• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1377-1378
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• 2011

• 기계저널
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• 제32권7호
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• pp.613-619
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• 1992

짧은 시간의 주행 실험과 랜덤 응답 해석을 통한 차체의 피로수명을 해석하는 방법을 제시하 였다. 주파수 영역에서 다축 응력을 폰 미제스 응력으로 변환시키고 응력 진폭의 확률 분포를 와이블 분포를 고려하여 처리함으로써 더욱 신뢰도가 큰 해석이 되도록 하였다. 여기에 제시된 해석 과정은 일반적으로 적용 가능한 것이므로, 양산 전 단계의 차체 피로 설계에 좋은 참고가 될 것이다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2016년도 춘계학술논문요약집
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• pp.35-36
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• 2016

• 대한기계학회논문집A
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• 제22권3호
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• pp.595-602
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• 1998

Specimens of 304 stainless steel were tested to failure at elevated temperatures under multiaxial stress states, uniaxial tension using smooth bar specimens, biaxial shearing using double shear bar specimens, and triaxial tension using notched bar specimens. Rupture times are compared for uniaxial, biaxial, and triaxial stress states with respect to the maximum principal stress, the von Mises effective stress, and the principal facet stress. The results indicate that the principal facet stress gives the best correlation for the material investigated, and this parameter can predict creep life data under multiaxial stress states with rupture data obtained with specimens under uniaxial stresses. The results also suggest that grain boundary cavitation, coupled with localized deformation processes such as grain boudary sliding, controls the lifetimes of the specimens.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.8-15
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• 2013

Recently many kinds of electric vehicles have been developed as many governments demand the environmental friendly vehicles. In this paper, study of load optimization for the electric vehicle which has multiple axle power system was conducted. For the analysis of the vehicle which has three or four driving axles, a method based on the geometry and assumptions that considering axles as a spring model and normal forces of the axles are proportional to the displacement of the axles was applied with basic vehicle dynamics. With the developed vehicle analysis technique, algorithm to find the optimal motor operating points was developed. Using this algorithm, it was possible to find the optimization of vehicle load distribution for multiple axles according to the driving cycles. Also, control logic for the vehicle can be developed based on the optimization simulation results.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.368-374
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• 2008

Multi-axial simulation table(MAST) is widely used in motor companies as the multi-axial excitor for vibration fatigue of target component, which provides the vibrational condition as close as the vehicle test. However, the vibration fatigue performance of target component can be guaranteed with MAST system only in case the input profile covers the required severity of the target component on field test. In this paper, the signal processing for multi-axial vibration fatigue test on vehicle component is presented, from the data acquisition of the target component to the derivation of input profile. To compare the severity of vibration condition between field and proving ground, the energy principle of a equivalent damage is proposed and then, it is determined the optimal combination of special events on proving ground using a sequential searching optimal algorithm. To explain the vibration methodology clearly, seat and door component of vehicle are selected as a example.

• 한국정밀공학회지
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• 제32권8호
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• pp.719-726
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• 2015

This paper presents a velocity-synchronizing control for the multiple axes of an injection unit; based on MBS, a virtual design model has been developed for the multiple-axes servomechanism. Prior to the design of the controller, a linear plant model was derived via open-loop response simulations. To synchronize the motions of the multiple axes, a cross-type synchronizing controller was designed and combined with the PID control to accommodate any parameter mismatches among the multiple axes. From the tracking control simulations, a significant reduction of both velocity-tracking and position-tracking errors was achieved through the use of the proposed control scheme.

• 한국정밀공학회지
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• 제14권3호
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• pp.98-106
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• 1997

In this paper, a new method of position synchronizing control is proposed for multi-axes driving system. The proposed position synchronizing control system is constituted with speed and synchronizing controller. The speed controller is aimed at the following to speed reference. Furthermore, it is designed to guarantee low sensitivity under some disturbance as well as robustness against model uncertainties using $H_{\infty}$technique. The synchronizing controller is designed to keep minimizing the position error using PID control law which is considered to reduce the dimension of transfer function in the control system. Especially, the proposed method can be easily conducted by controlling only slave axis speed, because it, has variable structure which is decided to master and slave axis by the sign of synchronizing error. Therfore, the master axis which is smaller influenced than another axes by disturbance can be controlled without reducing or increasing its speed for precise position synchronization. The effectiveness of the proposed method is sucessfully confirmed through many experiments.s.

• 한국콘텐츠학회논문지
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• 제15권8호
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• pp.46-52
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• 2015

공연장의 거대한 무대 세트나 장치에 움직임이 부여되면, 다양한 극적 효과를 연출할 수 있다. 본 논문에서 제안하는 프로그래밍 가능한 다축 체인 호이스트 서버 시스템은 이러한 연출의 자동화를 가능하게 한다. 본 시스템에는 PTP 기반의 임의 궤적 생성 방법, 다축 실시간 통신 제어 방법, 그리고 4 단계의 순차적인 안전 진단 알고리즘이 적용 되었으며, 호이스트들은 콘솔의 동기 제어에 의하여 시나리오의 연출 순서에 따라 자동적으로 움직인다. 12대 체인호이스트로 구성된 멀티 체인 호이스트 서버 시스템에 대한 1 ton 부하 및 대칭-비대칭 배치 부하에 대한 실험을 통해서 우수성을 검증하였다. 아울러 K-POP 공연에서 극적효과를 연출하는데 성공적으로 적용되었다.

• 한국항공우주학회지
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• 제39권12호
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• pp.1160-1165
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• 2011

본 연구는 무인항공기 및 헬리콥터 등에 장착되어 운용되는 고정밀 관측 다축 구동 EO/IR 카메라의 진동해석에 관한 것이며, 카메라에 적용된 볼 베어링을 모델링 하는데 있어서 3축 스프링요소를 적용하는 방법을 제시하였고, 이것에 의한 유한요소모델의 진동 응답 결과를 얻었다. 볼 베어링을 3축 스프링 요소로 모델링한 진동해석결과는 시험결과와 비교 되었으며, 잘 일치함을 알 수 있었다. 또한, 랜덤진동 시간이력해석을 통하여 다축 구동 EO/IR 카메라의 진동 응답 특성을 해석하고 분석하였다. 이의 연구결과는 우주용 카메라들에 사용되는 볼 베어링의 유한요소모델링 기법에 응용될 수 있다.