RADIAL POSITION SEEK TUNING FOR ACOUSTIC PERFORMANCE
Examples of the present invention relate to reduction in acoustic noise by tuning seek characteristics of a servo controller, depending on a radial position of a head relative to a disk. The servo controller can provide compensation for acoustic resonance modes.
1 . A device comprising:
a servo controller configured to move a head based on previously measured acoustic characteristics corresponding to a radial position of the head.
2 . The device of claim 1 , wherein the servo controller is further configured to move the head based on a position mode seek table, wherein the position mode seek table contains seek characteristics dependent upon the previously measured acoustic characteristics.
3 . The device of claim 2 , wherein the position mode seek table provides the seek characteristics for seeks of less than five tracks.
4 . The device of claim 2 , wherein the seek characteristics provided by the position mode seek table are tuned to address resonance mode variations of a disk drive.
5 . The device of claim 2 , wherein the seek characteristics provided by the position mode seek table are tuned to address excitation variations.
6 . The device of claim 1 , wherein the servo controller is further configured to move the head based on a plurality of position mode seek tables, each position mode seek table tuned to avoid excitation to a resonance mode for a corresponding cylinder range of the head.
7 . The device of claim 1 , further comprising:
a disk having a surface provided with a plurality of tracks for storing data; and
a first actuator for positioning the head relative to the disk.
8 . The device of claim 7 , further comprising:
a second actuator mounted on an arm movable by the first actuator, the second actuator being a microactuator and configured to further position the head relative to the disk.
9 . The device of claim 2 , wherein the servo controller selects the position mode seek table from a plurality of position mode seek tables according to the radial position of the head.
10 . The device of claim 1 , wherein the position of the head is along a radius of a disk.
11 . The device of claim 2 , wherein the servo controller provides the seek characteristics based on a corresponding cylinder range of the head.
12 . The device of claim 1 , wherein the radial position of the head is prior to moving the head to a new location during a seek operation.
13 . A method, comprising:
measuring acoustic characteristics corresponding to each of a plurality of radial positions of a head relative to a disk; and
controlling an actuator to move the head to a new radial position based on the previously measured acoustic characteristics corresponding to the radial position of the head.
14 . The method of claim 13 , wherein the controlling operation uses seek characteristics dependent upon the previously measured acoustic characteristics to control the movement of the head.
15 . The method of claim 14 , further comprising:
populating a position mode seek table with values corresponding to the seek characteristics to avoid excitation to a resonance frequency corresponding to each of the plurality of radial positions of the head relative to the disk.
16 . The method of claim 14 , further comprising:
determining a filter to produce values corresponding to the seek characteristics to avoid excitation to a resonance frequency corresponding to each of the plurality of radial positions of the head relative to the disk.
17 . The method of claim 13 , further comprising:
populating at least one position mode seek table with values to minimize resonance of the head during short seeks, the values dependent on the radial position of the head relative to the disk.
18 . The method of claim 13 , wherein the actuator moves the head based on a plurality of position mode seek tables, further comprising:
selecting a position mode seek table from the plurality of position mode seek tables based on a cylinder range of the head where a short seek is requested.
19 . A method, comprising:
measuring acoustic characteristics dependent on a radial position of a head relative to a disk; and
determining seek characteristics dependent on the radial position of the head and the acoustic characteristics of the head.
20 . The method of claim 19 , further comprising:
filtering to produce seek characteristics that avoid excitation to a resonance frequency corresponding to the radial position of the head relative to the disk.
21 . The method of claim 19 , further comprising:
populating at least one position mode seek table with a plurality of the determined seek characteristics.
22 . The method of claim 19 , further comprising:
controlling an actuator to cause movement of the head using the determined seek characteristics.