Feedforward decoupling control design for dual-actuator system in hard disk drives

The dual-actuator hard disk drive (HDD) with two actuators mounted in the diagonal corners of the baseplate allows faster data access with relatively slower spindle speed. However, the mechanical interaction between the actuators tends to affect the head positioning accuracy. In this paper, the dual-actuator structure is formulated as a dual-input dual-output (DIDO) system and then identified in frequency domain. Based on the interaction models, the feedforward decoupling control (FDC) is developed to compensate for the vibration due to interaction. Experimental results on a dual-actuator prototype demonstrate that the position error signal (PES) value due to interaction is reduced by 72% even under the severest condition.