二阶离散线性时变系统的一种稳定性判据

本文对二阶离散线性时变稳定性问题进行了研究。在离散线性时变系统Lyapunov稳定理论的基础上，给出二阶离散线性时变系统稳定的充分条件。即系统系数满足系数冻结条件和系数变化条件。仿真验证了结论的正确性。     

离散线性时变系统稳定性研究

本文对离散线性时变系统的稳定性问题进行了研究。给出离散线性定常系统收敛速度的定义，基于离散线性时变系统Lyapunov稳定理论，给出离散线性时变系统稳定的充分条件，即系统系数满足系数冻结条件和系数变化条件。仿真验证了结论的正确性。     

一类欧-拉系统的全系数自适应控制研究

对于动力学方程未知的全驱动多变量欧-拉系统,进行了基于特征模型的全系数自适应控制方法研究.根据全系数自适应控制思想,针对全驱动欧-拉系统提出了差分方程形式的特征模型,并得到该特征模型各系数的一些性质.基于建立的特征模型,提出多变量黄金分割控制律和相应的自适应控制策略,并对闭环系统的稳定性进行了分析.最后对两连杆的空间机器人进行了仿真,仿真结果表明了该自适应控制方法的优越性.     

一类线性时变大系统的运动稳定性

本文运用向量李雅普诺夫函数和比较原理的方法研究一类线性时变大系统的运动稳定性同时扩大了文[1]所研究的n阶常系数线性方程组和文[2]所研究的一类时变大系统的参数稳定性区域。     

非线性时变离散大系统的稳定性

本文应用标量李雅普诺夫函数法研究了线性时变离散大系统及非线性时变离散大系统的稳定性分解。同时分别给出了分解系数与稳定域的参数估计公式。     

时变多变量系统辨识的一种方法

本文提出时变多变量系统辨识的一种新方法，并分析了算法的收敛性和稳定性。仿真例子表明所提出算法是有效的。     

一类具有区间时变多状态时滞系统的稳定性分析

研究一类具有区间时变多状态时滞且时滞导数不确定的系统的稳定性问题. 通过选择合理的Lyapunov-Krasovskii函数结合辅助变量和广义状态法, 以LMI的形式给出了时滞相关的稳定性充分条件. 文中的结论对时滞的导数没有任何限制, 可用于具有快时变时滞系统. 与已有的相关研究成果相比, 结论更具有一般性, 保守性也更低. 最后通过仿真及数值算例说明了本文方法的有效性和优越性.     

多变量强耦合时变系统的PID神经网络控制

介绍了一种新的神经网络———PID神经网络及其多变量强耦合时变控制系统。文中给出了网络的结构和算法,分析了时变对象的特点,对一组二变量强耦合时变系统进行了实时仿真。仿真结果显示:PID神经网络对多变量强耦合时变对象具有良好的解耦性能和自学习控制特性。     

时滞正反馈控制下汽车悬架系统的多目标优化

兼顾时滞正反馈控制下汽车悬架系统的隔振效果和控制力输入,提出设计变量的多目标优化策略。建立时滞正反馈控制下1/4汽车悬架系统的力学模型;分析系统的稳定性,得到反馈增益系数和时滞两参数平面上的稳定性分区图;以反馈增益系数和时滞为设计变量,将车身加速度与控制力幅值的线性加权组合为优化目标,通过粒子群优化算法得到设计变量的最优值。研究结果表明,与无时滞正反馈控制下汽车悬架系统相比,最优时滞正反馈控制下汽车悬架系统的隔振效果显著提升,控制力幅值大幅下降。     

一类时变非线性控制系统的绝对稳定性

用“二次型加积分项”形式的Ｌｙａｐｕｎｏｖ函数研究一类时变非线性控制系统的绝对稳定性，给出了系统绝对稳定的充分条件以及时变系数导数界限的估计，明显地优于［１］中的结果。     

A new calculation method of feedback controller gain for bilinear paper-making process with disturbance

This paper presents a new method to calculate the feedback control gain for a class of multivariable bilinear system, and also applied this method on the control of two sections of paper-making process with disturbance. The robust H∞ control problem is to design a state feedback controller such that the robust stability and a prescribed H∞ performance of the resulting closed-loop system are ensured. The controller turns out to be robust with respect to the disturbance in the plant. Utilizing the Schur complement and some variable transformations, the stability conditions of the multivariable bilinear systems are formulated in terms of Lyapunov function via the form of linear matrix inequality (LMI). The gain of controller will be calculated via LMI. Finally, the application examples of a headbox section and a dryer section of paper-making process are used to illustrate the applicability of the proposed method.     

Constrained robust model predictive control via parameter-dependent dynamic output feedback

This paper considers output feedback robust model predictive control for the quasi-linear parameter varying (quasi-LPV) system with bounded disturbance. The so-called quasi-LPV means that the varying parameters of the linear system are known at the current time, but unknown in the future. The control law is parameterized as a parameter-dependent dynamic output feedback, and the closed-loop stability is specified by the notion of quadratic boundedness. An iterative algorithm is proposed for the on-line synthesis of the control law via convex optimization. A numerical example is given to illustrate the effectiveness of the controller.     

Quantitative feedback design of air and boost pressure control system for turbocharged diesel engines

For modern diesel engines, variable geometry turbocharger (VGT) is used to boost engine power output. In addition, exhaust gas recirculation (EGR) is utilized to reduce engine out NO_x emission. To realize these functions, a multivariable control system needs to control both VGT and EGR valve to deliver desired intake manifold (or boost) pressure, and desired EGR flow rate. This two-input and two-output system is nonlinear with cross-couplings between the boost and EGR responses to the input actuators, the system parameters are varying with different engine operating conditions. This paper proposes a closed loop design of a multivariable VGT/EGR control system for a turbocharged diesel engine. The control system is synthesized based on quantitative feedback theory to maintain robust stability and performance via sequential MIMO loop shaping in the frequency domain. Experiment results are included from a turbocharged diesel engine to show the effectiveness of the proposed control design.     

使用黄金分割法的管道压力系统自适应控制

压力是工业过程控制常用参数,为了探索黄金分割自适应控制在工业过程控制中的应用技术,本文将其应用于水流管道的压力控制.利用控制实验平台,搭建了以变频调速驱动水泵的压力控制实验系统.阐述了特征建模与黄金分割自适应控制对该系统的适用性和稳定性,并通过分析确定了特征模型类型和控制算法.考虑到时延的影响,采用数字外推预测算法对管道压力误差进行处理.对控制方案进行了仿真分析,完成了与黄金分割自适应控制相关的管道压力控制实验.实验结果表明,黄金分割自适应控制能够实现管道压力的高精度控制,现场调试简单,该控制方案的优越性得到了验证.     

Time‐varying feedback for stabilization in prescribed finite time

This paper provides a time‐varying feedback alternative to control of finite‐time systems, which is referred to as “prescribed‐time control,” exhibiting several superior features: (i) such time‐varying gain–based prescribed‐time control is built upon regular state feedback rather than fractional‐power state feedback, thus resulting in smooth (C^m) control action everywhere during the entire operation of the system; (ii) the prescribed‐time control is characterized with uniformly prespecifiable convergence time that can be preassigned as needed within the physically allowable range, making it literally different from not only the traditional finite‐time control (where the finite settling time is determined by a system initial condition and a number of design parameters) but also the fixed‐time control (where the settling time is subject to certain constraints and thus can only be specified within the corresponding range); and (iii) the prescribed‐time control relies only on regular Lyapunov differential inequality instead of fractional Lyapunov differential inequality for stability analysis and thus avoids the difficulty in controller design and stability analysis encountered in the traditional finite‐time control for high‐order systems.     

Global output feedback regulation of nonlinear time delay systems subject to sensor measurement faults

This article studied the global output feedback regulation problem for a class of uncertain nonlinear time delay systems subject to unknown measurement faults on sensors. Different from the existing works, we consider the unknown time‐varying delays on the system states and relax their conservative condition on nonlinear functions. By introducing two novel time‐varying gains, a new global output feedback regulation algorithm is proposed, which ensures control parameters can be chosen flexibly. The proposed linear‐like controller is independent of the unknown time‐varying delays. Moreover, it has a simple structure, which is convenient for the implementation in practice. Based on the Lyapunov stability theory, it is strictly proved that all signals of the resulting closed‐loop system are globally bounded with the designed controller. Finally, a simulation example is presented to illustrate the effectiveness of the proposed output feedback regulation algorithm.     

多输入多输出非线性不确定系统连续高阶滑模控制

针对一类MIMO非线性不确定系统,提出一种新的连续高阶滑模控制算法.引入状态反馈使得系统高阶滑模控制问题等效转换为多变量不确定积分链的有限时间稳定问题,首先针对标称系统设计有限时间到达连续控制律,实现系统状态快速收敛,然后采用多变量非解耦形式超螺旋算法克服系统不确定性,实现鲁棒性,最终使得系统控制作用连续、滑模抖振得以大大抑制.基于二次型Lyapunov函数证明系统的有限时间稳定性.针对三阶不确定系统有限时间稳定和气垫船圆形航迹跟踪问题分别进行了仿真,验证了所提算法的有效性、鲁棒性.     

一类全局收敛的多变量自校正控制器*

本文将文[1]提出的多变量自校正控制算法推广到具有一般传输延时的多变量系统并进行了稳定性和收敛性分析。首先表明:即使对于具有任意传输延时的多变量系统,该自校正控制器仍具有全局收敛特性:以概率1输入输出向量采样均方有界,条件均方输出跟踪误差向量范数取得最小值。     

时变时滞不确定系统的鲁棒输出反馈控制

研究了时变时滞不确定系统基于状态观测器的动态输出反馈实现鲁棒镇定的分 析和综合问题.所研究的系统不仅同时包含时变状态时滞和时变控制时滞,而且包含时变未 知且有界不确定参数.提出了确保该系统可通过输出反馈鲁棒镇定的充分条件,并将该充分 条件转化为线性矩阵不等式(LMI)问题,最终通过求解两个LMI来构造输出反馈控制律.     

混合料矿槽模糊预估器的建立

混合料矿槽料位控制系统是一个大滞后、非线形、时变的控制系统。本文应用模糊预估器去实现混合料矿槽料位控制，通过近一年的运行，系统具有较强的鲁棒性。