同构阵列式自重构机器人的仿真与控制

针对同构阵列式模块化自重构机器人的特点,说明该机器人系统是一个分布式的多智能体系统,结合agent技术,对自重构模块的组成进行了分析,并提出一种能够准确描述该类机器人的拓扑结构、运动、位置及模块间连接关系的特征向量矩阵;对自重构模块的翻转、平移运动和元模块的构成及运动形式进行了描述,搭建了分布式多智能体的控制结构,结合模块的空间矢量进行路径规划,利用Java3D技术建立了可视化的模块化自重构机器人仿真环境,在此平台上对模块的运动进行了仿真,验证了该控制算法和仿真平台的有效性。     

基于加权非局部相似性的视频压缩感知多假设重构算法

分布式视频压缩感知(Distributed Compressed Video Sensing,DCVS)多假设重构算法将传统视频编码中的多假设预测运动估计思想引入到分布式压缩感知视频编码系统中,改善了对视频序列的重构质量。在该算法中,大变化块采用本帧邻域块信息作为参考,而当本帧邻域块含有较多纹理和细节时,算法性能有待提高。为此,对非局部相似性的思想进行改进,提出基于加权非局部相似性的分布式视频压缩感知多假设重构算法。在该算法中,对大变化块中的纹理块采用加权非局部相似性在相邻已重构帧中寻找自相似块,最终生成辅助重构信息块;对于非纹理块,则简单利用加权非局部相似性生成相似块。对不同特点的视频序列的仿真实验结果表明,改进后的算法有效改善了视频序列的重构质量,具有较优的重构SSIM,PSNR指标,其中PSNR约提高1dB。     

未知环境下分布式多机器人避碰协作算法

针对多机器人协作问题,提出一种未知环境下分布式多机器人协作避碰算法。该算法基于分布式投标模型协调多机器人运动,改进过去算法的前提假设,综合考虑机器人的实际尺寸和传感误差,通过自适应设定投标时间,提高算法的效率,针对通信延时引起的信息不一致,采用按优先级顺序进行探测的方法。仿真实验验证了该算法的可行性。     

基于Java 3D的自重构机器人仿真平台的构建

介绍了新设计的一种同构阵列式模块化自重构机器人的模块结构和运动方式,针对这种机器人系统,为了验证控制算法,构建了可视化的自重构机器人仿真平台。选用Java 3D作为开发工具,采用类的封装和线程技术,设计了仿真平台的软件结构,并实现了在界面上进行交互式地显示三维运动过程。在此平台上对模块的运动进行仿真,给出了一个4×2×2矩形阵列模块的平移仿真示例,验证了该仿真平台的有效性。此仿真平台界面简单,操作方便,能够实现算法仿真和运动显示。     

冗余自由度协作机器人运动规划研究

针对传统快速探索随机树(Rapidly Exploring Random Tree,RRT)路径规划算法在新枝点扩展上缺乏目标性和时间复杂度高的问题,以具有偏置构型的7自由度冗余机器人Rethink Sawyer为研究对象,利用引力势函数,对新枝点的扩展进行调节,提出了具有导向性的变步长双向RRT扩展算法完成协作机器人运动规划.采用阻尼最小二乘Newton-Raphson方法对Sawyer机器人逆运动学进行数值求解.通过机械臂运动学模型和运动规划算法仿真、ROS平台的运动规划实验,验证了改进RRT算法进行路径规划的正确性,在操作过程中有效地避免了与约束框架碰撞,降低了机械臂运动规划的时间复杂度.     

一种改进多机器人分布式滚动路径规划算法

针对多移动机器人全局静态环境未知的路径规划问题,采用了一个全局性能指标,在保证路径较优的情况下,最小化机器人的停顿时间,提出机器人之间以修正局部路径为主的协调策略。根据多机器人滚动路径算法的原理,设计了改进的多机器人分布式滚动路径规划算法。在已有仿真系统上进行测试,比较了所提出的协调策略与改变机器人移动速度协调策略对性能指标的影响。仿真结果表明,静态环境未知情况下,机器人可以并行规划各自的协调路径。     

基于栅格模型机器人路径规划的改进蚁群算法

提出了一种静态环境下机器人路径规划的改进蚁群算法.该算法使用栅格法对机器人的工作空间进行建模,通过模拟蚂蚁的觅食行为,采用折返的迭代方式对目标进行搜索;在搜索过程中,以移动方向一定范围内最大信息素和目标引导函数作为启发式因子;此外,根据蚁群算法处理本问题时信息素散播的特点,重构了信息素的更新策略和散播方式.仿真试验结果表明,改进措施使最优路径的寻找快速而高效,即使在障碍物非常复杂的环境下,算法也能迅速地规划出一条最优路径.     

广义Voronoi图求解多机器人运动规划

在拥挤环境中,由于障碍物的边界形状比较复杂,需要使用广义Voronoi图表示空间环境。且在多移动机器人的运动规划过程中,需要协调多个机器人的运动,必须得到Voronoi图通道的宽度。为此提出了一种计算拥挤障碍物环境中生成的广义Voronoi图及其通道宽度的算法。并在生成的Voronoi图上利用A*算法对多个机器人进行路径规划,并利用分布式方法协调多个机器人运动。对协调两个机器人运动的过程进行了仿真,仿真结果表明利用提出的算法生成的具有通道宽度信息的Voronoi图能够满足多移动机器人运动规划的需要。     

基于ATmega162的自重构机器人控制模式

本文通过对自重构机器人的特点和总体结构进行分析,提出一种基于ATmega162的部分主从分布式控制模式,该模式利用ATmega162的外扩存储器功能实现扩展总线,从而对自重构机器人上的部分功能模块采用集中式控制,而对另一些模块采用主从分布式控制。通过分析ATmega162对行走机构的控制证明了该模式的有效性。     

六轴工业机器人先验引导RRT*避障轨迹算法研究

针对六轴工业机器人装配避障路径运动问题,研究了机器人整体避障运动路径规划方法,提出一种RRT*改进算法;算法以RRT*算法为基础,在障碍物建模中引入包围盒算法,加入对机器人各轴与障碍物的碰撞检测;在路径规划中加入对随机点生成方向与树枝生长方向的先验引导机制,优化了算法路径长度与路径搜寻效率;通过Matlab进行了试验验证,结果表明与标准RRT*算法相比,先验引导RRT*算法缩短路径长度14%左右,且满足机器人末端路径与手臂各轴的避障需求。     

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.