E-028
Modeling and control of a dual stage actuator hard disk drive with piezoelectric
secondary actuator
Authors: R. Oboe, A. Beghi, B. Murari
Affiliation: University of Padova (R. Oboe, A. Beghi), STMicroelectronics (B. Murari)
Abstract
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 non-linear
friction on the VCM bearings. The use of a piezoelectric secondary actuator is analyzed,
first by determining the dynamic model of piezo-based dual stage actuator system,
then by including a detailed model of the piezoelectric actuator, comprehensive of
the effects of voltage or charge driving. With this detailed model, different control
strategies are evaluated. The results reported here suggest that voltage-driven
piezoelectric actuators should not be used in fine servo-positioning. Instead, charge
driven actuators exhibit promising performances when used with the control strategies
proposed here.
Roberto Oboe, Ph.D
Assistant Professor
Control Engineering and Technology
Dipartimento di Elettronica e Informatica
Universita' di Padova
via Gradenigo 6/a, 35131 Padova
Italy
Phone: +39-049-827-7696
Fax: +39-049-827-7699
oboe@dei.unipd.it