Position and Force Control of the SCARA Robot Based on Disturbance Observer

Mostly force sensor, used to measure external force, is equipped at the end effector. However force sensor is expensive and capable to measure only external force around the area that force sensor is attached. Therefore, the action could not be found outside the end effector. As a result, to improve the performance, disturbance observer (DOB), designed to control the position and force, is used to estimate external force instead of force sensor. In this paper, SCARA robot is used to draw the parabola on the board with a pen at end effector. From the results show effective position control of the SCARA robot and force control without using of force sensor as the robot is drawing.