Force feedback from micro environment considering nominal mass of disturbance observer

Motion control has been developed in recent decades. In particular, disturbance observer encouraged the development of motion control. Disturbance observer has parameter variations such as the variations of force constant and the variations of mass. Especially, this paper focuses on nominal mass variations. The nominal mass variations of disturbance observer work as phase compensator, but the nominal mass variations of reaction force observer are not considered until now. This paper shows that the nominal mass variations of reaction force observer reduce the oscillation of the system. This paper applies the proposed method to macro-micro bilateral control. Since some noises bring on the oscillation of the system, reduction of some noises are essential technique for stable tele-operation. The viability of the proposed method and the reduction of the oscillation are shown by some experimental results.