回旋式倒立摆的H∞控制

倒立摆系统具有多变量、非线性、强耦合和不确定的特点,常被用来验证控制算法的优劣性。H∞在干扰抑制和鲁棒性上均有较为突出的表现。在对倒立摆控制研究情况和 H∞控制理论发展情况进行简单介绍后,围绕一阶回旋式倒立摆的H∞控制进行研究。首先,基于拉格朗日方程对一阶倒立摆进行动力学分析,并近似地得到平衡点附近的线性方程;对倒立摆系统进行分析,得到倒立摆系统是能观能控系统、但平衡点不稳定的结论。其次,简单介绍基于里卡蒂方程的 H∞控制器求解方法,并证明该控制器能够保证系统的稳定性。最后,仿真确定加权矩阵各元素和 H∞性能指标的大小对系统性能的影响和对电机扭矩的要求,并最终确定一组相对合适的参数进行控制器设计。     

二级倒立摆的鲁棒建模及其鲁棒H∞最优控制

针对倒立摆系统本身存在的大量不确定性因素，建立其不确定数学模型。苦于最优控制的思想，针对二级倒立摆的参数摄动及干扰，设计了鲁棒H∞最优控制器，并在二级倒立摆实验装置上进行控制。实验结果表明；用鲁棒H∞最优控制器的二级倒立摆系统，具有很强的鲁棒稳定性和抗干扰性。     

基于Riccati方程和LMI算法的H∞控制器的设计与实现

H∞控制是一种重要的鲁棒控制方法,它以H∞范数作为控制性能指标,是一种最优控制方法,目的是求出系统内部稳定的控制器,使闭环传递函数的无穷范数极小,达到控制的目的。以固高公司的直线一级倒立摆为控制对象,实现基于Riccati方程和LMI算法的H∞控制器设计,采用M文件及simulink实现系统建模、控制器的设计,完成系统算法的验证,实验表明,控制器的输出、倒立摆系统的状态变量变化平稳,系统具有较强的鲁棒性,系统表现出良好的动态品质,验证了H∞控制器的有效性。     

基于H∞鲁棒控制的单级倒立摆控制器设计

以存在建模误差和干扰输入的非线性单级倒立摆为研究对象,建立了被控数学模型.在不确定性干扰因子影响下,利用基于Riccati方程的H∞控制分析研究了摆角和台车位置控制原理,设计了H∞鲁棒控制器.最后的实例仿真验证了在单级倒立摆系统上,H∞鲁棒控制较PID控制相比,具有优异的动态性能和稳定性能.     

不确定广义系统的降阶H∞控制器设计

研究基于函数观测器的不确定广义系统的降阶H∞控制器设计问题.首先提出了基于严格线性矩阵不等式的不确定广义系统H∞控制的充分条件,并用于状态反馈H∞控制设计.然后对所得控制增益进行降阶观测,基于广义Sylvester矩阵方程的显式通解,考虑系统的H∞性能约束,提出了降阶输出反馈控制器的参数化设计方法.     

单级倒立摆基于LMI的H∞控制

采用拉格朗日方法对单级倒立摆系统进行了数学建模,并进行了稳定性、可控性、可观测性分析。针对单级倒立摆系统的控制问题,采用基于线性矩阵不等式（LMI）的H∞控制算法,并应用matlab对该倒立摆系统进行了仿真实验。结果表明,基于LMI的H∞控制方法考虑了被控对象中存在的各种不确定因素,抑制了扰动对输出的影响,系统的振荡小,调节时间短,响应速度快,使系统具有较强的鲁棒性和较好的动态性能,能够较好地完成倒立摆的运动控制。     

单级倒立摆基于LMI的H∞控制

采用拉格朗日方法对单级倒立摆系统进行了数学建模,并进行了稳定性、可控性、可观测性分析。针对单级倒立摆系统的控制问题,采用基于线性矩阵不等式(LMI)的H∞控制算法,并应用matlab对该倒立摆系统进行了仿真实验。结果表明,基于LMI的H∞控制方法考虑了被控对象中存在的各种不确定因素,抑制了扰动对输出的影响,系统的振荡小,调节时间短,响应速度快,使系统具有较强的鲁棒性和较好的动态性能,能够较好地完成倒立摆的运动控制。     

基于观测器的参数不确定系统降阶H_∞控制器设计

本文研究了Luenberger观测器的参数不确定系统降阶H∞控制器设计问题,提出了参数不确定系统H∞状态反馈控制问题的一个充要条件,并利用线性矩阵不等式方法求解出参数不确定系统的H∞状态反馈增益。然后对该H∞状态反馈增益进行渐进降阶观测,基于广义Sylverster方程显式通解的参数化设计方法,实现了参数不确定系统的降阶H∞控制。     

基于鲁棒H∞理论的三级倒立摆控制系统研究

为了研究三级倒立摆的鲁棒控制方法,设计出三级倒立的状态反馈H∞控制器。仿真结果表明三级倒立摆具有良好的鲁棒稳定性、鲁棒性、抗干扰性,实现了对三级倒立摆的稳定控制。同时运用了状态空间极点配置法和LQR最优控制法,分别设计出针对三级倒立摆的控制器。经比较研究：采用状态反馈H∞方法设计的三级倒立摆控制器的控制效果非常好,使其具有较小的振荡和超调量,倒立摆起摆迅速,稳定控制性能优良。     

直线一级倒立摆分数阶控制器设计及仿真

针对直线一级倒立摆的稳定控制问题,设计了分数阶比例积分(FOPI和FO[PI])控制器。首先,根据Newton力学方法建立了倒立摆系统的数学模型。然后,采用基于向量的增益鲁棒性分数阶控制器参数求解简化算法,设计了分数阶比例积分控制器。最后,在MATLAB环境下进行了分数阶比例积分控制器参数整定方法的有效性验证,并且对倒立摆系统分别采用分数阶比例积分控制器和整数阶PID(IOPID)控制器进行了稳定控制仿真实验,并将得到的摆杆角度响应曲线进行了对比分析。结果表明:分数阶比例积分控制器对系统的稳定控制效果优于IOPID控制器,且在分数阶比例积分控制器中,FO[PI]控制器对系统稳定控制最好,响应时间较快、振荡幅值较小且具有鲁棒性。     

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.