一种不确定离散时间系统的变结构控制方法

针对离散时间系统变结构控制中存在的问题,利用指数趋近律的趋近特性,提出一种新的离散变结构控制方法.利用递推估计的方法设计变结构控制律,有效地抵消了线性系统中慢变不确定性的影响,实现了对慢变非线性系统的控制.该方法克服了以往控制方法中需已知扰动上界的限制,降低了抖振,加快了趋近速度.仿真结果证明了该方法的有效性.     

基于协调优化算法的滑模变结构控制研究

本文提出一种基于协调优化算法的滑模变结构控制方法.它以稳态误差和控制切换频率作为系统优化性能指标.边界层宽度调节率作为优化参数.采用基于遗传算法的多目标优化方法优化滑模变结构控制的设计.能使滑模变结构控制系统获得很好的综合性能.尤其是,在滑模变结构控制的设计中,使用多目标优化技术,可以为强非线性时变液压伺服系统系统提供强鲁棒性和高精度控制.     

舰船混沌运动的单输入自适应变结构控制

针对在舰船混沌运动控制中由模型不确定性及外部扰动无法确知所引起的控制结果无法保证的问题,采用自适应控制与滑模变结构控制相结合的方法,在设计切换函数时,将符号函数转移到控制输入的一阶导数当中,有效抑制了变结构控制中的抖振问题,并提出了一种单输入自适应滑模变结构控制方法.实验结果表明,与传统滑模变结构控制相比,新方法能够在系统模型具有不确定性及未知外部扰动的情况下实现舰船混沌运动的良好控制,为舰船混沌运动控制提供了一种可靠的工程实现途径.     

一种不确定离散时间系统的变结构控制方法

针对离散时间系统变结构控制中存在的问题，利用指数趋近律的趋近特性，提出一种新的离散变结构控制方法，利用递推估计的方法设计变结构控制律，有效地抵消了线性系统中慢变不确定性的影响，实现了对慢变非线性系统的控制，该方法克服了以往控制方法中需已知扰动上界的限制，降低了抖振，加快了趋近速度。仿真结果证明了该方法的有效性。     

基于趋近律滑模的台车式倒立摆系统控制研究

本文设计了一种基于趋近律方法的滑模控制器。趋近律方法是滑模变结构控制的一种典型控制策略。这种控制方法不仅可以对系统在切换面附近或沿切换面的滑模运动段进行分析,而且可以有效地对系统趋近段的动态过程进行分析和设计,从而保证系统在整个状态空间内具有较好的运动品质。仿真结果表明,将两种典型的趋近律滑模控制方法应用到台车式倒立摆系统中,指数趋近律滑模变结构方法有更好的稳定性和抗干扰能力。     

基于隐Lyapunov 函数的软变结构控制: 一种控制策略

针对变结构控制的抖振问题,基于隐Lyapunov函数,提出一种新的控制策略:软变结构控制.首先给出软变结构控制的定义和控制器的构造方法;然后设计软变结构控制器和隐Lyapunov区域,给出了控制不受限和控制受限两种情形的软变结构控制,同时,分析了带有状态观测器的软变结构控制.软变结构控制是无滑模的变结构控制,能有效削弱抖振,保持高速调节速度和缩短趋近时间.仿真实例表明了该方法的有效性和可行性.     

固定翼无人机自动着陆的一体化制导控制

本文基于制导控制一体化方法的思想,将滑模变结构控制和自抗扰控制技术结合于动态面控制结构中,提出一种固定翼无人机自动着陆方法.在建立六自由度无人机模型、无人机和目标点间的相对视线角度模型的基础上,在动态面控制框架下加入滑模变结构控制来设计制导控制一体化方法.在此过程中加入自抗扰控制技术,提高了系统对未建模部分、参数的不确定性和外界干扰的鲁棒性,并抑制了滑模变结构控制的抖振.该方法使得无人机在平稳地飞向目标点的同时能够满足着陆视线角度的约束.文中详细论述设计思想和设计方法,最后通过仿真验证说明本文方法的有效性.     

基于模糊神经网络的滑模控制

研究了一类不确定性非线性系统的滑模变结构控制,提出了一种基于模糊神经网络（Ｆｕｚｚｙ Ｎｅｕｒａｌ Ｎｅｔｗｏｒｋｓ）的滑模变结构设计方法,设计了控制器的结构,利用动态反向传播算法实现滑模控制,这种方法与一般变结构控制相比不但具有强的鲁棒性而且还能有效地消除抖动现象,同时在设计中不需要知识系统中不确定性和扰动的上界,另外还运用Ｌｙａｐｕｎｏｖ函数从理论上分析上了系统的稳定性。仿真结果说明了本文所提     

反馈线性化最优滑模变结构励磁控制

将滑模变结构控制具有对摄动的完全自适应性与反馈线性化理论和最优控制理论结合起来,针对励磁系统,提出了一种基于反馈线性化最优的滑模变结构控制方法,给出了控制器的设计过程,避免了通常设计滑模变结构控制器时参数选取的盲目性,保证系统运行在较佳状态,且按指数趋近律设计的滑模变结构控制器不易产生抖动。仿真结果表明,这种方法能够充分发挥滑模变结构控制的鲁棒性优点,对电力系统具有较好的稳定作用。     

基于液压定位系统的滑模变结构控制器的设计

由于液压定位系统的数学建模中各种简化计算,或者是系统建模参数的不精确导致了液压系统具有较差的鲁棒性能。采用常规的PID难以克服这些因数带来的影响。本文设计了一种滑模变结构控制器,通过Lyapunov方程来分析滑模变结构的控制方法。通过仿真实验表明:本文设计的滑模控制策略能够保证系统定位控制处于精度控制范围之内,同时也证明了滑模变结构控制策略在液压定位系统中具有很好的鲁棒性。     

变结构控制的抖振问题研究

变结构控制是一种鲁棒控制方法,它对系统参数的变化和外部干扰具有理论上的完全鲁棒性,然而,变结构控制系统在滑模面上的高频抖振是其工程应用的主要障碍.该文将抖振削弱方法分为两类：一类是传统控制方法,它通过改变变结构控制器的构造方式来削弱抖振;另外一类是组合控制方法,它通过引入其他先进控制理论（如智能控制、自适应控制等）来削弱抖振.目前,多种组合控制方法被广泛采用,但缺乏对结合方式的系统性分析,本文以模糊变结构组合控制方法为例,详细探讨了多种形式的结合方式.最后指出了处理抖振问题的发展方向.     

FUZZY SLIDING MODE CONTROL WITH PIECEWISE LINEAR SWITCHING MANIFOLD

Variable Structure Control (VSC) has been successfully established in control systems engineering in the past two decades. Recently, Fuzzy Sliding Mode Control (FSMC) techniques have drawn the attention of the scientific community, due to their effectiveness in reducing the typical chattering phenomenon arising in VSC. In this paper we present a novel FSMC technique for a class of second order dynamical systems based on a piecewise linear sliding manifold. The proposed approach enhances the effectiveness of VSC in the presence of a saturated control input. In addition, employing the proposed VSC with fuzzy rule based algorithms results in smooth dynamics when the trajectory is in the vicinity of the switching manifold, as opposed to the typical chattering arising under classical VSC. After illustrating the proposed strategy on a simple design example, the approach is applied to an inverted pendulum, a well‐known benchmark for automatic control techniques. The effectiveness of the technique is shown both by means of simulation tests and experiments on a lab equipment. Future research directions include the extension of the technique in the presence of uncertainties in the plant model.     

输电系统自动控制的变结构方法

远距离输电系统的传输能力受到暂态稳定极限的限制，本文对于非线性变结构控制系统的切换面的设计提出了一种新的方法，并且将此方法于输电系统综合控制，数值模拟表明用这种方法设计的变结构控制能够大幅度地提高输电系统的暂态稳定极限。     

Variable structure controllers for unstable processes

A variable structure control (VSC) method for unstable industrial processes is proposed. The proposed control method is able to provide a highly satisfactory system performance and to tackle with robustness issues of the processes in the presence of uncertainties. An ITAE-based numerical tuning algorithm for acquiring optimal control parameters, and a direct auto-tuning mechanism for the proposed controller are also provided. The performance of the proposed VSC method is illustrated on some unstable process models including a continuous stirred tank reactor (CSTR), in order to show its effectiveness, validity and feasibility.     

变结构预测控制

在变结构滑模控制的基础上，引入参数辨识和状态预估，形成了一种新的控制技术－变结构预测控制，变结构预测控制增强了变结构没模控制的鲁棒性，使之对具有大滞后和变参数的对象也能进行有效的控制，有较强的自适应能力。一般自适应控制技术闭环参数不完全辨识问题，在变结构预测控制中获得了解决，这就使控制更为精确和有效。本文探讨和研究了变结构预测控制技术的实同及其控制特性，并由仿真和实验结果加以验证。     

传统模糊控制的双重特性

对传统模糊控制的双重特性进行了深入探讨.定性和定量分析都显示出模糊控制 集中了相对应的线性控制和变结构滑模控制的特性.该双重特性可以通过改变属性函数和增 益来调整.高的增益和多个属性函数会导致强的变结构控制和弱的线性控制,反之亦然.仿 真结果证实了以上分析.因变结构控制更多地用于较复杂过程,而线性控制则用于较简单过 程,故独特的双重特性对模糊控制的设计和调整影响重大.对于简单过程,模糊控制的初始 增益可以用已调好的线性控制参数来设计;对于复杂过程,可用变结构控制理论来设计.模 糊控制的双重特性有助于解释其对复杂过程有较佳的鲁棒性.     

On the variable structure control approach with sliding modes to robust finite-time consensus problems: A methodological overview based on nonsmooth analysis

When controlling cyber–physical systems via consensus algorithms, the robustness issue is of paramount importance because of model mismatching and/or disturbances that generally modify the Laplacian flow dynamics associated to the overall network, compromising the possibility to achieve any expected, orchestrated emergent behavior. To face this issue, the Variable Structure Control (VSC) approach has recently been shown to be an effective tool in designing control protocols over networks, providing robustness and often yielding finite-time convergence. Moreover, VSC further enables the decoupling of simultaneous control objectives where reaching a consensus state is only part of a more complex task, for instance as it happens in distributed optimization. Thus motivated, this paper overviews, from a tutorial perspective, some selected recent advances in the application of VSC with Sliding Modes to design robust consensus controllers in both the leader-less and the leader-following settings. Efforts are also made to unify the notation and to discuss the theoretical foundations of the nonsmooth analysis tools at the basis of their design for a wide readership unfamiliar with these problems and formal tools. To this aim, examples supporting the treatment, and numerical simulations, are given and discussed in detail. Finally, hints for future investigations along with some current open problems are provided.     

Hybrid Control Scheme for Robust Tracking of Two-Link Flexible Manipulator

The hybrid control scheme is proposed to stabilize the vibration of a two-link flexible manipulator while the robustness of Variable Structure Control (VSC) developed for rigid manipulators is maintained for controlling the joint angles. The VSC law alone, which is designed to accomplish only the asymptotic decoupled joint angle trajectory tracking, does not guarantee the stability of the flexible mode dynamics of the links. In order to actively suppress the flexible link vibrations, hybrid trajectories for the VSC are generated using the virtual control force concept, so that robust tracking control of the flexible-link manipulator can also be accomplished. Simulation results confirm that the proposed hybrid control scheme can achieve more robust tracking control of two-link flexible manipulator than the conventional control scheme in the presence of payload uncertainty.     

Robust adaptive tracking control of distributed delay systems with actuator and communication failures

This paper is concerned with the robust adaptive fault‐tolerant tracking control problem for a class of distributed delay systems against faulted and perturbed actuators and communications. As all the faults on actuators and communications, network delays in control and communication channels, and perturbations in communications and exogenous disturbances are unknown, some adaptation schemes are developed to adjust controller parameters in real‐time for constructing a class of distributed compensation controllers based on the delayed signals. Then, according to the information from the adaptive mechanism, the effect of each actuator and communication fault, network delay, channel perturbation and exogenous disturbance can be eliminated completely by using the proposed distributed adaptive‐state feedback controllers. Furthermore, asymptotic tracking results of the distributed closed‐loop systems can be achieved based on Lyapunov stability theory. An example is provided to further illustrate the effectiveness of the proposed direct adaptive design technique. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society