PatentPDF Available

Methods for Closed-loop Compensation of Ultra-high Frequency Disturbances in Hard Disk Drives and Hard Disk Drives Utilizing Same

Authors:
(12)
United
States
Patent
Chen
et
al.
US008630059B1
US
8,630,059
B1
Jan.
14,
2014
(10)
Patent
N0.:
(45)
Date
of
Patent:
(54)
(75)
(73)
(*)
(21)
(22)
(51)
(52)
(58)
METHODS
FOR
CLOSED-LOOP
COMPENSATION
OF
ULTRA-HIGH
FREQUENCY
DISTURBANCES
IN
HARD
DISK
DRIVES
AND
HARD
DISK
DRIVES
UTILIZING
SAME
Inventors:
Xu
Chen,
Albany,
CA
(US);
Wei
Xi,
Mission
Viejo,
CA
(US);
Young-Hoon
Kim,
Cupertino,
CA
(US);
Kuang-Yang
Tu,
Irvine,
CA
(US)
Assignee:
Western
Digital
Technologies,
Inc.,
Irvine,
CA
(US)
Notice:
Subject
to
any
disclaimer,
the
term
of
this
patent
is
extended
or adjusted
under
35
U.S.C.
154(b)
by
142
days.
Appl.
No.:
13/408,974
Filed:
Feb.
29,
2012
Int.
Cl.
GIIB
5/596
(2006.01)
US.
Cl.
USPC
.....................................................
..
360/7814
Field
of
Classi?cation
Search
USPC
...........
..
360/7814,
78.09, 78.06,
244,
77.02,
360/7704;
369/3016,
44.27, 44.28,
44.29
See
application
?le
for
complete
search
history.
(56)
References
Cited
U.S.
PATENT
DOCUMENTS
7,158,334
B2
1/2007
IWashiro
7,319,570
B2
1/2008
Jia
et
31.
7,609,474
B2
*
10/2009
Takaishi
...................
..
360/7809
2004/0213100
A1
10/2004
IWashiro
2005/0096793
A1
5/2005
Takeuchi
2007/0064334
A1
3/2007
Jia
et
a1.
*
cited
by
examiner
Primary
Examiner
*
Nabil
Z
Hindi
(57)
ABSTRACT
A
disk
drive
comprises
a
disk,
an
actuator
arm
and
a
servo
controllerusing
a
position
error
signal
to
generate
a
controller
output
signal
to
control
the actuator
arm.
A
plant
mechani
cally
models
at
least
a
portion
of
the
disk
drive,
receives a
control
command
to
Which
an
unknown
disturbance
is
added
and
generates
a
plant
output.
A
disturbance
observer
(DOB)
uses
the
control
command
and
the plant
output
to
generate
a
delayed
and