Dexterity Analysis of Human and Robotic Grasping Motions from the Viewpoint of Dynamics

This paper is concerned with dexterity in grasping a rigid object motion by a pair of robot fingers. In grasping of human, concurrent pinching and controlling of orientation of the object are executed quickly and precisely with the thumb and index finger. However, it is not easy to realize the two tasks concurrently by using robot fingers. An attempt to enhance dexterity in grasping by a pair of robot fingers with hemispherical finger tips is presented in the following ways: 1) comparing robotic grasping with human grasping 2) investigating the functional role of each human finger joint 3) reconsidering robotic grasping in an aspect of human grasping. Finally, a method to enhance dexterity in grasping by robot fingers is proposed.