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48
Automated Tracking and Grasping of a Moving Object with a Robotic HandEye System
 IEEE Transactions on Robotics and Automation
, 1991
"... Most robotic grasping tasks assume a stationary or fixed object. In this paper, we explore the requirements for tracking and grasping a moving object. The focus of our work is to achieve a high level of interaction between a realtime vision system capable of tracking moving objects in 3D and a rob ..."
Abstract

Cited by 102 (7 self)
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Most robotic grasping tasks assume a stationary or fixed object. In this paper, we explore the requirements for tracking and grasping a moving object. The focus of our work is to achieve a high level of interaction between a realtime vision system capable of tracking moving objects in 3D and a robot arm equipped with a dexterous hand that can be used pick up a moving object. We are interested in exploring the interplay of handeye coordination for dynamic grasping tasks such as grasping of parts on a moving conveyor system, assembly of articulated parts or for grasping from a mobile robotic system. Coordination between an organism's sensing modalities and motor control system is a hallmark of intelligent behavior, and we are pursuing the goal of building an integrated sensing and actuation system that can operate in dynamic as opposed to static environments. The system we have built addresses three distinct problems in robotic handeye coordination for grasping moving objects: fast computation of 3d motion parameters from vision, predictive control of moving robotic arm to track a moving oblect, and grasp planning. The system is able to operate at approximately human arm movement rates, and we present experimenatl result in which a moving model train is tracked, stably grasped, and picked up by the system. The algorithms we have developed that relate sensing to actuation are quite general and applicable to a variety of complex robotic tasks that require visual feedback for arm and hand control.
Modeling the Mighty Maple
"... A method is presented for representing botanical trees, given threedimensional points and connections. Limbs are modeled as generalized cylinders whose axes are space curves that interpolate the points. A freeform surface connects branching limbs. "Blobby" techniques are used to model the tree tru ..."
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Cited by 88 (1 self)
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A method is presented for representing botanical trees, given threedimensional points and connections. Limbs are modeled as generalized cylinders whose axes are space curves that interpolate the points. A freeform surface connects branching limbs. "Blobby" techniques are used to model the tree trunk as a series of noncircular cross sections. Bark is simulated with a bump map digitized from real world bark; leaves are textures mapped onto simple surfaces.
The Curve Of Least Energy
, 1983
"... Here we search fi)r the curve which has the smallest integral of the square of curvature, while passing through two given points with given orientation. This is the true shape of a spline used in lofting. In computeraided design, curves have been sought which maximize "smoothness". The curve discus ..."
Abstract

Cited by 72 (2 self)
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Here we search fi)r the curve which has the smallest integral of the square of curvature, while passing through two given points with given orientation. This is the true shape of a spline used in lofting. In computeraided design, curves have been sought which maximize "smoothness". The curve discussed here is the one arising in this way from a commonly used measure of smoothness. The human visual system may use such a curve when it constructs a subjective contour.
Superquadrics and angle preserving transformations
 IEEE Computer Graphics and Applications
, 1981
"... new and powerfulfamily ofparametric shapes extends ..."
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Cited by 46 (0 self)
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new and powerfulfamily ofparametric shapes extends
Free Form Surface Analysis Using a Hybrid of Symbolic and Numeric Computation
, 1992
"... Detailed analysis of many mathematical properties of sculptured models has been hindered by the fact that the properties do not have the same representation as the surface. For example, unit tangents, surface normals, and principal curvatures are typically computed at predefined discrete sets of poi ..."
Abstract

Cited by 40 (19 self)
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Detailed analysis of many mathematical properties of sculptured models has been hindered by the fact that the properties do not have the same representation as the surface. For example, unit tangents, surface normals, and principal curvatures are typically computed at predefined discrete sets of points on the surface. As such, aliasing can occur and features between samples can be missed. Synthesizing information about the shape of an object and operating on the model, whether by physical machining tools, graphics display programs, or mathematical analysis, has been treated as either a discrete or local problem in general. The researchbeing reported on here has focused on another approach, that of creating algorithms that construct the mathematical properties in closed form, or construct approximations to those mathematical properties through symbolic computation. Global analysis can then be applied while an accurate error bound is obtained.
Robotic Object Recognition Using Vision and Touch
 Proceedings of the 9th International Joint Conference on Artificial Intelligence
, 1987
"... A system is described that integrates vision and tactile sensing in a robotics environment to perform object recognition tasks. It uses multiple sensor systems (active touch and passive stereo vision) to compute three dimensional primitives that can be matched against a model data base of complex cu ..."
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Cited by 26 (0 self)
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A system is described that integrates vision and tactile sensing in a robotics environment to perform object recognition tasks. It uses multiple sensor systems (active touch and passive stereo vision) to compute three dimensional primitives that can be matched against a model data base of complex curved surface objects containing holes and cavities. The low level sensing elements provide local surface and feature matches which arc constrained by relational criteria embedded in the models. Once a model has been invoked, a verification procedure establishes confidence measures for a correct recognition. The three dimen* sional nature of the sensed data makes the matching process more robust as does the system's ability to sense visually occluded areas with touch. The model is hierarchic in nature and allows matching at different levels to provide support or inhibition for recognition.
Second Order Surface Analysis Using Hybrid Symbolic and Numeric Operators
, 1992
"... Results from analyzing the curvature of a surface can be used to improve the implementation, efficiency, and effectiveness of manufacturing and visualization of sculptured surfaces. In this paper ..."
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Cited by 24 (13 self)
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Results from analyzing the curvature of a surface can be used to improve the implementation, efficiency, and effectiveness of manufacturing and visualization of sculptured surfaces. In this paper
Sweeping of Threedimensional Objects
 ComputerAided Design
, 1989
"... this paper addresses is the following: given an arbitrary threedimensional object, which moves along an arbitrary path (possibly rotating as it does so), to compute the volume swept out by the solid object as it moves, or in other words, to find the new solid volume which represents all of the poin ..."
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Cited by 23 (0 self)
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this paper addresses is the following: given an arbitrary threedimensional object, which moves along an arbitrary path (possibly rotating as it does so), to compute the volume swept out by the solid object as it moves, or in other words, to find the new solid volume which represents all of the points in space which the object has occupied at some time during the motion
Classification of Sketch Strokes and Corner Detection using Conic Sections and Adaptive Clustering
 ASME Journal of Mechanical Design
, 1995
"... This paper presents a method for classifying pen strokes in an online sketching system. The method, based on linear least squares fitting to a conic section equation, proposes using the conic equation's natural classification property to help classify sketch strokes and identify lines, elliptic arcs ..."
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Cited by 22 (3 self)
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This paper presents a method for classifying pen strokes in an online sketching system. The method, based on linear least squares fitting to a conic section equation, proposes using the conic equation's natural classification property to help classify sketch strokes and identify lines, elliptic arcs, and corners composed of two lines with an optional fillet. The hyperbola form of the conic equation is used for corner detection. The proposed method has proven to be fast, suitable for realtime classification, and capable of tolerating noisy input, including cusps and spikes. The classification is obtained in o(n) time in a single path, where n is the number of sampled points. In addition, an improved adaptive method for clustering disconnected endpoints is proposed. The notion of incontext analysis is discussed, and examples from a working implementation are given. Introduction Freehand sketching is occupying a growing place in the realm of userinterface approaches f