Grasping Points Determination Using Visual Features

This paper discusses some issues for generating point of contact using visual features. To address these issues, the paper is divided into two sections: visual features extraction and grasp planning. In order to provide a suitable description of object contour, a method for grouping visual features is proposed. A very important aspect of this method is the way knowledge about grasping regions are represented in the extraction process, which is used also as filtering process to exclude all undesirable grasping point (unstable points) and all line segments that do not fit to the fingertip position. Fingertips are modelled as point contact with friction using the theory of polyhedral convex cones. Our approach uses three-finger contact for grasping planar objects. Each set of three candidate of grasping points is formulated as linear constraints and solved using linear programming solvers. Finally, we briefly describe some experiments on a humanoid robot with a stereo camera head and an anthropomorphic robot hand within the ”Centre of excellence on Humanoid Robots: Learning and co-operating Systems” at the University of Karlsruhe and Forchungszentrum Karlsruhe.