By Topic

Active damping in HDD actuator

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

4 Author(s)
Fu-Ying Huang ; IBM Almaden Res. Center, San Jose, CA, USA ; Semba, T. ; Imaino, W. ; Lee, F.

One of the limitations inherent in high-track-density hard disk drive design is the effect of actuator mechanical resonant modes on the head-positioning servo. The first servo bandwidth limiting mode is the so-called “butterfly mode,” which is the major mode in the head mechanical transfer functions and can not be avoided through mechanical design. A special active damping technique has been developed for rotary actuators of 3-1/2" drives. With an additional sensor on the actuator and an external feedback loop, the butterfly mode can be damped and stiffened while the system stability is maintained. A theoretical system model, based on FEM, modal superposition and feedback control, is developed for analytical prediction of system stability and dynamics. Drive level experiments are conducted on actuators of two different designs, and show that the butterfly mode can be totally damped such that the gain of the head mechanical transfer function is close to 1/s 2. The end arm mode is also damped by about 8 dB for one actuator design. Servo improvement is also studied. It shows that the butterfly mode notch filter can be removed, and the phase margin can be improved by 7 degrees

Published in:

Magnetics, IEEE Transactions on  (Volume:37 ,  Issue: 2 )