GRASPING FORCE CONTROL OF ROBOT HAND

In this paper, a grasping force control of robot hand is presented with consideration of workpiece dynamics. It is difficult to control a manipulator without the knowledge of Its dynamics, because its handling with unknown workpiece may bring about overshoots and vibrations. Then it is necessary to adjust control gains according to the handling workpieces in order to achieve good control performances. The authors propose a new control strategy which uses adaptive observer and VSS (${\underline{V}}ariable$ ${\underline{S}}tructure$ ${\underline{S}}ystem$) controller to subdue these overshoots and vibrations. Some simulations of the proposed method are carried out for a grasping system to control the grasping force to various workpieces, whose dynamics cannot be known in advance.