检索结果-内蒙古大学图书馆

INTERPROCESS COMMUNICATION FOR DISTRIBUTED robotics

IEEE JOURNAL OF robotics AND AUTOMATION 1987年第6期3卷 493-504页

作者： GAUTHIER, D FREEDMAN, P CARAYANNIS, G MALOWANY, AS Computer Vision and Robotics Laboratory McGill Research Center for Intelligent Machines McGill University Montreal QUE Canada

Robot tasks have come to demand flexible sensory-based "intelligent" behavior. The single robot has given way to multiple robots cooperating in three-dimensional dynamic environments which allow them to accomplish complex and intricate tasks. Because of the complex nature of the tasks performed, centralized control is no longer practical; workcells have become centers of distributed computing. This motivates the need for an interprocess communication (IPC) facility which would integrate the individual elements both within and between workcells. A survey of IPC is presented in the context of distributed robotics. To make the survey more meaningful, it is introduced by some remarks about general approaches to communication within a distributed computing environment. A discussion of the main IPC design issues for distributed robotics is included.

关键词： Robot kinematics Robot sensing systems intelligent robots Distributed computing Context Communication system control Robot control Centralized control Open systems computer vision

来源：评论

学校读者我要写书评

暂无评论

FROM ORIENTATION SELECTION TO OPTICAL-FLOW

引用

computer vision GRAPHICS AND IMAGE PROCESSING 1987年第2期37卷 196-220页

作者： ZUCKER, SW IVERSON, L Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montréal Québec Canada

Optical flow can be thought of as a generalization of orientation selection to include time, and this is a first attempt to develop this generalization. This paper is informal, and begins with an overview of a computational theory of orientation selection that has been developed in our laboratory during the past few years. A theory of optical flow computations is then sketched on the basis of this background, and a number of consequences important for both computational modeling and psychophysics are discussed. We concentrate in particular on two notions—dimensionality and structure—and describe a series of experiments that demonstrate that sensitivity to discontinuities in optical flow patterns has significant similarities to those in orientation patterns. Such similarities lend strong support to the analogy.

关键词： vision

来源：评论

学校读者我要写书评

暂无评论

A DATABASE DESIGN FOR THE RUNTIME ENVIRONMENT OF A ROBOTIC WORKCELL

引用

robotics AND computer-INTEGRATED MANUFACTURING 1989年第1期5卷 21-31页

作者： FREEDMAN, P MICHAUD, C CARAYANNIS, G MALOWANY, A Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montréal Québec Canada

intelligent robotic workcell activities have come to require a database framework for arranging, storing and accessing information in real-time about the workcell environment in a standard way. After a brief introduction to the theory of databases (DB), we examine the general topic of robotic workcells, identify characteristics typical of robotic applications, and then present a survey of DB-related work in the robotics domain. We then construct a set of design constraints based on our analysis of robotic applications, and describe a suitable software architecture. The paper concludes with a discussion of experience gained with two generations of DB implementations.

关键词： Database Systems

来源：评论

学校读者我要写书评

暂无评论

LINE DETECTION IN DIGITAL PICTURES - A HYPOTHESIS PREDICTION VERIFICATION PARADIGM

引用

computer vision GRAPHICS AND IMAGE PROCESSING 1987年第1期40卷 95-114页

作者： MANSOURI, AR MALOWANY, AS LEVINE, MD Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montréal Québec Canada

We present an efficient method for detecting straight line segments in digital pictures using a hypothesis prediction/verification paradigm. In this paradigm, a straight line segment of predefined length is predicted to exist at some particular pixel location. The orientation of this predicted line segment is based on the edge orientation at the pixel location. This prediction is then verified against statistical tests performed on the line. As a result, the predicted line is either validated as being a line segment, or it is rejected. An extension of this algorithm for the detection of lines at different lengths is also presented, and a criterion is defined in order to evaluate the significance of the detected line segments.

关键词： Image processing

来源：评论

学校读者我要写书评

暂无评论

AN INTEGRATED PROGRAMMING ENVIRONMENT FOR A GENERIC ROBOTIC WORKCELL

引用

JOURNAL OF ROBOTIC SYSTEMS 1989年第2期6卷 149-173页

作者： CARAYANNIS, G FREEDMAN, P MALOWANY, A Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montreal Quebec Canada

AbstractThe complexity of modern robotic workcells, consisting of many cooperating elements (e.g., robots, sensing systems) makes programming applications enormously difficult. Even when the application can be easily decomposed into workcelll operations, the tight coupling among these operations due to constraints on precedence and resource sharing makes it difficult to identify and take advantage of possible concurrency. Since robotic workcells are typically configured to repetitively perform an application, we seek to minimize the ‘cycle’ time required, by optimizing the order in which operations take place. Eventually, a sequential program must be written for each workcell element, and they must then execute concurrently. Commercial robot languages and systems provide neither the necessary tools for programming such a distributed collection of elements nor a mechanism for inter‐element communication. In this article the authors propose a two‐part solution to this workcell programming problem: SAGE/WRAP. A graphics interface is provided to the user in order to define the application. Then, from the user's input, SAGE builds a Petri Net description of the workcell application; this is used to obtain a time‐optimal sequence of operations for each workcell element. The time‐optimal sequence then becomes the basis of the runtime program that performs the application. This program is interpreted and executed by the hierarchical workcell runtime environment called WRAP. An example is provided to illustrate t

关键词：

来源：评论

学校读者我要写书评

暂无评论

Kinematics of common industrial robots

引用

robotics and Autonomous Systems 1988年第2期4卷 169-191页

作者： Lloyd, John Hayward, Vincent Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University MontréalQuébec Canada

An approach to finding the solution equations for simple manipulators is described which enhances the well known method of Paul, Renaud, and Stevenson, by explicitly making use of known decouplings in the manipulator kinematics. This reduces the set of acceptable equations from which we obtain relationships for the joint variables. For analyzing the Jacobian, such decoupling is also useful since it manifests itself as a block of zeros, which makes inversion much easier. This zero lock can be used to obtain a concise representation for the forward and inverse Jacobian computations. The decoupling also simplifies the calculations sufficiently to allow us to make good use of a symbolic algebra program (MACSYMA) in obtaining our results. Techniques for using MACSYMA in this way are described. Examples are given for several industrial manipulators. © 1988

关键词： Kinematics

来源：评论

学校读者我要写书评

暂无评论

CURVATURE CONSISTENCY IMPROVES LOCAL SHADING ANALYSIS

CVGIP-IMAGE UNDERSTANDING

引用

CVGIP-IMAGE UNDERSTANDING 1992年第1期55卷 95-105页

作者： FERRIE, FP LAGARDE, J Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montréal Québec Canada H3A 2A7

This paper describes how a surface reconstruction algorithm, based on minimizing the variation of surface curvature, can be used to stabilize and correct the results of local shading analysis. What is novel about this approach is that it is viewpoint independent and applicable to any process that can provide estimates of local surface orientation. The assumptions used in formulating the minimization are derived from standard differential geometry. When applied as a second stage of processing after local shading analysis, the algorithm can recover a close approximation of the true surface orientation under realistic assumptions about image noise. Results are presented that show the performance of the algorithm on synthetic and real data. In particular, they demonstrate how this form of reconstruction can compensate for some of the shape distortion incurred in local shading analysis.

关键词： Image Processing

来源：评论

学校读者我要写书评

暂无评论

PART DECOMPOSITION OF OBJECTS FROM SINGLE VIEW LINE DRAWINGS

CVGIP-IMAGE UNDERSTANDING

引用

CVGIP-IMAGE UNDERSTANDING 1992年第1期55卷 73-83页

作者： BERGEVIN, R LEVINE, MD Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montréal Québec Canada H3A 2A7

We describe an algorithm for segmenting a 3D object into its constituent volumetric parts from a single 2D line drawing. This algorithm is part of the bottom-up line drawing description process of PARVO, a generic object recognition system. In PARVO, an object is recognized as being a member of a class defined by qualitative geometrical properties and topological structure. Similarity between different 3D views of any member of a given class is a result of building coarse part-based structural descriptions from limited information. A preliminary stage to part segmentation of an object consists of extracting viewpoint-invariant and nonaccidental features from the line drawing. The segmentation process itself is described as a hierarchical decomposition of the line drawing on the basis of pairs of high-concavity points in its silhouette. The pairing of these so-called segmentation points rests on (i) an object visibility model describing the generic structures present in any line drawing satisfying our assumptions, and (ii) the feature instances extracted from the specific line drawing analyzed. First, we discuss the properties of the line drawings in the domain of PARVO. From them, geometrical models of important line drawing features may be developed. The latter are used both as cues in the segmentation process and as precursors to the representation from which part structure is understood.

关键词： Pattern Recognition

来源：评论

学校读者我要写书评

暂无评论

Aggregation of boundary points into solid models

Aggregation of boundary points into solid models

引用

Sensor Fusion: Spatial Reasoning and Scene Interpretation

作者： Aubry, Stéphane Hayward, Vincent Computer Vision and Robotics Laboratory McGill Research Center for Intelligent Machines McGill University MontréalQC Canada

ISBN: (纸本)9780819400383

We consider the problem of aggregating the information provided by sensors such as range finders and its applications to scene modelling. This information consists of collections of three-dimensional points which form a discrete subspace of the objects-to-free-space boundaries within the world to be modelled. The ultimate goal is to obtain a valid surface model which can in turn be transformed into an efficient volumetric representation for solid interference detection algorithms. We first relate our work to that of other researchers, and we then show that surface connectivity is a non-trivial but essential element of a valid representation. To that end, we introduce a formal definition for model validity which we use to guide the process of aggregating the different views and we provide a proof of its correctness under stated assumptions. We eventually suggest heuristic methods for extending our approach when the strict validity conditions do not suffice to construct a perceptually consistent model. Finally, we quickly introduce the topological problems posed by objects non-homeomorphic to spheres, such as multi-holed tori. The methods we develop do not depend on the physical nature of the sensing technique. For example, our results can also be used from data obtained by stereo analysis and to some extent by haptic sensing.

关键词： Heuristic methods

来源：评论

学校读者我要写书评

暂无评论

SAGE: A decision support system for the sequencing of operations within a robotic workcell

引用

Decision Support Systems 1988年第3期4卷 329-343页

作者： Freedman, P. Malowany, A. Computer Vision and Robotics Laboratory McGill Research Centre for Intelligent Machines McGill University Montréal Que. Canada

This paper describes a new approach to decision support based on logic programming. SAGE, Sequence Analysis by Graphical Evaluation, is a both a logic framework and a set of Prolog programs to express and then solve the problem of repetitive sequencing of operations within a robotics workcell. We create a Timed Petri Net from the user description consisting of the initial state of the workcell, plus the operations to be performed. Each operation is defined by (i) the command to be executed, (ii) a list of enabling conditions, (iii) a list of changes made to the state of the workcell by executing the command, and (iv) its relative integer duration. After some preliminary analysis, this net is used to generate the Task Space of all feasible time histories of workcell events. Repetitive sequences of all the workcell operations are then constructed from cycles in the Task space. From the feasible sequences thus identified, the time-optimal one is selected. SAGE clearly demonstrates both the power of symbolic expression, and the power of pattern matching as a basis for decision support systems. © 1988.

关键词： Petri Nets Prolog robotics

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：