Method and apparatus for noise reduction during seeks using signal blending
View Patent ↗The blending of control indicators of a non-linear seek mode control and settle mode is done in a transition period between a non-linear seek mode and settle mode of the arm actuator in a hard disk drive. Such a blended transition avoids acoustical clicking that can occur for short distance seeks.
1. A method of calculating a control signal for an arm actuator of a rotating media storage device:
in a non-linear seek mode, determining non-linear seek mode control indications to produce a control signal for an arm actuator;
in a settle mode, determining settle mode control indications to produce the control signal for arm actuator; and
during a transition between the non-linear seek mode and settle mode, blending the non-linear seek mode control indications and the settle mode control indications to produce the control signal for the arm actuator.
2. The method of claim 1 , wherein the non-linear seek mode control indications and settle mode control indications are current commands.
3. The method of claim 2 , wherein the non-linear seek mode and settle mode current commands are used to produce a blended current command during the transition.
4. The method of claim 1 , wherein the non-linear seek mode control indications and settle mode control indications are target velocities.
5. The method of claim 4 , wherein the non-linear seek mode and settle mode target velocities are used to produce a blended target velocity which is used to determine a command current.
6. The method of claim 1 , wherein the blending uses a blending factor, b.
7. The method of claim 6 , wherein a blended control indication is produced equal to a non-linear seek mode control indication multiplied by (1-b) plus a settle mode control indication multiplied by b.
8. The method of claim 6 , wherein the blending factor is a monotonic function of time.
9. The method of claim 6 wherein the blending factor goes from 0 at time t 0 to 1 at time t 0 +P.
10. The method of claim 9 , wherein the blending factor is linear from time t 0 to time t 0 +P.
11. The method of claim 1 , wherein the settle mode uses a linear control law.
12. The method of claim 1 , wherein the settle mode is used for a small position error signal.
13. An apparatus comprising:
a rotating media storage device arm actuator unit; and
a controller to produce control signals for the arm actuator unit, the controller, in a non-linear seek mode, determining non-linear seek mode control indications to produce the control signal for the arm actuator, the controller, in a settle mode, determining settle mode control indications to produce the control signal for arm actuator and, the controller, during a transition between the non-linear seek mode and settle mode, blending the non-linear seek mode control indications and the settle mode control indications to produce the control signal for the arm actuator.
14. The apparatus of claim 13 , wherein the non-linear seek mode control indications and settle mode control indications are current commands.
15. The apparatus of claim 14 , wherein the non-linear seek mode and settle mode current commands are used to produce a blended current command during the transition.
16. The apparatus of claim 13 , wherein the non-linear seek mode control indications and settle mode control indications are target velocities.
17. The apparatus of claim 16 , wherein the non-linear seek mode and settle mode target velocities are used to produce a blended target velocity which is used to determine a command current.
18. The apparatus of claim 13 , wherein the blending uses a blending factor, b.
19. The apparatus of claim 18 , wherein a blended control indication is produced equal to a non-linear seek mode control indication multiplied by (1-b) plus a settle mode control indication multiplied by b.
20. The apparatus of claim 18 , wherein the blending factor is a monotonic function of time.