基于输出反馈的非完整链式系统跟踪控制研究

针对非完整链式系统设计了基于输出反馈的全局跟踪控制律. 首先, 利用时变坐标变换和非自治系统的级联控制方法构造了状态观测器;然后对于时变坐标变换以后的误差系统继续利用非自治系统的级联控制方法设计了输出跟踪控制律. 区别于已有文献对于非完整链式系统跟踪控制问题的研究, 设计得到的输出跟踪控制律放松了参考轨迹所必需满足的不趋于零条件或持续激励条件. 结论表明在非完整链式系统跟踪控制问题 的研究中, 参考轨迹所必须满足的不趋于零的条件或者持续激励条件是不必要的. 最后的仿真结果验证了所给控制方法的有效性.     

辫识时变随机系统遗忘因子算法的收敛性分析

文「１」给出了辨识时变随机系统遗忘因子算法的收敛性分子,本文指出了文「１」中的一些证明和结论上的错误,并给出了相应的改正和完善。     

Continuous–discrete-time adaptive observers for nonlinear systems with sampled output measurements

This paper considers the continuous–discrete-time adaptive observer (CDAO) design for a class of nonlinear systems with unknown constant parameters and sampled output measurements. The proposed observer is actually an impulsive system, since the observer state flows according to a set of differential equations and with instantaneous state jumps corresponding to measured samples and their estimates, and an inter-sample output predictor is used to predict the output during sampling intervals. By assuming appropriate persistent excitation conditions and following a technical lemma, an upper bound of the sampling intervals is derived, with which the convergence of the observer state and unknown parameters can be ensured. Finally, the proposed observer is used in examples of chaotic oscillators and single-link flexible-joint robot manipulator to show the effectiveness.     

Smooth Switching Output Tracking Control for LPV Systems

This paper is concerned with the problem of smooth switching state feedback controller design for aircraft dynamic systems with multiple operating points. Based on the theory of robust control, a single state feedback controller which considers smooth switching is constructed. With the constant controller, the output response can be considerably improved in the switching process when the flight condition changes. An example for autopilot design of an F‐18 aircraft is given to illustrate the effectiveness of the proposed approach.     

基于线性矩阵不等式的分散鲁棒跟踪控制器设计

应用线性矩阵不等式（ＬＭＩ）方法研究不确定性关联大系统的分散鲁棒输出跟踪控制问题。系统中不确定项具有数值界,可不满足匹配条件。基于不确定基项的表达形式,给出了存在分散控制鲁棒跟踪控制器的ＬＭＩ条件。在此基础上,通过建立求解受ＬＭＩｓ约束的凸优化问题,提出了具有较小反馈增益ＬＭＩ设计方法,使受控系统渐近跟踪给定的参考输入。ＬＭＩ方法求解简单,最后用示例说明了该方法的应用。     

梯度神经网络实时求解线性方程组之收敛性分析

探讨归纳了一类用于在线求解线性方程组的梯度神经网络, 并且证明了该类梯度网络具有全局指数收敛特性, 而非以往提出的渐进收敛特性. 此外, 相对于使用线性激励函数的情况, 当使用幂S形激励函数时网络具有更好的收敛效果. 计算机仿真结果进一步验证了上述分析的准确性和该网络求解线性方程组问题的有效性.     

不确定变时滞随机系统的鲁棒均方指数稳定性

研究了不确定变时滞随机系统的鲁棒均方指数稳定性问题, 不确定性是范数有界的. 通过构造Lyapunov泛函, 得到了基于线性矩阵不等式的鲁棒均方指数稳定的充分条件. 最后给出实例加以验证所提出方法的有效性.     

Identification of the gain system with quantized observations and bounded persistent excitations

System identification with quantized observations and persistent excitations is a fundamental and difcult problem.As the first step,this paper takes the gain system for example to investigate the identification with quantized observations and bounded persistently exciting inputs.Firstly,the identification with single threshold quantization is considered.A projection recursive algorithm is proposed to estimate the unknown parameter.By use of the conditional expectation of quantized observations with respect to the estimates,the algorithm is shown to be both mean-square and almost surely convergent.The upper bound of the convergence rate is also obtained,which has the same order as the one of the optimal estimation in the case where the system output is exactly known.Secondly,for the multi-threshold quantization,the identification algorithm is similarly constructed and its asymptotic property is analyzed.Using a multi-linear transformation,the optimal scheme of quantization values and thresholds is given.A numerical example is simulated to demonstrate the efectiveness of the algorithms and the main results obtained.     

时滞系统采样迭代学习控制

针对一类具有状态时滞的连续系统提出一种采样迭代学习控制算法。给出并证明了算法指数收敛的充分条件,该条件可保证系统输出无论在采样点或非采样点上,都能以指数收敛速率收敛至期望输出的一个与采样周期有关的误差范围内。仿真结果表明了该算法的有效性。     

非线性系统指数型降维观测器设计

1 引言 控制系统的状态反馈对各种综合问题显示了其极大的优越性,但系统状态通常不可直接测量到,这就有必要引入状态观测器.对线性系统,著名的Kalman滤波器和Luenberger观测器设计方法为其提供了较为完善的答案.对非线性系统而言,观测器设计是一项具有复杂性的研究工作并引起了众多人的关注.通常来说,有这样几类非线性观测器设计方法:扩展Kalman 滤波器[1]及扩展Luenberger观测器方法[2],非线性坐标变换法[3～5]及类Lyapunov方法[6～10].与线性系统一样,非线性系统按其结构可分为全维观测器和降维观测器.本文对Lipschitz非线性系统降维观测器设计方法进行了讨论.     

Positive N-periodic descriptor control systems

A small-gain theorem is presented for almost global stability of monotone control systems which are open-loop almost globally stable, when constant inputs are applied. The theorem assumes “negative feedback” interconnections. This typically destroys the monotonicity of the original flow and potentially destabilizes the resulting closed-loop system.     

一种机器人轨迹的鲁棒跟踪控制

把基于拉格朗日方程的n关节机器人动力学模型,转化成了一线性状态方程.基于这种线性状态方程,利用李雅普诺夫函数方法分别针对机器人标称模型和有外界不确定性干扰时,设计前馈控制器和反馈控制器,使得机器人的实际运动轨迹在标称模型下,指数收敛于所给定的期望运动轨迹;在有外界不确定性干扰时,它与期望轨迹的误差是终值有界的.并且,针对后者所提出的控制律进行仿真.仿真结果表明,这种连续鲁棒控制律对于机器人系统存在外界不确定性干扰时是十分有效的.     

基于嵌套侵润控制的非线性前馈系统的全局镇定

In this paper, we discuss global stabilization procedure for convergence of a more general feedforward nonlinear systems. Our stabilizer consists of a nested saturation function, which is a nonlinear combination of saturation functions. We extend the existing stabilization results and prove that our stabilizer is exponential convergent.     

A Durbin–Watson serial correlation test for ARX processes via excited adaptive tracking

We propose a new statistical test for the residual autocorrelation in ARX adaptive tracking. The introduction of a persistent excitation in the adaptive tracking control allows us to build a bilateral statistical test based on the well-known Durbin–Watson statistic. We establish the almost sure convergence and the asymptotic normality for the Durbin–Watson statistic leading to a powerful serial correlation test. Numerical experiments illustrate the good performances of our statistical test procedure.