• 한국공간구조학회논문집
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• 제14권2호
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• pp.87-94
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• 2014

In this study, a smart isolation platform has been developed for control of microvibration of high-technology facilities, such as semi-conductor plants and TFT-LCD plants. Previously, microvibration control performance of a smart base isolation system has been investigated. This study compared microvibration control performance of a smart isolation platform with that of conventional base isolation and fixed base. For this purpose, train-induced ground acceleration is used for time history analysis. An MR damper was used to compose a smart isolation platform. A fuzzy logic controller was used as a control algorithm and it was optimized by a multi-objective genetic algorithm. Numerical analysis shows that a smart isolation platform can effectively control microvibration of a high-technology facility subjected to train-induced excitation compared with other models.

• 한국공간구조학회논문집
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• 제13권2호
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• pp.37-45
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• 2013

Reduction of microvibration is regarded as important in high-technology facilities with high precision equipments. In this paper, smart control technology is used to improve the microvibration control performance. Mr damper is used to make a smart base isolation system amd fuzzy logic control algorithm is employed to appropriately control the MR damper. In order to develop optimal fuzzy control algorithm, a multi-objective genetic algorithm is used in this study. As an excitation, a train-induced ground acceleration is used for time history analysis and three-story example building structure is employed. Microvibration control performance of passive and smart base isolation systems have been investigated in this study. Numerical simulation results show that the multi-objective genetic algorithm can provide optimal fuzzy logic controllers for smart base isolation system and the smart control system can effectively reduce microvibration of a high-technology facility subjected to train-induced excitation.

• Structural Engineering and Mechanics
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• 제10권6호
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• pp.561-575
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• 2000

Microvibration of high technology facilities, such as semiconductor plants and facilities with high precision equipments, due to nearby road and rail traffic has attracted considerable attention recently. In this paper, a preliminary study is conducted for the possible use of various protective systems and their performance for the reduction of microvibration. Simulation results indicate that passive base isolation systems, hybrid base isolation systems, passive floor isolation systems, and hybrid floor isolation systems are quite effective and practical. In particular, the performances of hybrid floor isolation systems are remarkable. Further, passive energy dissipation systems are not effective for the reduction of microvibration. Finally, the protections against both microvibration and earthquake are also investigated and presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2492-2494
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• 2004

A system, featuring the electromagnetic levitation actuator for control in the vertical direction, of active microvibration control was proposed. The main components of this system are a vibration isolation table with built-in acceleration sensors for detecting microvibration, electromagnetic levitation actuators with built-in permanent magnets and electromagnets, and a digital controller with high precision signal converters.

• 한국공간구조학회논문집
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• 제12권2호
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• pp.99-108
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• 2012

정밀한 공정을 요구하는 반도체 및 TFT-LCD와 같은 첨단 기술산업 공장의 미진동 문제는 제품의 성능에 영향을 주는 주요한 인자로서 정밀기기 및 부품의 제조공정에 있어서 중요시 되어왔다. 본 논문에서는 이러한 첨단시설물의 미진동 문제를 해결하기 위하여 기초면진시스템의 미진동제어성능을 검토하였다. 이를 위하여, 기차에서 유발되는 인공지반운동을 생성하여 시간이력해석을 수행하였고 3층 예제구조물을 사용하였다. 수치해석을 통하여 수동 기초면진 및 스마트 면진시스템의 미진동제어성능을 고정기초구조물과 비교하였다. 그 결과 스마트 면진시스템이 미진동제어에 있어서 우수한 제어성능을 나타내는 것을 확인하였다.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.56-65
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• 2011

A new hybrid mount system is proposed for microvibration control in a high-tech factory. The mount consists of an airspring as a passive device and a piezostack actuator as an active device. The two devices are connected in series. Some numerical simulations and experimental tests are carried out to evaluate isolation performance of the mount system comprising of four proposed hybrid mounts. As a control logic, the specific algorithm is adopted for considering multiple target frequencies of excitation based on a Filtered-X LMS algorithm. The results are compared with isolation performance of the passive airspring mount system. It is confirmed that the proposed hybrid mount system has great performance on microvibration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2495-2497
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• 2004

A system, featuring the hybrid isolator for control in the vertical direction, of active microvibration control was proposed. The main components of this system are a stage vibration isolation table with built-in acceleration sensors for detecting microvibration, hybrid isolators and a digital controller with high precision signal converters. The vibration control algorithm is focused on settling-time critical application and feedback/feedforward combination.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.533-539
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• 2013

Number of components and payload systems installed in satellites were found to be exposed to various disturbance sources such as the reaction wheel assembly, the control moment gyro, coolers, and others. A micro-level of vibration can introduce jitter problems into an optical payload system and cause significant degradation of the image quality. Moreover, the prediction of on-orbit vibration effects on the performance of optical payloads during the development process is always important. However, analyzing interactions between subsystems and predicting the vibration level of the payloads is extremely difficult. Therefore, this paper describes the analytical and experimental approach to microvibration effects on satellite optical payload performance with integrated jitter analysis framework, micro vibration emulator and satellite structure testbed.

• 한국소음진동공학회논문집
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• 제24권1호
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• pp.5-13
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• 2014

Number of components and payload systems installed in satellites were found to be exposed to various disturbance sources such as the reaction wheel assembly, the control moment gyro, coolers, and others. A micro-level of vibration can introduce jitter problems into an optical payload system and cause significant degradation of the image quality. Moreover, the prediction of on-orbit vibration effects on the performance of optical payloads during the development process is always important. However, analyzing interactions between subsystems and predicting the vibration level of the payloads is extremely difficult. Therefore, this paper describes the analytical and experimental approach to microvibration effects on satellite optical payload performance with integrated jitter analysis frame-work, microvibration emulator and satellite structure testbed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.299-304
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• 2009

A hybrid electromagnetic actuator with an air spring is designed so as to achieve the desired isolation reduce the vibration efficiency on the floor vibration. The performance specification of the hybrid electromagnetic actuator is determined based on the vibration criterion for vibration-sensitive equipment. In basic design stage of the electromagnetic actuator, the simple reluctance method is adapted to analyze magnetic circuits. The result is verified by finite element analysis using ANSYS Emag. Finally, some design parameters are optimized under several constraint conditions. Through this study, the design procedure for a specific electromagnetic actuator is set up using a simple reluctance method.