Modeling and control of a dual stage actuator hard disk drive with MEMS-based secondary actuator

High capacity of new magnetic material can be exploited only with a fine servo-positioning of the hard disk heads. This can be achieved by means of dual stage actuation, where the secondary actuator can be realized with different technologies. In this paper, the need for a secondary actuator is proven by explicitly including the nonlinear friction on the voice coil motor bearings. The use of a MEMS-based secondary actuator is analyzed, and the dynamic model of the MEMS-based dual stage actuator system is determined. With this detailed model, a control strategy is developed and evaluated.