Abstract
The disk drive industry has employed head load/unload technology for mobile drives and desktop drives for more than 12 years. The read/write heads are parked on a ramp structure when the drive is non-operational. The velocity of loading the heads onto the disk and unloading them back onto the ramp is critical for both the head/media reliability and the drive performance. Head loading control is a typical mechatronic system that involves a firmware algorithm, control electronics, and drive mechanics. Key performance criteria of a load control system include the successful load, well-controlled head velocity, load time, acoustics and robustness. Various electrical and mechanical design parameters affect the load performance. This analysis investigates the sensitivity of these parameters for head load control system design using simulation model that has been verified by comparison to experimental measurement. Model parameters include the voice coil motor torque constant, composite load torque function, electronic circuit offsets, coil resistance and its calibration accuracy, and ramp alignment error. The information revealed by this analysis helps improve disk drive head load control system design, performance, and robustness in the face of parameter variations introduced by high volume manufacturing. The results are also very helpful for product failure analysis.
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Ding, J., Desai, A., Liebman, M. et al. Parameter sensitivity analysis of disk drive head load control system. Microsyst Technol 15, 1657–1662 (2009). https://doi.org/10.1007/s00542-009-0867-5
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DOI: https://doi.org/10.1007/s00542-009-0867-5