• 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.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.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1380-1385
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• 2004

In this paper, auto-tuning technique of the PID controller gain by particle swarm optimization algorithm is presented. PID controller is easy to implement to numerous control systems. After PID gain tuning is completed, its result could be implemented to control spacecraft vibration such as jitter that is high frequency vibration usually over 10Hz. The off-line PID controller tuning is done under system nonlinearities and uncertainties existence, then its result is applied to control experiment device to prove the PSO efficiencies.

• 한국소음진동공학회논문집
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• 제17권1호
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• pp.72-79
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• 2007

정밀 장비 운전시 지반진동 절연을 목적으로 널리 사용되는 공압제진대는 정밀 장비에서 요구하는 지반진동 규제의 강화에 따라 보다 개선된 절연성능을 요구받는다. 수동형 공압제진대의 경우, 제진대의 설계 변수들을 이용하여 그 성능을 개선하고 있으나, 제진대의 고유진동수 및 그 부근에서의 절연 성능 향상에는 한계가 있다. 이 연구에서는 진폭 의존성 등의 비선형성을 가지는 공압제진대에 대하여 비선형 강인성 능동제어이론인 시간지연 제어 기법을 적용하여 고유진동수 및 그 부근에서의 절연성능을 향상시키고자 한다. 공압제진대에 시간지연 제어기법을 적용하는 과정 및 능동제어 이론 적용에 따른 절연 성능 향상에 대한 모사실험 결과를 기술하고자 하며, 실험을 통하여 그 유효성 보이고자 한다.

• 한국항공우주학회지
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• 제38권9호
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• pp.882-889
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• 2010

수동형 진동제어 방식과 같이 시스템이 안정되며, 수동형에 비해 높은 제진 효과가 기대되는 반능동 진동제어 방식은 시스템의 안정화가 요구되는 우주구조물의 제진방법에 유효한 진동제어 방식중 하나이다. On-Off 제어방식에 근거한 반능동 제어는 On-Off 스위칭 시에 전달력의 불연속성으로 인한 chattering을 발생시킬 수 있으며, 이는 탑재체 구조물의 고유진동수와의 커플링으로 인하여 지향성능을 저하시키는 원인으로 작용할 수 있다. 본 논문에서는 chattering 영향 최소화를 통한 지향성능향상을 목적으로 LQ(Linear Quadratic)이론에 기반한 가변 감쇠형 반능동 제어기법을 제안하였다. 시뮬레이션 결과는 본 논문에서 제안한 반능동 제어기법은 기존의 skyhook와 LQ를 기반으로 하는 Bang-Bang 반능동 제어기법과 비교하여 높은 진동절연 성능을 나타내고 있다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.237-242
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• 2008

This paper presents vibration control of an active hybrid engine mount featuring magneto-rheological (MR) fluid and a piezostack actuator. On the basis of the conventional passive rubber mount, MR fluid is adopted to improve isolation performance at resonant frequencies, whereas the piezostack actuator is adopted for performance improvement at non-resonant frequencies, especially at high frequencies. Based on some particular practical requirements of engine mounts, the proposed mount is designed and manufactured. The characteristics of rubber element, piezostack actuator and MR fluid are verified for system analysis and controller synthesis. The model of the proposed mount with a supported mass (engine) is established. In this work, a sliding mode controller is synthesized for the mount system to reduce vibrations transmitted from the engine in a wide frequency range. Computer simulations are performed to evaluate the performances of the proposed active engine mount in time and frequency domains.

• 한국소음진동공학회논문집
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• 제18권11호
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• pp.1150-1156
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• 2008

This paper presents vibration control of an active hybrid engine mount featuring a magneto-rheological(MR) fluid and a piezostack actuator. The MR fluid is adopted to improve isolation performance at resonant frequencies, while the piezostack actuator is adopted for performance improvement at non-resonant frequencies, especially at high frequencies. Based on some particular practical requirements of engine mounts, the proposed mount is designed and manufactured. The characteristics of rubber element, piezostack actuator and MR fluid are verified for system analysis and controller synthesis. The dynamic model of the proposed mount with a supported mass (engine) is established. In this work, a sliding mode controller is synthesized for the mount system to reduce vibrations transmitted from the engine in a wide frequency range. Computer simulations are performed to evaluate control performances of the proposed active engine mount in time and frequency domains.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.1048-1053
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• 2003

This paper proposed a MR(Magneto-rheological) seat damper for a commercial vehicle. After formulating the governing equation of motion, an appropriate size of damper is designed and manufactured. Following the equation of fie d-dependent damping force characteristics, a semi-active seat suspension installed with the proposed MR-damper is constructed and its dynamic model id established, Subsequently, vibration isolation performance of the semi-active suspension system is demonstrated by incorporating with a MRAC(Model referenced adaptive control) fer the MR Seat Damper

• Smart Structures and Systems
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• 제17권2호
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• pp.195-208
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• 2016

Seismic isolation systems are essentially designed to preserve structural safety, prevent occupants injury and properties damage. An active saturated LMI-based control design is proposed to attenuate seismic disturbances in base-isolated structures under saturation actuators. Using a mathematical model of an eight-storied building structure, an active control algorithm is designed. Performance evaluation of the controller is carried out in a simplified model version of a benchmark building system, which is recognized as a state-of-the-art model for numerical experiments of structures under seismic perturbations. Experimental results show that the proposed algorithm is robust with respect to model and seismic perturbations. Finally, the performance indices show that the proposed controller behaves satisfactorily and with a reasonable control effort.

• 한국소음진동공학회논문집
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• 제24권3호
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• pp.236-246
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• 2014

This paper presents a hybrid rubber mount with magnet to isolate effectively the vibration in vehicle, forklift, and so on. The hybrid mount does not have any controller of the magnetic force. Dynamic stiffness of the mount is reduced by only magnetic suction according to the applied magnetic field and damping coefficient increased. Performance of conventional rubber mount with using electromagnet has been investigated by MTS Tester. The governing equation of the hybrid mount was derived and verified by comparison with experimental and theoretical results. The equation can be used practically and usefully in the design of the mount and analysis of the mounting system. The hybrid mount provides excellent performance in vibration isolation and its structure is very simpler than active with controller and a semi-active mount with a functional fluid. Furthermore, production cost of the mount using permanent magnets is very lower than that of the active mount with electromagnets. Therefore, commercial potential of the mount is very high.