• [2013-07-22]

  Grasping Deformable Planar Objects: Squeeze, Stick/Slip Analysis, and Energy-Based Optimalities

Speaker： Prof. Yan-Bin Jia 
Time：14:30 pm
Date：July 23, 2013
Venue：Room 314, COE Mechanics Building
Host: Prof. Caishan Liu 

Abstract:

Robotic grasping of deformable objects is difficult and under-researched not simply due to the high computational cost of modeling.  More fundamentally, several issues arise with the deformation of an object being grasped: a changing wrench space, (generally) growing finger contact areas, and pointwise varying contact modes inside these areas.  Consequently, constraints needed for deformable modeling by the finite element method (FEM) are hardly established at the beginning of the action.  In this talk I will present a grasping strategy that squeezes the object with two fingers under specified displacements rather than forces.  Assuming linear elasticity, an FEM-based analysis ensures equilibrium and the uniqueness of deformation during the action.  An event-driven algorithm tracks the contact regions as well as the modes of contact in their interiors, which in turn serve as the needed constraints for deformation update.  The classes of ``stable'' and ``pure'' squeezes are introduced.  Grasp quality is characterized by the amount of work done by the grasping fingers to resist a known disturbance by some adversary finger.  An optimization algorithm is progressively developed for segment contacts under Coulomb friction.  I will also show results from simulation and multiple experiments to validate the introduced methods over solid and ring-like 2D objects. 

Biography:

Yan-Bin Jia is an Associate Professor of Computer Science at Iowa State University.   His research interests in robotics include modeling and grasping of deformable objects, multiple impacts with compliance, and shape from tactile data.  Dr. Jia received the US National Science Foundation CAREER Award in 2002.  He was an associate editor of the IEEE Transactions on Automation Science and Engineering in 2008-2011 and a co-editor of a Special Issue of the International Journal of Robotics Research in 2000. He also served on the Conference Editorial Board of the IEEE Robotics and Automation Society from 2006 to 2008.  His papers have included a Semi-Finalist for the Best Conference Paper Award, a Finalist for the Anton Philips Best Student Paper Award, at the IEEE International Conferences on Robotics and Automation in 1996 and 1998, respectively, and a Finalist for IEEE Transactions on Robotics King-Sun Fu Memorial Best Paper Award in 2010.  In 2006-2007, Dr. Jia was a visiting associate professor at Department of Computer Science, Stanford University, and The Robotics Institute, Carnegie Mellon University. Dr. Jia received the B.S. degree in Computer Science from University of Science and Technology of China in 1988, and the M.S. and Ph.D. degrees in Robotics from Carnegie Mellon University in 1993 and 1997, respectively.