Force sensorless impedance control by disturbance observer

This paper describes a force sensorless control in a multi-degree-of-freedom manipulator. In active compliance control, the force sensor is attached to the manipulator to detect the reaction force. The force sensor is powerful and convenient. However it makes the structure of the manipulator system complicated. To improve this problem, the authors propose a force sensorless control strategy based on a disturbance observer. This paper shows that the disturbance observer is utilized not only for disturbance suppression but also reaction force estimation. The experimental results of force sensorless compliance control are also shown to confirm the validity of the proposed control method.>