The hard disk drive is one of the finest examples of the precision control of mechatronics,
with tolerances less than one micrometer achieved while operating at high speed …

A design method to suppress the disturbances by using a resonant filter for track-following
control has been developed. The resonant filter can realize a stable resonant mode by a …

In this article, we present a magnetic-head positioning system in hard disk drives (HDDs)
with a quadruple-stage actuator system. The quadruple-stage actuator system consists of a …

We have developed a loop-shaping methodology for robust control design in single-input
single-output (SISO) systems with structured and unstructured uncertainties. This design …

High-precision stages are industrial equipment used in micro-fabrications. Fast and precise
positioning control is a very important technology for improving the throughput and the …

We have developed a user-friendly loop-shaping method employing the Robust Bode
(RBode) plot for optimizing the head-positioning system in a hard disk drive (HDD). The …

The best way to enhance the input/output (I/O) performance of a hard disk drive is by
increasing the spindle speed. Therefore, the effect of windage vibrations caused by the …

To decrease the seek time of hard disk drives, a feedforward control method was developed
by using a sampled-data polynomial. The sampled-data polynomial satisfies the boundary …

In conventional hard disk drives, a control system compensates for vibration in which the
frequency is higher than the Nyquist frequency by using a multi-rate filter that decreases the …

In conventional hard disk drives, a control system compensates for the mechanical
resonance above the Nyquist frequency by using sampled-data control theories or multirate …