基于磁流变减振器的半主动悬架时滞变结构控制

针对控制输入通道中存在的时滞对磁流变半主动悬架系统控制品质的影响,建立含时滞的1/4汽车磁流变半主动悬架模型。从磁流变半主动悬架系统的时滞微分方程出发,根据滑模变结构控制理论设计出磁流变半主动悬架系统时滞依赖滑模控制器。通过理论推导,利用线性矩阵不等式(Linear matrix inequality,LMI)处理方法把系统时滞稳定的条件转化为LMI可行性分析,保证系统稳定的最大临界时滞求取转化成LMI中的广义特征值最小化问题。Matlab/Simulink仿真及道路模拟振动台上实车试验结果表明,在系统临界时滞范围内,时滞依赖滑模控制器能从根本上保证系统的稳定性,削弱时滞对系统控制效果的影响,有效地改善汽车的乘坐舒适性。     

汽轮机/调速器系统的时滞无关分散控制器的设计

针对具有非线性关联作用和时变时滞的一类关联电力大系统,对其进行分散反馈控制。首先把非线性函数变化成子系统状态变量的二次有界不等式形式,然后基于Lyapunov稳定性理论,利用矩阵的Schur补定理及线性矩阵不等式方法,通过构造适当的Lyapunov泛函,得到了使电力系统渐近稳定的时滞无关的充分条件,并作为特例,给出了常...     

时滞独立的网络控制系统H∞控制器设计

介绍了网络控制系统中的时滞独立系统.利用Lyapunov稳定性定理和线性矩阵不等式(LMI)工具给出了H∞控制器存在的时滞独立网络控制系统的充分条件.通过求解一个具有线性矩阵不等式的凸优化问题,得出γ最小的H∞控制率.仿真实验结果显示,整个系统对干扰信号有较好的抑制作用.     

一类时滞系统的PID稳定控制器设计

针对工业控制过程中常见的时滞系统,给出了快速计算PI和PID控制器所有稳定参数集的方法。推导了系统开环不稳定情形下稳定控制器存在的必要性条件．通过在该稳定参数区域上进行性能指标寻优,可以得到满足控制器设计性能指标要求的PID控制器参数区域。仿真实例表明了该方法的优越性。     

一种改进的时滞不确定性系统鲁棒容错控制算法

研究了一类具有时滞不确定性系统的鲁棒容错控制问题,针对既有传感器失效,又有执行器失效的故障情形,通过引入一种无记忆的状态反馈控制器,基于Lyapunov稳定定理和运用线性矩阵不等式(LMI)的方法,给出了在传感器失效和执行器失效故障下具有鲁棒完整性的充分条件,并进行了证明。最后利用Matlab中的LMI工具箱进行了算例仿真,证实了这种设计方法的有效性和可行性,减少了当出现故障时需要先判断哪类故障的任务,为容错控制提供了便利。     

MATLAB LMI工具在鲁棒稳定性分析中的应用

针对一类普遍存在的不确定时滞系统，基于线性矩阵不等式(LMI)的描述进行系统的稳定性分析，得到了用一个线性矩阵不等式系统的可行性表示的鲁棒稳定性滞后依赖型条件。介绍了如何利用MATLAB软件中的LMI工具箱进行分析与设计，据此计算出最大的允许时滞界。针对此类系统的鲁棒稳定性分析给出了数值算例。     

一类不确定时滞混沌系统的输出追踪控制

对一类不确定时滞混沌系统的输出追踪控制问题进行了研究，提出了一种新的控制方法。该方法表明具有期望系统动力学行为的线性时不变系统可作为时滞沌系统输出跟踪的参考模型。然后设计了追踪控制器驱动时滞混沌的输出跟踪期望的线性系统。基于这种设计方法，被控时滞混沌系统的输出可以具有同期望的系统相同的行为。最后给出的仿真实例说明了所给方法的有效性。     

一类非线性切换系统的研究与仿真

利用MATLAB对一类非线性切换系统进行了仿真研究.利用多李雅普诺夫函数方法,通过解线性矩阵不等式,得到依赖状态的切换信号,从而得到渐进稳定的性质.最后通过仿真例子证明了所提出方法的有效性.     

广域测量时变时滞电力系统鲁棒稳定性的新判据

针对某一增广的Lyapunov-Krasovskii函数,利用二阶Bessel-Legendre不等式和改进的逆凸不等式方法导出了稳定性判据,并在求导过程中对改进的广义Lyapunov-Krasovskii函数的积分项进行分段处理,避免缩放性误差。通过单机无穷大系统进行实例仿真,得出系统时滞稳定裕度的计算结果,由此实现了对这一方法有效性与可行性的成功验证。     

Robust absolute stability criteria for uncertain Lurie interval time-varying delay systems of neutral type

This study investigates the delay-dependent robust absolute stability analysis for uncertain Lurie systems with interval time-varying delays of neutral type. First, we divide the whole delay interval into two segmentations with an unequal width and checking the variation of the Lyapunov–Krasovskii functional (LKF) for each subinterval of delay, much less conservative delay-dependent absolute and robust stability criteria are derived. Second, a new delay-dependent robust stability condition for uncertain Lurie neutral systems with interval time-varying delays, which expressed in terms of quadratic forms of linear matrix inequalities (LMIs), and has been derived by constructing the LKF from the delayed decomposition approach (DDA) and integral inequality approach (IIA). Finally, three numerical examples are given to show the effectiveness of the proposed stability criteria.     

Improved delay-dependent stability analysis for neural networks with time-varying delays

In this paper, the problem of delay-dependent asymptotic stability analysis for neural networks with time-varying delays is considered. A new class of Lyapunov functional is proposed by considering the information of neuron activation functions adequately. By using the delay-partitioning method and the reciprocally convex technique, some less conservative stability criteria are obtained in terms of linear matrix inequalities (LMIs). Finally, two numerical examples are given to illustrate the effectiveness of the derived method.     

Stability analysis of multiple time-delayed system

A general class of linear time-invariant systems with time delays is studied. A number of methodologies have been suggested to assess the stability in the parametric domain of time delay or coefficient. This study offers an exact, structured and robust methodology to determine the stability regions of uncertain parameters in both time-delay space and coefficient space. The Rekasius transformation is used as a connection between time-delay space and coefficient space. An explicit analytical expression in terms of the system parameters which reveals the stability regions(pockets) in the domain of time delay and coefficient is presented. The method starts with the determination of all possible values of uncertain parameters which result in purely imaginary characteristic roots. In addition, some special stability boundaries are also discussed. After generating stability boundaries in parametric space, the two-step determination procedure is proposed to determine the actual stability regions. Such an approach can be used to determine the stability regions of any uncertain parameters of any retarded time-delay system. A complete example case study is also provided.     

基于工程轮式车辆模型的悬架系统研究(二)——工程轮式车辆悬架模型的仿真控制研究

继《基于工程轮式车辆模型的悬架系统研究(一)》对工程轮式车辆模型的悬架系统进行了建模之后,首先求解LMI的输出反馈控制器,并提出主动悬架的干扰抑制指标及评价函数,进而用MATLAB进行仿真.经过对仿真结果分析可知,主动悬架系统较被动悬架系统的工况有很大的改善,车身的质心加速度、俯仰角加速度以及前后悬架的动行程都有较大幅度的降低,减震效果明显,车辆的行驶平顺性得到了改善.     

Improved delay-dependent stability of neutral type neural networks with distributed delays

This paper deals with the problem of improved delay-dependent stability analysis of neutral type neural networks with distributed delays. These conditions are in terms of linear matrix inequality (LMI), easily checked by recently developed algorithms in solving linear matrix inequalities (LMIs). Finally, numerical examples demonstrate effectiveness of the proposed method.     

闭式水循环系统的稳定性分析

针对闭式水循环系统,采用关闭某个支路,进行网络求解,计算其他支路的流量偏离系数的方法,分析了稳定性随各种影响因素的变化规律。结果表明：减小干线阻抗,增大支路阻抗,可以提高系统的稳定性。改变动力的集中调节对系统的稳定性没有影响,改变阻力的集中调节将使系统的稳定性变差。泵的特性曲线对系统的稳定性有影响,平坦型对应的稳定性优于陡降型对应的稳定性。异程系统,离热源最远支路的稳定性最差。同程系统,网路中部的支路稳定性最差;同程系统的稳定性总体上不如异程系统。     

匹配机械弹性车轮的电子稳定控制器参数分析

为了提高匹配机械弹性车轮(MEW)的某越野车操纵稳定性,考虑MEW与传统子午线轮胎侧偏特性存在的不确定性摄动,基于Lyapunov稳定性理论为电子稳定控制(ESC)程序设计了鲁棒反馈控制器;引入轮胎侧偏刚度不确定性的范数有界模型,运用Schur补引理和线性矩阵不等式(LMI)求解反馈矩阵。设定不同的车速和路面附着系数,通过搭建CarSim/Simulink联合仿真平台对控制器展开鱼钩试验,仿真结果表明,匹配MEW的ESC控制器能够保证车辆行驶的稳定性,横摆角速度与质心侧偏角跟踪误差分别稳定在0.03~0.3 rad/s与0.06~0.1 rad之内,并且设计的控制算法对MEW在05倍普通充气车轮侧偏刚度变化范围内具有很好的鲁棒性,从而为匹配MEW的整车主动安全控制提供了理论参考。     

Robust stability and stabilization of fractional order linear systems with positive real uncertainty

This paper investigates the robust stability and stabilization of fractional order linear systems with positive real uncertainty. Firstly, sufficient conditions for the asymptotical stability of such uncertain fractional order systems are presented. Secondly, the existence conditions and design methods of the state feedback controller, static output feedback controller and observer-based controller for asymptotically stabilizing such uncertain fractional order systems are derived. The results are obtained in terms of linear matrix inequalities. Finally, some numerical examples are given to validate the proposed theoretical results.     

Robust state estimation for a class of uncertain nonlinear systems: Comparison of two approaches

In this paper, two approaches for robust state estimation of a class of Lipschitz nonlinear systems are proposed. First, a novel Unknown Input Observer (UIO) is designed without observer matching condition satisfaction. Then, an $H_{\infty }$ observer for approximate disturbance decoupling is proposed. Sufficient conditions for the existence of both proposed observers are derived based on a Lyapunov function. The achieved conditions are formulated in terms of a set of linear matrix inequalities (LMIs) and optimal gain matrices are obtained. The minimum values of the disturbance attenuation levels for both methods are obtained through solving optimization problems. Finally, the proposed approaches are compared by simulation studies of an automated highway system.     

船用起重机主动升沉补偿系统时延的实时控制研究

针对基于液压驱动的主动升沉补偿系统在工作过程中所存在的非线性以及系统时滞等使系统稳定控制难度加大的问题,进行了基于广义预测控制的控制系统算法的设计;在系统控制稳定的基础上,引入极短期预报技术,解决了控制系统实时补偿输出总是滞后于起重母船升沉运动的问题,实现了主动升沉补偿系统对实时补偿功能的要求;最后在MATLAB/Si...