时滞不确定线性系统的滑模控制

针对一类具有参数不确定性,并且具有状态时滞的线性系统,基于LMI方法,给出了系统存在滑动模态的充分条件,基于滑动面,进一步设计了到达运动控制器。仿真结果证实了该控制策略的可行性。     

一类不确定Markov跳跃系统的自适应滑模控制

讨论了一类具有Markov跳跃参数的不确定混合线性系统的滑模控制问题.通过线性矩阵不等式方法,给出了系统在滑模面上均方意义下指数稳定的充分条件.当匹配参数不确定项范数上界未知时,提出了一种参数自适应滑模控制器,确保系统的运动轨迹在有限时间内到达滑模面并一直保持在滑模面上.仿真结果表明,所设计的自适应滑模控制器对匹配参数不确定性具有的鲁棒性.     

不确定分布式时滞系统的鲁棒H∞状态反馈控制

针对一类不确定分布式时滞系统的鲁棒H∞控制问题,采用线性矩阵不等式的方法通过选择适当的lyapunov函数,得到了自治系统的鲁棒渐进稳定的充分条件。推导出了闭环系统鲁棒渐近稳定的充分条件,并设计了无记忆性H∞状态反馈控制器,使得对于所有允许的不确定性,闭环系统鲁棒渐近稳定且具有给定的H∞性能指标。给出了控制器存在时滞相关的充分条件,且控制器参数能够通过求解线性矩阵不等式得到,对于一个高阶的数值仿真系统,通过对线性矩阵不等式的求解可以得到最优H∞性能指标,及相应不等式的解。仿真证明了该设计方案的有效性。     

基于LMI的奇异不确定时滞系统鲁棒保成本控制

针对一类奇异不确定时滞系统的鲁棒保成本控制,假定其中的不确定性是范数有界,采用基于线性矩阵不等式（LMI）和构造适当的Lyapunov泛函相结合的方法,给出了系统的鲁棒保成本状态反馈控制器存在的条件。通过求解相应的线性矩阵不等式就可得到鲁棒保成本控制,所设计的保成本控制器对所有容许的不确定性不仅使得相应的闭环系统达到二次稳定,也能保证闭环成本函数不超过一个确定的界。通过数值算例及仿真验证了所给方法的有效性。     

时滞不确定奇异系统的鲁棒H∞控制

针对带时滞的奇异系统,研究基于状态反馈的鲁棒H∞问题,系统的状态矩阵、状态滞后矩阵和输入矩阵均含有范数有界不确定项。采用Lyapunov泛函方法,给出了带时滞的不确定奇异系统鲁棒渐近稳定且具有H∞范数界γ充分条件;利用含等式约束的线性矩阵不等式（LMI）方法,给出了此类系统控制存在状态反馈的充分条件,该条件等价于严格线性矩阵不等式可解性问题,利用严格LMI的可行解,得到控制器矩阵的参数化表示。该鲁棒控制器的渐进稳定性条件宽松,克服了时滞奇异系统稳定性问题条件中的等式约束,控制器求解算法可行、高效,并通过一个数值实例说明了该方法的有效性。     

具有饱和执行器的不确定时滞系统鲁棒控制

针对一类具有饱和执行器的不确定时滞系统鲁棒镇定问题,且不确定项满足范数有界条件.基于一个适当的Lyapunov泛函,通过引入奇异系统变换,得到了闭环系统渐近稳定的充分条件,给出了一种时滞相关的控制器设计方法,并以矩阵不等式形式表示.若事先选定参数,则该矩阵不等式可以转化为线性矩阵不等式.数例表明了该方法的有效性.     

含有时滞和时滞微分不确定系统的H∞滤波

研究含有状态时滞和状态时滞微分的参数不确定性系统的H∞滤波问题,其不确定性为多框架目标类型.对所有允许的参数不确定性系统,设计一个线性滤波器,使得由不确定性系统和滤波器构成的误差系统为渐进稳定的,同时使误差系统输入输出的传递函数的H∞范数满足性能指标要求.基于线性矩阵不等式技术,给出滤波器存在的充分条件及参数计算.以一个数值例子说明该方法的有效性和可行性.     

时滞不确定系统的广义H2控制

研究了一类同时具有时变状态时滞和凸多面体不确定性的连续时间系统的广义H2控制问题，采用线性矩阵不等式技术推导了此类不确定系统的鲁棒L2－L∞状态反馈控制器存在的充分条件，并将控制器的设计转化为一个凸优化的求解问题，所设计的控制器能够保证相对于所有能量有界的外界扰动信号，闭环系统的L2－L∞性能指标小于一定值，数值仿真验证了所提出方法的可行性。     

时滞相关滑模L2-L∞控制非线性不确定系统

针对一类非线性不确定时滞系统,依据变结构控制理论,设计了时滞相关滑模控制器使系统状态到达并保持在预先设计的比例-积分型滑模面上。在此基础上设计了无记忆L2-L∞状态反馈控制器,应用线性矩阵不等式方法,给出了系统滑动模态鲁棒渐近稳定且具有L2-L∞扰动衰减水平γ的时滞相关充分条件。应用锥补线性化方法将非凸可行性求解问题转化为受线性矩阵不等式约束的序列最小化问题。结合数值实例,通过时滞相关滑模控制器使系统状态稳定在给定的滑模面,应用Matlab中的LMI（Linear Matrix Inequation）工具箱求解得到了状态反馈控制器,并应用该状态反馈控制器使系统滑动模态鲁棒渐近稳定,且具有L2-L∞扰动衰减水平γ,证实了该方案的可行性。     

不确定时滞广义系统的H∞保性能控制

针对一类具有范数有界不确定性的连续时滞广义系统,采用线性矩阵不等式处理方法,研究了具有鲁棒H∞性能的保性能控制问题,并给出了问题可解的一个充分条件和H∞保性能控制器的设计,使得闭环系统不仅对于容许的参数不确性保持正则、稳定、无脉冲,而且能保证闭环系统的二次性能指标具有某一个上界以及给定的H∞性能γ。进一步,通过求解一个凸优化问题,给出了系统的H∞最优保性能控制器的设计方法。算例和仿真结果表明该方法的正确性和可行性。     

Robust adaptive sliding mode control for uncertain delta operator systems

In this paper, a robust adaptive sliding mode controller is presented for delta operator systems with mismatched uncertainties and exogenous disturbances. The parameters of the delta operator system are taken for norm‐bounded uncertainties. The exogenous disturbance is also assumed to be bounded. After the statement of a sufficient condition for the existence of linear sliding surface based on linear matrix inequality technique, a robust reaching motion control method for delta operator systems is presented. Afterwards, an adaptive sliding mode controller for delta operator systems is designed. A bridge between the robust adaptive sliding mode control and the delta operator system framework is made. Numerical example is given to illustrate the effectiveness of the developed techniques. Copyright © 2009 John Wiley & Sons, Ltd.     

Adaptive robust H∞ state feedback control for linear uncertain systems with time‐varying delay

This paper considers the problem of adaptive robust H_∞ state feedback control for linear uncertain systems with time‐varying delay. The uncertainties are assumed to be time varying, unknown, but bounded. A new adaptive robust H_∞ controller is presented, whose gains are updating automatically according to the online estimates of uncertain parameters. By combining an indirect adaptive control method and a linear matrix inequality method, sufficient conditions with less conservativeness than those of the corresponding controller with fixed gains are given to guarantee robust asymptotic stability and H_∞ performance of the closed‐loop systems. A numerical example and its simulation results are given to demonstrate the effectiveness and the benefits of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.     

Robust adaptive sliding mode control for uncertain time‐delay systems

This paper is devoted to robust adaptive sliding mode control for time‐delay systems with mismatched parametric uncertainties. Sufficient conditions for the existence of linear sliding surfaces are given in terms of linear matrix inequalities, by which the corresponding adaptive reaching motion controller is also designed. Simulation studies show the effectiveness of the control scheme. Copyright © 2008 John Wiley & Sons, Ltd.     

永磁直线同步电机自适应互补滑模控制

针对永磁直线同步电机(PMLSM)易受非线性因素影响而降低伺服系统鲁棒性的问题,提出一种自适应互补滑模控制方法。永磁直线同步电机的非线性因素包括系统参数变化、电机端部效应及外部不确定性的扰动。互补滑模控制将积分滑模面与广义误差滑模面相结合,将系统状态轨迹限定在两个面的交线上,缩短了状态轨迹达到滑模面的时间,提高了位置跟踪精度。为了进一步改善系统鲁棒跟踪性能,利用自适应控制对不确定扰动因素的上界进行估计,减小不确定因素对系统的影响,改善滑模控制的抖振现象。实验结果表明所提出的控制方法是有效可行的,自适应互补滑模控制不仅提高了系统的跟踪性能,而且更有效地抑制了不确定因素对控制系统的影响。     

Adaptive sliding mode control for fuzzy singular systems with time delay and input nonlinearity

This paper addresses the sliding mode control problem for a class of uncertain Takagi‐Sugeno fuzzy singular systems with state delay and subject to input nonlinearity. Our purpose is focused on designing an adaptive sliding mode controller for such a complex system. First, a new fuzzy integral‐type sliding function is designed. Then, an adaptive sliding mode control scheme is established such that the resulting closed‐loop system is insensitive to all admissible uncertainties and satisfies the reaching condition. Moreover, delay‐dependent sufficient conditions are derived such that the admissibility and the L₂‐L_∞ performance requirement of the sliding mode dynamics can be guaranteed in the presence of time delays, external disturbances, and sector nonlinearity input. Finally, the validity and applicability of the proposed theory are illustrated by a numerical example.     

一类不确定非线性系统的自适应模糊滑模控制

针对一类不确定非线性系统自适应模糊控制中,为了保证系统稳定性而附加监督控制问题,根据滑模控制原理并利用模糊系统的逼近能力,提出了一种Ⅰ型间接自适应模糊滑模控制方法。该方法取消了监督控制,用滑模控制器增加了逼近误差的自适应补偿,李雅普诺夫稳定性理论分析证明,控制系统全局稳定且跟踪误差收敛到零。将这种控制器应用到过程控制的典型对象液位控制中,仿真结果表明了该控制器的有效性和可行性。     

Delta算子不确定系统的最优保性能控制

研究了Delta算子描述下的具有范数有界参数不确定线性系统的最优保性能控制律的设计问题．运用线性矩阵不等式，首先证明了保性能控制律的存在的充分必要条件，然后用一个线性矩阵不等式的可行解给出了所有保性能控制律的一个参数化的表示．在此基础上，通过建立和求解一个凸优化问题，给出了最优保性能控制律的设计．最后，用一个例子验证了给出方法的可行性．     

Adaptive sliding mode observer design for a class of uncertain systems

State feedback method is quite popular in control engineering field. However, some popular properties of state feedback approach cannot be used while any of the system states cannot be obtained beforehand. Therefore, this paper proposes a new observer design for a class of uncertain systems through sliding mode control theory. Based on strictly positive real concept, the stability of the equivalent error system is verified. Further, by using the generalized matrix inverse approach, the proposed switching term can drive the error states to zero, and it ensures the global reaching condition of the sliding mode of the error system. Moreover, the presented sliding mode observer is proposed to possess the invariance property to the uncertainty and/or external disturbance. Furthermore, the developed sliding mode observer is extended to release the limitation of knowing the bounds of the lumped perturbations in advance. That is, not only a new sliding mode observer but also a new adaptive sliding mode observer is proposed in this paper. Finally, three examples are illustrated to demonstrate the validity of the proposed sliding mode observer and the proposed adaptive sliding mode observer. Copyright © 2014 John Wiley & Sons, Ltd.