Selection of hand configurations for power grasps

A power grasp is one of two basic categories of grasps by multifingered hands that cannot impart any small motions to the grasped object, but passively resists arbitrary external forces exerted on the object. This paper investigates how to select hand configurations to achieve a power grasp. Starting with a definition of power grasp, an enumeration of grasp configurations is conducted by looking only at the degrees of freedom in the joints and contacts of a hand-object system. A unified method is developed for systematically enumerating grasp configurations for all types of contacts. Based on characteristics of the contact force spaces, three criteria are proposed to select the configurations. To illustrate the advantage of selected configurations, the authors examine two numerical examples