• 제목/요약/키워드: disk drives.

검색결과 214건 처리시간 0.024초

정보저장기기용 회전디스크의 임계속도 및 플러터 속도에 관한 연구 (Critical and Flutter Speeds of Rotating Disks in Information Storage Devices)

  • 이승엽;윤동화
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2001년도 춘계학술대회논문집
    • /
    • pp.484-489
    • /
    • 2001
  • Recent trends in information storage devices disk are the transition from CD drives to high density DVD drives, the development of writable disk drives and the appearance of several high-density portable disk drives. In some flexible disk drives, self-excited disk vibrations become severe as rotation speed increases near or above critical speed. Critical speeds of CD/DVD, ASMO and floppy disks are experimentally measured and compared with analytical predictions. Flutter instability caused by aero-induced disk vibration at high speeds are experimentally observed. In ASMO, three nodal-diameter mode experiences its flutter at 8750 rpm with the frequency lock-on phenomenon. The CD/DVD disk does not have the aero-induce flutter up to 14,000 rpm.

  • PDF

광디스크 드라이브의 충격해석 (Shock Analysis of Optical Disk Drives)

  • 홍석준;장영배;박노철;박영필
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2003년도 추계학술대회논문집
    • /
    • pp.412-417
    • /
    • 2003
  • As optical disk drives become designed for portable and hostile environment, higher storage density and smaller size, optical disk drives have a possibility to miss the track and not to read the data. This paper presents the modeling of an optical disk drive as 3-DOF system. Optical disk drives are tested with a linear drop test device and their results are compared with simulation results in order to verify the shock analysis. Finally, this paper shows shock response of a optical disk drive with changes of parameters

  • PDF

초소형 광자기 드라이브용 HGA의 동적 충격 시뮬레이션 (Dynamic Shock Simulation of Head-gimbal Assembly in Micro MO Drives)

  • 오우석;홍어진;박노철;양현석;박영필
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2004년도 춘계학술대회논문집
    • /
    • pp.189-194
    • /
    • 2004
  • As a disk drive becomes widely used in portable environments, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes In contact with outer shock disturbance, the system gets critical damage in head-gimbal assembly or disk. This paper describes analysis of a HGA(head-gimbal assembly) in micro MO drives to shock loading during both non-operating state and operating state. A finite element model which consists of the disk, suspension, slider and air bearing was used to find structural response of micro MO drives. In the operational case. the air bearing is approximated with four linear elastic springs. The commercially available finite element solver, ANSYS/LS-DYNA, is used to simulate the shock response of the HGA in micro MO drives. In this paper, the mechanical robustness of the suspension is simuiated considering the shock responses of the HGA.

  • PDF

광디스크 드라이브 공기베어링 슬라이더의 최적설계를 위한 형상민감도 해석 (Shape Sensitivity Analysis for the Optimal Design of Air Bearing Sliders of Optical Disk Drives)

  • 김현기;장혁;김광선;임경화;정태건
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2000년도 추계학술대회논문집
    • /
    • pp.742-747
    • /
    • 2000
  • The optical storage device has recently experienced significant improvements, especially for the aspects of high capacity and fast transfer rate. However, it is the fact that the optical storage device has the lower access time for the randomly scattered data compared to the hard disk drives. It is, therefore, necessary to develop a new type of optical storage system. In this study, we investigate the air bearing characteristics for the optical disk drives which have the swing arm actuator similarly to the hard disk drives. Considering the requirements of the optical disk drives, we parametrize the shape of the air bearing surface and investigate its sensitivity to the flying characteristics for further optimized design outputs.

  • PDF

광디스크 드라이브의 최근 동향과 기계적 진동의 영향 (MECHANICAL VIBRATIONS IN OPTICLA DISK DRIVES)

  • 이승엽
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
    • /
    • pp.218-226
    • /
    • 1998
  • Recent trends and the effect of mechanical vibrations in optical disk drives are reviewed in this paper. The Nation from CD drives to high density DVD drives and the development of writable optical disk drives require tighter mechanical tolerance. The demand for faster access time and higher data transfer rate also leads to critical mechanical problems to limit the tracking and focusing servo performance. The current mechanical issues to limit the performance of the drives and various technologies to overcome the mechanical problems are introduced. Vibrations of disk-spindle system, actuator and suspension designs of the optical pick-up, and general mechanical designs for the fast and stable access mechanism are considered.

  • PDF

광 디스크 드라이브의 공력소음 감소에 관한 연구 (A Study on Reduction of Sound Noise Induced by Disk Rotation in Optical Disk Drives)

  • 송인상;박건순;최학현;김수경;이승엽
    • 소음진동
    • /
    • 제9권4호
    • /
    • pp.693-702
    • /
    • 1999
  • We study the characteristics of airflow and sound noise induced by disk rotation in optical disk drives. The characteristics of airflow around a rotating disk surrounded by various tray structures are numerically investigated using a commercial CFD program and then compared with experimental results. Sound pressure and intensity caused by the fluid-structure interactions in the CD/DVD-ROM drive are measured, and the effect of the ariflow on the sound noise and disk vibration is discussed. In order to reduce airflow-induced noise and vibration around the rotating disk, tray geometry is modified. Both numerical and experimental studies implemented with different tray models show that the improved tray model alters the characteristics of the disk-induced airflow, causing the reduction of the airflow-induced sound level.

  • PDF

디스크 드라이브의 주기적 외란 고속 보상 제어 (Fast Compensator of Periodic Disturbance in Disk Drives)

  • 부찬혁;김호찬;강창익
    • 제어로봇시스템학회논문지
    • /
    • 제10권2호
    • /
    • pp.153-163
    • /
    • 2004
  • The control objective in hard disk drives is to move head as fast as possible to target track and position the head over the center of target track in the presence of external disturbances. The external shock or disk clamping error in manufacturing process causes the disk center to deviate from the disk rotation center. The disk shift acts on the control system as disturbance and degrades severely the performance of disk drives. In this paper, we present a new controller that compensates for the periodic disturbances very fast. The disturbance compensator is arranged in parallel with the state feedback controller. To avoid the interference with the state feedback controller, the compensator creates compensation signal without the feedback of system output until steady state. The pulse type controller is included additionally for improving the transient performance due to initial state. Finally, in order to demonstrate the superior performance of the proposed compensator. we present some experimental results using a commercially available disk drive.

반복 학습 제어를 이용한 NFR 디스크 드라이브의 2단 서보 시스템 (A Dual-Stage Servo System for an NFR Disk Drive using Iterative Learning Control)

  • 문정호;도태용
    • 제어로봇시스템학회논문지
    • /
    • 제9권4호
    • /
    • pp.277-283
    • /
    • 2003
  • Recently, near-field recording (NFR) disk drive schemes have been proposed with a view to increasing recording densities of hard disk drives. Compared with hard disk drives. NFR disk drives have narrower track pitches and are exposed to more severe periodic disturbances resulting from eccentric rotation of the disk. It is difficult to meet servo system design specifications for NFR disk drives with conventional VCM actuators in that the servo system for an NFR disk drive generally requires a feater gain and higher bandwidth. To tackle the problem various dual-stage actuator systems composed of a microactuator mounted on top of a conventional VCM actuator have been proposed. This article deals with the problem of designing a tracking servo system far an NFR disk drive adopting a dual-stage actuator. We summarize design constraints pertaining to the dual-stage servo system and present a new servo scheme using iterative teaming control. We design feedback compensators and an iterative teaming controller for a target plant and verify the validity of the proposed control scheme through a computer simulation.

디스크와 픽업을 고려한 광디스크 드라이브의 충격응답해석 (Shock Response Analysis of the Optical Disk Drive in Consideration of Disk and Pick up)

  • 신은정;장영배;박노철;박영필
    • 한국소음진동공학회논문집
    • /
    • 제14권12호
    • /
    • pp.1261-1267
    • /
    • 2004
  • As the optical disk drives are designed for portable and hostile environment, they have a possibility to miss the track and not to read the data. The shock response of optical disk drives must be analyzed. This research shows the shock response analysis of the optical disk drive. The optical disk drive is modeled as the lumped parameter system in consideration of the pickup and the disk. The lumped parameter model is compared with finite element model in order to verify results. Finally, shock responses are compared with the change of the shock magnitude and the duration.

광디스크 드라이브 공기베어링 슬라이더의 형상민감도 해석 (Shape Sensitivity Analysis of Air Bearing Sliders of Optical Disk Drives)

  • 김현기;장혁;김광선;임경화
    • 마이크로전자및패키징학회지
    • /
    • 제7권4호
    • /
    • pp.37-42
    • /
    • 2000
  • 고성능과 고속화의 면에서 광저장장치의 관심은 상당히 높다. 그러나 하드디스크와 비교하여 광저장장치는 임의의 데이터에 대한 탐색속도가 매우 늦다. 따라서, 광저장장치에서의 새로운 형태의 연구가 필요하다. 본 연구는 하드디스크 장치와 유사한 스윔 암 구동기를 사용한 광저장장치의 공기베어링의 특성에 관해 연구하였다. 광저장장치에서 요구되어지는 최적의 슬라이더 형상을 구하기 위하여 공기 베어링면의 형상변화에 따른 부상상태에 관한 민감도를 연구하였다.

  • PDF