Advanced unloading analysis considering lateral velocity and disk RPM drop in emergency parking

Yonghyun Lee, Ki Hoon Kim, Seokhwan Kim, No Cheol Park, Young Pil Park, Kyoung Su Park, Cheol Soon Kim, Jingyoo Yoo

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


A conventional unloading analysis was carried out in no consideration for fast lateral velocity and disk rpm drop during the emergency parking. However, current hard disk drive (HDD) systems need an improved performance in the portable aspect. Therefore, much faster emergency parking is absolutely necessary to protect the system from sudden power-off or an external shock. In case of fast emergency parking, the fast lateral velocity causes an effective skew, and then there is a flying height (FH) loss which does not occur in a normal unload. Also, the FH loss induced by a disk rpm drop occurs at an unloading point in case that a portable small form factor HDD like 1.8 in is suddenly parking from inner diameter to outer diameter. This means that the unloading performance considering the effective skew becomes lower than one of the conventional unloading analysis. In this paper, we propose the advanced unloading analysis that can be applied to the fast emergency parking velocity. To do so, we investigate the FH loss by the fast lateral velocity and the disk rpm drop, and introduce the result of the advanced unloading analysis.

Original languageEnglish
Article number5297532
Pages (from-to)4937-4940
Number of pages4
JournalIEEE Transactions on Magnetics
Issue number11
Publication statusPublished - 2009 Nov

Bibliographical note

Funding Information:
This work was supported by the Korea Science and Engineering Foundation (KOSEF) by a Grant funded by the Korea government (MEST) (No. R17-2008-040-01001-0).

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


Dive into the research topics of 'Advanced unloading analysis considering lateral velocity and disk RPM drop in emergency parking'. Together they form a unique fingerprint.

Cite this