An interpretation of unbalance vibration compensator for five-axes active magnetic bearing systems based on internal model principle

Five-axes active magnetic bearing (AMB) systems are widely utilized for the field of precision such as semiconductor exposure machines. This paper considers an interpretation of an unbalance vibration compensator PGC for five-axes AMB. As methods for the rejection of periodic disturbance, repetitive control and PIS control, which are based on internal model principle, have been known. The PIS control can be considered as a special case of the repetitive control. This paper investigates the relationship between the PGC and the PIS control from the similarity of the pole assignment and shows that the PGC suppresses the unbalance vibration from the perspective of the internal model principle.