The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform

Lydia E Kavraki - One of the best experts on this subject based on the ideXlab platform.

  • Part Orientation with one or two stable equilibria using programmable force fields
    International Conference on Robotics and Automation, 2000
    Co-Authors: Karl F Bohringer, Lydia E Kavraki, Bruce R Donald, Florent Lamiraux
    Abstract:

    Programmable force fields are a representation of a class of devices for distributed, nonprehensile manipulation for applications in Parts feeding, sorting, positioning, and assembly. They generate force vector fields in which the Parts move until they reach a stable equilibrium pose. Research has yielded open-loop strategies to uniquely position, orient, and sort Parts. These strategies typically consist of several fields employed in sequence to achieve a desired final pose. The length of the sequence depends on the complexity of the Part. We show that unique Part poses can be achieved with just one field. First, we exhibit a single field that positions and orients any Part (except certain symmetric Parts) into two stable equilibrium poses. Then, we show that for any Part there exists a field in which the Part reaches a unique stable equilibrium pose (again, except for symmetric Parts). Besides giving an optimal upper bound for unique Parts positioning and Orientation, our work gives further evidence that programmable force fields are a powerful tool for Parts manipulation. Our second result also leads to the design of "universal Parts feeders", proving an earlier conjecture about their existence. We argue that universal Parts feeders are relatively easy to build, and we report on extensive simulation results which indicate that these devices may work very well in practice. We believe that the results in this paper could be the basis for a new generation of efficient, open-loop, parallel Parts feeders.

  • a distributed universal device for planar Parts feeding unique Part Orientation in programmable force fields
    2000
    Co-Authors: Karl F Bohringer, Lydia E Kavraki, Bruce R Donald, Florent Lamiraux
    Abstract:

    Programmable vector fields are an abstraction to represent a new class of devices for distributed, non-prehensile manipulation for applications in Parts feeding, sorting, positioning, and assembly. Unlike robot grippers, conveyor belts, or vibratory bowl feeders, these devices generate force vector fields in which the Parts move until they may reach a stable equilibrium pose.

  • Part Orientation with programmable vector fields two stable equilibria for most Parts
    International Conference on Robotics and Automation, 1997
    Co-Authors: Lydia E Kavraki
    Abstract:

    Part manipulation is an important but also time-consuming operation in industrial automation. Recent work explores alternative solutions to the mechanical Parts feeders which have been traditionally used to sort and orient Parts for assembly. One of the proposed alternatives is the use of programmable vector fields. The fields are realized on a plane on which the Part is placed. The forces exerted on the Part's contact surface translate and rotate the Part to an equilibrium Orientation. Certain vector fields can be implemented in the microscale with actuator arrays and in the macroscale with transversely vibrating plates. Although current technology is still limited, the dexterity that programmable vector fields offer has prompted researchers to further explore their capabilities. This paper presents a vector field that can simultaneously orient and pose most Parts into two stable equilibrium configurations. The equilibrium configurations are easily computed a priori given the Part to be oriented. Our analysis makes no assumptions about the shape of the Part or its connectivity except that it moves as a rigid body. The proposed vector field offers the great advantage of stability of the equilibrium configurations under small perturbations of the Part which is key for the Orientation of toleranced Parts.

Florent Lamiraux - One of the best experts on this subject based on the ideXlab platform.

  • Part Orientation with one or two stable equilibria using programmable force fields
    International Conference on Robotics and Automation, 2000
    Co-Authors: Karl F Bohringer, Lydia E Kavraki, Bruce R Donald, Florent Lamiraux
    Abstract:

    Programmable force fields are a representation of a class of devices for distributed, nonprehensile manipulation for applications in Parts feeding, sorting, positioning, and assembly. They generate force vector fields in which the Parts move until they reach a stable equilibrium pose. Research has yielded open-loop strategies to uniquely position, orient, and sort Parts. These strategies typically consist of several fields employed in sequence to achieve a desired final pose. The length of the sequence depends on the complexity of the Part. We show that unique Part poses can be achieved with just one field. First, we exhibit a single field that positions and orients any Part (except certain symmetric Parts) into two stable equilibrium poses. Then, we show that for any Part there exists a field in which the Part reaches a unique stable equilibrium pose (again, except for symmetric Parts). Besides giving an optimal upper bound for unique Parts positioning and Orientation, our work gives further evidence that programmable force fields are a powerful tool for Parts manipulation. Our second result also leads to the design of "universal Parts feeders", proving an earlier conjecture about their existence. We argue that universal Parts feeders are relatively easy to build, and we report on extensive simulation results which indicate that these devices may work very well in practice. We believe that the results in this paper could be the basis for a new generation of efficient, open-loop, parallel Parts feeders.

  • a distributed universal device for planar Parts feeding unique Part Orientation in programmable force fields
    2000
    Co-Authors: Karl F Bohringer, Lydia E Kavraki, Bruce R Donald, Florent Lamiraux
    Abstract:

    Programmable vector fields are an abstraction to represent a new class of devices for distributed, non-prehensile manipulation for applications in Parts feeding, sorting, positioning, and assembly. Unlike robot grippers, conveyor belts, or vibratory bowl feeders, these devices generate force vector fields in which the Parts move until they may reach a stable equilibrium pose.

Pio G Iovenitti - One of the best experts on this subject based on the ideXlab platform.

  • a generic algorithm for a best Part Orientation system for complex Parts in rapid prototyping
    Journal of Materials Processing Technology, 2003
    Co-Authors: Syed H. Masood, Wanchai Rattanawong, Pio G Iovenitti
    Abstract:

    Abstract This paper presents a generic mathematical algorithm to determine the best Part Orientation for building a Part in a layer-by-layer rapid prototyping (RP) system. The algorithm works on the principle of computing the volumetric error (VE) in a Part at different Orientations and then determining the best Orientation based on the minimum VE in the Part. The algorithm is shown to work for a Part of any shape and complexity, with any slice thickness, and for the Orientation of a Part about any selected axis. The Part Orientation system based on this algorithm graphically displays the VE at different Part Orientations and recommends the best Part Orientation. The system will help RP users in creating RP Parts with a higher level of accuracy and surface finish.

Karl F Bohringer - One of the best experts on this subject based on the ideXlab platform.

  • Part Orientation with one or two stable equilibria using programmable force fields
    International Conference on Robotics and Automation, 2000
    Co-Authors: Karl F Bohringer, Lydia E Kavraki, Bruce R Donald, Florent Lamiraux
    Abstract:

    Programmable force fields are a representation of a class of devices for distributed, nonprehensile manipulation for applications in Parts feeding, sorting, positioning, and assembly. They generate force vector fields in which the Parts move until they reach a stable equilibrium pose. Research has yielded open-loop strategies to uniquely position, orient, and sort Parts. These strategies typically consist of several fields employed in sequence to achieve a desired final pose. The length of the sequence depends on the complexity of the Part. We show that unique Part poses can be achieved with just one field. First, we exhibit a single field that positions and orients any Part (except certain symmetric Parts) into two stable equilibrium poses. Then, we show that for any Part there exists a field in which the Part reaches a unique stable equilibrium pose (again, except for symmetric Parts). Besides giving an optimal upper bound for unique Parts positioning and Orientation, our work gives further evidence that programmable force fields are a powerful tool for Parts manipulation. Our second result also leads to the design of "universal Parts feeders", proving an earlier conjecture about their existence. We argue that universal Parts feeders are relatively easy to build, and we report on extensive simulation results which indicate that these devices may work very well in practice. We believe that the results in this paper could be the basis for a new generation of efficient, open-loop, parallel Parts feeders.

  • a distributed universal device for planar Parts feeding unique Part Orientation in programmable force fields
    2000
    Co-Authors: Karl F Bohringer, Lydia E Kavraki, Bruce R Donald, Florent Lamiraux
    Abstract:

    Programmable vector fields are an abstraction to represent a new class of devices for distributed, non-prehensile manipulation for applications in Parts feeding, sorting, positioning, and assembly. Unlike robot grippers, conveyor belts, or vibratory bowl feeders, these devices generate force vector fields in which the Parts move until they may reach a stable equilibrium pose.

Michael A Erdmann - One of the best experts on this subject based on the ideXlab platform.

  • nonprehensile two palm manipulation with non equilibrium transitions between stable states
    International Conference on Robotics and Automation, 1996
    Co-Authors: N B Zumel, Michael A Erdmann
    Abstract:

    Manipulation without prehension is a natural way of handling objects for both humans and machines. Nonprehensile operations are appropriate when complete constraint over the object to be manipulated is either undesirable or impractical, but some control over the object is desired over its entire trajectory in order to bring the object reliably to a desired final state. Research to date has explored only a small portion of this class. We are interested in controlling the shape of the constraint surfaces so that constraint and external forces naturally attract the system to the desired state, even if the object momentarily loses stability during the motion. We present a preliminary analysis of the nonprehensile Orientation of planar objects by two low friction palms joined at a central hinge. These palms support an object in a gravitational field, without grasping or gripping. We determine connected regions of stable states of the object, and give a method of planning Part Orientation based on a graph search over these regions, allowing nonequilibrium transitions between them. We conclude with the results of simulations and tests of an example plan.