• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.153-163
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• 1999

본 연구에서는 격자패널을 통한 소음전달을 감소시키기 위하여 외부 구조적 가진으로부터 유발된 경량 패널의 진동을 능동 제어하는 기법을 기술한다. 최적 되먹임제어기와 적응 앞먹임제어기가 결합된 혼합형 제어기가 진동제어기로 사용된다. 되먹임제어기는 주파수 영역의 모델규명법에 의해 추출된 다중 입/출력 패널진동계 모델에 대하여 LQG 최적기법을 이용하여 감쇠능을 향상시키도록 설계된다. 앞먹임제어기는 되먹임 궤환의 결합효과를 자동적으로 보정할 수 있는 제안된 학습법칙에 기초하여 패널의 잔류진동이 최소가 되도록 적응된다. 45.7${\times}$45.7${\times}$2.54 ${cm^3}$ 벌집형상의 고강도 패널, 4개의 관성형 구동기 및 이산신호처리장치에 의해 구현된 패널 진동계에 대한 능동제어 실험을 수행해 본 결과 600Hz 주파수대역에 대한 12dB 진동저감이 이루어 질 수 있었다.

• Journal of KSNVE
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• v.10 no.6
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• pp.1048-1058
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• 2000

Thipaper presents a methodology to suppress the vibration of thin rectangular plate clamped all edges using piezo-ceramic material as actuators and sensors. Dynamic characteristics of the structure bonded with distributed actuators/sensors are identified by the Multi-Input Multi-Output (MIMO) frequency domain modeling technique based on the experimental data. Hybrid control scheme is adopted and feedback controller is designed by LQG(Linear Quadratic Gaussian). Feedforward controller is adapted by multiple filtered -$x$ LMS(least mean square) algorithm. Experiment result demonstrates the effective reduction of the vibration label for both the transient and persistent external disturbances.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.4
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• pp.39-46
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• 2008

• Composites Research
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• v.14 no.1
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• pp.39-46
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• 2001

Experimental studies on the adaptive multi-mode vibration control of composite beams have been performed using neuro-controller. Neuro-controllers require too much computational burden, which blocks wide real-time applications of neuro-controllers. Therefore, in this paper, an adaptive notch filter is proposed to separate a vibration signal into each modal vibration signal. Two neuro-controllers with fewer weights are connected to the corresponding modal signals to generate proper modal control forces. The vibration controls using the adaptive notch filter and neuro-controllers have been performed for two specimens. A and B, which have different natural frequencies because of different positions of tip masses. Significant vibration reduction has been observed in both cases. The vibration control results show that the present neuro-controller has good adaptiveness under the system parameter variations.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.375-376
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.179-180
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• 2010

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.1
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• pp.5-11
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• 2002

Active vibration control of intelligent laminated composite plates is performed experimental1y Laminated composite place is modeled by the system identification method. For the system identification process, the laminated composite place is excited by two piezoelectric actuators with PRBS signals. At the same time, the displacement of the laminated composite plate is measured by a gap sensor. From these excited PRBS signals and the measured displacement sequence, system parameters of the laminated composite plate are estimated using a recursive prediction error method. Model of the laminated composite plate with two piezoeletric actuators is assumed to be the form of ARMAX. From the estimated ARHMAX model, a state space equation of the observable canonical form is obtained. With this state space equation, a controller and an observer for active vibration control is designed using the optimal control method. Controller and observer are implemented on a digital system. Experiments on the vibration control are Performed with changing the outer layer fiber orientation of intelligent composite plates.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.582-585
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• 2006

Attempts have been applied to reduce the vibration of slab. There are several method in the vibration control of slab from a traditional method such as increment of mass or stiffness of slab to a innovative method augmenting damping of slab. In this study, a attempt has been made to increase the effective damping in slab using the Multi Tuned Mass Damper. we evaluate the reduction effect of the slab selected through numerical simulation and optimization process by applying it to a FEM model. The numerical simulation shows that the effective damping is increased as the number of bean is increased and the vibration control effect is very high.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.10
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• pp.3173-3185
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• 1996

Multi-model vibration control of laminated composites plates for various fiver orientations has been carried out by making use of piezolectric materials(PZT) as sensors and actuators. Cantilever plate is used as a specimen to test multi-modal vibration supression under random exitation. Impulse technique is applied to determine the natural frequency, the damping ratio(.zeta.) and the modal damping(2.zeta..omega.) of the first bending and the trosion modes. Two independent controllers are implemented to control the two modes simultaneously and established digitally on the basis of the direct negative velocity feedback control with collocated sensor/actuator. Experimental results for various fiber orientations and feedback gains are compared with finite element analysis considering stiffnesses and dampings of piezoeletiric sensors, actuators and bonding layer.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.04a
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• pp.262-263
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• 2011