2012 METU Lecture 5 Control of Smart Systems - Department of ...

Design Challenges
• The pivot bearing also has nonlinear friction dynamics, which
include hysteresis and which primarily affect seek performance.
• Flutter vibration modes in the disks and other modes in the
spindle contribute to tracking errors by moving the data track
relative to an inertial frame of reference.
• Noise and distortion are two other important sources of
tracking error in disk drives. Noise arises not only from
electronics, but also from the magnetic media.
• The magnetoresistive head readers are nonlinear devices.
• Quantization noise is, of course, present in this digital control
system.
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