Generalized Grasping and Manipulation

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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

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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
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Outline

1. Grasp control
2. Control-based dexterous manipulation
3. Transport and grasp schemas (skills)

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Opposition Space
from The Grasping Hand, C. MacKenzie, T. Iberall,
Springer, 1994
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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
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Grasp Control
f
grasp
Grasp artificial potential displaces contacts to
descend wrench-closure error function
Coelho, J., Grupen, R., 1997 Platt, R., Fagg,
A., Grupen R., 2002
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Sliding Grasp Control Video
f
f
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Sliding Grasp Controller
g
k
f
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Four Control Primitives
grasp control
collision free motion
kinematic conditioning
force control
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Combining Control Primitives
Carry
f
f
f
f
f
g
m
k
Grasp
f
f
f
g
k
f
Platt, R., Fagg, A., Grupen R., 2004
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Controller Equivalence Classes Common Suffix
common suffix
f
f
f
f
g
k
f
m
f
f
f
f
g
k
f
k
f
f
f
f
g
k
f
g
Platt, R., Fagg, A., Grupen R., 2004
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Experiment Transport Schema
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Schematic Transport Skill
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Schematic Grasp Skills
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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?

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Localize-Reach-Grasp
P(transition blob parameters)
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Reach Primitives
Position
Orientation
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Pilot Results
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Pilot Results Learning Curves
(results averaged over three experiments.)
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Pilot Results Frictional Surface
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Pilot Results Bagging Groceries
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Pilot Results Bagging Groceries