检索结果-内蒙古大学图书馆

The Geometry of Visual Coordination 9

9th National Conference on Artificial Intelligence, AAAI 1991

作者： Hervé, Jean-Yves Sharma, Rajeev Cucka, Peter Computer Vision Laboratory Center for Automation Research Department of Computer Science University of Maryland College ParkMD20742 United States

ISBN: (纸本)0262510596

We present a new model for the perceptual reasoning involved in hand/eye coordination, and we show how this model can be developed into a control mechanism for a robot manipulator with a visual sensor. This new approach overcomes the high computational cost, the lack of robustness, and the need for precise calibration that plague traditional approaches. At the heart of our model is the Perceptual Kinematic Map (PKM), a direct mapping from the control space of the manipulator onto a space defined by a set of measurable image parameters. By exploring its workspace, the robot learns, qualitatively, the topology of its PKM and thus acquires the dexterity for future tasks, in a striking parallel to biological systems. © 1991, AAAI (***). All rights reserved.

关键词： Robot applications

来源：评论

学校读者我要写书评

暂无评论

Medial axis representation and encoding of scanned documents

引用

Journal of Visual Communication and Image Representation 1991年第2期2卷 151-165页

作者： Brandt, Jonathan W. Jain, Anil K. Ralph Algazi, V. Computer Vision Research Lab CIPIC: The Center for Image Processing and Integrated Computing United States Department of Electrical Engineering and Computer Science University of California Davis CA 95616 United States

The medial axis transform (MAT) is a sparse representation of shape, which, being reversible, has potential for binary image compression. The MAT also provides structural information not accessible with alternative binary image codes. This structural information is often used for line extraction and pattern recognition. Therefore, the MAT occupies an interesting middle ground between lower-level, compressible image codes and higher-level, meaningful image representations. In an attempt to realize this middle ground, a MAT-based coding scheme which respects its structural properties is developed. The MAT-based coding method is applied to the CCITT facsimile test images. The resulting compression is comparable to that of known coding schemes for textual and somewhat better for graphical data. Some simple modifications to improve skeleton coding performance are suggested. To substantiate the claim that the MAT is effective for higher-level processing, the representation is extended to perform line segment and curve extraction. The extraction takes place under the control of a global error tolerance parameter and thus provides a new method to trade off data compression with distortion for binary images. © 1991.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Quadric surface fitting for sparse range data

Quadric surface fitting for sparse range data

引用

IEEE International Conference on Systems, Man and Cybernetics

作者： X. Cao N. Shrikhande Center of Computer Vision and Robotics Research Computer Science Department Central Michigan University Mount Pleasant MI USA

The authors present a systematic comparison of three commonly used least-squares based methods that describes the relationship between noise levels, patch sizes and reliability of surface classification in computer vision. The different methods were tested on several sets of synthetic and real data. Complete sets of quadric surfaces were tested. In each case the standard deviation of the Gaussian noise ranged from 0 to 0.05. Four different patch sizes were tested in each case representing data from the entire surface, half surface, quarter surface and from a small patch of the surface. Similar tests were made for two different types of real range data, a sphere and a cylinder. Both synthetic and real data showed improvement in the results obtained by using the M-estimate method in the case of gross outlying points.< >

关键词： Surface fitting Testing Noise level computer vision Least squares methods Differential equations Robot vision systems computer science Object recognition Singular value decomposition

来源：评论

学校读者我要写书评

暂无评论

On seeing spaghetti: A novel self-adjusting seven parameter hough space for analyzing flexible extruded objects

On seeing spaghetti: A novel self-adjusting seven parameter ...

引用

Geometric Methods in computer vision 1991

作者： Kender, John R. Kjeldsen, Rick Department of Computer Science Columbia University New YorkNY10027 United States Exploratory Computer Vision Group IBM Thomas J. Watson Research Center P.O. Box 704 Yorktown HeightsNY10598 United States

We present a model for flexible extruded objects, such as wires, tubes, or grommets, and demonstrate a novel, *** seven-dimensional Hough transform that derives and analyzes their three-space curved axes from position and surface normal information. The method is purely local and is very cheap to compute. The model considers such objects as piecewise toroidal, and decomposes the seven parameters of a torus into three nested subspaces, the structure of which counteract the errors implicit in the analysis of objects of great size and/or small curvature. We believe it is the first example of a parameter space stmcture designed to cluster ill-conditioned hypotheses together so that they can be easily detected and ignored. This work complements existing shape-from-contour approaches for analyzing tori: it uses no edge information, and it does not require the solution of high-degree non-linear equations by iterative techniques. Most of the results, including the conditions for the existence of more that one solution (phantom 'anti-tori'), have been verified using a symbolic mathematical analysis systern. We present, in the environment of the IBM ConVEx system, robust results on both synthetic CAD-CAM range data (the hasp of alock), and actual range data (a knotted piece of coaxial cable), and discuss several system tuning issues. © 1991 SPIE. All rights reserved.

关键词： Hough transforms

来源：评论

学校读者我要写书评

暂无评论

Navigation in a hazardous environment with distributed shelters

Navigation in a hazardous environment with distributed shelt...

引用

IEEE International Conference on Systems, Man and Cybernetics

作者： R. Sharma D.M. Mount Y. Aloimonos Computer Vision Laboratory Center of Automation Research and Department of Computer Science University of Maryland College Park MD USA

The problem of efficient path planning for a point robot in a partially known dynamic environment is considered. The static known part of the environment consists of point shelters distributed in planar terrain, and the dynamic, unknown part is abstracted in the form of alarms that cause the robot to leave its current (pre-planned) path and divert to the nearest shelter. A probabilistic analysis of the expected times for the dynamic paths generated when the alarms follow a Poisson distribution with parameter lambda is given. A case study with three shelters serves to illustrate the dependence of the expected travel times on lambda for two alternate static paths. Two different strategies are presented for the general case of n shelters and shown to be superior for different ranges of values of the alarm rate lambda (very low and very high values, respectively).< >

关键词： Navigation Path planning Motion planning Robot sensing systems robotics and automation computer vision computer science Educational institutions Robot vision systems Mobile robots

来源：评论

学校读者我要写书评

暂无评论

A framework for vision-guided manipulation of a moving target

A framework for vision-guided manipulation of a moving targe...

引用

IEEE International Conference on Systems, Man and Cybernetics

作者： R. Sharma J.-Y. Herve P. Cucka Computer Vision Laboratory Center of Automation Research and Department of Computer Science University of Maryland College Park MD USA

The authors present a general framework for reasoning about robotic manipulation tasks involving a moving target, where manipulation is loosely defined to include catching, hitting, interception, etc. This framework may be used to achieve robust vision-based control. The different levels at which visual input is involved in pursuing the dynamically defined goal are considered. A given task is first transformed into one of constrained trajectory planning on a topological space defined by a set of image parameters. A learning phase first learns the qualitative features of this perceptual control surface so that further operations may be carried out autonomously without precise calibration of different parts of the system. The framework facilitates the incorporation of learning strategies to automate the control mechanism.< >

关键词： Robot vision systems Orbital robotics Robot sensing systems Service robots computer vision robotics and automation Manipulators Computational geometry Intelligent sensors Intelligent robots

来源：评论

学校读者我要写书评

暂无评论

Visual feedback for autonomous navigation

Visual feedback for autonomous navigation

引用

IEEE International Conference on Systems, Man and Cybernetics

作者： J.-Y. Herve Computer Vision Laboratory Center of Automation Research Department of Computer Science University of Maryland College Park MD USA

The author addresses the problem of visual navigation, and through it the more general problem of sensor-mediated movement. A new approach to the navigation problem is proposed, in which visual processes are closely and actively integrated with the control of the robotic system. In the case of obstacle avoidance, the concepts of free space doors and corridors are introduced and it is shown that this dynamic information is easier to extract from the sequence of incoming images than the depth map traditionally used. Though poorer in content, the information is still sufficient for the purpose of closed-loop planning and control of trajectories to the goal.< >

关键词： Feedback Navigation Computational geometry Robot sensing systems Laboratories robotics and automation Robot control Control systems Legged locomotion Backpropagation algorithms

来源：评论

学校读者我要写书评

暂无评论

Toward robust vision-based control: hand/eye coordination without calibration

Toward robust vision-based control: hand/eye coordination wi...

引用

IEEE International Symposium on Intelligent Control (ISIC)

作者： J.-Y. Herve R. Sharma P. Cucka Computer Vision Laboratory Center of Automation Research and Department of Computer Science University of Maryland College Park MD USA

An approach to hand/eye coordination that does not require any calibration and hence overcomes some of the shortcomings of traditional approaches is presented. It is demonstrated how the concepts of the perceptual kinematic map and control surface of the hand/eye system allow the modeling and solution of the grasping problem. The close integration of visual information with the decision process and reliance on qualitative, topological information rather than on the exact values of the maps allow robust visual control of the robot manipulator. The principles of the approach are general, and the algorithm and system presented here represent only one of many possible ways to implement and test the approach.< >

关键词： Robust control Calibration Robot kinematics Robot vision systems Orbital robotics Laboratories computer errors Cameras computer vision robotics and automation

来源：评论

学校读者我要写书评

暂无评论

Purposive and qualitative active vision

Purposive and qualitative active vision

引用

Mediterranean Electrotechnical Conference (MELECON)

作者： J. Aloimonos Computer Vision Laboratory Center for Automation Research Institute for Advanced Computer Studies Computer Science Department University of Maryland College Park MD USA

Qualitative vision, which in the past has been wrongly called inexact, makes sense when it is coupled with purposive vision, which formulates questions for which qualitative solutions are possible. To demonstrate the usefulness of this approach, the author considers visual motion (or navigation) problems, and assumes that the observer is active. He describes the preliminary design of Medusa, a purposive and qualitative visual motion machine that can robustly solve many navigational problems without reconstructing the scene.< >

关键词： Layout Organisms Robustness computer vision Educational institutions Laboratories Automation computer science Stereo vision Animals

来源：评论

学校读者我要写书评

暂无评论

Motion-boundary illusions and their regularization

Motion-boundary illusions and their regularization

引用

Workshop on Visual Motion

作者： Y. Aloimonos Liuqing Huang Computer Science Department and Institute for Advanced Computer Studies University of Maryland College Park MD USA Center for Automation Research Computer Vision Laboratory

The authors performed several experiments where they made sure that the only cues available to the observer were contour and motion. It turns out that when humans combine information from contour and motion to reconstruct the shape of an object in view, if the results of the two modules-shape from contour and structure from motion-are inconsistent, they totally discard one of the cues and an illusion is experienced. The authors describe examples of such illusions and identify the conditions under which they happen. Finally, they introduce a computational theory for combining contour and motion using the theory of regularization. The theory explains such illusions and predicts many more.< >

关键词： Humans Shape Engine cylinders computer vision Laboratories Image reconstruction Surface topography Visual system Automation computer science

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：