US5901009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reduced seek acoustic noise direct access storage device
Assignee: HGST Netherlands BV
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Filing: 1995-05-31
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Granted: 1999-05-04
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Expires: 2015-05-31
Abstract
Abstract A disk drive with reduced seek acoustic noise and a method for implementation, without any additional hardware or mechanical modifications to the actuator includes a filter such that servo-loop stability is unaffected. The filter is inserted outside the existing servo loop to reshape the existing velocity profile in real time and to facilitate the suppression of forcing components that produce seek acoustics. A weighting factor may be used to provide a weighted average of the filtered and unfiltered velocity reference signal to the servo loop so that at the end of a track seek operation, the unfiltered reference signal is applied to the velocity servo, and there is almost no change in settle-out performance when the target track is reached. It is not necessary to store large volumes of velocity profile data to deal with different seek lengths.
Inventors
- 👤 Muthuthamby Sri-Jayantha
- 👤 Arun Sharma
- 👤 Satoshi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:22
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/5547
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
108 words
A direct access storage device comprising: a head for interaction with a storage medium; an actuator for moving the head; and a servo system including a velocity servo loop for operating the actuator in response to a reference signal, said reference signal varying as a function of time, said reference signal comprising an arbitrary signal having an arbitrary, asymmetrical velocity trajectory, filter means for real time filtering of the reference signal outside the velocity servo loop to produce a filtered reference signal, said filtered reference signal having less abrupt changes than said reference signal whereby abrupt transients in the signal applied to the actuator are reduced in magnitude.
Claim 2
Dependent Claim
108 words
A direct access storage device comprising: a head for interaction with a storage medium; an actuator for moving the head; and a servo system including a velocity servo loop for operating the actuator in response to a reference signal, said reference signal varying as a function of time, said reference signal comprising an arbitrary signal having an arbitrary, asymmetrical velocity trajectory, filter means for real time filtering of the reference signal outside the velocity servo loop to produce a filtered reference signal, said filtered reference signal having less abrupt changes than said reference signal whereby abrupt transients in the signal applied to the actuator are reduced in magnitude.
Claim 3
Dependent Claim
27 words
The direct access storage device of claim 1 wherein said filter is configured to reduce acoustic noise produced by said actuator, when said actuator moves said head.
Claim 4
Dependent Claim
27 words
The direct access storage device of claim 1 wherein a combination of said reference signal and said filtered reference signal is used to control said servo system.
Claim 5
Dependent Claim
15 words
The direct access storage device of claim 3 wherein said combination comprises a weighted average.
Claim 6
Dependent Claim
24 words
The direct access storage device of claim 4 wherein said weighted average is dependent on the number of tracks remaining to the target track.
Claim 7
Dependent Claim
27 words
The direct access storage device of claim 3 wherein said combination is used to control said servo system when said servo system is in a deceleration mode.
Claim 8
Dependent Claim
15 words
The direct access storage device of claim 6, wherein said combination comprises a weighted average.
Claim 9
Dependent Claim
24 words
The direct access storage device of claim 1 further comprising means for dynamically changing characteristics of the filter means as a function of time.
Claim 10
Dependent Claim
19 words
The direct access storage device of claim 1 further comprising means for changing initial characteristics of the filter means.
Claim 11
Dependent Claim
16 words
The direct access storage device of claim 1 wherein said filter means comprises a digital filter.
Claim 12
Dependent Claim
17 words
The direct access storage device of claim 1, wherein an output of said filter means is asymmetric.
Claim 13
Dependent Claim
30 words
The direct access storage device of claim 1, wherein said reference signal comprises an existing reference velocity representing a number of tracks-to-go for said head in traversing said storage medium.
Claim 14
Dependent Claim
52 words
The direct access storage device of claim 1, wherein said filter means is positioned outside of said velocity servo loop, said servo system comprising a closed velocity servo loop, and wherein said reference signal comprises an existing reference velocity representing a number of tracks-to-go for said head in traversing said storage medium.
Claim 15
Dependent Claim
34 words
The direct access storage device of claim 1, wherein said reference signal comprises an existing reference velocity signal and said filtered reference signal produced by said filter means comprises a modified, composite velocity signal.
Claim 16
Dependent Claim
18 words
The direct access storage device of claim 1, wherein said reference signal comprises an existing reference velocity signal.
Claim 17
Dependent Claim
24 words
The direct access storage device of claim 1, wherein said filter means comprises one of a first order filter and a second order filter.
Claim 18
Dependent Claim
30 words
The direct access storage device of claim 1, wherein said filtered reference signal produced by said filter means is kinematically unrelated to the reference signal input to said filter means.
Claim 19
Dependent Claim
57 words
The direct access storage device of claim 1, wherein said filter means employs said velocity servo loop such that a velocity reference signal in relation to a distance from the target track is found using a velocity profile, and wherein a calculation of said velocity reference signal does not rely on a seek time of said head.
Claim 20
Dependent Claim
59 words
The direct access storage device of claim 1, wherein said filter means removes a predetermined change of velocity of said head at transition points occurring at at least one of an interface between an acceleration phase and a constant velocity phase of said head and an interface between said constant velocity phase and a deceleration phase of said head.
Claim 21
Dependent Claim
25 words
The direct access storage device of claim 1, wherein said filter means smooths an original velocity profile of said head output in the time domain.
Claim 22
Dependent Claim
63 words
The direct access storage device of claim 1, wherein said reference signal corresponds to an original velocity profile signal of the head in the time domain, and said filter means merges said original velocity profile signal in the time domain with the filtered reference signal using a weighted average, and wherein said filtered reference signal is obtained from the original reference signal itself.
Claim 23
Dependent Claim
41 words
The direct access storage device of claim 1, wherein said storage medium includes a plurality of tracks and is rotatable, and wherein a velocity profile of the head is sampled at each sector of the rotating medium during a track-access mode.
Claim 24
Dependent Claim
58 words
The method of claim 1, wherein said step of filtering includes removing a predetermined change of velocity of said head at transition points occurring at at least one of an interface between an acceleration phase and a constant velocity phase of said head and an interface between said constant velocity phase and a deceleration phase of said head.
Claim 25
Dependent Claim
27 words
The direct access storage device of claim 1, wherein said step of filtering includes smoothing an original velocity profile of said head output in the time domain.
Claim 26
Dependent Claim
47 words
The method of claim 1, wherein said storage medium includes a plurality of tracks and is rotatable, further comprising a step of sampling a velocity profile of the head at each sector of the rotating medium during a track-access mode, to provide a reference signal for filtering.
Claim 27
Independent Claim
95 words
A method for operating a direct access storage device having a head for interaction with a storage medium, an actuator for moving the head, and a servo system including a velocity servo loop for operating the actuator in response to a reference signal, said reference signal varying as a function of time, comprising: filtering in real time the reference signal outside the velocity servo loop to produce a filtered reference signal, said reference signal comprising an arbitrary signal having an arbitrary, asymmetrical velocity trajectory; and supplying said filtered reference signal to the velocity servo loop.
Claim 28
Independent Claim
95 words
A method for operating a direct access storage device having a head for interaction with a storage medium, an actuator for moving the head, and a servo system including a velocity servo loop for operating the actuator in response to a reference signal, said reference signal varying as a function of time, comprising: filtering in real time the reference signal outside the velocity servo loop to produce a filtered reference signal, said reference signal comprising an arbitrary signal having an arbitrary, asymmetrical velocity trajectory; and supplying said filtered reference signal to the velocity servo loop.
Claim 29
Dependent Claim
32 words
The method of claim 26 wherein the filtered reference signal has less abrupt changes than said reference signal whereby abrupt transients in the signal applied to the actuator are reduced in magnitude.
Claim 30
Dependent Claim
32 words
The method of claim 26 further comprising configuring a filter to produce said filtered reference signal so that acoustic noise produced by said actuator when said actuator moves said head is reduced.
Claim 31
Dependent Claim
18 words
The method of claim 28 further comprising dynamically changing characteristics of the filter as a function of time.
Claim 32
Dependent Claim
13 words
The method of claim 28 further comprising setting initial characteristics of the filter.
Claim 33
Dependent Claim
24 words
The method of claim 26 further comprising using a combination of said reference signal and said filtered reference signal to control said servo system.
Claim 34
Dependent Claim
12 words
The method of claim 31 wherein said combination comprises a weighted average.
Claim 35
Dependent Claim
24 words
The method of claim 32 further comprising selecting said weighted average as a function of the number of tracks remaining to a target track.
Claim 36
Dependent Claim
22 words
The method of claim 31 further comprising using said combination to control said servo system when it is in a deceleration mode.
Claim 37
Dependent Claim
12 words
The method of claim 34 wherein said combination comprises a weighted average.
Claim 38
Dependent Claim
12 words
The method of claim 26, wherein said filtered reference signal is asymmetric.
Claim 39
Dependent Claim
27 words
The method of claim 26, wherein said reference signal comprises an existing reference velocity representing a number of tracks-to-go for said head in traversing said storage medium.
Claim 40
Dependent Claim
54 words
The method of claim 26, wherein said step of filtering includes filtering by a filter positioned outside of said velocity servo loop, said servo system comprising a closed velocity servo loop, and wherein said reference signal comprises an existing reference velocity representing a number of tracks-to-go for said head in traversing said storage medium.
Claim 41
Dependent Claim
31 words
The method of claim 26, wherein said reference signal comprises an existing reference velocity signal and said filtered reference signal produced by said filter step comprises a modified, composite velocity signal.
Claim 42
Dependent Claim
15 words
The method of claim 26, wherein said reference signal comprises an existing reference velocity signal.
Claim 43
Dependent Claim
24 words
The method of claim 26, wherein said step of filtering includes filtering by one of a first order filter and a second order filter.
Claim 44
Dependent Claim
18 words
The method of claim 26, wherein said filtered reference signal produced is kinematically unrelated to the reference signal.
Claim 45
Dependent Claim
56 words
The method of claim 26, wherein said step of filtering includes employing said velocity servo loop such that a velocity reference signal in relation to a distance from the target track is found using a velocity profile, and wherein a calculation of said velocity reference signal does not rely on a seek time of said head.
Claim 46
Dependent Claim
62 words
The method of claim 26, wherein said reference signal corresponds to an original velocity profile signal of the head in the time domain, and said step of filtering includes merging said original velocity profile signal in the time domain with the filtered reference signal using a weighted average, and wherein said filtered reference signal is obtained from the original reference signal itself.
Claim 47
Dependent Claim
106 words
A direct access storage device comprising: a head for interaction with a storage medium; an actuator for moving the head; and a servo system including a velocity servo loop for operating the actuator in response to a reference signal, said reference signal varying as a function of time and comprising an arbitrary signal having an arbitrary, asymmetrical velocity trajectory, a filter for real time filtering of the reference signal outside the velocity servo loop to produce a filtered reference signal, said filtered reference signal having less abrupt changes than said reference signal whereby predetermined transients in the signal applied to the actuator are reduced in magnitude.
Claim 48
Dependent Claim
106 words
A direct access storage device comprising: a head for interaction with a storage medium; an actuator for moving the head; and a servo system including a velocity servo loop for operating the actuator in response to a reference signal, said reference signal varying as a function of time and comprising an arbitrary signal having an arbitrary, asymmetrical velocity trajectory, a filter for real time filtering of the reference signal outside the velocity servo loop to produce a filtered reference signal, said filtered reference signal having less abrupt changes than said reference signal whereby predetermined transients in the signal applied to the actuator are reduced in magnitude.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-05-03 | 2002-11-02 | 2003-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-03 | 2006-11-02 | 2007-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-03 | 2010-11-02 | 2011-05-04 | $7700.00 | Window Closed / Lapsed |