An Analysis Method of Head Positioning Error for Magnetic Disk Drives. An Analysis Method of PES in Track-Following Mode.

Numasato, H.; Usui, K.; Hamada, Yosuke; Yamaguchi, Takashi

doi:10.1299/kikaic.65.3245

Cited by 16 publications

(8 citation statements)

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“…(10) (11) (12) (13) (9) mental data shown by dotted lines. These identification data exhibit a flat phase characteristic in the low-frequency range as well, which agrees well with the theory.…”

Section: Modeling Of Hdd Using Differential Iteration Methodsmentioning

confidence: 99%

High‐precision positioning control for hard disk drives: 1st report: High‐precision simulator using differential iteration method

Kawafuku

Otsu

Iwasaki

et al. 2007

Electrical Engineering Japan

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SUMMARYThe paper proposes a high-precision simulator for the following mode system design in hard disk drives (HDDs). The simulator is composed of two models: one is a precise mechanical plant which includes numerous high-frequency vibration modes, and the other is a disturbance signal model which is separated into various disturbances. In the proposed approach, a differential iteration method is applied to identify the precise mechanical plant, providing accurate experimental model analyses. The effectiveness of the syn-

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Section: Modeling Of Hdd Using Differential Iteration Methodsmentioning

confidence: 99%

High‐precision positioning control for hard disk drives: 1st report: High‐precision simulator using differential iteration method

Kawafuku

Otsu

Iwasaki

et al. 2007

Electrical Engineering Japan

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show abstract

“…According to this system, the position disturbance caused by circuit noise (dp) is strongly affected by the Kp varying in the off-track direction. In this block diagram, df, dp, and dm can be sources of NRRO (Numasato et al 1999). As previously mentioned, the Kp value tends to increase and decrease periodically.…”

Section: Criterion In the Off-track Directionmentioning

confidence: 99%

“…These problems degrade the quality of the position signal, increasing the non-repeatable runout (NRRO) in the servo loop of the head positioning system (Numasato et al 1999) and the repeatable runout (RRO) in servo writing system and thus degrading the accuracy with which the magnetic heads can be positioned. Position-signal nonlinearity, for example, reduces the positioning sensitivity of the following-control loop and can destabilize the control system.…”

Section: Introductionmentioning

confidence: 99%

Optimizing servo-signal design for a hard-disk drives

2005

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To improve the non-repeatable runout (NRRO), repeatable runout (RRO), and nonlinearity of the position signal in hard-disk drives (HDDs), we established criteria for the off-track direction and for the bit direction. Position-signal nonlinearity and NRRO degradation are largely due to the interaction between track width, erase band size, and the sensitivity distribution of the head. So one criterion is for position-signal sensitivity. The other criterion is for burst-bit density, which causes RRO degradation. Using these criteria to compare, theoretically and experimentally, the effectiveness with which the quality of the position signal could be maintained using amplitude and phase patterns confirmed that the phase pattern is superior to the amplitude pattern.

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“…A comprehensive identification and analysis of each disturbance component can be found in reference (Numasato et al, 1999) and (Abramovitch et al, 1998). The frequency characteristics of each disturbance is shown in Fig is known that d f and d p are almost random signal.…”

Section: Identification Of Disturbancesmentioning

confidence: 99%

Rejection of Repeatable Run-Out in HDDS Using Inverse Frequency Dynamics

Kawafuku

Iwasaki

Hirai

et al. 2005

IFAC Proceedings Volumes

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In order to suppress the Repeatable Run-Out (RRO) of a following control system in HDDs is quite effective to increase the disk density. Many approaches were presented in former literatures, e.g. by applying adaptive filters and/or repetitive controllers. These approaches, however, require the complicated design in structures and parameters, preventing the controller design from saving time and labor. This paper presents a novel algorithm to suppress the effects of RRO on following control performance. In the proposed algorithm, the FFT (Fast Fourier Transform) is applied to identify a frequency characteristic of RRO. Based on the identified characteristics, an inverse system in frequency domain can be achieved to reject the effect of RRO. Numerical simulations and experimental results show the effectiveness of the proposed control.

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An Analysis Method of Head Positioning Error for Magnetic Disk Drives. An Analysis Method of PES in Track-Following Mode.

Cited by 16 publications

References 0 publications

High‐precision positioning control for hard disk drives: 1st report: High‐precision simulator using differential iteration method

High‐precision positioning control for hard disk drives: 1st report: High‐precision simulator using differential iteration method

Optimizing servo-signal design for a hard-disk drives

Rejection of Repeatable Run-Out in HDDS Using Inverse Frequency Dynamics

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