BTT导弹的自适应模糊反演控制律设计

结合反演控制、自适应控制和模糊控制方法,针对具有非匹配不确定性的BTT导弹非线性动力学模型,设计了一种基于自适应模糊控制的BTT导弹反演控制律.针对传统反演控制律设计的不足,采用模糊控制法逼近BTT导弹控制系统中带有未知成分的非线性函数,实现了无需精确数学模型的全新控制律,避免了因建模误差对控制带来的不良影响.设计了自适应控制律以调整设计参数的变化,利用李亚普诺夫方法证明了系统的稳定性和收敛性.仿真结果表明,所设计的控制律对导弹控制系统中存在的非匹配不确定因素具有较强的鲁棒性和自适应性.     

基于LS-SVM的BTT导弹动态逆反演控制

基于LS -SVM理论、动态逆控制和反演控制方法,针对具有非匹配不确定性的BTT导弹非线性数学模型,设计了一种基于LS- SVM的BTT导弹动态逆反演控制律;对传统反演控制律设计的不足之处,采用LS- SVM法逼近BTT导弹控制系统中带有未知成分非线性函数,从而实现了无需精确数学模型的全新控制律,避免了因建模误差对控制带来的不良影响,在此基础上,利用李亚普诺夫方法证明了系统的稳定性和收敛性;仿真结果表明,文章所设计的控制律,对导弹控制系统中存在的不确定因素具有较强的鲁棒性和自适应性.     

空空导弹增益调度鲁棒H_∞控制自动驾驶仪设计

为了满足空空导弹大空域、高机动飞行的技术指标要求,提出了BTT导弹的增益调度鲁棒H∞自动驾驶仪设计方法;建立了BTT导弹线性变参数(LPV)系统数学模型;提出了LPV系统增益调度鲁棒H∞控制设计方法和设计过程;通过把BTT导弹自动驾驶仪分为俯仰、偏航/滚转通道分别进行设计,并以俯仰通道为例进行了仿真验证;仿真结果表明该控制算法具有良好的控制性能,从而,验证了增益调度鲁棒H∞控制算法的正确性和有效性。     

多枚倾斜转弯导弹的滚转通道之分布式有限时间姿态协调控制

对多枚倾斜转弯(BTT)导弹设计滚转通道自动驾驶仪时,基于分布式协调控制理论,本文提出了一类分布式有限时间姿态协调控制器.由于BTT导弹的气动参数变化强烈、机动要求高,要求控制器响应速度高,抗干扰能力强.本文基于有限时间控制技术,并结合多智能体系统的协调控制理论,对多枚BTT导弹滚转通道提出了一种分布式有限时间姿态协调控制律.在该控制律作用下,所有的BTT导弹通过相互协调,其滚转角可以在有限时间内达到一致并为给定的参考指令信号.仿真结果表明了该方法的有效性.     

飞航导弹横测通道协调变结构飞行控制系统设计

某型面对称布局飞航导弹采取BTT控制方式,可以使战术导弹在各方面获得良好的性能.但由于其横侧向通道之间具有强烈的耦合,传统的STT导弹采用的控制系统及其综合方法已经不再适用于BTT导弹,一个具有运动学耦合,惯性耦合,以及控制作用耦合的多自由度的系统综合问题被提出;应用变结构控制理论,结合经典的双回路飞行控制系统方案分别设计了偏航和滚动通道自动驾驶仪;仿真结果表明用该方法设计的飞行控制系统能够有效克服横侧向通道间的耦合以及参数摄动影响.     

基于鲁棒模糊控制理论的BTT导弹动态逆控制

将模糊控制理论应用于BTT导弹动态逆系统控制中,设计了BTT导弹控制系统鲁棒模糊控制器.首先应用动态逆系统方法设计BTT导弹控制器,然后用参数化线性模糊逻辑系统逼近动态逆控制器中的不确定项,并设计了自适应律以调整参数的变化,最后根据Lyapunov稳定性定理,证明了所提出的方法能保证BTT导弹控制系统是渐近稳定的,系统的跟踪误差将收敛到零.仿真结果表明,设计的控制器,对参数和外界扰动等不确定因素具有较强的鲁棒性和自适应性.     

BTT导弹横侧通道H∞鲁棒控制器设计研究

考虑到BTT导弹存在较大的耦合和不确定性,传统频域控制理论以及三通道独立设计方法不再适用于自动驾驶仪的设计.为此,研究了BTT导弹横侧通道H∞鲁棒控制器的设计问题,用以抑制不确定性、外来扰动以及通道间耦合给系统带来的不利影响.首先分析了H∞鲁棒控制器设计中存在的关键问题,包括不确定性的分析及加权函数的选择;然后通过建立包含未建模不确定的被控对象、引入加权函数,得到了扩展的广义受控系统,利用Matlab鲁棒控制工具箱设计了BTT导弹横侧通道的H∞鲁棒控制器;最后通过仿真验证,表明设计的H∞鲁棒控制器具有良好的控制性能和鲁棒性.     

考虑参数优化的BTT导弹三维非线性制导律

针对BTT（bank-to-turn）导弹制导过程中的通道耦合问题,设计了一种考虑制导参数优化的新型的三维非线性制导律.首先,采用旋量描述方法构建弹目视线方位模型,采用矢量描述方法构建弹目视线角速度模型,从而得到了导弹制导的三维非线性模型;然后,将制导律分为制导控制项和耦合补偿项.基于制导控制项最优设计相应的目标函数.同时,在不损失制导信息的情况下,将制导模型转化为线性形式;最后,分别针对无终端约束和有终端约束情况,基于二次型最优方法得到了三维制导律.该制导律既解决了通道解耦,其制导参数又满足一定物理意义下的最优性.仿真结果验证了本文所设计制导律的有效性.     

BTT导弹控制系统设计问题的研究

针对BTT导弹控制技术进行研究无疑具有很高的应用价值,对巩固和提高我国的国防科技水平具有重要意义;BTT导弹因其自身的机动方式而成为典型的非线性强耦合系统,给其控制系统设计工作带来很大难度;能否选择合适的控制方法对控制系统进行设计成为制约BTT导弹性能的关键问题;文中从控制方法设计的角度对BTT导弹控制系统设计问题进行了研究,通过采用不同控制方法进行控制律设计和稳定性分析,来对各方法的特点进行比较和分析。     

基于Nussbaum增益滑模自适应控制的 导弹制导控制一体化设计

采用Nussbaum增益滑模自适应控制方法解决导弹制导控制一体化设计问题. 充分考虑一体化模型具有通道间耦合、气动建模不确定性、气动参数摄动和目标机动引起的干扰等特点, 基于自适应控制对未知量的辨识能力和滑模控制的抗干扰能力, 以及Nussbaum增益控制对系数不确定系统所具有的较好的控制能力, 设计Nussbaum增益滑模自适应控制律, 并证明系统的稳定性. 仿真结果验证了所提出方法的有效性.     

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.