• Title/Summary/Keyword: reduced-order control

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Vibration Control of Plates Using Resonant Shunted Piezoelectric Material (공진분기회로를 이용한 평판의 진동제어)

  • Kim, Young-Ho;Park, Chul-Hue;Park, Hyun-Chul
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.881-886
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    • 2003
  • Vibration control of plates with a passive electrical damper is presented in this paper. This electrical absorber, piezoelectric patches connected with a resistor and an inductor in series, is analogous to the damped mechanical vibration absorber. For estimating the effectiveness of piezoelectric absorber, the governing equations of motion are derived using a classical laminate plate theory and Hamilton principle. The developed theoretical analyses are validated experimentally for simply-supported aluminum plates in order to demonstrate the performance of passive electrical damper. The result shows that the vibration amplitude is reduced about 14dB for the targeted first vibration mode.

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A Study of Position Control and Design for Microelectrostatic Mechanical Actuator (미세 작동기의 설계 및 위치 제어에 관한 연구)

  • Choi, Won-Seok;Jee, Tea-Young;Kim, Kun-Nyun;Park, Hyo-Derk;Heo, Hoon
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.911-916
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    • 2003
  • Microactuator is frequently used in some optical or electrical applications such as light modulators and spatial scanner devices. When microactuator is implemented, it should be operated at accurate positions proportional to input voltage. Therefore in order to obtain rapid responses and reduced errors, a position control technique is used. In the paper, design procedure for the mems actuator and a typical PID controller is adapted to improve performance of microactuator as well. Also electrostatic force for the torsional microactuator is calculated via well-known Hornbeck's method.

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Visual-Servoing Control of Robot Manipulator (로봇 매니퓰레이터의 시각구동제어)

  • 신행봉;정동연;한성현
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.213-218
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    • 2003
  • The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS). We can save much efforts and time in adjusting robots to newly defined workcells by using OLPS. A proposed visual calibration scheme is based on position-based visual feedback. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test and construction of simple silhouette figures. Then camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

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Improvement of Tracking Accuracy of Positioning Systems with Iron Core Linear DC Motors

  • Song, Chang-Kyu;Kim, Gyung-Ho
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.1
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    • pp.31-35
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    • 2005
  • Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or reduced. In order to reduce motor ripple, this research adapted the feedforward compensation method and neural network control. Experiments carried out with the linear motor test setup show that these control methods are effective in reducing motor ripple.

Vibration Control of Plates Using Resonant Shunted Piezoelectric Material (공진분기회로를 이용한 평판의 진동제어)

  • Kim, Young-Ho;Park, Chul-Hue;Park, Hyun-Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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    • pp.1778-1784
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    • 2003
  • Vibration control of plates with a passive electrical damper is presented in this paper. This electrical absorber, piezoelectric patches connected with a resistor and an inductor in series, is analogous to the damped mechanical vibration absorber. For estimating the effectiveness of piezoelectric absorber, the governing equations of motion are derived using a classical laminate plate theory and Hamilton principle. The developed theoretical analysis is validated experimentally for a simply-supported aluminum plate in order to demonstrate the performance of passive electrical damper. The result shows that the vibration amplitude is reduced about 14dB for the targeted first vibration mode.

Force Limited Vibration Tests of Micro-Satellites (힘제한 방법을 이용한 소형 위성의 진동시험)

  • 김영기;김홍배;김경운;우성현;김성훈;문상무
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.446-451
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    • 2004
  • Over testing problems of satellites and theirs components have been issued due to their effects on satellite development cost and schedule. Force limited vibration tests were introduced as solution of the problems in 1980s. Over testing phenomena occurs due to the lack of similarity on interface impedance. Force limited vibration tests control interface force to simulate actual interface impedance. In this research, force limited vibration tests are applied on two satellites environmental tests. Force limits are calculated by using TDFS method and Semi-Empirical method. Four force sensors are employed to control interface force. The tests prove that force limited control reduced maximum interface acceleration in order of 3.

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Estimation of Tire-Road Friction Coefficient using Observers (관측기를 이용한 노면과 타이어 간의 마찰계수 추정)

  • 정태영;이경수;송철기
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.6
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    • pp.722-728
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    • 1998
  • In this paper real-time estimation methods for identifying the tire-road friction coefficient are presented. Taking advantage of the Magic Formula Tire Model, the similarity technique and the specific model for the vehicle dynamics, a reduced order observer/filtered-regressor-based method is proposed. The Proposed method is evaluated on simulations of a full-vehicle model with an eight state nonlinear vehicle/transmission model and nonlinear suspension model. It has been shown through simulations that it is possible to estimate the tire-road friction from measurements of engine rpm, transmission output speed and wheel speeds using the proposed identification method. The proposed method can be used as a useful option as a part of vehicle collision warning/avoidance systems and will be useful in the implementation of a warning algorithm since the tire-road friction can be estimated only using RPM sensors.

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Numerical Study on Flow Characteristics of Synthetic Jet with Slot Exit (Synthetic Jet 출구 형상의 변화에 따른 유동 특성 파악을 위한 수치적 연구)

  • Kim, Min-Hee;Kim, Woo-Re;Kim, Chong-Am
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.356-361
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    • 2011
  • The flow characteristics of synthetic jet depending on rectangular and circular jet exit configuration are investigated using numerical computation with cross flow. In rectangular slot, synthetic jet generates the strong vortex, however, supply fewer momentum and effectiveness of flow control is reduced along flow direction. In circular slot, regular vortex is fanned from slot center to end and developed in flow direction. It affects the wider region than rectangular slot. The distribution of wall shear stress is considered in order to indicate the effectiveness of flow control device for flow separation delay. As a result, circular slot is a more suitable candidate for delaying flow separation.

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Studdy for Force Ripple Suppression of the Iron Core Linear Motors (철심형 리니어모터의 추력 리플 억제에 관한 연구)

  • 송창규;김정식;김경호;박천홍
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.358-362
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    • 2004
  • Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or reduced. In order to reduce motor ripple, this research adapted the feedforward compensation method and neural network control. Experiments carried out with the linear motor test setup show that these control methods are effective in reducing motor ripple.

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Vibration Control of Real-Size Steel Structure by Hybrid Linear Motor Damper (혼합형 리니어 모터 댐퍼를 이용한 실규모 철골 구조물의 진동제어)

  • 정정교;김두훈;박해동;박진일;정태영;문석준;임채욱
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.740-745
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    • 2002
  • To control vibration of real-size steel structure, a hybrid-type linear motor damper was designed and applied to 30m steel structure at UNISON. The LMD was tuned to the first mode natural frequency of the building. In order to use for simulation data and control parameters, dynamic response characteristics of building and damper were tested. The response of building was reduced by 10 dB with LMD and H$\infty$ algorithm. This value was similar to the result of simulation.

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