An Investigation of Frictionless Enveloping Grasping in the Plane

Grasping by a two-dimensional hand composed of a palm and two hinged fingers is studied. The mathematics of fric tionless grasping is presented and used in the development of a planner/simulator. The simulator computes the motion of the object using an active constraint set method and assuming exact knowledge of the physical properties of the polygonal object, hand, and support. Grasping is divided into three phases. During the first phase, the initial grasping configura tion is found. In the second phase, the object is manipulated away from the support, bringing it into contact with the palm. In the last phase, the grip is adjusted to minimize the contact forces acting on the object.