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Volume 21 Issue 05/06 - Publication Date: 1 May 2002
 
Nonholonomy on Purpose
 
On Fitted Stratified and Semi-Stratified Geometric Manipulation Planning with Fingertip Relocations
 
István Harmati Dept. of Control Engineering and Information Technology Budapest University of Technology and Economics H-1117 Pázmány Péter sétány 1/D Budapest, Hungary and Experimental Robotics Laboratory School of Engineering , Béla Lantos Dept. of Control Engineering and Information Technology Budapest University of Technology and Economics H-1117 Pázmány Péter sétány 1/D Budapest, Hungary and Shahram Payandeh Experimental Robotics Laboratory School of Engineering Science Simon Fraser University Burnaby, British Columbia, Canada V5A 1S6
 
This paper presents two object manipulation planning methods based on fitted stratified and semi-stratified approaches using finger relocations. The problem is discussed in the framework of a motion planning problem. The goal of the methods is to steer an object from an initial configuration to a final configuration while it is possible to reposition the fingertips on the surface in a predefined way. We assume there is no rolling and sliding but finger relocations are allowed. The first technique follows a pure stratified approach, however unlike the previously published method, the exact kinematic model of the manipulation system is matched with a virtual model masking the behavior of the original system. This provides a simpler model than the earlier stratified method by reducing the generally hard symbolic computation problem to a simple (almost pure numerical) one. The paper also introduces a semi-stratified manipulation planning based on the newly defined fitted system. This second method enhances the stratified motion planning with a definition of systematic finger relocation sequence. The proposed decomposition is based on the selection of suitable reference contact points. As the main benefit, the method enables a greater freedom in defining the desired fingertip trajectories. The methods are illustrated through an example of object reorientation.
 
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