Shape analysis and hand preshaping for grasping

Observations of human grasping show two phases. During the reaching phase of grasping, the hand preshapes in order to prepare for the second phases which is shape-matching with the object. Planning of grasping with dextrous robot hands cannot be summarized to these two phases. It is necessary to split the grasping process into several phases (frequently overlapped), and to consider problems such as object recognition, planning accessibility, task planning, initial touch and grab phase, and stable grasp phase. These are consciously or unconsciously generated by a human being. A major issue is to integrate a part of these components in preshaping, and in particular in automatic planning accessibility and preshaping of objects to be grasped. The system is based on 2D analysis of slices extracted from an octree representation of objects.