基于状态预估的非线性时滞系统控制的分步设计

研究了非线性时滞系统基于状态预估和分步设计思想的稳定化控制器设计问题。针对一类单控制滞后的仿射非线性时滞系统,利用非线性状态变换得到—简单的中间非线性时滞系统模型,引入带有将来预估值的非线性状态反馈,得到一线性时滞系统模型,并利用一带有控制记忆的积分变换进行精确无滞后化变换,最后得到一无滞后的线性能控型系统,从而利用分步设计的思想,实现非线性时滞系统的稳定化控制。最后通过一数值例子的仿真说明了该方法的有效性。     

基于分步变换的离散时滞系统控制器设计及应用

研究基于分步变换及设计思想的具有控制滞后的离散时滞系统控制器设计问题.针对一 类控制滞后的离散时滞系统,提出了一种带控制记忆的时滞变换,使得原时滞系统经过分步等 价变换后得到无滞后的线性能控系统,从而利用分步设计的思想实现离散时滞系统控制器设 计的目的,并给出了其稳定性证明.最后以一工业电加热炉被控对象为例,通过仿真说明了 该方法的有效性和可行性.     

一种基于随机平均的最优时滞控制方法

基于时滞系统的随机平均法与随机动态规划原理,提出一种非线性系统的随机最优时滞控制方法．先应用时滞随机平均法,将非线性系统的随机最优时滞控制问题变换成非时滞的最优控制问题;再根据随机动态规划原理,建立其动态规划方程;由此确定最优时滞控制律;最后,通过一个例子说明该时滞控制方法的控制效果．     

离散区间二型Tagaki-Sugeno模型时滞系统广义耗散控制设计

对带有时变时滞和外部扰动的一类离散区间二型Tagaki-Sugeno(T–S)模型非线性系统,研究了其广义耗散性能分析与状态反馈控制器的设计问题.与一型T–S模糊系统相比,区间二型模糊系统能更好地处理隶属函数中的不确定信息.首先,通过模型转换的方法,对系统的滞后状态进行变换,从而将时变时滞的不确定性从原系统中分离出.根据转换后的仅含定常时滞和具有有界误差范数的两个子系统,利用时滞依赖的李雅普诺夫-克拉索夫斯基泛函方法推导出了使系统渐近稳定并具有广义耗散性能的充分条件.接着,设计了保证闭环系统渐近稳定并具有广义耗散性能指标的状态反馈控制器.最后由数值仿真验证了设计方法的有效性.     

一类非线性状态时滞系统的基于采样控制器的渐近稳定问题

针对一类含有状态时滞的非线性系统,利用采样控制方法研究其渐近稳定问题.解决这一问题的关键在于对系统时滞的处理,以及对由于采样方法而产生的状态增长误差进行估计.由于所考虑的时滞是常时滞,可以利用分割方法对系统时滞进行分割,将时滞划分成与采样时间长度相同的数个时间区间,并基于这种分割,通过数学归纳法对系统状态增长误差进行估计.通过坐标变换引入一个比例增益压制系统的非线性项,然后设计含有比例增益的状态采样观测器和采样控制器,结合非线性时滞系统的Lyapunov泛函方法分析闭环系统的稳定性,最终确定比例增益和采样时间需要满足的条件,以保证闭环系统的渐近稳定性.最后通过数值例子表明所用研究方法以及所得研究结果是有效的.     

线性时滞系统的时滞相关鲁棒控制

讨论了同时具有输入时滞与状态时滞的线性系统的时滞相关鲁棒控制问题.将矩阵分解思想应用于线性时滞系统的控制综合,借助于积分不等式,利用Lyapunov_Krasovskii泛函方法,得到了系统经无记忆状态反馈后可镇定的、基于LMI的时滞相关条件.既不要对原系统进行模型变换,也不要对交叉项进行界定.最后的实例说明了本文方法的有效性.     

非线性滞后It(?)随机系统的滞后无关均方渐近稳定性

研究非线性滞后Ito随机系统的滞后无关均方渐近稳定性,将关于线性时滞不等式的Halanay不等式推广到非线性情形,用Lyapunov函数和关于时滞随机系统的比较原理,得到了非线性滞后Ito随机系统滞后无关均方渐近稳定性的一些判据。     

分数阶时滞复Lorenz混沌系统的控制与同步

基于分数阶时滞非线性系统稳定性理论,设计线性反馈控制器,实现分数阶时滞混沌系统的控制;基于矩阵配置控制器的设计方法,利用时滞分离法,实现参数未知的分数阶时滞混沌系统的同步。以分数阶时滞复Lorenz系统为例进行了研究,分别分离原系统各个变量的实部和虚部,将其转化为分数阶时滞非线性系统,研究其混沌特性,实现了混沌系统的控制以及利用矩阵配置控制器的设计方法实现了参数未知的混沌系统的同步,数值仿真验证了结果的有效性,易于工程实现。     

不确定时滞系统鲁棒镇定新方法

针对一类同时具有状态和控制滞后的不确定时滞系统,提出了一种新的时滞依赖型鲁棒镇定设计方法.通过引入一种新的线性状态变换,分离出时滞依赖因子,采用Lyapunov-Krasovskii泛函方法,导出了不确定时滞系统可鲁棒镇定的时滞依赖型的新判据,所得结论以线性矩阵不等式组的解的形式表示.仿真结果表明所得结论较之已有结果更为简单,具有更小保守性,且有更广泛的应用范围,不仅可以解决小时滞问题,也可用于解决大时滞问题.     

低速行驶重型车辆的动力学系统建模与非线性控制

考虑低速行驶工况下的重型车辆，本文建立其纵向行驶驱/制动系统的非线性动力学方程. 在此基础上采用反馈线性化方法将驱/制动工况下的非线性系统转化为线性可控正则型，并针对制动工况下非线性系统存在的控制时滞，提出一种基于非线性SMITH 预估方法的反馈线性化变换，该变换在有效补偿控制时滞同时，实现了制动系统的线性可控正则型转换. 最后，分别基于驱/制动系统的线性可控正则型设计跟踪控制器，实现了车辆低速工况的加/减速度精确跟踪控制.     

Research on the Low-order Control Strategy of the Power System With Time Delay

In this paper, the design problem of the low-order controller is considered for the power system with a fixed time delay. A linear model of the power system with time delay is firstly established. Then the proportional-integral-differential (PID) controller, which is the typical low-order controller, is designed to improve the stability of the power system. The stabilizing region of the PID controller is obtained. The control parameters chosen arbitrarily in the resultant region can ensure the stability of the power system. Finally, based on the stabilizing result, the PID controller satisfying the H_∞ performance index is designed, which improves the robustness of the whole power system. The main advantage of the proposed method lies in that there is no need to approximate the model of the power system. The method can be further extended to the power system which is more complex.      

一类非线性不确定时滞系统的鲁棒H∞控制

基于稳定性理论，研究了一类具有状态非线性不确定性的线性时变时滞系统的鲁棒控制器的设计问题．在非线性不确定性满足增益有界条件下，得到了该类时变时滞系统依赖于时变延迟导数的最大值的满足鲁棒性能的一个充分条件．通过求解一个线性矩阵不等式（LMI），即可获得鲁棒H∞控制器．给出的两个具体算例说明了该方法的有效性．     

多输入非线性系统控制的分步变换与设计

研究多输入非线性系统基于分步变换及设计思想的非线性控制器设计问题。针对一般多输入非线性系统，首先利用非线性状态变换的方法进行非线性变换，得到一中间非线性系统模型，然后引入状态反馈，使得闭环系统为线性能控标准模型；从而利用分步设计的思想，实现非线性系统的最优控制。最后以－液位－温度控制系统为例，通过仿真说明该方法的有效性和可行性。     

不确定性时滞系统的鲁棒镇定控制器设计——LMI 方法*

采用线性矩阵不等式方法,研究一类不确定性动态系统,这类系统具有多重时变状态时滞多重时变控制输入时滞,其不确定性满足范数有界条件。我们得到一了类不确定性时滞系统的可状态反馈镇定的充分条件。     

具有时滞的线性奇异系统镇定的Riccati方程方法

本文考虑了具时滞的线性奇异系统的镇定问题，利用Ｒｉｃｃａｔｉ方程方法给出了系统无记忆反馈控制器的设计，并得到了系统可经状态反馈镇定的条件。     

STATE FEEDBACK CONTROLLER DESIGN OF NETWORKED CONTROL SYSTEMS WITH PARAMETER UNCERTAINTY AND STATE‐DELAY

This paper is concerned with the controller design of networked control systems. The continuous time plant with parameter uncertainty and state delay is studies. A new model of the networked control system is provided under consideration of the nonideal network conditions. In terms of the given model, a controller design method is proposed based on a delay dependent approach. The maximum allowable synthetical bounds related with the discarded data packet and network‐included delay and the feedback gain of a memoryless controller can be derived by solving a set of linear matrix inequalities for the stabilizablity of the networked control system based on Lyapunov functional method. An example is given to show the effectiveness of our method.     

Stabilization Criteria for Singular Fuzzy Systems With Random Delay and Mixed Actuator Failures

The problem of reliable sampled‐data control design for uncertain singular fuzzy system with randomly occurring delay and nonlinear actuator failures is studied in this paper. The fault model is composed of two parts in which, linear part stands for the gain missing of actuators that vary with the true control input linearly, while the nonlinear part indicates some bounded nonlinear variation. Moreover, the time delay which encountering in the proposed controller is assumed to be randomly varying and satisfies Bernoulli distributed probabilities. By constructing a proper time‐dependent Lyapunov functional, some novel sufficient conditions are derived in terms of linear matrix inequalities (LMIs) for the existence of robustly stochastically stabilizing reliable sampled‐data controllers. Two simulation examples are given to demonstrate the effectiveness of the proposed method.     

Delay‐range‐dependent control of nonlinear time‐delay systems under input saturation

This paper describes a delay‐range‐dependent local state feedback controller synthesis approach providing estimation of the region of stability for nonlinear time‐delay systems under input saturation. By employing a Lyapunov–Krasovskii functional, properties of nonlinear functions, local sector condition and Jensen's inequality, a sufficient condition is derived for stabilization of nonlinear systems with interval delays varying within a range. Novel solutions to the delay‐range‐dependent and delay‐dependent stabilization problems for linear and nonlinear time‐delay systems, respectively, subject to input saturation are derived as specific scenarios of the proposed control strategy. Also, a delay‐rate‐independent condition for control of nonlinear systems in the presence of input saturation with unknown delay‐derivative bound information is established. And further, a robust state feedback controller synthesis scheme ensuring L₂ gain reduction from disturbance to output is devised to address the problem of the stabilization of input‐constrained nonlinear time‐delay systems with varying interval lags. The proposed design conditions can be solved using linear matrix inequality tools in connection with conventional cone complementary linearization algorithms. Simulation results for an unstable nonlinear time‐delay network and a large‐scale chemical reactor under input saturation and varying interval time‐delays are analyzed to demonstrate the effectiveness of the proposed methodology. Copyright © 2015 John Wiley & Sons, Ltd.