Extension of the Form-Closure Property to Underactuated Hands

The property of form-closure of a grasp, as generally defined in the literature, is based on the assumption that contact points between the hand and the object are fixed in space. However, this assumption is false when considering a grasp exerted by an underactuated hand, since in this case, it is not possible to control the position of each phalanx independently. In spite of researchers' interest in studying formclosure, none of the available published work on this subject takes into consideration the particular kinematics of underactuated hands. Actually, there are few available tools to qualify or quantify the stability of a grasp exerted by an underactuated hand, thus the design of underactuated hands mostly results from an intuitive approach. This paper aims to reduce this gap. A classification of underactuated hands is proposed, based on the expression of contact forces. This highlights the influence of non-backdrivable mechanisms introduced in the transmission of the closin...

• Type: Journal
• Year: 2010
• Where: TROB
• Authors: Sébastien Krut, Vincent Begoc, Etienne Dombre, François Pierrot
• Keywords: Hardware, Order Form-closure, TROB 2010, Underactuated Grasp, Underactuated Hands