇定意义上抑制了干扰对状态的影响.     

带有时变不确定性的线性系统族的同时镇定

本文考虑了具有时变不确定性的线性系统族的状态反馈同时二次镇定问题，这个问题能更全面地刻划考虑系统的不确定性，并将其转注多个ｙａｐｕｎｏｖ方程的同一解的问题，最后给出一个数值算例。     

不确定线性系统输出反馈鲁棒镇定的充要条件

研究不确定性线性系统的输出反馈鲁棒镇定问题，给出了具有范数有界参数不确定线性系统静态输出反馈鲁棒镇定的充要条件。所给方法的设计过程只需解一个特殊的代数Ｒｉｃｃａｔｉ不等式或代数Ｒｉｃｃａｔｉ方程算法实现简便。最后通过实例验证了本方法的有效性。     

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.     

基于动态补偿的线性系统最优干扰抑制

本文针对受外部干扰的线性时不变系统研究了基于动态补偿的最优干扰抑制问题,其中干扰信号为已知动态特性的扰动信号.首先,将原系统与扰动系统联立构成增广系统,进而转化为无扰动的标准线性二次最优问题.其次,给出了经具有适当动态阶的补偿器补偿后的闭环系统渐近稳定并且相关的Lyapunov方程正定对称解存在的条件,进一步给定的二次性能指标可写成一个与该解和闭环系统初值相关的表达式.为了得到系统的最优解,将该Lyapunov方程转化为一个双线性矩阵不等式形式,并给出了相应的路径跟踪算法以求得性能指标最小值以及补偿器参数.最后,通过数值算例说明应用本文方法可以不仅能够最小化线性二次指标,而且能够使得系统的干扰得到抑制.     

一类含未建模动态和时滞系统的鲁棒二次镇定

研究一类同时含有参数摄动和未建模动态的线性时滞系统的鲁棒控制问题。获得了系统可二次镇定的充分条件,给出一种不依赖于系统时滞的状态反馈控制器设计方法,最后给出了计算示例。     

一类非线性MIMO不确定系统的动态输出反馈镇定

考察其标称系统的相对阶大于{1,1,…,1}同时含匹配和非匹配不确定性的MIMO非线性系统的动态输出反馈镇定问题.文中直接用Lyaunov方法构造一类输出反馈动态补偿器,该补偿器可以实现对所论非线性不确定系统的动态输出反馈渐近镇定.     

带有时滞及不确定性的循环大系统分散镇定状态反馈H∞设计

研究了较对称组合系统及循环对称组合系统更为一般的系统──循环系统，利用Ｈ∞理论及Ｒｉｃｃａｔｉ方程方法分别就确定性时滞系统和不确定性时滞系统得出使闭环系统稳定的分散状态反馈控制器的设计方法。所得结论均可平行推广到对称组合及循环对称组合系统。     

含不匹配扰动非严格反馈系统的输出反馈补偿控制

针对一类非严格反馈非线性系统,系统中包含不确定函数和未知外部扰动,提出一种带不匹配扰动补偿的输出反馈模糊控制器.采用模糊逻辑系统逼近未知的非线性函数,同时构造模糊状态观测器观测系统未知状态.考虑观测器和控制器会受到外部扰动和模糊逼近误差构成的不匹配总扰动信号影响,采用改进的扰动观测器对不匹配扰动进行估计和补偿,使扰动观...     

带边界非线性干扰的反稳定波方程的镇定

本文研究了一类具有边界控制匹配非线性干扰的反稳定波动方程的镇定问题. 本文只用了两个量测, 构造了一个无限维干扰估计器来实时估计状态和总干扰, 该估计器既不要求干扰的导数有界, 也不需要高增益. 基于估计的总干扰和估计的状态, 本文设计了输出反馈控制律稳定原系统. 此外, 本文还证明了闭环系统的其他状态是有界的. 为了说明理论结果, 下文给出了一些数值模拟.     

Constrained linear system with disturbance: Convergence under disturbance feedback

This paper proposes a disturbance-based control parametrization under the Model Predictive Control framework for constrained linear discrete time systems with bounded additive disturbances. The proposed approach has the same feasible domain as that obtained from parametrization over the family of time-varying state feedback policies. In addition, the closed-loop system is stable in the sense that the state converges to a bounded set that has a characterization determined by a feedback gain.     

Inverse-compensation-based DETC for nonlinear hysteresis system with disturbance

To control a nonlinear system with both hysteresis and disturbance, it is necessary to establish a hysteresis model and improve the disturbance rejection ability. However, the input signal implicitly involved in the classical hysteresis model can lead to difficulty in constructing a compensator. In this study, a hysteresis model in explicit form is proposed with a bounded auxiliary variable. Then, a model-based inverse is constructed for approximate compensation for the hysteresis. Moreover, the compensation error, which is considered a part of the disturbance, is proved to be bounded. Disturbance estimation triggered control (DETC) is utilized to address the compensation error coupled with the external disturbance. According to the disturbance effect indicator (DEI), DETC can improve the system control performance by considering the disturbance effect judgment. Experimental results are presented to illustrate the potential of the proposed technique.     

Model reference resilient control for the helicopter with time‐varying disturbance

In this paper, the problem of model reference resilient control is investigated for the helicopter system with the time‐varying disturbance and unmeasurable states. Firstly, a disturbance observer and a state observer are built to estimate the time‐varying disturbance and unmeasurable states. Then, combining the methods of model reference control and disturbance observer–based control, the state feedback robust resilient control scheme and the dynamic output feedback robust resilient control method are proposed, respectively. Under the two developed robust resilient control schemes, sufficient conditions are obtained to guarantee that the helicopter system asymptotically tracks the reference model with H_∞ performance. Finally, simulation results are presented to show the effectiveness of the model reference resilient control method.     

Stabilization of ODE with hyperbolic equation actuator subject to boundary control matched disturbance

ABSTRACT

In this paper, we consider stabilisation for a cascade of ODE and first-order hyperbolic equation with external disturbance flowing to the control end. The active disturbance rejection control (ADRC) and sliding mode control (SMC) approaches are adopted in investigation. By ADRC approach, the disturbance is estimated through a disturbance estimator with both time-varying high gain and constant high gain, and the disturbance is canceled online in the feedback loop. It is shown that the resulting closed-loop system with time-varying high gain is asymptotically stable and is practically stable with constant high gain. By SMC approach, the existence and uniqueness of the solution for the closed loop via SMC are proved, and the monotonicity of the ‘reaching condition’ is presented. The resulting closed-loop system is shown to be exponentially stable. The numerical experiments are carried out to illustrate effectiveness of the proposed control law.     

Stabilization of linear system with input saturation and unknown constant delays

In this paper, we study the stabilization of linear critically unstable systems subject to input saturation and multiple unknown input delays. We find tight upper bounds for delays which are inversely proportional to the maximal magnitude of open-loop eigenvalues on the imaginary axis. For delays satisfying these upper bounds, linear low-gain state and finite dimensional dynamic measurement feedbacks are constructed to solve the semi-global stabilization problem. The effectiveness of the proposed design is illustrated by an example.     

Stabilization of exponentially unstable discrete-time linear systems by truncated predictor feedback

Predictor state feedback solves the problem of stabilizing a discrete-time linear system with input delay by predicting the future state with the solution of the state equation and thus rendering the closed-loop system free of delay. The solution of the state equation contains a term that is the convolution of the past control input with the state transition matrix. Thus, the implementation of the resulting predictor state feedback law involves iterative calculation of the control signal. A truncated predictor feedback law results when the convolution term in the state prediction is discarded. When the feedback gain is constructed from the solution of a certain parameterized Lyapunov equation, the truncated predictor feedback law has been shown to achieve asymptotic stabilization of a system that is not exponentially unstable in the presence of an arbitrarily large delay by tuning the value of the parameter small enough. In this paper, we extend this result to exponentially unstable systems. Stability analysis leads to a bound on the delay and a range of the values of the parameter for which the closed-loop system is asymptotically stable as long as the delay is within the bound. The corresponding output feedback result is also derived.     

一类非线性切换系统输出与扰动的解耦

研究了一类单输入单输出非线性切换系统输出与扰动的完全解耦的可解性问题,提出了此类非线性切换系统输出与扰动的完全解耦的充要条件,并进一步给出了干扰可测并且能够用于反馈控制律的设计的情况下系统输出与扰动的完全解耦的条件.最后给出了仿真实例说明了本文结果的有效性.