变论域模糊控制的无刷直流电机控制系统

为了改善无刷直流电机(BLDCM)的调速性能,研究了基于变论域思想的自适应模糊PID控制器及其在BLDCM控制系统中的应用,变论域自适应模糊控制对模型无精确要求、速度快、精度高、鲁棒性好、适应性强.详细分析了BLDCM电机模型的建立、控制结构设计、伸缩因子的选择等,给出了具体的控制算法设计,并在Matlab仿真平台下,构建了BLDCM的电流、转速双闭环控制的仿真系统,其中,转速环采用了变论域自适应模糊PID控制器.仿真结果表明,与常规PlD控制和普通模糊PID控制相比,采用变论域自适应模糊PID控制时,转速输出无超调,响应速度快.转矩脉动小,控制精度高,为无刷直流电机在军事、办公设备、家电等需要快速、高精度控制、抗扰能力强的场合的应用提供了一种有效的解决方案.     

基于TS-PID控制的静止无功发生器研究

引入逻辑开关函数建立了静止无功发生器的动态数学模型。根据该数学模型的非线性特性,提出了基于TS模型的PID模糊控制方法。对常规PID控制和TS-PID控制进行了理论研究。结果表明:采用TS模型的模糊PID控制比常规PID控制具有更大范围的鲁棒性与稳定性。用Matlab对系统进行了仿真,仿真结果表明利用TS-PID控制器控制静止无功发生器的无功电流具有可行性与有效性。     

在非理想电源电压下静止无功发生器控制策略的研究

提出了静止无功发生器在非理想电源电压情况下,补偿无功电流指令的准确计算方法,并进一步提出了产生补偿电流的预测电流控制法.该方法具有控制精度高,响应速度快,主电路开关频率恒定等优点.理论分析和仿真结果验证了所提出方法的有效性,基于预测电流控制方法的静止无功发生器在非理想电源电压条件下具有良好的工作性能.     

基于变论域模糊PID的分解炉温度控制研究

分解炉温度控制系统具有非线性、时变、纯滞后的特点,针对传统PID控制及模糊.PID控制难以很好地满足控制要求,提出了一种变论域模糊自适应PID控制方法。利用变论域思想,设计了一种基于函数模型的伸缩因子控制器,动态地调整模糊控制器的量化因子和比例因子,提高了控制精度。在Matlab环境下分别对PID控制、模糊PID控制和变论域模糊PID控制方法进行了仿真对比,结果表明变论域模糊PID控制方法具有更好的动静态性能和自适应能力。     

SVG的电压定向控制算法仿真

针对电流控制方法在静止无功发生器SVG无功补偿上的缺陷,提出了一种先进的电压定向控制算法（VOC）. 首先介绍了VOC的基本原理,然后详细论述了电压定向控制的拓扑结构及无功电流与有功电流解藕过程,最后在MATLAB/Simulink的环境下进行了系统建模和仿真. 仿真结果表明,运行基于电压定向控制方法的SVG装置,系统将得到良好的动态特性,功率因数大大提高,弥补了传统电流控制的缺点,对于SVG的无功补偿效果提高具有重要的现实意义.     

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。     

基于链式SVG三相不平衡负荷的平衡补偿方法的仿真分析

本文对链式静止无功发生器的工作原理进行了分析,在深入研究三相不平衡负荷的平衡化补偿原理的基础上,提出了一种基于链式静止无功发生器在不平衡补偿时的分相补偿控制方法.该方法是通过对静止无功发生器各相输出电压与电网电压的相角差δ进行调节来控制各相输出电流,从而可以有效地对三相负载不平衡的系统进行平衡补偿.对所提出的补偿方法进行了仿真研究,仿真结果表明运用分相控制方法补偿三相不平衡负载,具有比较好的稳态补偿效果,补偿后电网电流三相平衡,各相电流与电压基本同相位并且幅值成相同的比例,达到了负载功率平衡和无功补偿的目的.     

直升机变论域模糊自适应缆位控制系统设计

针对模糊控制适应性差和控制精度低的问题,提出了一种改进的变论域模糊自适应控制器.提出了参考缆位角的计算方法并设计了相应的直升机缆位控制器.研究用于连续域寻优的改进蚁群优化算法,用于动态调整模糊控制器论域的伸缩因子,从而构成基于蚁群算法的变论域模糊自适应控制器.将该控制器应用于直升机缆位控制系统,控制直升机地速保持在零附近,同时实现缆位角的精确控制.     

静止无功发生器的微分几何变结构控制方法

根据静止无功发生器(SVG)数学模型的非线性特性,提出了微分几何变结构控制方法,运用微分几何精确线性化理论,把非线性系统转化成了一个线性系统,在此基础上应用非线性变结构控制理论进行设计控制器。结果表明,微分几何变结构控制方法对补偿SVG的无功电流具有有效性和可行性。     

STATCOM的电流间接控制方法设计与实现

本文介绍了基于数字信号处理(DSP)设计的静止无功发生器控制器的结构、功能、特点,具体分析了电流间接控制方法,详细介绍了控制方法及其编程实现,并通过仿真证明了电流间接控制方法的有效性。     

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.