Please use this identifier to cite or link to this item: http://scholarbank.nus.edu.sg/handle/10635/70112
Title: Efficient position encoding in hard disk drive using dual frequency servo bursts
Authors: Al Mamun, A. 
Heng, L.T. 
Hung, T.G.
Issue Date: 2001
Source: Al Mamun, A.,Heng, L.T.,Hung, T.G. (2001). Efficient position encoding in hard disk drive using dual frequency servo bursts. IECON Proceedings (Industrial Electronics Conference) 3 : 609-614. ScholarBank@NUS Repository.
Abstract: This paper presents a new scheme to encode the position information in hard disk drive. The conventional method uses amplitudes of 4 servo bursts, placed sequentially along the track (down-track direction), are used to find the displacement between the head and the centre of the track. Each of these bursts consists of equidistant, parallel magnetic transitions, forming a specific offset pattern in the direction of disk radius (cross-track). The read-back signal from each servo burst contains series of alternating Lorentzian pulses at fixed intervals. The amplitudes of the burst signals are functions of displacement between the head and the centre of the track. The demodulator finds the magnitude of read-ack pulses for each burst, and estimates the position error signal (PES) from there. Since all the bursts use same pattern of magnetic transitions, they are separated from each other in the down-track direction. This leaves empty spaces between burst patterns, increasing the servo overhead or the percentage of storage area used for servo information. The proposed servo pattern uses two different frequencies for two servo bursts, making it possible to place them at the same angular location. The read-back burst signals are contributions of the servo patterns having two different frequencies. The demodulator extracts the amplitude of each of these frequency components, which is then used for PES calculation. Several detection rules are used to extract the amplitude of each frequency, and the results are compared. The effectiveness of the scheme is shown using experimental results.
Source Title: IECON Proceedings (Industrial Electronics Conference)
URI: http://scholarbank.nus.edu.sg/handle/10635/70112
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

Page view(s)

24
checked on Dec 16, 2017

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.