In this paper we discuss the controller design of a PZT-actuated suspension dual-stage servo system in hard disk drives. The proposed control structure includes an active vibration damping control loop and a track-following control loop. The vibration damping control loop, which runs at a faster rate than the track-following control loop, utilizes a PZT element on a PZT-actuated suspension as a vibration sensor to damp the resonance modes of the voice coil motor (VCM) and the PZT actuator. The vibration damping controller is designed using Kalman filter based state feedback control techniques. A simple dual-stage track-following controller is designed, based on the damped actuator model, using the sensitivity function decoupling design method. Simulation and experimental results are presented to demonstrate the benefits of this control scheme in expanding servo control bandwidth and suppressing airflow excited structural vibrations.

Issue Section:
Technical Papers
Keywords:
piezoelectric actuators, control system synthesis, disc drives, hard discs, vibration control, Kalman filters, state feedback, servomechanisms, suspensions (mechanical components)
Topics:
Actuators, Control equipment, Damping, Design, Kalman filters, Sensors, Servomechanisms, Vibration, Air flow, Disks, Frequency response, Displacement, Control systems, State feedback
1.
Evans
,
R. B.
,
Griesbach
,
J. S.
, and
Messner
,
W. C.
, 1999, “
Piezoelectric Microactuator for Dual-Stage Control
,”
IEEE Trans. Magn.
0018-9464,
35
, pp.
977
–
981
.
Crossref
Search ADS
 
2.
Huang
,
F.-Y.
,
Semba
,
T.
,
Imaino
,
W.
, and
Lee
,
F.
, 2001, “
Active Damping in HDD Actuator
,”
IEEE Trans. Magn.
0018-9464,
37
, pp.
847
–
849
.
Crossref
Search ADS
 
3.
Abramovitch
,
D.
,
Hurst
,
T.
, and
Henze
,
D.
, 1997, “
The PES Pareto Method: Uncovering the Strata of Position Error Signals in Disk Drives
,”
Proceedings of American Control Conference
, Vol.
5
, pp.
2888
–
2895
.
4.
Kobayashi
,
M.
,
Nakagawa
,
S.
, and
Nakamura
,
S.
, 2003, “
A Phase-Stabilzed Servo Controller for Dual-Stage Actuators in Hard Disk Drives
,”
IEEE Trans. Magn.
0018-9464,
39
, pp.
844
–
850
.
Crossref
Search ADS
 
5.
Ewins
,
D. J.
, 2000,
Modal Testing: Theory, Practice and Application
, 2nd edition,
Research Studies Press Ltd.
,
City
.
6.
Li
,
Y.
,
Horowitz
,
R.
, and
Evans
,
R.
, 2003, “
Vibration Control of a PZT Actuated Suspension Dual-Stage Servo System Using a PZT Sensor
,”
IEEE Trans. Magn.
0018-9464,
39
, pp.
932
–
937
.
7.
Åström
,
K. J.
, and
Wittenmark
,
B.
, 1997,
Computer Controlled System
, 3rd ed.,
Prentice-Hall
,
Englewood Cliffs, NJ
.
8.
Mori
,
K.
,
Munemoto
,
T.
,
Otsuki
,
H.
,
Yamaguchi
,
Y.
, and
Akagi
,
K.
, 1991, “
A Dual-Stage Magnetic Disk Drive Actuator Using a Piezoelectric Device for a High Track Density
,”
IEEE Trans. Magn.
0018-9464,
27
, pp.
5298
–
5300
.
Crossref
Search ADS
 
9.
Li
,
Y.
, and
Horowitz
,
R.
, 2002, “
Design and Testing of Track-Following Controllers for Dual-Stage Servo Systems with PZT Actuated Suspensions
,”
Microsyst. Technol.
0946-7076,
8
, pp.
194
–
205
.
Crossref
Search ADS
 
10.
Anderson
,
E. H.
, and
Hagood
,
N. W.
, 1994, “
Simultaneous Piezoelectric Sensing/Actuation: Analysis and Application to Controlled Structures
,”
J. Sound Vib.
0022-460X,
174
, pp.
617
–
639
.
Crossref
Search ADS
 
Copyright © 2006
 by American Society of Mechanical Engineers
You do not currently have access to this content.