• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.596-602
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• 2001

본 논문에서는 중수로 원자력발전소에서 사용되는 핵연료 교환기 브리지의 상태를 감시하는데 필요한 진단 방법을 도출하였다. 핵연료 교환기는 고방사능 지역에서 작동하기 때문에 신호의 취득은 원격에서 비침투적으로 이뤄져야한다는 제약이 있다. 따라서 비침투적으로 원격에서 측정 가능한 신호들이 선정되었고 선정된 신호를 이용하여 정확한 진단을 위해서 필요한 여러 가지 진단 신호들의 장단점을 비교하였다. 진단 신호로는 모터의 출력 토크를 선정하였고 진단 신호의 타당성을 모형 브리지를 대상으로 수행한 실험을 통하여 검증하였다. 그리고 마지막으로 다양한 환경에서 실험을 하여 브리지의 작동 특성과 결함과 진단 신호와의 관계를 살펴보았다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.235-240
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• 2001

A four degrees of freedom (dof) motion platform for bicycle simulator is developed. The motion platform, capable of the vertical linear and three angular motions, is designed based on analysis of the typical motion characteristics revealed by the existing six dof bicycle simulator. The platform essentially consists of two parts： the three dof parallel manipulator, consisting of a moving platform, a fixed base and three actuators, and the turntable to generate the yaw motion. The nonlinear kinematics and dynamics of the three dof parallel manipulator with multiple closed loop chains are analyzed for tracking control of the motion platform. The tracking performances of the three control schemes are experimentally compared： the computed torque method (CTM), the sliding mode control (SMC) and the PD control. The CTM and SMC, incorporated with the system dynamics model, are found to be equally better in performance than the PD controller, irrespective of the presence of external disturbance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 추계학술대회 논문집
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• pp.52-56
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• 2011

Recently, KARI(Korea Aerospace Research Institute) has been developing a modern 11.5m diameter four bladed bearingless main rotor system, and this rotor system can be used for 7,000lb class helicopter. Flexbeam and torque tube can be considered as the key structural components, and large elastic twist of flexbeam induced by pitch control motion of torque tube can influence the nonlinear aeroelastic behavior. In this paper, the dynamic characteristic analysis results of bearingless rotor system were presented. In order to construct a input model and validate the analysis procedures, calculated results using the comprehensive helicopter analysis program CAMRAD II were compared with the measured natural frequencies and lag damping data from small-scale wind tunnel test. Next, the analysis model was extended to a full-scale model, and the dynamic analysis results were presented.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.383-389
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• 2013

Rotor system is a very important part which produces lift, thrust and control force in helicopter. Component of rotor system must endure various flight load for the required life. In helicopter rotor system, bearingless rotor system is the highest technology rotor system compare with articulated and hingeless rotor system. Baaringless rotor system is not include mechanical flap hinge, lag hinge and pitch bearing. Bearingless rotor component flexbeam which made by composite material has conduct hinge and bearing role instead of mechanical flap hinge, lag hinge and pitch bearing. These characteristics has less part number and lass weight than others. In this paper, conduct safe life analysis of bearingless composite component flexbeam and torque tube applying to utility helicopter load condition.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.341-346
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• 2014

Intake E-CVVT noise, generally caused by collision sound of roller and cage clearance at idle and driving condition, is considerable source of annoyance in passenger cars using the gasoline engine. Main source of this noise is the cam torque variation of an intake E-CVVT system, and can be controlled by clearance decrease such as backlash reduction, but which may increase the manufacturing cost. Thus in this paper, most effective solution for low noise intake E-CVVT was achieved through not only reduction of backlash and cam angular acceleration but also improvement of vehicle transfer system, which is optimal configuration through acoustic sensitivity optimization of engine mount support bracket.

• 한국소음진동공학회논문집
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• 제22권2호
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• pp.187-192
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• 2012

Recently, KARI(Korea Aerospace Research Institute) has been developing a modern 11.5 m diameter four bladed bearingless main rotor system, and this rotor system can be used for 7,000 lb class helicopter. Flexbeam and torque tube can be considered as key structural components, and large elastic twist of flexbeam induced by pitch control motion of torque tube can influence the nonlinear aeroelastic behavior. In this paper, the dynamic characteristic analysis results of bearingless rotor system were presented. In order to construct a input model and validate the analysis procedures, calculated results using the comprehensive helicopter analysis program CAMRAD II were compared with the measured natural frequencies and lag damping data from small-scale wind tunnel test. Next, the analysis model was extended to a full-scale model, and the dynamic analysis results were presented.

• 한국자동차공학회논문집
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• 제3권2호
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• pp.102-111
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• 1995

The non-periodic fluctuation of the engine torque appears to be the major source of the torsional vibration of the automotive driveline. The reduction of this torsional vibration has become a significant problem along with the requirements of higher performance. The torsional vibration of the automotive driveline can be reduced by smoothing the fluctuation by adjusting the torsional characteristics of the clutch-disc. Computer simulation of the driveline is a useful investigative tool on studying the torsional characteristics of the clutch-disc. In this paper, a dynamic model for the automotive driveline was developed, and the engine torque of the model were evaluated with experimental data. By executing a simulation using the model, it has become possible to obtain the clutch-disc torsional characteristics for reducting the torsional vibration at creeping.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.612-615
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• 2005

This studies presented truss frame which use aluminum beam by damage model. Truss frame which each joint part is contracted by bolt contracted conclusion of each bolt by 3.0 N/m. And measured impedance change that appear making bolt 0.5 N/m on damage condition 8 times. Compares impedance change of 5 segments that was set by measurement area and displayed result. To measure torque change of bolt, other damage model did not apply.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 추계학술대회논문집
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• pp.809-814
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• 2000

이 연구의 목적은 비침투적으로 펌프의 유량을 알아내고, 이를 이용하여 펌프의 성능을 감시하는데 있다. 그리고 운전중인 펌프의 상태를 감시함으로써 펌프의 결함을 진단하는데 있다. 위 목적을 달성하기 위하여 본 연구에서는 비침투적으로 측정이 가능한 변수인 모터 토크와 회전속도를 이용하여 펌프의 성능을 예측할 때 필수석인 유량을 알아내는 Simulator를 개발하였다. 유량의 변화를 감시함으로써 펌프의 성능 변화를 감시하는 일반적인 방법을 적용하면 펌프의 성능을 효율적이며 경제적으로 감시를 하는데 이용할 수 있다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2005년도 한국우주과학회보 제14권1호
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• pp.138-142
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• 2005

위성자세제어용 구동기 인 반작용 휠은 축 방향 토크뿐만 아니 라 횡 축 방향 외 란 토크와 힘을 발생시켜 위성의 정밀 지향 안정성에 영향을 미치게 된다. 이를 위해서는 반작용 휠 구동시의 발생 외란을 정밀하게 측정할 필요가 있다. 그러나 반작용 휠의 구동은 측정테이블의 진동을 야기 시키고 테이블의 공진 주파수 영역에서 큰 측정 오차를 유발한다. 본 논문은 이러한 진동오차들을 줄이기 위하여 주파수 보정법에 의한 사후처리 과정을 제시하고, 이 보정법으로 얻어진 데이터들로부터 외란 파라미터를 결정함으로써 구동기 외란의 보다 정밀한 측정을 가능케 하기 위함이다. 이 보정법을 적용함으로써 구동기 외란 측정 주파수범위를 넓힐 수 있다.