On explicit implementation of multiple disturbance observers derived from three-degree-of-freedom control

This paper analyzes three-degree-of-freedom (Three-DoF) control based multiple disturbance observers (TDoF-DOB). Three-DoF control has multiple DOBs equivalently; therefore, its explicit implementation is verified in this paper for the force estimation problem. As the comparative study, differences between TDoF-DOB and position and acceleration integrated disturbance observer (PAIDO) are analyzed. TDoF-DOB has one advantage in terms of a noise sensitivity performance in the case of being applied for two-inertia systems. Finally, the analysis is verified by simulations and fundamental experiments for one and two-inertia systems.