• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.1912-1912
• /
• 2000

• 대한공업교육학회지
• /
• v.31 no.2
• /
• pp.364-380
• /
• 2006

This paper presents a procedure for designing command to maneuver flexible structure with very little residual vibration, even in the presence of modeling errors. For the open loop maneuver, the various shaped profiles using multiple step inputs delayed in time are considered for robustness and compared with the responses of rigid body and flexible body in virtue of simulations and experiments. Input shaping generates vibration-reducing shaped commands through convolution of an impulse sequence with the desired command. A flexible model with a cylindrical hub and four symmetric appendages is considered to examine the responses to real plant, and to illustrate the effectiveness of the proposed shapers. The appendages are long and flexible, leading to low frequency vibration under any control action. It is shown by a series of simulation that a properly designed feedback controller with input shaper performs well, as compared with open loop controller with input shaper. The control objective is to achieve a fast settling time of residual vibration to flexible structure and robustness (insensitivity)to plant uncertainty, to eliminate residual vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.04a
• /
• pp.516-517
• /
• 2014

• Journal of KSNVE
• /
• v.9 no.4
• /
• pp.714-719
• /
• 1999

Because the residual vibration of a gun barrel acts negatively on the firing of a large calibers gun, the fast stabilization of theresidual vibration is indispensible to the precise and successive firing. In this study, the residual vibrations of a gun barrel carrying a bore evacuator and a muzzle brake are investigated by the experimental method. The influence of the eigenfrequencies and the mode shapes of gun barrel on the fast stabilization of the residual vibration is studied for the various masses of bore evacuator and muzzle brake, the possition of bore evacutor. Also the relationships between the funcamental frequencies and the settling times of the gun barrel are investigated for the various parameters. The experiments to reduce the residual vibration using the viscoelastic damping treatment gives the best result among the various treatments for the reduction of residual vibration of the system.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.1
• /
• pp.3-10
• /
• 2008

In this paper, the optimal command input is considered in order to minimize the residual vibrations of a flexible cantilever beam when the beam simply changes its position by translation or rotation. Although a cantilever beam has many modes of vibration, it is shown that the consideration of the first mode is sufficient in this case. Thus, the problem becomes a single-degree-of-freedom system subjected to a ground excitation. Two simple methods are proposed to find the optimal command input based on the shock response spectrum (SRS). The first method is the simplest and can be applied to lightly damped cases, and the second method is applicable to more general problems. The second method gives almost the same results as the input shaping method. However the proposed method gives a easier and clearer control strategy.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.2
• /
• pp.222-231
• /
• 1985

유연한 구조물의 진동은 이론적으로는 무한개의 진동모우드를 포함하고 있기 때문에 진동을 감 소시키기 위한 제어시스탬을 설계할 때에는 유한개의 진동모우드로 진동하고 있다는 가정하에서 제어기를 설계하는 것이 보통이다. 그러나 이러한 방법으로 구조물 진동을 제어할 때에는 설계 시에 제외된 잔류 진동모우드에 의해서 오히려 구조물의 진동이 더욱 심하게 되어 안정성을 해 치는 결과를 낳는 수가 있다. 본 연구에서는 잔류 모우드에 의한 불안정성을 제거하기 위해 최 적제어 이론을 바탕으로 제어이론을 개발하였다. 구조물 진동이 안정화되기 위한 필요조건을 제시하였고 외팔보 진동의 예를 시뮬레이션하여 제어이론을 증명하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2008.11a
• /
• pp.101-102
• /
• 2008

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.589-594
• /
• 2007

In this paper, the optimal command input is considered in order to minimize the residual vibrations of a flexible cantilever beam when the beam simply changes its position by translation or rotation. Although a cantilever beam has many modes of vibration, it is shown that the consideration of the first mode is sufficient in this case. Thus, the problem becomes a singledegree-of-freedom system subjected to a ground excitation. Two simple methods are proposed to find the optimal command input based on the Shock Response Spectrum (SRS). The first method is the simplest and can be applied to lightly damped cases, and the second method is applicable to more general problems. The second method gives almost the same results as the input shaping method. However the proposed method gives a easier and clearer control strategy.

• Journal of the Korean Society for Precision Engineering
• /
• v.16 no.2 s.95
• /
• pp.153-163
• /
• 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 the Korean Society for Precision Engineering
• /
• v.24 no.3 s.192
• /
• pp.67-75
• /
• 2007

This paper deals with a problem of vibration suppression of a piezoelectric beam using a self-sensing algorithm. Two methods, which are PPF(positive position feedback) and SRF(strain rate feedback), are considered to suppress a residual vibration of a piezoelectric beam developed during the step positioning of a beam end point. A self-sensing algorithm treated here is basically a strain rate estimator of a beam movement and is to be used for the closed loop control. The efficacy of the proposed idea is evaluated through experiments.