一种模糊PID-Smith污水处理的控制方法

针对污水处理控制系统的大惯性、大时滞及时变等特点,在分析常规PID控制和模糊控制不足的基础上,以溶解氧DO为控制对象,建立了一种Smith预估器+模糊PID组合控制器.该组合模型中的模糊控制部分以误差和误差变化率作为输入,通过模糊推理实现对PID的3个参数,即比例常数、积分常数和微分常数的自整定,以满足被控对象DO的不同误差和误差变化率对控制器参数的要求:采用Smith预估器实现对被控制对象的时间滞后的修正.该模型集成了模糊控制器鲁棒性高、PID静态控制,及Smith预估器可以补偿时滞的优点.通过对SBR污水处理系统的控制仿真,并与常规PID和模糊PID控制效果比较,超调量和调节时间明显降低,证实了组合控制器的优越性,从而为解决大滞后大惯性系统提供一种有效途径.     

羰基合成模式评价装置温控器的算法研究

以羰基合成模式评价装置的温度控制系统为研究对象,针对加热系统存在的惯性、纯延迟、非线性、热耦合等特性,提出将模糊控制、PID控制及纯滞后控制算法有机地结合起来实现加热系统的模糊自整定PID参数的Smith预估控制策略,以实现温度的高精度控制.并运用MATLAB对研究结果进行了仿真,结果表明该控制策略自适应能力、控制品质和鲁棒性明显优于常规Smith预估控制.     

预估模糊免疫PID在房间温度控制中的应用

针对空调房间温度对象的大滞后、大惯性、多干扰的特性,设计了具有史密斯(Smith)预估功能的模糊免疫PID控制器.该控制器采用Smith预估和免疫PID控制相结合的结构,借鉴免疫算法的生物免疫反馈机理进行PID参数的在线自适应调整;用模糊控制器来逼近免疫PID的非线性函数,并用遗传算法优化它的隶属度函数.对该控制方案进行系统仿真结果表明:该方法抗扰能力强、调节速度快、超调量小,可用于精确的控制房间温度.     

基于Smith预估模糊PID控制的加热器温控系统

针对工业加热器出口温度具有大滞后、大时变、非线性以及精确模型难以建立等特性导致的工况复杂、控制难度大的问题,提出一种Smith预估模糊PID复合控制方案,利用模糊控制规则实现PID的3个参数在线自整定,采用Smith预估器对温控系统的纯滞后进行补偿。详细阐述温控系统的硬件配置和软件实现,实际运行结果表明该方案有效提高了系统的抗干扰能力和适应参数变化的能力,具有鲁棒性强、动态响应快及稳态精度高的优点。     

基于模糊自适应控制的温度控制系统研究

针对一些系统大延时滞后的特点,本文以温度为对象,结合模糊控制技术和自适应Smith预估器,组成模糊自适应Smith预估控制系统。运用Simulink建立温度控制系统的仿真模型,并分别用常规模糊控制技术和模糊自适应Smith预估控制技术对温度加温进行仿真试验。仿真结果表明在温度加温的模糊控制系统中增加自适应Smith预估器后,系统具有更强的适应能力,系统的动态特性都有了较大的改善。     

模糊Smith在温控系统中的仿真研究

研究电厂锅炉温度优化控制问题,由于温度的稳定性受到多种因素的影响,所以温度控制系统是一个具有时滞性、非线性和时变性的复杂系统,传统PID控制和模糊控制难以建立精确的数学模型,控制系统的超调时间长,超调大.为了解决控制系统的超调时间长,超调大等问题,为了优化温控制系统,在传统PID控制和Smith预估计器的基础上,结合模糊控制系统良好非线性优点,提出模糊Smith的温控制系统.方法通过Smith预估器对模型的时滞性进行补偿,使时滞系统的超调减小,系统的稳定性增强.通过建立温控制系统数学模型并进行仿真实验,结果表明模糊Smith的控制方法降低了超调量,缩短了超调时间,有效提高了温控制系统的鲁棒性和抗干扰性.     

Smith模糊积分控制在焦炉系统中的应用

针对常规PID控制器在控制具有时变、大滞后等特性的焦炉温度系统时,控制效果不太理想的情况,提出了Smith模糊积分控制器;该控制器利用Smith预估控制克服大滞后因素对系统的影响;利用模糊控制解决被控对象参数时变的问题;利用积分控制来消除系统的稳态误差;仿真结果表明,采用Smith模糊积分控制器,系统的调节时间缩短,响应速度加快,抗干扰能力和适应参数变化的能力都比较强,并且具有更好的动态特性和稳态特性,有效地减少了炉温的波动。     

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。     

积分分离PID算法的电阻炉温度控制系统

为使大惯性、纯滞后的电阻炉温度控制系统的动态性能和稳态精度满足要求,提出了Smith预估结合积分分离PID算法;设计了温度控制器的硬件系统;对控制系统进行辨识;分析了Smith预估结合积分分离PID算法与单纯Smith预估控制算法的区别,并对两种控制算法进行了比较分析,确定了电阻炉温度控制系统参数;最后对Smith预估结合积分分离PID算法进行了电阻炉的温度控制实验;实验结果表明,采用Smith预估结合积分分离PID算法提高了电阻炉温度控制系统的稳定性,降低了系统的超调,稳态精度达到0.2℃,其动态性能和稳态精度满足系统控制要求.     

模糊Smith智能温度控制器的设计与仿真

结合模糊PID控制与模糊自适应Smith预估控制的优点,提出了模糊Smith智能控制方法。用模糊控制方法设计了改进型Smith预估器的滤波时间常数,并制定了其整定规则和参数的模糊自适应调整机构。仿真研究表明,模糊Smith智能控制能改善参数时变的纯滞后系统的控制性能,提高系统控制时的鲁棒性与自适应性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.