Picking up soft 3D objects with two fingers

This paper describes a simple strategy for a robot hand to grasp and lift a deformable 3D object resting on a table. Inspired by the human hand grasping, the strategy employs two rigid hemispherical fingers to first squeeze the object until a secure grip is achieved under contact friction, and then translate vertically upward. During the squeeze, a lift test is repeatedly conducted to determine if the maximum hypothetical liftable weight of the object reaches its real weight. Actual lifting follows when the test is passed. The object's deformation and configuration of contact with the fingers and the plane are tracked using the finite element method (FEM) in an event-driven manner, based on varying contact displacements induced by the finger movements. The gravitational force acting on the object is accounted for. Slips inside the contact regions are determined from solving quadratic systems. Experiment has been conducted to demonstrate the efficiency and accuracy for this sensorless grasping approach.

[1]  Kenneth Y. Goldberg,et al.  D-space and Deform Closure Grasps of Deformable Parts , 2005, Int. J. Robotics Res..

[2]  A. Bower.  Applied Mechanics of Solids , 2009 .

[3]  Nathaniel E. Helwig,et al.  An Introduction to Linear Algebra , 2006 .

[4]  Yan-Bin Jia,et al.  Squeeze grasping of deformable planar objects with segment contacts and stick/slip transitions , 2013, 2013 IEEE International Conference on Robotics and Automation.

[5]  Richard H. Gallagher,et al.  Finite Element Analysis: Fundamentals , 1975 .

[6]  H. Saunders,et al.  Book Reviews : AN INTRODUCTION TO THE MECHANICS OF SOLIDS S. H. Crandall; N.C. Dahl; and T. J. Lardner McGraw-Hill Book Co. , New York, N. Y. (1972) , 1975 .

[7]  Serge Lang.  Introduction to Linear Algebra 2nd edition , 1970 .

[8]  Yan-Bin Jia,et al.  Optimal two-finger squeezing of deformable objects , 2013, 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[9]  D. S. Dugdale,et al.  Introduction to the Mechanics of Solids , 1967 .

[10]  Hong Liu,et al.  On computing three-finger force-closure grasps of 2-D and 3-D objects , 2003, IEEE Trans. Robotics Autom..

[11]  S. Lang,et al.  Introduction to Linear Algebra , 1972 .

[12]  E. Allgower,et al.  Numerical path following , 1997 .

[13]  Van-Duc Nguyen,et al.  Constructing force-closure grasps in 3D , 1987, Proceedings. 1987 IEEE International Conference on Robotics and Automation.

[15]  C. Ramakrishnan,et al.  A finite element solution for the two‐dimensional elastic contact problems with friction , 1981 .

[16]  Vijay Kumar,et al.  Robotic grasping and contact: a review , 2000, Proceedings 2000 ICRA. Millennium Conference. IEEE International Conference on Robotics and Automation. Symposia Proceedings (Cat. No.00CH37065).

[17]  Kazuaki Iwata,et al.  Static analysis of deformable object grasping based on bounded force closure , 1996, Proceedings of IEEE International Conference on Robotics and Automation.

[18]  Shinichi Hirai,et al.  Robust grasping manipulation of deformable objects , 2001, Proceedings of the 2001 IEEE International Symposium on Assembly and Task Planning (ISATP2001). Assembly and Disassembly in the Twenty-first Century. (Cat. No.01TH8560).

[19]  Van-Duc Nguyen,et al.  Constructing force-closure grasps , 1986, Proceedings. 1986 IEEE International Conference on Robotics and Automation.

[20]  W. E. Haisler,et al.  A finite element solution method for contact problems with friction , 1987 .