• Title/Summary/Keyword: Dual Stage

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Bond Graph Modeling, Analysis and Control of Dual Stage System (본드그래프를 이용한 듀얼 스테이지 시스템의 모델링, 해석, 및 제어)

  • Wang, Wei-Jun;Han, Chang-Soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1453-1459
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    • 2012
  • The dual stage manipulator is composed of the voice coil motor (VCM) and piezoelectric ceramics transducer (PZT), which can produce the high precise displacement and express a well dynamic performance. However, inaccurate modeling of the dual stage will exacerbate the positioning accuracy. This paper presents an approach to model the dual stage system by using bond graph theory. And the state space equations can be derived through the bond graph straightforwardly, which can be used in computing simulations. Through designing the compensators for the dual stage system and simulating, the dual stage performs better dynamics characteristic than the single actuator system.

Robust Minimum-Time Control with Coarse/Fine Dual-Stage Mechanism

  • Kwon, Sang-Joo;Cheong, Joo-No
    • Journal of Mechanical Science and Technology
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    • v.20 no.11
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    • pp.1834-1847
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    • 2006
  • A robust minimum-time control (RMTC) strategy is addressed and it is extended to the dual-stage servo design. Rather than conventional switching type sub-optimal controls, it is a reference following control approach where the predetermined minimum-time trajectory (MTT) is tracked by the perturbation compensator based feedback controller. First, the minimum-time trajectory for a mass-damper system is derived. Then, the perturbation compensator to achieve robust tracking performance in spite of model uncertainty and external disturbance is suggested. The RMTC is also applied to the dual-stage positioner which consists of coarse actuator and fine one. To best utilize the actuation redundancy of the dual-stage mechanism, a null-motion controller to actively regulate the relative motion between the two stages is formulated. The performance of RMTC is validated through simulation and experiment.

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

  • 문정호;도태용
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.4
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    • pp.277-283
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    • 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.

Design of Dual-Stage Actuator Controller for Hard Disk Drive using Piezoelectric Microactuator (압전형 초소형 구동기를 이용한 하드 디스크 드라이브의 Dual-stage 구동기 제어기 설계)

  • 김종철;정정주
    • 제어로봇시스템학회:학술대회논문집
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    • pp.173-173
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    • 2000
  • This paper discusses a observer based discrete-time controller design and presents a modified control structure for dual-stage hard disk drive systems using piezoelectric microactuator(MA). In plant modeling, dynamic coupling between VCM and MA is not considered. Each controller is organized independently and designed using pole placement. Simulation result shows that 4th-order controller achieves about 3kHz servo bandwidth and 0.22msec of 2% settling time.

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Robust Time-Optimal Control for Coarse/Fine Dual-Stage Systems

  • Kwon, Sang-Joo;Chung, Wan-Kyun;Youngil Youm
    • 제어로봇시스템학회:학술대회논문집
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    • pp.317-320
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    • 1999
  • A robust end time optimal conかof strategy for dual-stage servo system is presented. The time optimal trajectory for a mass-damper system is determined and given os a reference input to the servo system. The feedback controller is constructed so that the fine stage tracks the coarse stage errors and robustly designed as the“perturbation compensated sliding mode control(PCSMC)”law, a combination of slid-ing mode controller(SMC) and perturbation observer(PO). In addition, a null motion controller which regulates the fine stage at its neutral position is designed based on the“dynamic consistency”So, the overall dual-stage servo system exhibits the robust and time-optimal performance. The inherent merit and performance of the dual-stage system will be shown.

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Dual Stage Servo Controller for Image Tracking System (듀얼 스테이지 서보 시스템을 이용한 영상 추적장치의 정밀제어)

  • Choi, Young-Joon;Kang, Min-Sig
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.2
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    • pp.86-94
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    • 2007
  • In this paper, a dual stage servo mechanism has been developed for image tracking system to improve control performances such as small rise time, small overshoot, small settling time, small stabilization error etc. A secondary stage, a platform, actuated by a pair of electro-magnets is mounted on a conventional elevation gimbal. In this mechanism, the gimbal provides large range but slow motion and the platform provides small range but fast positioning. A sliding mode control is applied to the platform positioning to attain robust performances and stability in the presence of the disturbance related to dynamic coupling of the gimbal and the platform. Results from experiments illustrate that the suggested dual stage mechanism controlled by the sliding mode control is effective in improving responses and attenuating the disturbance response related with dynamic coupling.

AN OPTIMUM DESIGN METHOD OF DUAL-STAGE AGE-ACTUATORS FOR MINIMUM SEEK TIMES (최소 탐색시간을 위한 2단 구동기의 최적설계법)

  • Kim, Sun-Mo;Gweon, Dae-Gab
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.1533-1539
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    • 2000
  • In this paper, we propose a design method using Taguchi method and a neural network. Using this method, we can design a dual-stage actuator having the required tracking/focusing properties in real time. Also, as an application of this method, a proposed dual-stage pick-up actuator having the required properties was designed. The seek time of this designed actuator is less than 13 msec by a time optimal technique. Simulation results show that this method can potentially be implemented in all the dual-stage actuators.

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