A new grasp quality measure considering the physical limits of robot hands

In this article, we introduce the extended grasp wrench space (GWS) to identify the applied location and the magnitude of the critical external wrench. We jointly use the task wrench space (TWS), which is made up of all possible external wrenches produced from the unit normal force to the surface points of the grasped object (i.e., the object wrench space [OWS]). In the extended GWS, the torque bound of each joint of the robot hand is considered to determine the grasp capability. Through convexity analysis and a linear programming technique, we propose a new way of obtaining an enhanced grasp measure which shows a clear physical meaning. We verify the proposed grasp analysis and quality measure using a visual grasp simulator and polygonal objects of various shapes.