• 한국소음진동공학회논문집
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• 제11권4호
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• pp.22-30
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• 2001

In this paper, active control of vibrational intensity at a reference point in an infinite, elastic plate was discussed. The plate is excised harmonically by a vibrating source, which has a vertical point force. The optimal condition of controller was investigated to minimize the vibrational intensity being transmitted from the vibrating source to a reference point. Hence the method of feedforward control was employed for the control strategy and then the cost function was evaluated to find the optimal control force. Three types of control force (Vertical force, Moment, and Coupling force (a set of vertical force and moment) ) and controller's positions were examined to define the optimal condition of the controller. The vibrational intensity at a reference point was found to be reduced down to a zero level, compared with the uncontrolled case. Especially maximum reduction of vibrational intensity was achieved when the controller was collinearly positioned between a vibrating source and a reference point.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.83-91
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• 2010

In this paper, the feasibility of the cost function having two control factors were discussed in compared to two others which has one different control factor respectively. As of the control factors, the dynamic response of a discrete system and the vibrational intensity at the reference point which is the connecting point of a discrete system to a flexible beam were controlled actively by the control force obtained from the minimization of the cost function. The method of feedforward control was employed for the control strategy. The reduction levels of the dynamic response of a discrete system and the vibrational intensity at a reference point, and also the input power induced by the control force were evaluated numerically in cases of the three different cost functions. In comparison with the results obtained from the cost functions of one control factor, which is the dynamic response or the vibrational intensity, in most cases of the cost function of two control factors the better or similar results were obtained. As a conclusion, it is surely noted that both the dynamic response and the vibrational intensity of the vibrating system be controlled up to the expected level by using the single cost function having two control factors.

• 한국정밀공학회지
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• 제19권6호
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• pp.109-118
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• 2002

The vibrational intensity and the dynamic response of a compound vibratory system had been controlled actively by means of a feedforward control method. A compound vibratory system consists of a flexible beam and two discrete systems - a vibrating source and a dynamic absorber. By considering the interactive motions between discrete systems and a flexible beam, the equations of motion for a compound vibratory system were derived using a method of variation of parameters. To define the optimal conditions of a controller the cost function, which denotes a time averaged power flow, was evaluated numerically. The possibility of reductions of both of vibrational intensity and dynamic response at a control point located at a distance from a source were fecund to depend on the positions of a source, a control point and a controller. Especially the presence of a dynamic absorber gives the more reduction on the dynamic response but the less on the vibrational intensity than those without a dynamic absorber.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.151-154
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• 1997

An open loop vibrational control of underactuated mechanical systems with amplitude and frequency modulations is investigated. The underactuated systems considered in the paper are assumed to have free joints with no brake. The active joints are positioned first by a linearizing control, and then periodic oscillatory inputs are applied to them to move the remaining free joints to their desired states. A systematic way of obtaining averaged systems for the underactuated systems with oscillatory vibrations is developed. A complete solution to the open loop control strategy in terms of determining amplitudes and frequencies for general system is still under investigation. However, a specific control design for 2R manipulator which is obtained the averaging system is demonstrated.

• 제어로봇시스템학회논문지
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• 제5권4호
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• pp.385-393
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• 1999

An open loop vibrational control for an underactuated mechanical system with amplitude and frequently modulation is investigated. Since there is no direct external input to an unactuated joint, the dynamic coupling between the actuated and unactuated joints is utilized for controlling the unactuated joint. Feedback linearization has been performed to incorporate fully the known nonlinearities of the underactuated system considered. The actuated joints are firstly positioned to their desired locations, and the periodic oscillatory inputs are applied to the actuated joints to move the remaining unactuated joints to their target positions. The amplitudes and frequencies of the vibrations introduced are determined through averaging analysis. A systematic way of obtaining an averaged system for the underactuated system via a coordinate transformation is developed. A control design example of 2R planer manipulator with a free joint with no brake is provided.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.534-537
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• 1995

An open loop vibrational control of underactuated mechanical system with amplitude and frequency modulations is investigated. The underactuated systems sonsidered in the paper are assumed to have free joints with no brake. The active joints are positioned first by a linearizing control, and then periodic oscillatory input are applied to them to move the remaining free joints to their desired states. A systematic way of obtaining averaged systems for the underactuated systems with oscillatory vibration is developed. A complete solution to the open loop control strateegy in terms of determining amplitudes and frequencies for general system is still under investigation. However, a specific control design for 2R manipulator which is obtained through the averaged system is demonstrated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.539-542
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• 2005

In this study, we investigated the influence of vibrational stimulation on postural control. To study the effect, the sway of the center of pressure was observed fur two different visual conditions and for three different patterns of vibrational stimulation on plantar area. The two visual conditions were normal condition with visual feedback and blind condition with both eyes closed. The three vibrational stimulations were white noise, constant vibration, and vibration with amplitude modulations (sine curve modulation). The experimental results showed that the sway of the center of pressure distinctively reduced with white noise vibrational stimulation. This result showed that it's possible to use vibrational stimulation for improving the ability of postural control.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 추계학술대회
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• pp.533-536
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• 2016

본 논문에서는 진동 에너지를 이용한 MPPT 제어기능을 갖는 에너지 하베스팅 회로를 설계하였다. Body-bias technique과 bulk-driven technique을 이용하여 저전압에서도 높은 효율특성을 갖는 고성능 AC-DC 변환기를 제안하고 진동에너지 하베스팅 회로 설계에 적용하였다. MPPT (Maximum Power Point Tracking) 제어는 진동소자의 개방회로전압과 MPP 전압간의 관계를 이용하였으며, 진동소자의 개방회로전압을 주기적으로 샘플링 함으로써 이를 이용해 MPPT 기준전압을 생성하고, 이를 기준으로 부하로의 에너지 공급을 제어한다. $0.35{\mu}m$ CMOS 공정으로 설계된 회로의 칩 면적은 $1.21mm{\times}0.98mm$이다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.667-673
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• 2000

A number of issues related with the vibrational behavior of pretwisted rotating beams featuring anisotropic properties and incorporating adaptive capabilities are considered in this paper. The adaptive capabilities are provided by a system of piezoactuators bonded or embedded into the structure. Based on the converse piezoelectric effect and on the out of phase activation, boundary control moments are pizoelectrically induced at the beam tip. A feedback control law relating the induced bending moments with the kinematical response quantities appropriately selected is used, and its beneficial effects, considered in conjunction with that of the beam anisotropy and structural pretwist upon the eigenvibration characteristics are highlighted

• 대한화학회지
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• 제46권1호
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• pp.14-18
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• 2002

산화질소 분자(NO)가 전자 한 개를 받아 산화질소 음이온$(NO^-)$으로 환원되는 반응의 정도가 진동에너지에 따라 크게 달라질 수 있음을 제시하였다. NO와 $NO^-$의 포텐샬에너지 표면은 진동에너지가 많아짐에 따라 NO 분자가 전자를 받아 $NO^-$음이온으로 바뀔수 있는 에너지적 측면을 가짐을 보여준다. 또한, 진동 파동함수간의 Franck-Condon 인자를 계산하였다. 진동에너지가 많아지면 NO에서 $NO^-$로 바뀔 경로가 더 많이 증가함을 보인다. 이 결과는 NO 분자에게 적절한 빛을 조사시킴으로 $NO^-$이온으로의 환원반응속도를 조절할 수 있음을 의미한다.