非完整移动机器人的复合编队控制

主要研究了非完整自主机器人之间的队形保持和避障问题,提出了一种新的复合编队控制方法,该方法根据机器人的期望位置在其运动约束区域内外的不同,分别以一种灵活的反馈线性化算法和最优近似目标算法来建立控制规则,并提出了编队环境中存在静态障碍物时的队形控制策略,从而实现多机器人的稳定编队控制．该方法降低了传统线性反馈控制对编队初始误差范围的要求,并且解决了非完整机器人编队的避障问题．实验结果表明了该编队控制方法的可行性和有效性．     

基于行为的多机器人任意队形的控制

针对多机器人队形优化控制任务,提出一种快速收敛的机器人任意队形的控制算法。各机器人在奔向目标的过程中以队形的几何中心为参考点,自主地确定队形向量。在保持队形的过程中,采用动态死区法,通过对各个区域大小的控制达到对机器人速度的控制,维持规定队形。采用反向避碰、切线避障,根据各机器人间的位置,引入整体队形向量约束机器人的方向,达到机器人整体队形的方向与机器人运动方向一致。实验结果表明该算法可以快速、有效地完成各种编队任务。     

群体觅食行为启发的多机器人分布式编队控制方法研究

群集智能由简单个体之间的相互作用涌现出来,这种涌现出来的智能可以解决许多复杂的问题.首先,从细茵群体觅食特性出发,引出了该行为与多机器人编队任务的相关性.然后,通过对群体觅食行为模型的扩展,建立了基于势场的多机器人分布式编队控制模型;最后,在不同规模下的多机器人编队仿真实验表明,本文的方法能够控制多机器人完成编队任务,并且使得机器人在遇到障碍物时能灵活躲避障碍物,离开障碍物后又快速恢复队形.     

多移动机器人避障编队控制

研究多移动机器人避障优化设计,针对多移动机器人在障碍物环境下的编队控制问题,为了保持整体合理避障和控制系统的稳定性和安全性,提出一种多机器人避障编队控制策略.首先获得多移动机器人编队的队形结构模型,结合多机器人完成避障编队任务的问题描述;在此基础上引入导航函数采用一种避障编队控制算法,使移动机器人能以设定的队形运动到目标点,可保证编队运动过程中未与障碍物发生碰撞.进行仿真的结果证明,所提算法解决了多机器人编队与避障问题,并保证了闭环系统的稳定性与安全性,验证了设计方法的有效性.     

基于动态目标点的行为分解编队算法

多机器人编队可以分解为队形形成和队形保持控制两部分.针对多机器人编队控制任务中的队形形成问题,提出了一种基于动态目标点的行为分解编队算法.此算法是一种改进的基于行为的编队控制方法,这种控制方法的思路为,首先要求各机器人在每一时刻确定一个运动目标点,此运动目标点是根据运动过程中机器人实时的位置运算出来的,是一个动态的目标点.根据此目标点进而产生一个运动需求.再将此运动需求按照有限状态机(FSM)原理分解为不同的子行为,然后给这些子行为分别赋予不同的权值,并求出一组控制变量,最终对这组控制变量加权平均产生一个综合控制变量.仿真实验表明,该方法能快速有效地实现多机器人的编队控制.此编队算法可以有效应用于军事搜索、围捕或机器搬运等多个领域.     

考虑障碍环境下的多机器人编队控制研究

编队和避障控制是机器人路径规划设计中的典型问题,文中提出了将leader-following法和人工势场法相结合的方法,来更好地完成多机器人在未知环境下的编队和避障控制。之前的研究只将leader-following算法用于多机器人的编队控制,而文中提出此方法也可以用于多机器人系统的避障控制。基于leader-following法,多机器人能自动编队并保持队形;而结合人工势场法,多机器人可以保持队形行进,在遇到障碍物的情况下变换队形避障,在避障后恢复原队形,最终到达目标。通过仿真实验证明,该算法实现了多机器人在未知环境下的自动编队和避障,从而证明了leader-following算法可以用于机器人的避障控制。     

考虑障碍环境下的多机器人编队控制研究

编队和避障控制是机器人路径规划设计中的典型问题,文中提出了将leader—following法和人工势场法相结合的方法,来更好地完成多机器人在未知环境下的编队和避障控制。之前的研究只将leader—following算法用于多机器人的编队控制,而文中提出此方法也可以用于多机器人系统的避障控制。基于leader—following法,多机器人能自动编队并保持队形;而结合人工势场法,多机器人可以保持队形行进,在遇到障碍物的情况下变换队形避障,在避障后恢复原队形,最终到达目标。通过仿真实验证明,该算法实现了多机器人在未知环境下的自动编队和避障,从而证明了leader—following算法可以用于机器人的避障控制。     

动态环境下的多机器人编队控制方法的研究

多机器人编队控制是研究机器人协调合作问题的基础.在诸多的编队方法中,传统人工势场法以其算法简单,易于实现等特点被广泛应用于机器人避障.但上述方法无法适应动态未知环境,并且存在着局部极小问题,为解决上述问题,提出一种改进的人工协调场方法,即在排斥力的垂直方向增加一个协调力,从而消除零势能点,克服局部极小.同时与领航—跟随法结合,将编队信息预先存储在领航机器人中,通过队伍行进中领航者所发出的位置信息,跟随者保持队形,不仅可以达到灵活躲避动态障碍物,同时可以保持队形稳定.最终在TEAMBOTS平台上进行了仿真,结果证明了改进方法的有效性,实现了动态环境中的多机器人编队的灵活控制.     

行军启发的多机器人紧密队形保持策略

多机器人协同编队是多机器人研究的关键技术之一,是通过控制队伍中的机器人,使其按照预定的队形进行前进。本文基于领航者-追随者结构的编队控制方法,从军队急行军中得到启发,设计了同列依次替补和末排向内收拢原则,提出多机器人紧密队形保持策略。并引入能耗和队形紧密度两个编队性能评价指标,验证了多机器人紧密队形保持策略的优越性。仿真实验证明了多机器人紧密队形保持策略的有效性。     

不确定环境下多机器人编队控制研究

针对多机器人在不确定环境下难以保持某种队形到达预定目标等问题,提出了一种无须全局坐标的多机器人编队控制算法。该算法通过Reynolds类鸟群模拟方法设计了“分离”“对齐”“队形”三规则的控制器来实现多机器人任意队形保持控制,并增加切换规则来实现多机器人队形变换。在不同场景及复杂环境下进行仿真实验,验证了提出方法的优越性。该算法能够使多机器人在不确定环境下保持队形到达目标,对于救援、救灾下多机器人的运用具有重要意义。     

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.