基于轧制力信号多分辨分析的AGC系统

针对目前热连轧生产轧制过程中实时反映生产状况的轧制力数据中所包含的大量丰富信息没有被充分利用的现象,从轧制力方面探讨了提高带钢成品厚度精度的新方法.从理论上分析了热轧轧制力信号特性,并结合小波在不同频率尺度上可以提取信号相关特征的优势,提出了一种基于小波多分辨分析的轧制力AGC系统.该算法采用小波多分辨分析算法提取出轧辊偏心、水印等引起的轧制力波动,并分别针对各因素引起的轧制力波动量进行相应的控制.仿真结果表明,该方法是有效可行的,提高了带钢厚度精度,具有广阔的推广应用前景.     

热连轧粗轧机的控制系统

本文简介了带钢热连轧粗轧生产线的主要设备和工艺过程，描述了该控制系统的构成及其实现的主要功能，着重讨论了粗轧主轧机的速度控制和轧辊压下量控制环节，因为这是决定轧制质量的关键因素。     

液压厚度控制系统的数据驱动预测控制

热连轧液压厚度控制系统是由多机架协调工作完成的,针对液压厚度控制系统的大时滞特性,结构不确定性以及外部扰动等扰动的影响,提出液压厚度控制系统的数据驱动预测控制策略。采用串级控制方式,将监控AGC系统测得的实际厚度和压力AGC系统利用弹跳方程计算得到的厚度数据反馈给控制系统,利用子空间辨识方法,直接设计数据驱动预测控制器,增强抗干扰能力,提高控制精度。仿真结果表明该方法能够提高控制精度,具有较好的控制性能。     

轧机自动位置控制系统混沌特性研究

针对轧机自动位置控制系统(APC)控制后的钢板不能准确停车,出现类似振动的现象,在考虑轧辊与钢板间的阻尼力、弹性力和轧辊偏心力的基础上,建立了一个轧机自动位置控制系统停车后的非线性模型.阐述了Lyapunov特性指数的计算方法,将Lyapunov指数作为APC系统非线性运动的混沌的判据.给出了Lyapunov指数与AP...     

基于混合控制的冷轧带钢厚控系统仿真

带钢轧制是一个复杂的非线性过程，轧辊偏心是高精度冷轧机厚度控制不能忽视的问题。当带钢原料性质、处理量变化等也会导致过程模型发生变化。该文提出一种基于重复控制进行偏心补偿、鲁棒PID控制器对模型不确定性不敏感的带钢厚度控制系统。重复控制是基于内模原理的一种新型控制策略，优点是对周期信号的初始状态没有要求，对轧辊偏心扰动有很强的抑制力；鲁棒PID采用基于最小-最大原理的参数整定方法，对于过程模型在一定变化范围内，控制器具有良好的控制性能。仿真结果证明：系统具有良好的跟随和抗扰性能，表明这种混合控制方法有一定的适用性。     

基于改进分形预测的板厚优化控制

针对热连轧机监控厚度自动控制(automatic gauge control,AGC)系统存在时滞、参数失配问题导致出口板厚控制精度低和超调震荡问题,首先,提出基于综合小波互相关度的时滞评估方法来确定滞后步长;然后,引入分形外推插值算法给出了考虑时滞的预测模型,并利用混沌优化算法确定分形外推插值算法中的垂直尺度因子;最后,利用阶梯式动态矩阵控制(dynamic matrix control,DMC)优化PID控制器参数,使得PID控制器参数能够根据不同工况变化自适应调整.仿真结果表明,与传统监控AGC,Smith–AGC和IFEIP–AGC(改进分形外推插值预测,IFEIP)相比,本文方法有效地缓解了由时滞引起的出口板厚控制超调和震荡现象,并且在有外部干扰及系统时滞参数失配情况下,具有较好的动静态特性.     

双机架可逆冷连轧机的计算机控制

对北京科技大学高效轧制国家工程研究中心的试验轧机-双机架可逆冷连轧机计算机控制系统中的仪表配置、系统组成、厚度控制、顺序控制和板形控制进行了介绍和研究，着重对基础自动化控制系统配置和厚度控制进行了分析，提出了在控制系统中增加激光测速仪，采用流量AGC的控制方案，解决了传统AGC控制方案中存在的系统大滞后不易稳定的缺点和厚度计AGC控制方案中存在的测量精度太低的缺点。     

基于小波的热连轧轧辊偏心控制

本文提出了一种用于热连轧的基于小波分析的轧辊偏心控制方法,该方法首先根据偏心信号的特点,利用小波对轧制力信号进行多分辨分解,把偏心从轧制力信号中提取出来,然后在控制中对偏心进行补偿。仿真试验表明该方法是有效的,为继续深入这方面研究与应用提供了良好的基础。     

基于KPLS和TD的热连轧精轧末架微调AGC

热连轧传统的厚度控制方式主要依靠精轧机组下游机架的监控AGC(automatic gauge control)来消除厚差,易造成末架调节量过大,对板形产生非常不利的影响.为此提出一种基于KPLS(kernel partial least squares)和TD(tracking differentiator)的热连轧精轧末架微调AGC,通过对前一卷带钢轧制信息进行非线性特征抽取,找出F5,F6机架间过程变量的关系,从而可以在F6机架保持辊缝和压力基本不变的前提下,仅通过调节F5机架的辊缝而使厚度精度达到控制要求.现场实验证明了这一观点.     

FM458在轧机控制系统中的应用

本依托热轧实验轧机项目，主要针对SIEMENS的CPU功能模板FM458在轧机控制系统中的应用进行了具体的介绍，同时阐述了AGC自动厚度控制的原理，并且介绍了FM458完成其控制时的硬件配置。     

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.