WRITING SPIRALS WITH ACCURATE SLOPE ON A DISK DRIVE MEDIA

摘要

A reference spiral is written on a recording surface of a magnetic storage disk that is free of position or timing information. The reference spirals are written on the recording surface with a substantially uniform slope by using open loop control of the position of a read/write head in conjunction with an iterative learning control scheme. A voltage profile applied to a voice coil motor is adapted over multiple iterations of moving the read/write head across the recording surface to closely approximate a target voltage profile, and the reference spiral is written using the adapted voltage profile. In addition, ramp contact detection based on actuator current profile may be employed to achieve full utilization of available actuator stroke.

主权项

1. A method of writing a servo spiral on a recording surface of a magnetic storage disk, the method comprising:
controlling a write head according to a first velocity profile using open-loop control to move the write head from an inner diameter of the recording surface to an outer diameter of the recording surface; measuring a second velocity profile of the write head while the write head is moved from the inner diameter to the outer diameter; adjusting control parameters of the open-loop control to move the write head from the inner diameter of the recording surface to the outer diameter of the recording surface according to the second velocity profile; and writing a servo spiral on the recording surface as the write head is moved from the inner diameter of the recording surface to the outer diameter of the recording surface according to the adjusted control parameters.