Effects of vibration on the off-track positioning of the piezoelectric head gimbal assembly in hard disk drive

Abstract

The piezoelectric head gimbal assembly was designed to compensate the off-track vibration in a harddisk drive. The off-track vibration caused by the torsion and sway vibration modes induces the read-write error rate. Thus, vibration modes of the piezoelectric head gimbal assembly that may causethe off-track positioning are reported in this work. The vibration characteristic of the piezoelectric headgimbal assembly is studied by using the finite element method. The finite element model is validatedby compared with the experimental result. The frequency response function result of the experimentwas measured by using the laser doppler vibrometer at the side of the slider in the horizontal plane.The comparison of natural frequencies and vibration mode shapes shows good agreement betweenthe finite element and experimental results. This research provides a procedure and a validated modelof the piezoelectric head gimbal assembly which is useful for further design and development of itsstructure and the control system to reduce the read-write error due to the off-track vibration.