Runout compensation in active magnetic bearings with iterative learning control scheme

Active magnetic bearing is a promising candidate for next generation spindle motors of hard disk drives. In this paper, an iterative learning control scheme is proposed to suppress the rotor poison runout induced by the unbalanced forces in AMB. The ILC controller can produce the synchronous compensation force by iteratively "learning" rotor runout information. This compensation force makes the rotor rotate about its geometric axis