网络控制系统Smith预估时滞补偿方法的研究

为了减小网络控制系统中网络诱导时延以及非线性系统本身的滞后对系统控制性能的影响,提出了一种改进的Smith预估时滞补偿方法,采用最小二乘法对被控对象进行测量、辨识,同时引入模糊自适应PID控制,无需确定系统的随机时延。实验结果表明,此种方法是简单而且可行的,提高了系统的稳定性。     

数字Smith补偿器在温度控制系统中的应用

介绍了数字Smith补偿器的调节原理 ,VI87MA数字调节器Smith补偿的实现 ,以及数字调节器在温度控制系统中的应用。     

网络控制系统Smith Fuzzy PID控制器的设计

针对网络控制系统中普遍存在的时延问题,提出了一种将模糊自适应算法和Smith预估补偿算法与常规PID控制器相结合的智能控制策略。该方法充分利用了Smith预估控制算法对带时延系统的良好控制能力,同时利用模糊推理算法实现对PID参数的在线自整定,进一步改善PID控制器的性能。仿真结果表明,基于该智能控制器的网络控制系统克服了传统PID控制超调量大及常规Smith预估补偿过分依赖于被控对象精确数学模型的缺陷,可以有效降低时延对系统性能的不利影响,使被控对象具有良好的动、静态特性。     

基于模糊自适应PI改进的Smith预估器在网络化控制系统中的应用研究

网络化控制系统（NCS）中不可避免的网络诱导时延使传统的控制器难以达到较好的控制效果,针对网络化控制系统中前向传输时延无法精确测量的特点,提出了一种有效的控制方法。仿真结果表明,采用Smith预估控制与模糊自适应PI控制算法相结合的方法,能有效地增强网络化控制系统控制规律的自适应性,显著改善和提高系统的抗干扰性和鲁棒性能。     

网络控制系统中的时延分析

介绍了网络控制系统的概念,论述了网络控制系统中的基本问题并分析了网络控制系统中的网络诱导时延.     

网络控制系统中的时延分析

介绍了网络控制系统的概念,论述了网络控制系统中的基本问题并分析了网络控制系统中的网络诱导时延。     

基于Smith预估器的口腔治疗仪控制系统研究

基于Smith预估器原理设计了单片机控制的口腔治疗仪系统。单片机利用PWM调速原理输出控制信号调节气泵电机的转速，保持治疗仪容器内气压值恒定。Smith预估器的引入补偿了纯滞后环节对控制系统的影响，在此基础上介绍了系统硬件组成及软件编程。     

网络控制系统中基于时延辨识的模糊控制器研究

针对网络控制问题，建立包含变网络时延及网络传输丢包等的统一模型．提出基于允许误差阈值及最大时延等多重准则的网络调度算法．在被控对象模型已知的情况下，本文采用模糊控制器作为Smith控制的内模控制部分，同时将Smith预估环节与被控对象放在一处，减少了冗余信息的传输，补偿了网络时延．仿真结果说明该调度算法及控制方案对于模型精确已知的一类网络控制对象能取得较好的控制效果．     

数字Smith0补偿器在温度控制系统中的应用

介绍了数字Smith补偿器的调节原理,VI87MA数字调节器Smith补偿的实现,以及数字调节器在温度控制系统中的应用。     

基于弹性控制器的网络控制系统稳定性分析

研究了一类不确定网络控制系统的弹性控制器设计问题。针对一类具有不确定参数的被控对象模型,考虑网络诱导时延的作用,建立基于弹性反馈控制器的网络控制系统闭环模型。采用Lyapunov方法,给出保证该闭环系统稳定的允许时延上界。仿真结果证明了本文方法的正确性和有效性。     

改进型Smith预估控制系统的仿真

该文针对工业过程中常呈现的纯滞后特性提出了一种改进型Ｓｍｉｔｈ预估控制算法，并提出了控制器参数整定方案。通过引入一个动态补偿器，提高系统对扰动的克服能力，从而改善了系统响应性能。对工业上典型的二阶加纯滞后过程进行了仿真，结果表明了算法的有效性。     

Smith predictor with inverted decoupling for square multivariable time delay systems

This paper presents a new methodology to design multivariable Smith predictor for n×n processes with multiple time delays based on the centralised inverted decoupling structure. The controller elements are calculated in order to achieve good reference tracking and decoupling response. Independent of the system size, very simple general expressions for the controller elements are obtained. The realisability conditions are provided and the particular case of processes with all of its elements as first-order plus time delay systems is discussed in more detail. A diagonal filter is added to the proposed control structure in order to improve the disturbance rejection without modifying the nominal set-point response and to obtain a stable output prediction in unstable plants. The effectiveness of the method is illustrated through different simulation examples in comparison with other works.     

Robust stability analysis of Smith predictor-based congestion control algorithms for computer networks

Congestion control is a fundamental building block in packet switching networks such as the Internet due to the fact that communication resources are shared. It has been shown that the plant dynamics is essentially made up of an integrator plus time delay and that a proportional controller plus a Smith predictor defines a simple and effective controller. It has also been shown that the TCP congestion control can be modelled using a Smith predictor plus a proportional controller. Due to the importance of this control structure in the field of data network congestion control, we analyse the robust stability of the closed-loop system in the face of delay uncertainties that are present in data networks due to queuing. In particular, by applying a geometric approach, we derive a bound on the proportional controller gain which is necessary and sufficient to guarantee the closed-loop stability for a given bound on the delay uncertainty.     

Elman网络在Smith预测控制中的应用

Smith预测控制在实际应用中的难点在于很难得到实际系统精确的数学模型. 通过Elman网络拟合传统Smith估计器的模型误差, 并对其进行补偿. 实验结果表明, 这种基于Elman网络补偿模型的Smith预测控制充分利用了神经网络的非线性拟合能力, 只要对纯滞后环节精确建模, 就可以完全抵消纯滞后环节对控制品质及系统稳定性的不利影响. 这种方法使得Smith预测控制可以用于模型不易精确确定的系统.     

不确定时滞模糊系统的鲁棒H∞网络控制

A robust H_∞networked control method for Takagi-Sugeno (T-S) fuzzy systems with uncertainty and time delay is presented.A state feedback controller is designed via the networked control system (NCS) theory.Sufficient condition for robust stability with H_∞performance is obtained.Network-induced delay in network transmission and packet dropout are analyzed. Simulation result shows the validity of this control scheme.     

filtering of nonlinear plants over networks

In this paper, we consider the filtering problem for Lipschitz systems in a networked environment. We assume that the measurements transmitted over the network are subject to quantization, uncertain delays and communication constraints. We first analytically demonstrate how each of the these issues affect the filtering problem. Second, we tackle the filter design as an optimization problem with LMI constraints. The optimization maximizes the Lipschitz constant and thus the region of attraction for which the filter is stable and an bound is satisfied by the error system. Copyright © 2013 John Wiley & Sons, Ltd.     

网络控制系统的能控性和能观性

给出了网络控制系统的定义，并基于线性时不变系统的被控对象，建立了传感器为时钟驱动，控制器和作动器为事件驱动时长时滞网络控制系统的数学模型，对网络控制系统的均值能控、均方能控、均值能观及均方能观作了定义，得到了网络控制系统能控的充分或必要条件及能观的充要条件．     

Distributed agent-based control and estimation over unreliable networks for a class of nonlinear large-scale systems

A new technique for distributed estimation and control of large-scale systems is presented in this paper. The proposed method makes use of a set of agents that implement local H _∞ controllers and Luenberger-like observers, improved with consensus-based corrections that incorporate information received from other agents. The communication between agents is assumed to be unreliable, this is modelled by time-varying delays and packet dropouts. The proposed methodology is an application for a class of nonlinear system affected by external disturbances. Some simulations are presented to illustrate the performance of this technique compared to the centralised case.     

采用Smith预估器模型的时滞系统自适应控制

在实际生产控制系统中时滞现象相当普遍,而传统的PID控制方法对时滞系统的控制很难达到满意的效果且易引起系统的不稳定.Smith预估器是一种广泛应用于时滞系统闭环控制的有效方法,但存在预估器模型和被控对象参数不匹配时系统控制特性的劣化甚至发生振荡发散的问题.本文提出了一种基于李雅普诺夫稳定性理论,用于改善Smith预估器...     

浅析Smith预估与OC控制方案

时滞系统普遍存在于控制系统中,对系统的行为有重要的影响.本文讨论了smith预估与观测补偿器(OC)两种控制方案,并进行了大量了仿真与比较,得出了一些有意义的结论.