Sensory Feedback for Stable Grasping and Posture Control by using a Pair of Minimum-DOF Robot Fingers with Soft Tips

Abstract

This paper firstly derives and analyzes non-linear dynamics of pinch motions generated by a pair of robot fingers (1 D.O.F. and 2 D.O.F.) with soft tips and finds a feedback control signal for stable grasping and posture control of a rigid object based on passivity analysis. It is shown that measurements of rotation angle of the object by means of optical devices play a crucial role in construction of such feedback signals. Secondly, results of computer simulation by using the derived non-linear differencial equations with geometric constraints and results of experiments by using such robot fingers are presented. Then, usefulness of this control method is discussed from the practical viewpoint.