一类非线性MIMO系统的模糊自适应输出反馈控制

针对一类MIMO非线性状态不可测系统,提出一种基于观测器的模糊自适应输出反馈控制方法,通过应用“主导输入”的概念,并将自适应控制、H∞控制与模糊逻辑系统相结合,导出了输出反馈控制律以及参数的自适应律.基于李亚普诺夫函数证明了该控制方法可保证闭环系统的全局稳定,并获得了H∞跟踪性能指标.     

不确定系统具有圆盘区域极点约束的鲁棒控制

对一类不确定线性系统,提出了存在状态反馈控制律,使得闭环系统的所有极点均位 于一给定圆盘中的一个充分必要条件.结合控制律反馈增益参数极小化的要求,建立了一个具 有线性矩阵不等式约束的凸优化问题,通过该问题的解,可以构造一个具有较小反馈增益参数 和给定要求的控制律.所提出的方法既可应用到连续系统,也可应用到离散系统.     

一类高阶非线性参数化系统自适应重复学习控制

针对一类高阶非线性参数化系统,利用参数重组技巧,提出了一种自适应重复学习控制方法.该方法结合反馈线性化,可以处理参数在一个未知紧集内周期性、快时变的非线性系统.通过引进微分-差分参数自适应律,设计了一种自适应控制策略,使广义跟踪误差在误差平方范数意义下渐近收敛于零.通过构造Lyapunov泛函,给出了闭环系统收敛的一个充分条件.实例仿真结果说明了该方法的可行性和有效性.     

一类具有积分输入到状态稳定未建模动态的高阶非线性系统的状态反馈调节

本文研究了一类具有积分输入到状态稳定(iISS)未建模动态的高阶非线性系统的状态反馈调节问题.基于反推技术和iISS的性质,通过恰当地选取设计函数和参数修正律,给出了一个状态反馈控制器的设计过程.设计的控制器保证了闭环系统所有信号的有界性,并且状态渐近调节到零.仿真例子验证了该控制方案的有效性.     

高阶系统方法—Ⅱ.能控性与全驱性

本文首先简述了基于状态空间模型的一阶动态系统的能控性进展, 指出了一阶系统方法中卡尔曼能控性体系的一些问题.然后证明了线性定常系统能控的充要条件是它能化成一个高阶全驱系统, 同时还在一定程度上将这一结果推广到非线性系统的情形.基于这一发现, 本文定义了一般动态系统的完全能控性, 明确其意义在于存在控制律使得闭环系统为一线性定常的高阶系统, 并且可以任意配置闭环特征多项式的系数矩阵, 同时还指出其多方面相关结论.     

一类非线性参数化系统自适应重复学习控制

针对一类高阶非线性参数化系统, 利用分段积分机制, 提出了一种新的自适应重复学习控制方法. 该方法结合反馈线性化, 可以处理参数在一个未知紧集内周期性快时变的非线性系统, 通过引进微分-差分混合型参数自适应律, 设计了一种自适应控制策略, 使广义跟踪误差在误差平方范数意义下渐近收敛于零, 通过构造Lyapunov泛函, 给出闭环系统收敛的一个充分条件. 实例仿真结果说明了该方法的可行性.     

含高阶干扰的非仿射非线性系统自适应跟踪控制

本文考虑了一类带有高阶干扰和未知参数的非仿射非线性系统的自适应跟踪控制问题.为了提高系统的抗干扰性能,首先设计了扩张状态滤波器估计系统受到的高阶干扰,并把干扰估计值引入到控制器中.其次,在每一步递推设计中,为了避免backstepping方法固有的"微分爆炸"问题,引入滑模微分器估计虚拟控制律的微分,进而提出了一种新的自适应控制策略.借助Lyapunov函数理论方法分析了闭环系统的稳定性,即在所提控制策略作用下,可保证闭环系统所有信号是一致最终有界的.最后,利用MATLAB仿真验证了方法的有效性.     

一类高阶非线性不确定系统自适应稳定控制

研究了一类高阶非线性不确定性系统的自适应稳定控制设计问题.因该系统的非线性程度高,其控制系数不等同、符号已知、但数值未知,故在此之前其稳定控制设计问题没有得到解决.本文应用自适应技术,结合设计参数的适当选取,从而得到了设计该类非线性系统状态反馈稳定控制器的新方法,并基于反推技术,给出了稳定控制器的设计步骤.所设计的状态反馈控制器使得闭环系统的状态全局渐近收敛于零,其余闭环信号一致有界.最后通过一个仿真例子说明了控制设计方法的有效性.     

一类非线性参数化系统白适应重复学习控制

针对一类高阶非线性参数化系统,利用分段积分机制,提出了一种新的自适应重复学习控制方法．该方法结合反馈线性化,可以处理参数在一个未知紧集内周期性快时变的非线性系统,通过引进微分一差分混合型参数自适应律,设计了一种自适应控制策略,使广义跟踪误差在误差平方范数意义下渐近收敛于零,通过构造Lyapunov泛函,给出闭环系统收敛的一个充分条件．实例仿真结果说明了该方法的可行性．     

多变量非线性系统的间接模糊输出反馈自适应控制

针对一类多输入多输出非线性不确定系统，提出一种基于观测器的模糊间接自适应控制方法，并基于李亚普诺夫函数方法，导出了输出反馈控制律以及参数的自适应律，证明了整个控制方案不但能保证闭环系统稳定，而且取得了良好的跟踪控制性能。     

Parametric control to a type of quasi-linear second-order systems via output feedback

This paper considers the design of output feedback control for a type of quasi-linear second-order systems with the time-varying coefficient matrices containing the state variables and a time-varying parameter vector. Based on the solution to a type of second-order generalised Sylvester matrix equations, general complete parameterisation of a quasi-linear output feedback controller is established with respect to the state variables, the time-varying parameter vector, the constant closed-loop system and another two groups of arbitrary parameters, and also for the left and right closed-loop eigenvectors matrices. With the proposed parametric output feedback control, the closed-loop system can be transformed into a constant linear system with desired eigenstructure. Finally, simulation results are provided to illustrate the convenience and effectiveness of application in the general spacecraft rendezvous problem.     

H∞ and positive-real control for linear neutraldelay systems

This note is concerned with the H_∞ and positive-real control problems for linear neutral delay systems. The purpose of H_∞ control is the design of a memoryless state feedback controller which stabilizes the neutral delay system and reduces the H_∞ norm of the closed-loop transfer function from the disturbance to the controlled output to a prescribed level, while the purpose of positive-real control is to design a memoryless state feedback controller such that the resulting closed-loop system is stable and the closed-loop transfer function is extended strictly positive real. Sufficient conditions for the existence of the desired controllers are given in terms of a linear matrix inequality (LMI). When this LMI is feasible, the expected memoryless state feedback controllers can be easily constructed via convex optimization     

State feedback stabilization for high-order stochastic nonlinear systems with zero dynamics

In this paper, for a class of high-order stochastic nonlinear systems with zero dynamics which are neither necessarily feedback linearizable nor affine in the control input, the problem of state feedback stabilization is investigated for the first time. Under some weaker assumptions, a smooth state feedback controller is designed, which ensures that the closed-loop system has an almost surely unique solution on [0,∞）, the equilibrium at the origin of the closed-loop system is globally asymptotically stable in probability, and all the states can be regulated to the origin almost surely. A simulation example demonstrates the control scheme.     

State feedback stabilisation for stochastic high-order feedforward nonlinear systems with input time-delay

This paper devotes to solve the problem of state feedback stabilisation for a class of stochastic high-order feedforward nonlinear systems with input time-delay. First, the delay-dependent control input is skillfully handled by using variable transformation technique. Then, by introducing the homogeneous domination approach and the appropriate Lyapunov--Krasovskii functional to deal with the time-delay, we construct a state feedback controller through a backstepping recursive design. It is shown that the proposed controller can guarantee the closed-loop system to be globally asymptotically stable (GAS) in probability. Finally, an example is given to verify the effectiveness of the obtained analytical results.     

Global stabilisation for a class of more general high-order time-delay nonlinear systems by output feedback

This paper addresses the problem of global stabilisation by output feedback for a class of high-order time-delay nonlinear systems with more general uncertainties, which cover both high-order and low-order nonlinearities. By introducing sign function and necessarily modifying the homogeneous domination approach, an output feedback controller is successfully constructed to guarantee the global asymptotic stability of the resulting closed-loop system. Due to the versatility of the homogeneous domination approach and homogeneous properties, the proposed method is also utilised to the control design of upper-triangular systems.     

Partial-state feedback control of high-order cascade systems with unknown control direction

Without a priori knowledge of the signs of control directions, this paper investigates the robust asymptotic regulating problem for a class of high-order non-linear cascade systems with both dynamic and static uncertainties. Under some weaker assumptions, a partial-state feedback controller is proposed which ensures that all the signals of closed-loop system are globally uniformly bounded and all states can be regulated to the origin. The design procedure is illustrated through an example.     

Adaptive regulation of uncertain nonlinear systems by output feedback: A universal control approach

The problem of global state regulation via output feedback is investigated for uncertain nonlinear systems. The class of uncertain systems under consideration is assumed to be dominated by a bounding system which is linear growth in the unmeasurable states but can be a polynomial function of the system output, with unknown growth rates. To achieve global state regulation in the presence of parametric uncertainty, we propose a non-identifier based output feedback control scheme by employing the idea of universal control integrated with the design of a linear high-gain observer, whose gains are composed of two components, both of them are not constant and need to be dynamically updated. In particular, we explicitly design a universal output feedback controller which globally regulates all the states of the uncertain system while maintaining global boundedness of the closed-loop system.     

带有超大型挠性网状天线航天器姿控系统的参数化多目标设计

本文研究了带有超大型挠性附件的卫星的姿态控制问题.关于挠性航天器振动抑制与姿态控制,绝大多数已有的控制方法都是针对某一单一指标提出的.然而工程上要同时兼顾精度、快速性、平稳性、挠性部件的振动抑制以及各种鲁棒性,因此挠性航天器的姿态控制系统设计实际上是一个典型的多目标设计问题.本文针对具有超大挠性网状天线卫星的俯仰通道姿态系统,提出了一种基于输出反馈的鲁棒极点配置的参数化多目标设计方法.首先给出了系统能控与能观的充分必要条件,然后给出了动态补偿器以及特征向量矩阵的参数化表达,并在此基础上进一步对自由参向量进行了多目标优化,使得控制系统具有:1)配置到期望区域的极点; 2)较低的特征值灵敏度;3)较强的高阶未建模动态抑制能力; 4)尽可能小的控制增益.最后,本文根据卫星工程参数进行了控制器设计与仿真验证,仿真结果表明本文提出的方法可以在动态响应、高阶未建模动态抑制能力、控制量峰值等方面优于传统的PID控制器.