• Title/Summary/Keyword: control vibration

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Evaluation of Vibration Control Performance of Outrigger Damper System for Tall Buildings Subjected to Seismic Load (아웃리거 댐퍼시스템의 고층건물 지진응답제어 성능 평가)

  • Yoon, Sung-Wook;Lee, Lyeong-Kyeong;Kim, Kwang-Il;Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.1
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    • pp.95-104
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    • 2016
  • Recently, the concept of damped outrigger system has been proposed for tall buildings. But, structural characteristics and design method of this system were not sufficiently investigated to date. In this study, the dynamic response control performance of outrigger damper has been analyzed. To this end, a simplified analysis model with outrigger damper system has been developed. Use the El Centro seismic(1940, NS) analysis was performed. Analysis results, on the top floor displacement response to the earthquake response, did not have a big effect. However, acceleration response control effect was found to be excellent. The increase of outrigger damper capacity usually results in the improved control performance. However, it is necessary to select that proper stiffness and damping values of the outrigger damper system because, the outrigger damper having large capacity is result in heavy financial burden.

An Experimental Study on the Stochastic Control of a Aeroelastic System (공탄성시스템의 확률론적 제어에 대한 실험적 연구)

  • Kim, Dae-Jung;Park, Sang-Tae;Jeong, Jae-Uk;Heo, Hun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.11 s.170
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    • pp.2007-2013
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    • 1999
  • A Newly proposed control methodology applied to the aeroelastic system experiencing flutter is investigated and its performance is verified experimentally. The flexible cantilever beam slicked with piezofilm sensor and piezoceramic actuator is modelled in physical domain. Dynamic moment equation for the system is derived via Ito's stochastic differential equation and F-P-K equation. Also system's characteristics in stochastic domain is analyzed simultaneously. LQG controller is designed and used in physical and stochastic domain. It is shown experimentally that the vibration of beam is controlled effectively by designed LQG controller in physical domain. By comparing the result with that of LQG controller designed in stochastic domain, it is shown that the new control method, called Heo-stochastic control technique, has better performance as a controller.

Vibration Control of a Building Structure with a Tuned Liquid Damper Using Real-Time Hybrid Experimental Method (실시간 하이브리드 실험법을 이용한 동조액체댐퍼가 설치된 건물의 진동제어)

  • Lee Sung-Kyung;Lee Sang-Hyun;Min Kyung-Won;park Eun-Churn;Woo Sung-Sik;Chung Lan
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.256-263
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    • 2006
  • In this paper, an experimental hybrid method, which implements the earthquake response control of a building structure with a TLD(Tuned Liquid Damper) by using only a TLD as an experimental part, is proposed and is experimentally verified through a shaking table test. In the proposed methodology, the whole building structure with a TLD is divided into the upper TLD and the lower structural parts as experimental and numerical substructures, respectively. At the moment, the control force acting between their interface is measured from the experimental TLD with shear-type load-cell which is mounted on shaking table. Shaking table vibrates the upper experimental TLD with the response calculated from the numerical substructure, which is subjected to the excitations of the measured interface control force at its top story and an earthquake input at its base. The experimental results show that the conventional method, in which both a TLD and a building structure model are physically manufactured and are tested, can be replaced by the proposed methodology with a simple experimental installation and a good accuracy for evaluating the control performance of a TLD.

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A Study about Modeling and Control of Dynamic Absorber for Vehicle by Using Active Viscous Damping (능동적 점성감쇠를 이용한 차량용 동적 흡진기의 모델링과 제어에 관한 연구)

  • 김대원;배준영
    • Journal of KSNVE
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    • v.9 no.1
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    • pp.121-130
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    • 1999
  • Generally, A Dynamic Absorber by using Active viscous Damping is highlighted for effective suspension system, such as improved ride comfort and handling in the market. Lately, this system based on the Sky-Hook damper theory is introduced by the name of "Active Dynamic Absorber" to us. This system has an excellent performance in contrast to Passive. Adaptive Dynamic Absorber, besides having low cost components of system, low energy consumption. light weight of system. In this viewpoint. most of car-maker will adopt this system in the near future. For this reason, we developed Dynamic Absorber by using Active viscous Damping which is equipped with continuously variable Dynamic Absorber and Control logic consisting Filter and Estimator. control apparatus of Dynamic Absorber operated by 16-bit microprocessor of high performance. variable device of viscous Damping. G-sensor so on. In this paper. several important points of development procedure for realizing this system will be described with results in which is obtained from experiment by simulation and Full car test in Proving ground. respectively.pectively.

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The Displacement Control of a Belt Drive System using LQ Servo Controller (LQ 서보제어기를 이용한 벨트구동 시스템의 변위제어)

  • Kwon Se-Hyun
    • Journal of the Korea Computer Industry Society
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    • v.7 no.3
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    • pp.155-162
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    • 2006
  • Because of their lower cost, higher speed, and longer travel, a belt drive system are quite desirable over screw driven system. However, a belt drive system are inherently difficult to control due to belt flexibility, friction, vibration, backlash and other non-linearities. This thesis presents servo control algorithm and the designing method of controller appliable to a belt drive system. In this paper, a LQ servo controller for a belt drive system is proposed to accomplish an optimal design of improved control system. In this scheme a mathematical model for the control system is obtained in state space form. Finally, the effectiveness of the proposed servo controller was verified through the computer simulation results.

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A Study on Dynamic Characteristics of Rotating Transmission Using PID Control (PID 제어기를 이용한 회전전동장치의 동특성에 관한 연구)

  • Kim Jae-Kyung;Kim Jong-Tye;Kim Taek-Hyun
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.5
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    • pp.41-48
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    • 2005
  • The Rotating transmission is made up of belts, mass disks and gears. This transmission is controlled electro-mechanically by the motor and operation program. The control strategy of the system can be to change belts' stiffness and the masses of mass disk and gear. This system can be modeled as a rigid body, and also finds broad application in such diverse fields as machine tools, the cruise control system In automobiles, and control in the attitude and gimbals of spacecraft. This Transmission proves the necessity and effect of a closed loop control. The study of the Rotating Transmission excited by its base motion is able not only to predict the rotational performance, but to obtain the fundamental data for vibration isolation. In this research, we compared the response characteristics of the two controllers by means of the experiments on PD controller and PID controller added on integral action. Furthermore, we studied the response abilities such as steady state error, overshoot, and ect. and the response velocities such as rising time, settling time, and ect. in the rotating transmission.

Automatic Tension Control of a Timber Carriage Used for Biomass Collection

  • Choi, Yun-Sung;Oh, Jae-Huen;Euh, Seung-Hee;Oh, Kwang-Cheor;Choi, Hee-Jin;Kim, Dae-Hyun
    • Journal of Biosystems Engineering
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    • v.37 no.2
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    • pp.106-112
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    • 2012
  • Purpose: A lab-scale timber carriage using a servo motor system was built. When two motors move a carriage, wire tension is changed according to the different line speeds caused by a wire drum's changing diameter, leading to inappropriate traveling characteristics of the carriage. In order to overcome this problem, PID Control was used to control the motor speed. Methods: Ziegler-Nichols method was used to determine PID gains. Results: The initial PID gains were 1.8, 0.025, and 0.006, respectively, and optimal gains of 1.4 and 0.010 for P and I gain were obtained experimentally. Conclusions: The results showed that constant wire tension could be maintained by controlling the speed of the motor using PI control. Overshoot occurred at initial motor operation due to vibration and elasticity of the wire itself.

Design Method Development of Smart TMD for Retractable-Roof Spatial Structure (개폐식 대공간 구조물을 위한 스마트 TMD 설계기법 개발)

  • Kim, Hyun-Su;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.3
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    • pp.107-115
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    • 2017
  • In this paper, a structural design method of a smart tuned mass damper (TMD) for a retractable-roof spatial structure under earthquake excitation was proposed. For this purpose, a retractable-roof spatial structure was simplified to a single degree of freedom (SDOF) model. Dynamic characteristics of a retractable-roof spatial structure is changed based on opened or closed roof condition. This condition was considered in the numerical simulation. A magnetorheological (MR) damper was used to compose a smart TMD and a displacement based ground-hook control algorithm was used to control the smart TMD. The control effectiveness of a smart TMD under harmonic and earthquake excitation were evaluated in comparison with a conventional passive TMD. The vibration control robustness of a smart TMD and a passive TMD were compared along with the variation of natural period of a simplified structure. Dynamic responses of a smart TMD and passive TMD under resonant harmonic excitation and earthquake load were compared by varying mass ratio of TMD to total mass of the simplified structure. The design procedure proposed in this study is expected to be used for preliminary design of a smart TMD for a retractable-roof spatial structure.

On the control of vibratory MEMS gyroscopes

  • Choura, S.;Aouni, N.;El-Borgi, S.
    • Smart Structures and Systems
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    • v.6 no.7
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    • pp.793-810
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    • 2010
  • This paper addresses the control issue of vibratory MEMS-based gyroscopes. This study considers a gyroscope that can be modeled by an inner mass attached to an outer mass by four springs and four dampers. The outer mass itself is attached to the rotating frame by an equal number of springs and dampers. In order to measure the angular rate of the rotating frame, a driving force is applied to the inner mass and the Coriolis force is sensed along the y-direction associated with the outer mass. Due to micro-fabrication imperfections, including anisoelasticity and damping effects, both gyroscopes do not allow accurate measurements, and therefore, it becomes necessary to devise feedback controllers to reduce the effects of such imperfections. Given an ideal gyroscope that meets certain performance specifications, a feedback control strategy is synthesized to reduce the error dynamics between the actual and ideal gyroscopes. For a dual-mass gyroscope, it is demonstrated that the error dynamics are remarkably decreased with the application of four actuators applied to both masses in the x and y directions. It is also shown that it is possible to reduce the error dynamics with only two actuators applied to the outer mass only. Simulation results are presented to prove the efficiency of the proposed control design.

Design of piezoelectric transducer arrays for passive and active modal control of thin plates

  • Zenz, Georg;Berger, Wolfgang;Gerstmayr, Johannes;Nader, Manfred;Krommer, Michael
    • Smart Structures and Systems
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    • v.12 no.5
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    • pp.547-577
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    • 2013
  • To suppress vibration and noise of mechanical structures piezoelectric ceramics play an increasing role as effective, simple and light-weighted damping devices as they are suitable for sensing and actuating. Out of the various piezoelectric damping methods this paper compares mode based active control strategies to passive shunt damping for thin plates. Therefore, a new approach for the optimal placement of the piezoelectric sensors/actuators, or more general transducers, is proposed after intense theoretical investigations based on the Kirchhoff kinematical hypotheses of plates; in particular, modal and nilpotent transducers are discussed in detail. Based on the proposed distribution a discrete design for modal transducers is implemented, tested and verified on an experimental setup. For active control the modal sensors clearly identify the eigenmodes, whereas the modal actuators impose distributed eigenstrains in order to reduce the transverse plate vibrations. In contrast to the modal control, passive shunt damping works without requiring additional actuators or auxiliary power and can therefore act as an autonomous system, but it is less effective compensating the flexible vibrations. Exemplarily, an acryl glass plate disturbed by an arbitrary force initialized by a loudspeaker is investigated. Comparing the different methods their specific advantages are highlighted and a significant broadband reduction of the vibrations of up to -20dB is obtained.