Smooth touch control between position control and force control for industrial robots

Abstract

This paper proposes a new smooth touch control for operating industrial robots in unknown environments. The touch control is an useful strategy for the smooth switching from the position control to the force control. Many applications require flexibility to the environments. For example, direct teaching by using a manual control is one of the typical applications. A highperformance force control method is important for meeting this demand. This paper proposes a new sensor-less force control structure based on an I-P force controller and a disturbance observer. The experimental results presented herein confirm that the proposed method provides fine, smooth touch control in unknown environments such as a concrete block, a foamed styrol block and a cardboard box by using the tested structure of an actual industrial robot.