A nonprehensile method for reliable parts orienting

Abstract

Prehension may be defined as "The act of taking hold, seizing or grasping, as with the hand" (Webster's 3rd International Dictionary). Nonprehensile manipulation, then, can be defined as the manipulation of objects without grasping them. Manipulation without prehension is a natural way of handling objects for both humans and machines. The ability to manipulate objects which may not be graspable increases the flexibility of a robot interacting with its environment, without adding complexity to the mechanical design. This research analyses the mechanics of nonprehensile contact between a simple, two degree of freedom manipulator and a part. The intent is to develop reliable but sensorless manipulation routines for use in an automated assembly environment. While nonprehensile, sensorless devices are in common use in such environments, existing parts orienting devices, such as bowl feeders or the SONY Automatic Parts Orienting System, must be custom designed for each specific task. To decr...