A decision method of grasp region based on a fingertip force evaluation resisting external force

In this paper, we research optimal grasp regions on a polygonal shaped grasped object using a required external force set. The required external force set is given based on a task, and consists of the external forces and moments, which must be balanced by contact forces applied by a robotic hand. Even though the grasp position which satisfies the demands, the contact point moves due to position error and manipulation of objects if the fingertip of robot hand is a hemisphere shape. We consider an decision method of grasp regions from the viewpoint of decreasing the magnitudes of the contact forces needed to balance any external force and moment contained in a given required external force set. In order to solve the problem, we present an algorithm. Moreover, numerical examples to evaluate the method is presented for polygonal objects.