A method for improving the performance of a rotary actuator in a disk drive,
the
rotary actuator comprises a voice coil motor (VCM) characterized by a torque parameter,
the disk drive comprises a servo control system having a motor driver circuit for
receiving a series of command effort signals (CEFs) transmitted based on a first
seek profile, and for providing an operating current to VCM based on the CEFs for
causing a movement of the actuator from a first radial location to a target radial
location. The method includes recording the transmitted CEFs, and while actuator
is moving: adjusting each recorded CEF to account for a disk drive influence on
actuator movement; storing adjusted CEFs; monitoring velocity of moving actuator;
calculating an acceleration value corresponding to moving actuator from the stored
CEFs and monitored velocity; and adjusting the acceleration value to account for
a radial torque parameter variation.
