Data storage device managing peak current for multiple actuators

Patent metadata

Field	Value
Publication number	US-10839839-B1
Application number	US-202016781194-A
Country	US
Kind code	B1
Filing date	Feb 4, 2020
Priority date	Feb 4, 2020
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A data storage device is disclosed comprising a first actuator configured to actuate a first head over a first disk surface, and a second actuator configure to actuate a second head over a second disk surface. A first seek of the first head over the first disk surface is initiated during a first seek time based on a first seek profile. A second seek of the second head over the second disk surface is initiated during a second seek time based on a second seek profile. When the second seek time at least partially overlaps the first seek time and at least the second seek profile is a de-rated seek profile, the second seek profile is adjusted to avoid an overcurrent condition.

First claim

What is claimed is:

1. A data storage device comprising:
a first disk surface;
a first head;
a first actuator configured to actuate the first head over the first disk surface;
a second disk surface;
a second head;
a second actuator configure to actuate the second head over the second disk surface; and
control circuitry configured to:
first seek the first head over the first disk surface during a first seek time based on a first seek profile;
second seek the second head over the second disk surface during a second seek time based on a second seek profile, wherein the second seek time at least partially overlaps the first seek time and at least the second seek profile is a de-rated seek profile; and
adjust the second seek profile to avoid an overcurrent condition.

2. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to adjust the second seek profile by decreasing an acceleration current applied to the second actuator for a clamp interval.

3. The data storage device as recited in claim 2 , wherein after the clamp interval the control circuitry is further configured to increase the acceleration current applied to the second actuator.

4. The data storage device as recited in claim 3 , wherein the control circuitry is further configured to increase the acceleration current to a maximum level until the second actuator reaches a maximum velocity.

5. The data storage device as recited in claim 4 , wherein the control circuitry is further configured to set the clamp interval to achieve a just-in-time (JIT) arrival of the second head at the end of the second seek.

6. The data storage device as recited in claim 1 , wherein when the second seek profile terminates within a predetermined distance from an inner diameter or outer diameter of the second disk surface, the control circuitry is further configured to adjust the first seek profile to avoid the overcurrent condition.

7. The data storage device as recited in claim 6 , wherein first seek profile is a de-rated seek profile.

8. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to adjust a control signal applied to the second actuator closed loop based on a detected supply voltage in order to maintain the supply voltage near a target threshold.

9. The data storage device as recited in claim 1 , wherein the control circuitry is further configured to adjust a control signal applied to the second actuator closed loop based on a detected supply current in order to maintain the supply current near a target threshold.

10. A data storage device comprising:
a first disk surface;
a first head;
a first actuator configured to actuate the first head over the first disk surface;
a second disk surface;
a second head;
a second actuator configure to actuate the second head over the second disk surface; and
control circuitry configured to:
first seek the first head over the first disk surface during a first seek time based on a first seek profile;
second seek the second head over the second disk surface during a second seek time based on a second seek profile; and
when the first seek profile terminates within a predetermined distance from an inner diameter or outer diameter of the first disk surface, adjust the second seek profile to avoid an overcurrent condition.

11. The data storage device as recited in claim 10 , wherein the control circuitry is further configured to adjust the second seek profile by decreasing an acceleration current applied to the second actuator for a clamp interval.

12. The data storage device as recited in claim 11 , wherein after the clamp interval the control circuitry is further configured to increase the acceleration current applied to the second actuator.

13. The data storage device as recited in claim 12 , wherein the control circuitry is further configured to increase the acceleration current to a maximum level until the second actuator reaches a maximum velocity.

14. The data storage device as recited in claim 13 , wherein the control circuitry is further configured to set the clamp interval to achieve a just-in-time (JIT) arrival of the second head at the end of the second seek.

15. The data storage device as recited in claim 10 , wherein the control circuitry is further configured to adjust the second seek profile by adjusting a control signal applied to the second actuator closed loop based on a detected supply voltage in order to maintain the supply voltage near a target threshold.

16. The data storage device as recited in claim 10 , wherein the control circuitry is further configured to adjust the second seek profile by adjusting a control signal applied to the second actuator closed loop based on a detected supply current in order to maintain the supply current near a target threshold.

17. A data storage device comprising:
a first disk surface;
a first head;
a second disk surface;
a second head;
a means for first seeking the first head over the first disk surface during a first seek time based on a first seek profile;
a means for second seeking the second head over the second disk surface during a second seek time based on a second seek profile, wherein the second seek time at least partially overlaps the first seek time and at least the second seek profile is a de-rated seek profile; and
a means for adjusting the second seek profile to avoid an overcurrent condition.

18. The data storage device as recited in claim 17 , wherein at least the second seek profile is a de-rated seek profile.

19. The data storage device as recited in claim 17 , wherein the means for adjusting the second seek profile comprises a means for decreasing an actuator acceleration current for a clamp interval corresponding to a just-in-time (JIT) arrival of the second head at the end of the second seek.

20. The data storage device as recited in claim 17 , wherein when the second seek profile terminates within a predetermined distance from an inner diameter or outer diameter of the second disk surface, the data storage device further comprises a means for adjusting the first seek profile to avoid the overcurrent condition.

Assignees

• Western Digital Tech Inc

Inventors

• Uchida Hiroshi
• Numasato Hidehiko
• Liu Kexiu
• Khanna Shrey

Classifications

• G11B5/5547 Primary

  "Seek" control and circuits therefor (G11B5/5556 takes precedence) · CPC title

• G11B5/4813 Primary

  Mounting or aligning of arm assemblies, e.g. actuator arm supported by bearings, multiple arm assemblies, arm stacks or multiple heads on single arm (G11B5/484 takes precedence) · CPC title

• G11B21/083

  on discs · CPC title