基于行为的实时路径规划

针对室内移动机器人导航要求,开发了以二维激光雷达作为探测环境的传感器,基于4个反应式行为,设计了一种简单的实时路径规划算法.避障行为使机器人穿过狭小通道,或者在某些障碍物环境下绕出狭窄区域;接近行为使机器人顺着障碍物前进直到开阔地带;搜寻行为使机器人不断朝向目标运动;线性行为使机器人到达目标点.机器人表现出很强的路径寻找能力,并且不需要定位信息.仿真实验表明该算法速度快,实时性好,路径平滑无震荡,实现了有效避障.     

机器人二维环境下仿人虚拟力场避障研究

动态环境下避障是机器人实现自主运动的关键。首先建立了适合虚拟力场算法的机器人工作环境数学描述。将人避障行走策略引入虚拟力场中,具体包括：设计了单元格障碍物可信度的邻域平滑累积值计算方法,模拟人对移动障碍物的躲避策略;建立可信度的不确定推理计算方法,处理信号和环境存在干扰问题;设计了基于目标点方位角的吸引力计算公式来解决目标点超出感知空间问题;设计了变权重加权排斥力计算方法,使机器人对前进方向的障碍更敏感;借鉴人绕开障碍物策略,采用临时旋转目标点方向得到的虚拟目标点来使机器人沿障碍物运动直到绕开。针对房间和街面环境,在MobotSim平台上进行仿真实验,给出了实验结果和分析。在合理设置参数下,机器人能避开障碍物到达目标点,且避障路径优于传统的虚拟力场方法。结果验证了该方法的有效性。     

动态未知环境下一种新的机器人路径规划方法

针对机器人动态路径规划问题,提出了一种机器人在复杂动态环境中实时路径规划方法.该方法基于滚动窗口的路径规划和避障策略,通过设定可视点子目标、绕行障碍物和对动态障碍物的分析预测,实现机器人在复杂动态环境下的路径规划.针对障碍物分布情况,合理设计可视点法和绕行算法之间转换,有效地解决了局部路径规划的死循环与极小值问题.该方...     

基于BP神经网络的移动机器人避障设计及仿真

为了解决移动机器人在复杂环境中如何高效精确地躲避障碍物的问题,提出了一种基于BP神经网络的避障方法。建立了机器人的避障运动模型并设计了神经网络避障控制系统;分析了机器人在运动过程中与障碍物的位置关系,使用超声波传感器采集距离信息,进行BP神经网络输入、输出训练并采用Matlab工具进行仿真试验。结果表明,该方法可以高效精确地实现移动机器人的自主避障,运行相对稳定、轨迹连续平滑,达到了较为理想的避障效果。验证了方法的可行性和有效性,为移动机器人自主避障提供了一种新的控制方法。     

AS-R移动机器人的动态避障与路径规划研究

针对移动机器人的动态避障和路径规划问题,以AS-R移动机器人为平台,设计了一种基于行为分析的动态避障策略。根据避障问题将移动机器人整个运行过程中的行为划分成趋向目标行为、避障行为、沿墙走行为及紧急避障4种行为,有效实现了机器人的动态避障,并解决了两种避障难题:左右摆动问题和凹型障碍物问题。利用多传感器结合检测方法,通过红外传感器减少盲区和镜面反射带来的误差,通过间隔采样或分组采样技术避免多路串扰问题;对均值滤波与中值滤波进行实验对比后,提出一种递推型中值滤波方法,从而提高了数据在空间和时间上的连续性,有效地减少了超声波随机串扰信号及其它干扰信号,进而提高了探测模块的准确度。最后设计了几种复杂环境下机器人的动态避障和路径规划,并验证了所提方法的有效性。     

基于双目视觉和SIFT算法的羽毛球接球机器人避障研究

研究为了增强羽毛球接球机器人对羽毛球的识别和检测效率,并提高其接球效率和避障能力,提出了一种辅助羽毛球训练的接球机器人。首先利用无锚框检测的回归算法来实现机器人的目标检测和识别,此外引入了羽毛球轮廓识别技术和机器人避障技术来实现接球机器人的整体设计。最后通过尺度不变特征变换算法获取障碍物的环境特征点信息,使用加权最小二乘拟合法来获取障碍物的距离信息。在实验分析中显示,研究所提出的目标识别技术具有较低的误差,并长期保持在0.3以内,同时在羽毛球机器人的接球应用测试中显示,其避障反应时间较短,同时避障能力较强。特征点的误差整体控制在1～3的范围内。以上结果表明,通过双目视觉技术来实现羽毛球接球机器人的设计具有合理性,能够实现羽毛球的自动识别和接取,并有较强的避障能力,在羽毛球运动的智能化训练发展中具有重要价值。     

基于多行为的移动机器人路径规划

机器人由当前点向目标点运动的过程中,所处环境经常为动态变化且未知的,这使得传统的路径规划算法对于移动机器人避障过程很难建立精确的数学模型.为此,针对环境信息完全未知的情况,为移动机器人设计一种基于模糊控制思想的多行为局部路径规划方法.该方法通过对各种行为之间进行适时合理的切换,以保证机器人安全迅速地躲避静态和动态障碍物,并利用改进的人工势场法实现对变速目标点的追踪.对于模糊避障中常见的U型陷阱问题,提出一种边界追踪的陷阱逃脱策略,使得机器人成功解除死锁状态.另外,设计一个速度模糊控制器,实现了机器人的智能行驶.最后,基于Matlab平台的仿真结果验证了所提出算法的有效性和实时性,与A*势场法的对比结果更突出了该算法的可行性.     

基于模糊避障算法的履带式搬运机器人的设计

以HC-SR04超声波传感器模块获取机器人周围环境信息,以链式叉车作为搬运货物的执行机构,以STM32F103单片机作为机器人控制器,设计了一种自动搬运并且避障的小型履带式搬运机器人。针对局部静态环境下多障碍物对系统避障的复杂性,引入了模糊控制算法,通过对机器人与障碍物之间的距离进行模糊化,建立模糊规则,实现搬运机器人的避障控制。为了提高机器人的稳定性及避障的可靠性,对直流电机建立了数学模型,并利用积分分离PID算法进行仿真,最后实验结果表明该算法提高了直流电机的控制性能。     

一种多移动机器人避障的改进算法

为了使多机器人在有障碍物的环境中可靠地运行,针对多机器人的避障问题,融合沿墙行为的避障模式,构造出一类具有自适应特性l-ψ闭环控制律下的多机器人避障算法,以作为基于行为的控制策略的有益补充。仿真结果表明,该算法可以成功地解决机器人因融合参数不当而形成的避障"死锁"问题,使多机器人在有障碍物的环境下,在障碍物区能够顺利地通过障碍物,在离开障碍物后,快速恢复至稳定。     

结合光流和人工势场的风管机器人避障方法

风管清扫机器人是一种用来清扫中央空调通风管道内壁的机械手,工作环境恶劣、管道空间障碍复杂。风管清扫机器人的无碰撞运动对于实现其3D非重复接触和高速旋转刷的最优遍历清洗至关重要。以光流密度作为使用避障的光源,结合光流和人工势场法,以光流法进行障碍物检测,人工势场法进行避障规划,提出一种局部路径规划的障碍物检测及避障方法。实验结果表明,斥力势场矢量指向避开障碍物的方向,而且势场主要受障碍物的光流的影响,并由最近的障碍物来确定。通过与平衡策略方法对比,也验证了此方法的有效性。     

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.