基于SURF算法的双目视觉特征点定位研究

针对双目视觉立体图像特征点匹配质量不好导致定位精度低的问题,本文提出改进SURF匹配的特征点定位方法。在改进的SURF匹配算法中,采用双向匹配、NNDR约束、对称性约束、极线约束和交叉匹配约束的方法,提高了图像特征点匹配的质量。在双目视觉特征点定位中,采用公垂线段中点法具有更高的特征点定位精度。实验证明,该算法的特征点定位精度更高,同时可以达到实时三维重建效率。     

基于双目主动视觉监测平台的刀具匹配方法

为了解决并联机器人加工点定位精度问题,构建了双目主动视觉监测平台.基于双目主动视觉的刀具图像特征点的提取和匹配是加工点定位的核心.结合刀具边缘特点,对特征所在极线的区域局部校正算法改进,给出一种并联机器人加工刀具匹配方法及其实现.提取刀具图像的边缘线拐点作为特征点,根据对极几何的立体成像关系,对以特征点为中心的图像局部区域进行方向和尺度校正,通过区域相似度准则求取同名点,并对三维重建.采用对并联机器人加工刀具进行测量,实现了主要特征点匹配.进行仿真,实验表明,上述方法可提高图像匹配的精度和速度,能够较精确地对刀具加工点实现三维重建.     

基于灰度矩的脉搏图像亚像素特征点提取研究

在基于双目视觉脉搏图像传感器的脉搏三维信息检测中,图像特征点的提取是关键基础。为了提高脉搏图像特征点提取的精度,提出一种新的对脉搏图像特征点进行亚像素定位的算法。在完成脉搏图像的预处理后,对脉搏图像进行基于灰度矩的亚像素边缘检测,结合最小二乘拟合法得到圆形标志中心点,最终实现脉搏图像的特征点提取。实验结果表明该算法能够准确定位脉搏图像特征点,精度可达到0.03~0.04像素,为后续双目视觉的立体匹配及脉搏三维形态的重构奠定了基础。     

基于立体视觉的球形机器人定位方法

针对球形机器人定位问题,提出了基于立体视觉的球形机器人定位方法.通过双目相机采集环境图像序列,提取Shi-Tomasi特征点,计算尺度不变特征变换(SIFT)特征描述符,并利用欧氏距离进行立体匹配;通过KLT算法进行特征点跟踪;采用解析法求解机器人在前后帧图像之间的位姿变化量;同时采用特征点筛选、RANSAC算法和卡尔曼滤波等方法,提高运动估计的准确性和鲁棒性.实验结果验证了所提出方法的可行性.     

基于粗精立体匹配的双目视觉目标定位方法

针对双目视觉系统定位精度较低的问题,提出一种基于粗-精立体匹配的双目视觉目标定位方法。该方法采用粗-精匹配策略：在粗匹配阶段使用基于Canny-Harris特征点的随机蕨算法对左右图中的目标进行识别,提取目标矩形区域的中心点,实现中心匹配;在精匹配阶段建立一种基于图像梯度信息的二值特征描述子,将中心匹配得到的右中心点作为估计值,设定像素搜索范围,于该区域中找出左中心点的最佳匹配点。最后,将得到的中心点匹配对代入平行双目视觉的数学模型中,实现目标定位。实验结果表明,在500 mm距离范围内,所提出定位方法的定位误差控制在7 mm内,平均相对定位误差为2.53%,相比其他方法具有定位精度高、运行时间短的优点。     

砂轮地貌双目图像特征点提取和匹配研究

特征提取和匹配是双目视觉中的关键点和难点。对SIFT和Harris两种特征点提取算法应用于双目砂轮地貌图像的角点检测进行了研究,通过对SIFT特征采用欧式距离进行匹配,对Harris角点采用零均值归一化互相关算法(ZNCC)进行模板匹配,采用RANSAC算法剔除误匹配特征点对。实验结果表明,SIFT算法在双目砂轮地貌图像上应用较Harris算法效果理想。     

基于单目视觉和里程计的SLAM算法研究

已有的基于视觉的SLAM方法大多采用双目立体视觉,存在成本高,标定过程复杂,鲁棒性低等缺点.因此,提出了基于单目视觉和里程计的SLAM方法.该方法采用尺度不变特征变换算法提取特征,用扩展卡尔曼滤波更新地图.此外,由于单个CCD摄像头不能直接获得图像的深度信息,采用特征点延迟初始化的方法来解决这个问题,这种方法使得基于单目视觉的导航变得可能.在MATLAB环境下实现了SLAM算法仿真,实验结果表明,在室内环境下,该算法运行可靠,定位精度高.     

基于光束平差法的双目视觉里程计研究

机器人自定位是实现机器人自动导航及其他智能行为的前提, 一种基于光束平差法的移动机器人双目视觉里程计可以有效地实现机器人自定位. 为此, 首先采用点模式匹配方法建立相邻图像之间的特征匹配关系, 根据立体视觉算法得到匹配点对的三维对应关系; 然后, 计算摄像机的相对运动参数, 并采用光束平差分段优化算法对其进行优化. 所提出的双目视觉里程计能够避免车轮半径变化、空转、打滑等对里程计测量精度的影响, 相对定位精度较高.

     

基于SURF特征点的自主空中加油定位研究

针对硬式空中加油技术中加油插座的定位问题,提出了一种结合SURF(Speeded-up Robust Features)特征点的双目立体视觉定位方法,确定了加油插座的空间位置,实现伸缩管和加油插座的精确对准。基于SURF匹配算法,对双目视觉系统采集的左右图像进行目标检测,并获取匹配目标的SURF特征点,通过空间误匹配点对的剔除和目标点坐标的计算,确定左右图像中具有空间位置一致性的目标点(即加油插座),从而恢复目标点的三维信息。实验结果表明,结合SURF方法能够有效地对加油插座的空间位置进行定位,具有一定的实用价值。     

基于光流融合快速特征提取的视觉/惯性定位方法

针对地下遮蔽空间内弱纹理环境下视觉/惯性定位方法特征点提取、追踪困难问题,文章结合快速鲁棒性（Speeded Up Robust Features,SURF）特征点法提取速度快、识别精度高、光流法追踪精度高的特点,提出了一种基于光流融合快速特征提取的视觉/惯性定位方法。该方法改进视觉前端部分,以SURF算法构建Hessian矩阵对图像信息中的特征点进行提取,提高特征点匹配效率与提取效果;随后,利用LK(Lucas–Kanade)光流法对特征信息进行追踪,保证特征追踪速度,以提高算法精度与鲁棒性;在信息融合部分参考多状态约束卡尔曼滤波算法框架,对视觉信息与惯性信息进行融合。采用EuRoc室内数据集进行仿真实验。结果表明,该算法具有良好的定位精度。与传统MSCKF算法相比,该算法漂移较小,相比MSCKF平均轨迹误差减少8%,均方根误差减少21%,具有更好的定位效果。     

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。     

基于QTE的蒙古文显示机制研究与实现

蒙古语言是中国蒙古族使用的通用语言,由于蒙古文区别于其他文字的书写方式和其自身变形机制等特点,在很多通用的文字处理引擎中都不被支持。在嵌入式产品开发与应用领域中Linux加QTE已经成为流行方式。该文给出了一种在QTE环境上实现基于标准Unicode的蒙古文点阵显示和变形算法, 并自定义了支持蒙古文的QTE组件,扩展了QTE功能,为在Linux加QTE方式的嵌入式体系结构中处理蒙古文提供了一种解决方法。