一类关联非线性系统的全局镇定

研究一类线性部分为传递函数,且带有不确定非线性部分的两个相互独立的输出反馈非线性系统关联后的反馈镇定问题.结合Lurie型直接控制系统,给出系统输出全局稳定的充分条件,最后对一个数值例子作仿真,说明了本文方法的有效性.     

解析嵌入式计算机联锁控制系统

信号设备必须安全性和可靠性非常高,嵌入式计算机连锁控制系统能够满足信号设备的要求。本文主要分为三个部分,第一部分,简单介绍了嵌入式系统的功能、组成和特性;第二部分,详细分析了控制器的软件体系,具体包括Petri网原理,连锁软件建模,仿真测试连锁模型;研究了控器的安全性和可靠性,研究表明,该控制器达到了信号设备安全性、可靠性的相关要求。第三部分,概述嵌入式计算机连锁控制系统的作用和影响。     

非线性控制系统与状态空间的几何结构

首行从整体化的观点定义了一种建立在黎曼流形上的非线性控制系统,给出了系统的状态方程在黎曼流形的局部坐标系下的表达式,讨论了黎曼流形的几何结构对非线性系统的影响,研究了非线性系统的能控性和能观测性,其次,利用对合分布与全测地子流形的性质,给出了建立在黎曼流形上的非线性系统的局部能控结构分解,局部能观结构分解和Kalman分解,第三,分别利用彼此正交的对合分布族和递增对合分布族与全测地子流形族的性质。研究了建立在黎曼流形上的非线性控制系统平等解耦问题和级联解耦问题,以及仿射非线性控制系统的局部干扰解耦问题。     

非线性控制系统的发展

本文历史地将非线性控制系统的研究分成六个部分来回顾其发展线索,对重要的研究结 果和有代表性的方法进行了综述,并揭示了一些有待解决的问题.     

解析工业编程语言国际标准IEC 61131-3

IEC61131-3是第一个为工业控制系统提供标准化编程语言的国际标准。该标准针对工业控制系统所阐述的软件设计的概念和软件模型等适应了当今世界软件、工业控制系统的发展方向，是一种非常先进的设计技术。符合IEC61131—3的软件系统是一个结构完美、可重复使用、可维护的工业控制系统软件，不但能被应用在PLC（可编程控制器），而且还能被应用在运动控制系统、分散型控制系统和软逻辑／PC，SCADA等。本专题包括六章，第一、二、三、四、六章是对IEC61131—3国际标准的介绍，第五章是对IEC61131国际标准通信部分的介绍。 第一章主要对IEC61131—3国际标准的一些主要特点、PLCopen国际组织及其在国内外的发展情况作了简单介绍； 第二章通过IEC国际标准的两个模型的介绍，从理论角度对IEC国际标准所具备的诸多优点作了理论剖析和阐述； 第三、四章主要对IEC61131—3国际标准的两种文本化语言IL和ST及三种图形语言FBD，LD和SFC做了简单介绍，使读者对IEC61131—3程序语言及其编程有一基本认识； 第五章从理论上对IEC61131-3编程系统如何与其它的工业自动化系统进行通信和集成作了简介，以让读者了解到IEC61131国际标准所具有的开放性和先进性。 第六章包括两部分： 第一部分主要介绍了一个IEC61131—3编程系统所应具有的一些主要特征； 第二部分举例说明了如何用IEC61131—3编程系统解决一个实际的问题。[编者按]     

非线性系统的几何方法（上） 几何方法与几何基础

本文介绍控制理论的一个新的分支——非线性系统的几何理论。第一部分包括:几何理论的特点和分析方法,几何基础以及非线性系统是如何用几何方法来描述的。第二部分介绍几何理论的现状;主要研究方向,进展情况以及尚待解决的问题。最后,根据目前的动态对今后的主要发展趋势作一些分析和预测。     

非线性支持向量机若干关键问题研究

首先,对非线性二分类支持向量机方法中的几个关键问题进行了研究;其次,阐明了非线性映射在解决非线性分类问题时所起的作用,揭示了维数灾难的具体内涵,理清了核函数方法的本质;第三,提出了求取核函数中隐含非线性映射的方法,获取了非线性二分类支持向量机的表达式;第四,利用二分类支持向量机完成了一系列数据分类实验。     

基于支持向量机逼近的内模控制系统及应用

针对同步发电机组汽门系统, 文章研究了一种基于支持向量机逼近的内模控制系统. 所研究的控制系统包括两个主要部分: 支持向量机逼近逆控制器、内模框架下的不确定性补偿. 由基于泰勒扩展的输入输出逼近模型计算逆控制律, 并由非线性系统辨识来实现. 同时, 采用一个鲁棒滤波器实现内模框架下的不确定性补偿. 针对汽门系统的仿真实验验证了该控制系统的优良性能.     

基于EPA的电机控制系统的开发

本文首先介绍了基于EPA的控制系统的两个重要组成部分:EAP功能块和EPA组态软件。然后对基于EPA的电机控制系统各个设备作了简要介绍,接着重点论述了EPA功能块的组态和控制系统的工作原理。最后对控制系统的运行了分析,分析结果表明该控制系统达到了一定的控制效果。     

交流伺服系统摩擦力补偿和优化滑模仿真

低速稳定性是伺服系统的一个重要性能指标.低速下,摩擦力的扰动引起伺服控制系统的不稳定.首先建立了伺服系统的动力学模型.模型由线性部分和非线性部分组成,非线性部分主要由摩擦力等扰动组成,使用最小二乘支持向量机对摩擦力等非线性部分、不确定参数进行辨识.其次,建立了基于线性伺服控制系统和摩擦力模型的补偿控制系统,并提出使用改进的优化滑模控制算法,同时对采样时间周期提出了优化选择.仿真结果显示:使用支持向量机建立的摩擦力模型能够较准确地反映系统低速摩擦力情况,对系统的低速补偿效果良好.低速时,误差控制在0.5r/min;通过实验研究,使用了摩擦力补偿和优化滑模控制后伺服系统的低速性能得到了改善和提高,克服了低速爬行现象.     

Adaptive dynamical variable structure feedback regulation for nonlinear uncertain systems

In this article an adaptive discontinuous dynamical feedback strategy is presented for asymptotic output stabilization problems defined on nonlinear controlled systems exhibiting linear parametric uncertainty. A dynamical feedback controller, ideally achieving output stabilization via exact linearization, is obtained by means of output differentiation and sliding mode control ideas. The adaptive version of the dynamical variable structure controller is then obtainable via standard, direct, overparametrized adaptive control techniques available for linearizable systems through static state feedback. An illustrative example from the chemical process control area, including simulations, is provided.     

Orbital feedback linearization for multi‐input control systems

A nonlinear control system is said to be orbital feedback linearizable if there exist an invertible static feedback and a change of time scale (depending on the state) which transform the system into a linear system. We give geometric necessary and sufficient conditions describing multi‐input control‐affine systems that are orbital feedback linearizable out of equilibria and in the case of equal controllability indices. We also describe a construction of the time rescaling needed to orbitally linearize the system. Moreover, we analyze close relations between orbital feedback linearizable control‐affine systems and control‐linear systems that are feedback equivalent to a multi‐chained form comparing geometric structures corresponding to both problems. We illustrate our results by two examples, one being a rigid bar moving in .Copyright © 2014 John Wiley & Sons, Ltd.     

基于编码控制机制的混杂系统半全局实用镇定

混杂系统的鲁棒镇定是复杂控制系统领域的重要研究课题之一.提出了一种编码机制下的混杂控制策略,它能有效地克服传统连续反馈控制或不连续反馈控制在处理局部鲁棒镇定平衡点或不变集问题中的局限性,获得更好的控制效果.首先针对编码状态反馈,构建了一般的混杂系统模型来描述编码状态反馈作用下非线性系统的闭环系统模型.然后,基于逆Lyapunov定理开展了非线性系统的混杂控制鲁棒性分析,提出了闭环混杂系统的半全局实用渐近稳定性判据.最后,结合一个经典控制问题来说明所提出控制策略的优越性.     

非线性控制系统的全局输出调节

讨论了非线性控制系统的全局输出调节.首先推广精确线性化方法,通过状态反馈 和微分同胚将非线性系统的全局输出调节问题,转化为线性系统对非线性系统的跟踪问题. 通过提出可解性的概念,得到线性系统对非线性系统全局跟踪的条件,该结果是线性系统结 果的推广.在反馈同胚变换全局成立条件下,得到非线性控制系统全局输出调节问题的充分 条件,该条件对外部系统只做较弱的可解性假设,在反馈同胚变换局部成立的条件下,可得局 部结果.     

Suboptimal local feedback control for a class of constrained discrete time nonlinear control problems

In this paper, we consider a class of constrained discrete time optimal control problems involving general nonlinear dynamics with fixed terminal time. A method to solve the feedback control problem for a class of unconstrained continuous time nonlinear systems has been proposed previously. In that work, the solution is based on synthesizing an approximate suboptimal feedback controller locally in the neighbourhood of a certain nominal optimal trajectory. This paper expands on the same theme by considering problems involving discrete time systems. Taking advantage of the nature of discrete time systems, a further reduction on the computational effort of synthesising the feedback controller is made possible. Also, this paper extends the applicability of the method to constrained systems. For illustration, a numerical example is solved using the proposed method.     

一般非线性控制系统的局部反馈渐近镇定

运用微分几何方法讨论了存在相对阶的一般非线性控制系统的局部反馈渐近镇定问题。在给出这类系统基于相对阶的标准形之后，如果其零动态渐近稳定，则可找到控制律局部镇定该系统。所得结果适用于一般非线性控制系统局部反馈渐近镇定的临界问题。     

Transient performance for discrete‐time singular systems with actuators saturation via composite nonlinear feedback control

This paper is concerned with the transient performance improvement in tracking control problems for linear multivariable discrete‐time singular systems subject to actuators saturation. A composite nonlinear feedback control strategy is considered, and the resulting controller consists of a linear feedback law and a nonlinear feedback law without any switching element. The nonlinear term leads to a varying damping ratio of the closed‐loop system and yields a small overshoot as the output approaches the target reference, whereas the linear component is designed to achieve a quick response of the closed‐loop system. Two composite nonlinear feedback control laws by both state feedback and measurement output feedback are addressed. An illustrative example is included to show the validity of the obtained results. Copyright © 2012 John Wiley & Sons, Ltd.     

Robust control applications

This paper (first presented as a plenary lecture at the Fifth IFAC Symposium on Robust Control Design, Toulouse, July 2006) demonstrates the practical importance of robust control theory by describing its application to two non-trivial practical control problems. Part 1 considers helicopter control and Part 2 addresses saturation problems in high-performance head-positioning servo systems in high-density hard-disk drives.In Part 1, we present the design and flight test of a new batch of H_∞ controllers for the Bell 205 helicopter. At the heart of each controller is an H_∞ loop-shaping controller, augmented with a hand-tuned reference filter to improve tracking performance and to reduce a perceived phase lag which pilots had complained of previously. Flight testing revealed that, with such an architecture, it was relatively easy to get Level 1 handling qualities ratings in low aggression manoeuvres. Further fine tuning resulted in Level 1 qualities for high aggression manoeuvres and one controller performed to Level 1 standard in all manoeuvres tested.In Part 2, we consider how robust control techniques can be used to design anti-windup compensators to counter performance and stability problems associated with saturating actuators in state-of-the-art hard-disk drive servo systems. A promising two-stage approach is given and illustrated with experimental results.     

Robust control approach for input–output linearizable nonlinear systems using high‐gain disturbance observer

This paper addresses a robust control approach for a class of input–output linearizable nonlinear systems with uncertainties and modeling errors considered as unknown inputs. As known, the exact feedback linearization method can be applied to control input–output linearizable nonlinear systems, if all the states are available and modeling errors are negligible. The mentioned two prerequisites denote important problems in the field of classical nonlinear control. The solution approach developed in this contribution is using disturbance rejection by applying feedback of the uncertainties and modeling errors estimated by a specific high‐gain disturbance observer as unknown inputs. At the same time, the nonmeasured states can be calculated from the estimation of the transformed system states. The feasibility and conditions for the application of the approach on mechanical systems are discussed. A nonlinear multi‐input multi‐output mechanical system is taken as a simulation example to illustrate the application. The results show the robustness of the control design and plausible estimations of full‐rank disturbances.Copyright © 2012 John Wiley & Sons, Ltd.