A Method for the Control of Robot Arms Constrained by Contact with the Environment

A hybrid position/force control method for a robot constrained by contact with the work surface is presented. The effective stiffness and accuracy of a robot end effector may be significantly increased by coupling the end effector to the work surface through a device referred to as a jig hand. However, a more sophisticated controller is needed to generate the appropriate end effector trajectories in order to conform to the kinematic constraint imposed by the jig hand and to regulate the contact force. A hybrid position/force control method is devised and applied to a conventional commercially available robot which makes the effect of the constraint transparent to the control of the task.