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Explore control-based dexterous manipulation, grasp schemas, contact parameterization, and grasp control potentials in robotics. Learn about sliding grasp control, experiment with transport schema, and enhance grasp skills. Understand controller equivalence classes and action schema for effective robotics applications.
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Generalized Grasping and Manipulation Robert Platt Jr., Andrew Fagg, Roderic Grupen 5/25/2005 Laboratory for Perceptual Robotics University of Massachusetts Amherst
Motivation: Human Grasps from Mark Cutkosky, On Grasp Choice, Grasp Models, and the Design of Hands for Manufacturing Tasks, IEEE TRA Vol 5, No. 3, June 1989
Outline • Grasp control • Control-based dexterous manipulation • Transport and grasp schemas (skills)
Opposition Space from The Grasping Hand, C. MacKenzie, T. Iberall, Springer, 1994
Contact Parameterization of Grasp 1,2,3 f palm, fingertips grasp 1,2,3 f grasp palm, fingertips left, right f grasp left, right left f grasp left, gravity Platt, R., Fagg, A., Grupen R., 2003
f grasp Grasp Control: Grasp artificial potential displaces contacts to descend wrench-closure error function: Coelho, J., Grupen, R., 1997; Platt, R., Fagg, A., Grupen R., 2002
Sliding Grasp Control Video f f f Sliding Grasp Controller: g k f
f f f f f m k g Four Control Primitives grasp control collision free motion kinematic conditioning force control
Combining Control Primitives Carry: f f f f m k f g Grasp: f f f g k f Platt, R., Fagg, A., Grupen R., 2004
Controller Equivalence Classes: Common Suffix common suffix f f f f m k f g f f f f k k f g f f f f g k f g Platt, R., Fagg, A., Grupen R., 2004
Definition of Schema The Action Schema defines: • “Abstract” states and actions • A deterministic policy through the abstract space to the schema goal • A one-to-many mapping from the abstract policy onto instantiations in the underlying system. Subject of learning: • What instantiations are appropriate in what execution contexts?
Localize-Reach-Grasp P(transition | blob parameters)
Reach Primitives Position Orientation
Pilot Results: Learning Curves (results averaged over three experiments.)