• Smart Structures and Systems
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• 제23권6호
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• pp.695-702
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• 2019

The number of cable-stayed bridges has been increasing worldwide, causing issues in maintaining the structural safety and integrity of bridges. The stay cable, one of the most critical members in cable-stayed bridges, is vulnerable to wind-induced vibrations owing to its inherent low damping capacity. Thus, vibration mitigation of stay cables has been an important issue both in academia and practice. While a semi-active control scheme shows effective vibration reduction compared to a passive control scheme, real-world applications are quite limited because it requires complicated equipment, including for data acquisition, and power supply. This study aims to develop an Arduino-based integrated cable vibration control system implementing a semi-active control algorithm. The integrated control system is built on the low-cost, low-power Arduino platform, embedding a semi-active control algorithm. A MEMS accelerometer is installed in the platform to conduct a state feedback for the semi-active control. The Linear Quadratic Gaussian control is applied to estimate a cable state and obtain a control gain, and the clipped optimal algorithm is implemented to control the damping device. This study selects the magnetorheological damper as a semi-active damping device, controlled by the proposed control system. The developed integrated system is applied to a laboratory size cable with a series of experimental studies for identifying the effect of the system on cable vibration reduction. The semi-active control embedded in the integrated system is compared with free and passive mode cases and is shown to reduce the vibration of stay-cables effectively.

• 제어로봇시스템학회논문지
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• 제10권1호
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• pp.30-41
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• 2004

This paper is concerned with the active vibration control of flexible cantilever beam system using electromagnetic farce actuator. The main objective of this paper is to propose the control algorithms and to implement the experimental setups for active vibration control. Dynamic equations of the electromagnetic actuator and the beam are combined to find the transfer function from the electromagnetic actuator to the laser sensor. The final transfer function is determined by considering only the first and second modes, and experiments confirm that this model works well. Several control algorithms are proposed and implemented on the experimental setups to show their efficacy. These include a PID control design, an optimal H$_2$ control design, and a fuzzy PID control design. Effectiveness and performance of the designed controller were verified by both simulation and experiment results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.903-908
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• 2006

As environmental vibration requirements on precision equipment become more stringent. use of pneumatic isolators has become more popular and their performance is subsequently required to be further improved. Dynamic performance of passive pneumatic isolators is related to various design parameters in a complicated manner and, hence, is very limited especially in low frequency range by volume of chambers. In this study, an active control technique, so called time delay control which is considered to be adequate for a low frequency or nonlinear system, is applied to a single chamber pneumatic isolator. The procedure of applying the time delay control law to the pneumatic isolator is presented and its effectiveness in enhancement of transmissibility performance is shown based on simulation and experiment. Comparison between passive and active pneumatic isolators is also presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.229-234
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• 2001

A practical and effective semi-active on-off control law is developed for vibration attenuation of a natural, multi-degree-of-freedom suspension system, when its operational response mode is available. It does not need the accurate system parameters and dynamics of semi-active actuator. It reduces the total vibratory energy of the system including the work done by external disturbances and the maximum energy dissipation direction of the semi-active control device is tuned to the operational response mode of the structure. The effectiveness of the control law is illustrated with a three degree-of-freedom excavator cabin model.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.9-12
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• 2001

An active control of the vibration transmitted by longitudinal load in flight control system is investigated numerically. The flight control system is modeled as a finite, thin shell cylinder with constant thickness. A vibration source is generated by exterior monopole source. Distributed piezoelectric actuator is used to control of the vibration. Thin shell theory is used to formulate the numerical models. The amplitude of vibration at discrete location and power transmission are minimized by analytical optimization method. Genetic algorithm is used as numerical optimization method to search optimal actuator position and size which amplitude of vibration is minimized.

• 대한기계학회논문집A
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• 제25권12호
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• pp.1950-1959
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• 2001

An active control of the vibration transmitted by longitudinal load in flight control system is investigated numerically. The flight control system is modeled as a finite, thin shell cylinder with constant thickness. A vibration source is generated by exterior monopole source. Distributed piezoelectric actuator is used to control of the vibration. Thin shell theory is used to formulate the numerical models. The amplitude of vibration at discrete location and power transmission are minimized by analytical optimization method. Genetic algorithm is used as numerical optimization method to search optimal actuator position and size which amplitude of vibration is minimized.

• 한국소음진동공학회논문집
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• 제11권7호
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• pp.261-266
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• 2001

The flexural vibration of laminated composite beams with active and passive constrained layer damping has been investigated to design a structure with maximum possible damping capacity. The equations of motion are derived fro flexural vibrations of symmetrical,. multi-layer laminated beams. The damping ratio and model damping of the first bending mode are calculated by means of iterative complex eigensolution method. The direct negative velocity feedback control is used for the active constrained layer damping. It is shown that the flexible laminated beam is more effective in the vibration control for both active and passive constrained layer damping. and this paper addresses a design strategy of laminated composite under flexural vibrations with constrained layer damping.

• 소음진동
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• 제7권2호
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• pp.311-317
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• 1997

In this paper the active vibration control system using a linear oscillatory actuator(LOA) is studied to suppress structural vibration. In the LOA, the AC-power-energized armature generates a shift field in an air gap, which produces a oscillating force to the mover in the magnetic field generated by high density permanent magnets. LOA has relatively simple structure with almost maintenance free, compared with a hydraulic actuator. Performance test of the active vibration control system using a LOA is carried out on a steel test structure under base excitation. From this test, it is confirmed that the acceleration level of the test structure is drastically reduced near the resonant region.

• 대한조선학회논문집
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• 제41권4호
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• pp.77-84
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• 2004

Active control is regarded as one of the most efficient and economic countermeasures to reduce excessive vibration of ship superstructure. However, it is difficult to find its practical application in real ships in spite that many studies on such systems have been done. In this study, for the practical use of an active control system to reduce ship superstructure vibration, we have developed an active vibration compensator consisting of a mechanical actuator having compact size and expected lifetime over 20 years, its control panel including exclusive signal processing and computing board, sensors to detect phase and vibration, and its operation software providing various user-interface functions. From the performance verification test of the system at a 5,500 TEU container carrier, we have confirmed the system could reduce ship superstructure vibration of a harmonic component of main engine rotating frequency up to 0.1 mm/s.

• 항공우주산업기술동향
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• 제9권1호
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• pp.77-89
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• 2011

헬리콥터는회전하는구동시스템에의해추력및비행제어력을발생하기때문에회전체에서기체로전달되는 진동 및 소음을 줄이는 것이 아주 중요하다. 과거에는 수동적 방법으로 특정주파수에 해당하는 진동 및 소음을 줄였지만, 기술이 발달함에 따라 주파수를 변동시킬 수 있는 장치를 적용할 수 있는 능동적 진동 및 소음 제어방법이 개발되었다. 본 논문에서는 이러한 헬리콥터 진동 및 소음을 제어하는 능동적 방법에 대한 세계적인 기술동향 및 사례를 기술하였다. 서론에서는 헬리콥터 진동 및 소음을 제어하는 일반적인 방법론을 소개하고, 본론에서는 능동적으로 제어하는 사례 및 동향을 중심으로 기술하였다. 현재 가장 활발하게 진행되고 있는 능동적 플랩구동장치 및 비틀림장치 등을 중심으로 소개하였다.