Multivariable adaptive control: A survey

Adaptive control is a control methodology capable of dealing with uncertain systems to ensure desired control performance. This paper provides an overview of some fundamental theoretical aspects and technical issues of multivariable adaptive control, and a thorough presentation of various adaptive control schemes for multi-input–multi-output systems, literature reviews on adaptive control foundations and multivariable adaptive control methods, and related technical problems. It covers some basic concepts and issues such as certainty equivalence, stability, tracking, robustness, and parameter convergence. It discusses some of the most important topics of adaptive control: plant uncertainty parametrization, stable controller adaptation, and design conditions for different adaptive control schemes. The paper also presents a detailed study of well-developed multivariable model reference adaptive control theory and design techniques. It provides an introduction to multivariable adaptive pole placement and adaptive nonlinear control, and it concludes by identifying some open research problems.     

变论域自适应模糊PID控制系统仿真与应用

由于电液伺服系统具有非线性、时滞性等问题,自适应模糊PID控制方式仍难以精确控制马达转速,故设计了变论域自适应模糊PID控制算法。通过设计合适的伸缩因子,将变论域与自适应模糊PID控制相结合,该算法可以精确控制电磁比例阀的流量进而控制马达的转速。将PID控制、模糊控制、自适应模糊PID控制和变论域自适应模糊PID控制算法进行Matlab仿真,结果表明：变论域自适应模糊PID控制具有响应快、无超调、稳态误差基本为零的特点。通过可编程控制器实现了模糊PID控制与变论域自适应模糊PID控制算法在电液伺服系统中的应用,实验数据表明,变论域自适应模糊PID控制更加精确,符合工业控制要求。     

自适应模糊神经网络控制器在电阻加热炉中的应用

提出一种自适应模糊神经网络控制器,着重讨论了自适应模糊神经网络的混合学习算法和自适应动量解耦的最速下降法。给出了适于非线性时滞、基于径向基函数网络和自适应模糊神经网络控制器的控制方案,并把它用在电阻加热炉中。实际应用表明,模糊神经网络控制器具有良好的控制效果。     

A discrete-time parameter estimation based adaptive actuator failure compensation control scheme

This article studies discrete-time adaptive failure compensation control of systems with uncertain actuator failures, using an indirect adaptive control method. A discrete-time model of a continuous-time linear system with actuator failures is derived and its key features are clarified. A new discrete-time adaptive actuator failure compensation control scheme is developed, which consists of a total parametrisation of the system with parameter and failure uncertainties, a stable adaptive parameter estimation algorithm, and an on-line design procedure for feedback control. This work provides a new design of direct adaptive compensation of uncertain actuator failures, using an indirect adaptive control method. Such an adaptive design ensures desired closed-loop system stability and tracking properties despite uncertain actuator failures. Simulation results are presented to show the desired adaptive actuator failure compensation performance.     

基于LMS算法自适应噪声抵消器的分析研究

自适应信号处理的理论和技术已经成为人们常用的语音去噪技术,而Matlab为其提供了更为方便快捷的方法来对语音信号进行消噪处理。通过介绍自适应滤波器原理,在对自适应滤波器相关理论研究的基础上,重点研究了LMS自适应滤波算法,并对LMS自适应算法进行了分析,用Matlab对其进行了仿真和实现。     

Hybrid adaptive fuzzy identification and control of nonlinearsystems

We present a combined direct and indirect adaptive control scheme for adjusting an adaptive fuzzy controller, and adaptive fuzzy identification model parameters. First, using adaptive fuzzy building blocks, with a common set of parameters, we design and study an adaptive controller and an adaptive identification model that have been proposed for a general class of uncertain structure nonlinear dynamic systems. We then propose a hybrid adaptive (HA) law for adjusting the parameters. The HA law utilizes two types of errors in the adaptive system, the tracking error and the modeling error. Performance analysis using a Lyapunov synthesis approach proves the superiority of the HA law over the direct adaptive (DA) method in terms of faster and improved tracking and parameter convergence. Furthermore, this is achieved at negligible increased implementation cost or computational complexity. We prove a theorem that shows the properties of this hybrid adaptive fuzzy control system, i.e., bounds for the integral of the squared errors, and the conditions under which these errors converge asymptotically to zero are obtained. Finally, we apply the hybrid adaptive fuzzy controller to control a chaotic system, and the inverted pendulum system     

Comments on ‘ Asymptotic behaviour of root-loci of linear multivariable systems ’

In the first part of this paper, a continuous time adaptive identification algorithm via newly developed adaptive laws is presented. The principle of the algorithm is very simple, nevertheless the convergence property is quite excellent. In the second half part, two continuous time adaptive control algorithms via adaptive laws, as were used for adaptive identification, are presented. A new canonical form for adaptive control is first developed for this purpose. The design procedure for adaptive control systems requires neither positive realness nor augmented error signals and can be applied irrespective of the relative degree of the plant transfer function.     

自适应笔式用户界面开发的概念框架

提出了一个指导自适应笔式用户界面开发的概念框架CFAPUI(a conceptual framework for developing adaptive pen-based user interface).该框架详细描述了自适应笔式用户界面的软件体系结构,阐述了自适应笔式用户界面的软件体系结构中的各组成模块及其相互间的关系.同时,在体系结构的基础上提出自适应笔式用户界面开发时的具体过程步骤和方法,并通过一个笔式表单应用来说明该开发框架在指导自适应笔式用户界面开发中的具体应用.     

Adaptive programming

An adaptive program is one that changes its behavior base on the current state of its environment. This notion of adaptivity is formalized, and a logic for reasoning about adaptive programs is presented. The logic includes several composition operators that can be used to define an adaptive program in terms of given constituent programs; programs resulting from these compositions retain the adaptive properties of their constituent programs. The authors begin by discussing adaptive sequential programs, then extend the discussion to adaptive distributed programs. The relationship between adaptivity and self-stabilization is discussed. A case study for constructing an adaptive distributed program where a token is circulated in a ring of processes is presented     

Relations between semantic security and anonymity in identity-based encryption

Semantic security and anonymity are the two main properties that an identity-based encryption scheme can satisfy. Such properties can be defined in either an adaptive or a selective scenario, which differ on the moment where the attacker chooses the identity/ies that are the target of the attack. There are well-known separations between selective and adaptive semantic security on the one hand, and between selective and adaptive anonymity on the other hand.In this paper we investigate the relations between these selective and adaptive notions, for identity-based encryption schemes enjoying at the same time some security and anonymity properties. On the negative side, we prove that there is a separation between selective and adaptive anonymity even for schemes which enjoy adaptive semantic security. On the positive side, we prove that selective semantic security and adaptive anonymity imply adaptive semantic security.     

Theory and applications of adaptive control—A survey

Progress in theory and applications of adaptive control is reviewed. Different approaches are discussed with particular emphasis on model reference adaptive systems and self-tuning regulators. Techniques for analysing adaptive systems are discussed. This includes stability and convergence analysis. It is shown that adaptive control laws can also be obtained from stochastic control theory. Issues of importance for applications are covered. This includes parameterization, tuning, and tracking, as well as different ways of using adaptive control. An overview of applications is given. This includes feasibility studies as well as products based on adaptive techniques.     

一种统一的鲁棒自适应控制方法及近期自适应控制结果综述

针对离散/连续时间情况下时不变/时变多种不同的鲁棒自适应控制系统,基于归纳法提出一种统一的传统分析方法,该方法为鲁棒自适应控制器的设计提供了一般性的指导原则.在设计和实现鲁棒自适应控制器时要求具有与模型误差先验知识相关的假设,通过所提出的算法可以将该假设消除,使得已有的鲁棒自适应控制理论得到进一步发展.此外,通过稳定性分析证明了该算法对于更宽松边界的模型误差具有鲁棒性.最后,归纳总结了近期自适应控制方法在处理非光滑不确定性、执行器故障补偿、欠驱动非完整约束、分布式一致性和随机系统控制等问题上取得的代表性成果.     

基于参数估计误差的鲁棒自适应律设计及验证

针对传统自适应控制系统设计的自适应律参数收敛慢进而影响控制系统瞬态性能的问题,研究一类新的基于参数估计误差修正的鲁棒自适应律设计.首先引入滤波操作给出参数估计误差的提取方法,构建出含参数估计误差修正项的自适应律,进而将该自适应律用于控制器设计和分析中,可同时实现控制误差和参数估计误差指数收敛.对比分析了几类传统自适应律和所提出自适应律的收敛性和鲁棒性,并给出了保证参数收敛所需持续激励条件的一种直观、简便的在线判别方法.数值仿真及基于自制三自由度直升机系统俯仰轴实验结果表明,基于参数误差修正的自适应律及控制器可得到优于传统自适应方法的跟踪控制和参数估计性能.     

一种高效的功放自适应预失真器设计

在对高功率放大器(HPA)进行自适应预失真过程中,为提高自适应算法运用的灵活性和自适应的收敛速率,解决幅度自适应预处理过程中对幅度过度压缩而影响功放输出功率和效率的问题,设计出一种高效的HPA自适应预失真器。该方案中幅度、相位预失真器相级联,对幅度预失真器采用间接自适应结构进行训练;相位预失真器直接对功放幅度-相位(AM-PM)特性进行辨识,然后取反得到,AM-PM特性辨识器同时又是相位预失真器,能够提高HPA自适应预失真过程中自适应算法运用的灵活性和自适应收敛速率;幅度预失真器基于正弦函数系模型,自适应预失真过程可以同时兼顾功放效率、输出功率和线性度3项重要指标。最后以M-QAM和双音信号为例进行仿真测试,验证了该方法的优势。     

航空有源滤波器自适应谐波检测仿真研究

介绍了基于自适应滤波理论的谐波检测原理,分析了自适应神经元算法用于谐波检测的可行性,设计了基于自适应谐波检测的并联型航空混合有源滤波器,对滤波特性进行了仿真研究。结果表明,基于自适应滤波理论的谐波检测方法能够快速、精确地检测相电流谐波含量,在相电压波形发生畸变的情况下,也具有较好的自适应能力、快速补偿能力和跟踪性能。     

实数自适应遗传算法在雷达处理中的应用

实数自适应遗传算法在雷达处理中具有广泛应用。本文对基于实数自适应遗传算法原理、交叉概率和变异概率的自适应确定方法以及实数自适应遗传操作方法进行了阐述,在分析探地成像雷达电磁波在地下传播特性的基础上对雷达测得的电磁波信号的成像问题进行了研究,并通过计算机仿真验证算法的可行性,从而得出基于实数编码的稳态遗传算法克服了普通二进制算法的缺点,增加了普通遗传算法的搜索能力,对于求解大规模优化问题是适合的,是一种具有工程实用价值的算法。     

自适应滤波器在电参数测量系统中的应用

论述了基于LMS算法的自适应噪声抵消器和自适应谱线增强器的工作原理及改进的算法,并将自适应噪声抵消器和自适应谱线增强器合并为一个滤波器应用于电参数测量系统中,仿真实验证明这种滤波器去除噪声的性能较佳.     

Method of passification in adaptive control, estimation, and synchronization

The main results of the method of passification which are based on applying the Yakubovich-Kalman frequency theorem to the design of the feedback systems and examples of its use in the problems of adaptive control, state estimation, and synchronization were presented. Various types of the adaptive control algorithms with implicit reference model such as the algorithms of stabilization and tracking with the prescribed dynamics, algorithms with adaptive tuning of the standard control laws, and combined signal-parametric algorithm of adaptive control were described. Brief information about the shunting method in the adaptive control problem was given. The experimental results with the adaptive control on the “Helicopter” benchmark were described. Consideration was given to the problem of adaptive control of the nonlinear plants. Examples of applying the method of passification and adaptive observers to the problems of synchronization of the nonlinear oscillators and message transmission by chaotic signals were presented.     

σ校正混合自适应控制律

本文提出了一种σ校正混合自适应控制律,并且证明在对象具有相加和相乘未建模动 态(unmodeled dynamics)的情况下,若采用文中所给出的混合自适应控制系统结构,这种σ 校正混合自适应控制律可保证闭环系统中的所有信号有界,并且对于任何有界初始条件,系 统具有小的均值残余跟踪误差.数学模拟结果表明,本文所提出的混合自适应控制律优于相 类似的全连续和全离散自适应控制律.     

Adaptive Fuzzy Switched Swing-Up and Sliding Control for the Double-Pendulum-and-Cart System

In this paper, an adaptive fuzzy switched swing-up and sliding controller (AFSSSC) is proposed for the swing-up and position controls of a double-pendulum-and-cart system. The proposed AFSSSC consists of a fuzzy switching controller (FSC), an adaptive fuzzy swing-up controller (FSUC), and an adaptive hybrid fuzzy sliding controller (HFSC). To simplify the design of the adaptive HFSC, the double-pendulum-and-cart system is reformulated as a double-pendulum and a cart subsystem with matched time-varying uncertainties. In addition, an adaptive mechanism is provided to learn the parameters of the output fuzzy sets for the adaptive HFSC. The FSC is designed to smoothly switch between the adaptive FSUC and the adaptive HFSC. Moreover, the sliding mode and the stability of the fuzzy sliding control systems are guaranteed. Simulation results are included to illustrate the effectiveness of the proposed AFSSSC.