Identification of the Spectrum Signature of Air-Bearing Slider Dynamics

Abstract

Characterization of the motion of air-bearing slider with sub-10-nm clearance is becoming a critical aspect of developing advanced head-disk interfaces (HDI) in hard disk drives to achieve higher areal data densities. In this article, the response of sub-10-nm clearance air-bearing slider induced by a bump contact is recorded using laser Doppler vibrometer (LDV). To identify system dynamics in terms of spectral decomposition, the slider response is studied using FFT, power spectrum density, spectrogram, and Hilbert instantaneous spectrum analysis. The results demonstrate that the response of air-bearing slider in instantaneous contact exhibits nonstationary and nonlinear properties which can be accurately identified using Hilbert instantaneous spectrum. The interpretation and spectrum identification based on Fourier analysis and its extension in time-frequency domain could lead to inaccurate results due to their limitation in resolution and linearity assumption.

Friction-Induced Noise and Vibrations: Diagnosis and Prognosis

“…The prognostics and health management and health monitoring technology have been fully developed by the professional community of electronics, aerospace and civil engineering [48,49]. In [50][51][52][53][54][55][56], a framework of diagnosis and prognosis has been implemented and developed for contact/frictioninduced vibrations of near contact slider in hard disk drive system. The similar technology can be applied to tackle with frictioninduced friction and noise problems in automotive systems.…”

Sensing and Identification of Nonlinear Dynamics of Slider with Clearance in Sub-5 Nanometer Regime

“…The recent implementation of the contemporary nonlinear identification methods offers some promising approaches to identify certain core parameters of slider dynamics in sub-5 nanometer clearance regime by using experimental data [121][122][123][124][125]. In [121], the nonstationary and nonlinear response of sub-10-nm clearance air-bearing slider induced by a bump contact is recorded using laser Doppler vibrometer (LDV) and studied using FFT, power spectrum density, spectrogram, and Hilbert instantaneous spectrum analysis. When the response amplitude is relatively large, TFA plot can reveal fundamental frequency and harmonics of nonlinear vibrations with a relatively low resolution.…”