CONTROLLABILITY OF GRASPS AND MANIPULATIONS IN MULTIFINGERED HANDS

Manipulation of objects utilizing gravity and using general equilibriu m grasps, which are not necessarily force-closure, is discussed. Exami ning the controllability of the object's dynamics, in the presense of gravity, leads to the conclusion that almost all equilibrium grasps ar e locally controllable. This fact is used to show that manipulation fr om any one equilibrium point, to any other, is possible if there is a continuity of equilibrium points between them. In addition, the equili brium grasps can be used for changing grasps with Walking Finger Manip ulation. The system controllability matrix is also used to test grasp quality, depending not only on kinematic values but also on object ori entation and dynamic properties.