Computing Parallel-Jaw Grips

In this paper we propose a new model for gripping parts with an industrial parallel-jaw gripper. In contrast to many previous models, we use two grip points and define candidate grips that are resistant to slipping and torque about the part’s center of mass. These grips must also be accessible and robust to perturbations in part position. We give an O(n) algorithm for computing and ranking O(n) such grips on an n-sided polygonal slice through the part. The algorithm will be part of a design and simulation system that can rapidly provide feedback to designers; thus it must run quickly and reliably. We have also implemented the algorithm in a Java applet with a graphical user interface that allows Internet users to define a part; the applet computes, ranks, and displays the set of computed grips. To try the applet, please visit: http://ford.ieor.berkeley.edu/grip/