Grasping Force Optimization for Whole Hand Grasp

In tasks of grasping and manipulation, the hand sometimes uses not only fingertips but also fingers´ inner links and the palm to achieve more robust grasp. This kind of grasp is called whole hand grasp, or power grasp. One property of whole hand grasp is that the hand may not be able to generate grasping forces in any directions, so previous fingertip grasping analysis is no longer suitable for whole hand grasp. In this paper, concepts of active force and passive force are introduced. With these concepts, the contact force space is decomposed into four orthogonal subspaces. Considering the roles of both active force and passive force, a new cost index is proposed for the whole hand grasping force optimization, which is then reformulated into a convex optimization problem involving LMIs. Finally, numerical example and simulation results verify the validity and performance of our formulation of the problem with that new proposed cost index