Anticipatory track switching microactuator track switch to enable track profile interpolation and control
Positioning a transducer over a magnetic recording medium for sequential track seeking operations includes performing a data transfer operation on a current track. During the data transfer operation, a next track is identified for the transducer to be moved in a sequential access pattern and movement of the transducer is initiated toward the next track before completion of the data transfer operation on the current track. A feed-forward control signal is determined based on a feed-forward profile including an acceleration table, which is applied to a microactuator configured to move the transducer by applying a voltage to move the transducer in anticipation of the next track position based on a predefined seek profile, and completing the data transfer operation on the current track during a period of latency in the movement toward the next track, such that a portion of the data transfer and the seek operation overlap in time.
1 . A method for positioning a transducer over a magnetic recording medium for sequential track seeking operations, comprising:
performing a data transfer operation on a current track of the magnetic recording medium using the transducer;
during the data transfer operation, identifying a next track to which the transducer is to be moved in accordance with a sequential access pattern;
initiating movement of the transducer toward the next track before completion of the data transfer operation on the current track;
determining a feed-forward control signal based on a feed-forward profile comprising an acceleration table;
applying the feed-forward control signal to a microactuator configured to move and/or position the transducer according to the feed-forward control signal, the feed-forward control signal being configured to apply a voltage to move the transducer in anticipation of the next track position based on a predefined seek profile; and
completing the data transfer operation on the current track during a period of latency in the movement toward the next track, such that a portion of the data transfer and a portion of the seek operation overlap in time.
2 . The method of claim 1 , wherein the feed-forward control signal is determined based on the feed-forward profile according to at least one of a) a velocity value determined based on a first integral of an acceleration value of the acceleration table, or b) a position value determined based on a second integral of the acceleration value of the acceleration table.
3 . The method of claim 2 , wherein the microactuator is piezoelectric, and wherein the voltage at the microactuator corresponds to a movement and/or displacement of the transducer.
4 . The method of claim 3 , wherein the acceleration table associates discrete voltage values with corresponding microactuator acceleration values.
5 . The method of claim 3 , wherein the velocity value and the position value are each derivable from a voltage at the microactuator.
6 . The method of claim 1 , wherein the applied feed-forward control signal is configured to ensure a final acceleration value of substantially zero and a final velocity value of substantially zero at the transducer.
7 . The method of claim 1 , wherein the microactuator is positioned at a head or gimbal portion of a suspension supporting the transducer.
8 . The method of claim 1 , wherein the microactuator is positioned at a loadbeam of a suspension supporting the transducer.
9 . The method of claim 1 , wherein the microactuator comprises a first and a second microactuator, wherein:
the first microactuator is positioned at a head or gimbal portion of a suspension supporting the transducer; and
the second microactuator is positioned at a loadbeam of a suspension supporting the transducer, wherein the first and second microactuators are configured to cooperatively position the transducer relative to a target track on the disk.
10 . The method of claim 1 , wherein the acceleration table is a decimated acceleration table.
11 . The method of claim 10 , wherein the decimated acceleration table is upsampled.
12 . The method of claim 1 , wherein the feed-forward control signal applied to the microactuator comprises an output voltage different from a corresponding voltage value of the acceleration table.
13 . A data storage device, comprising:
a disk configured to store data in a plurality of concentric data tracks;
a head configured to read data from or write data to the data tracks;
an actuator configured to move the head radially across the disk; and
a control circuit for positioning a transducer over a magnetic recording medium for sequential track seeking operations, the control circuit configured to:
perform a data transfer operation on a current track of the magnetic recording medium using the transducer;
during the data transfer operation, identify a next track to which the transducer is to be moved in accordance with a sequential access pattern;
initiate movement of the transducer toward the next track before completion of the data transfer operation on the current track;
determine a feed-forward control signal based on a feed-forward profile comprising an acceleration table associating discrete voltage values with corresponding microactuator acceleration values;
apply the feed-forward control signal to a microactuator configured to move and/or position the transducer according to the feed-forward control signal, the feed-forward control signal being configured to apply a voltage to move the transducer in anticipation of the next track position based on a predefined seek profile; and
complete the data transfer operation on the current track during a period of latency in the movement toward the next track, such that a portion of the data transfer and a portion of the seek operation overlap in time.
14 . The data storage device of claim 13 , wherein the feed-forward control signal is determined based on the feed-forward profile according to at least one of a) a velocity value determined based on a first integral of an acceleration value of the acceleration table, or b) a position value determined based on a second integral of the acceleration value of the acceleration table.
15 . The data storage device of claim 14 , wherein the microactuator is piezoelectric, wherein the voltage at the microactuator corresponds to a movement and/or displacement of the transducer, and wherein the velocity value and the position value are each derivable from a voltage at the microactuator.
16 . The data storage device of claim 13 , wherein the applied feed-forward control signal is configured to ensure a final acceleration value of substantially zero and a final velocity value of substantially zero at the transducer.
17 . The data storage device of claim 13 , wherein the acceleration table is a decimated acceleration table.
18 . The data storage device of claim 17 , wherein the decimated acceleration table is upsampled.
19 . The data storage device of claim 13 , wherein the feed-forward control signal applied to the microactuator comprises an output voltage different from a corresponding voltage value of the acceleration table.
20 . A non-transitory computer-readable medium storing instructions which, when executed by a controller of a data storage device, cause the data storage device to position a transducer over a magnetic recording medium for sequential track seeking operations, including the steps of:
performing a data transfer operation on a current track of the magnetic recording medium using the transducer;
during the data transfer operation, identifying a next track to which the transducer is to be moved in accordance with a sequential access pattern;
initiating movement of the transducer toward the next track before completion of the data transfer operation on the current track;
determining a feed-forward control signal based on a feed-forward profile comprising an acceleration table associating discrete voltage values with corresponding microactuator acceleration values;
applying the feed-forward control signal to a microactuator configured to move and/or position the transducer according to the feed-forward control signal, the feed-forward control signal being configured to apply a voltage to move the transducer in anticipation of the next track position based on a predefined seek profile; and
completing the data transfer operation on the current track during a period of latency in the movement toward the next track, such that a portion of the data transfer and a portion of the seek operation overlap in time.