Techniques for adjusting for actuator non-linearities in a data storage system
AssigneesImation Corp., Sony Corporation
InventorsDenis Langlois, James Anderson
Life of this patent
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Abstract
The invention provides techniques for adjusting for actuator non-linearities in a data storage system. The invention is particularly useful for piezoelectric actuators, such as actuators that implement a bimorph piezoelectric crystal structure or a laminate piezoelectric crystal structure, although other actuators may present similar non-linearity issues. In one embodiment, the invention provides a method comprising applying a signal to an actuator of a data storage system, the actuator having a non-linear response, wherein the signal includes a linear drive component and a non-linear adjustment component, and positioning a data storage head with respect to a data storage medium via the actuator.
Claims20
A method comprising:
- applying a signal to an actuator of a data storage system, the actuator having a non-linear response, wherein the signal includes a linear drive component and a non-linear adjustment component;
- and
- positioning a data storage head with respect to a data storage medium via the actuator.
A method comprising:
- identifying a position of a magnetic head with respect to a magnetic tape by detecting a servo pattern on the magnetic tape;
- generating a position error signal (PES) based on the identified position of the magnetic head;
- performing a table lookup based on the identified position and the PES to account for a non-linear response of an actuator;
- and
- applying a signal to the actuator to adjust the position of the magnetic head, the signal being defined, at least in part, on the lookup to account for the non-linear response of the actuator.
An apparatus comprising:
- a magnetic head;
- an actuator coupled to the magnetic head to control positioning of the magnetic head with respect to a magnetic tape, the actuator having a non-linear response due to hysteresis;
- and
- a controller to provide an input signal to the actuator, the input signal including a linear drive component and a non-linear adjustment component, wherein the linear drive component of the input signal substantially defines actuator response in the absence of the hysteresis, and the non-linear adjustment component defines an adjustment for the hysteresis to reduce phase lag.
Dependencies are inferred from the claim text.