• 한국철도학회논문집
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• 제15권2호
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• pp.162-171
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• 2012

본 연구에서는 곡선부를 주행하는 틸팅열차와 궤도와의 동적상호작용을 고려한 동적해석을 수행하기 위한 해석기법을 제시하였다. 본 연구에서는 3차원 차량요소를 이용하여 틸팅열차를 모형화하였으며, 틸팅열차의 곡선부 주행시 차량의 주행방향이 크게 변화하는 상황에서 주행속도 및 원곡선 반경에 상응하는 원심력의 표현, 선로의 캔트량, 차륜-레일의 접촉각 및 열차의 틸팅각 등을 고려한 동적상호작용해석 방법을 제안하였다. 제안된 해석방법은 기본적인 검증예제들에서 만족할만한 결과를 보여주었으며, 실제적인 문제에 적용이 가능할 것으로 기대된다.

• 대한기계학회논문집B
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• 제32권9호
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• pp.645-651
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• 2008

For a high speed train driving at 300 km/h, aero-acoustic noise is a dominant component among various noise sources. The aeroacoustic noise is mainly due to inter-coach spacings because discontinuities in the train surface significantly disturb turbulent flows. This often leads to the uncomfortableness of passengers. Interestingly, the aero-acoustic noise reduces with decreasing the mud-flap spacing of the inter-couch spacing. We perform numerical simulations to investigate flow characteristics around the inter-coach spacing. We model the inter-coach spacing as a simple 2-D cavity with flaps, and calculate the velocity and pressure field using two equation turbulence models, varying the flap spacing. The results show that a wider flap spacing develops a higher inflection point in mean velocity profiles over the cavity. It is likely that large eddies generated near the inflection point persist longer in the downstream since they are less affected by the wall. This probably induces the more aero-acoustic noises. The wider spacing also results in the larger pressure difference between the inside and outside of the cavity. This is also responsible for the increased noise since the large difference would cause a strong flow oscillations in and out of the cavity.

• 한국철도학회논문집
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• 제14권6호
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• pp.477-483
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• 2011

본 논문에서는 고속철도 차량의 소음원을 측정 및 분석하는데 활용하기 위한 마이크로폰 어레이를 설계 및 제작하여 그 활용성을 검증하는 연구를 수행하였다. 우선 다수의 마이크로폰에서 측정된 신호를 바탕으로 음원의 위치 및 방사 형태를 구현하는데 널리 사용되고 있는 지연-합 빔형성 방법이 고려되었으며, 빔 패턴에 대한 이론과 가상 음원에 대한 이론이 소개되었다. 또한 고속철도 음원을 도출하기 위한 요구사항에 만족하는 마이크로폰 어레이의 형상을 설계하기 위한 분석을 수행하여 96채널 마이크로폰 어레이 형상을 설계하였다. 설계된 마이크로폰 어레이의 실제 시험을 통해서 성능을 분석하였으며, 300km/h대로 주행하는 고속열차 차량에 적용하여 본 논문에서 구현한 마이크로폰 어레이의 활용가능성을 확인하였다.

• 한국철도학회논문집
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• 제17권1호
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• pp.28-34
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• 2014

본 논문에서는 레일형 초고속 열차의 개념 설계안을 제안하고 동역학 해석을 통해 주행 동특성을 예측하고자 한다. 초고속 열차에는 단일 윤축세트가 포함된 새로운 형태의 대차가 적용되었으며, 기존의 일체형 차축 대신 독립차륜이 적용되었다. 초고속 열차의 동특성을 파악하기 위하여 먼저, 차량에 대한 동역학 수치해석모델을 개발하고 고유치 해석을 통해 해석 모델의 기본적인 타당성을 검증하였다. 또한, 임계속도 해석을 통하여 기존 고속철도 HEMU-430X 차량에 비해 향상된 성능을 확인하였으며, 7000R 곡선선로에서 550km/h 주행해석을 통하여 횡압, 탈선계수 등을 예측하고 초고속 열차 개념 설계안의 적용 가능성을 파악하였다.

• 드라이브 ㆍ 컨트롤
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• 제17권1호
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• pp.1-12
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• 2020

This study was to develop a simulation model of a compound planetary gear reducer for the final driving shaft using a gear analysis software (KISSsoft, Version 2017, KISSsoft AG, Switzerland). The aim of this study is to analyze transmission error and the tooth load distribution through micro-geometry using the simulation model. The tip and root relief were modified with Micro-geometry in the profile direction, and crowning was modified with Micro-geometry in the lead direction. The transmission error was analyzed using the PPTE (Peak to Peak Transmission Error) value, and the tooth load distribution was analyzed for the concentrated stress on the tooth surface. As a result of modifying tip and relief in the profile direction, the transmission error was reduced up to 40.7%. In the case of modifying crowning in the lead direction, the tooth load was more evenly distributed than before and decreased the stress on the tooth surface. After modifying the profile direction for the 1st and 2nd planetary gear train, the bending and contact safety factors were increased by 31.7% and 17%, and 18.3% and 12.5% respectively. Moreover, the bending and safety factors after modifying lead direction were increased by 59.5% and 32.7%, respectively for the 1st planetary gear train, and 59.6% and 43.6%, respectively for the 2nd planetary gear train. In future studies, the optimal design of a compound planetary gear reducer for the final driving shaft is needed considering both the transmission error and tooth load distribution.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.98-103
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• 2002

In this paper, static analysis of eddy current brake's frame, which is one of key structural components of brake system for high speed train, was performed in order to evaluate the design by computer simulation. Calculation was carried out in general for the driving modes 'braking' and 'frame in upper position(Brakes inactive)'. Several yield stress load cases and fatigue load cases were analysed for each of the driving modes. The fatigue load resulting from the Multi Body System simulation was also taken into consideration. The simulation results shows that some of structural part should be improved for more increasing reliability of frame.

• 오토저널
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• 제14권2호
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• pp.44-53
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• 1992

Automotive transmission is the principle component of vehicle driving system, which transmits the adjusted engine power. The automation of transmission arises from the annoyance of transmission operation such as the frequent stop/start of vehicle and the shifting transients. The study on the optimal shifting condition for the automation of transmission needs the investigation of shifting transients. However, the dynamic modeling theory during transient period is not well-established. In this study, the techniques of dynamic modeling for the power transmission system with Merrite-Wilson gear train are presented. To predict the shifting transients, a driving simulation program is developed, and the results of the analysis are cross-checked in the field test.

• 한국산업융합학회 논문집
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• 제17권2호
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• pp.69-76
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• 2014

This paper proposes a new approach to the design of cruise control system of a mobile robot with two drive wheel. The proposed control scheme uses a Gaussian function as a unit function in the fuzzy neural network, and back propagation algorithm to train the fuzzy neural network controller in the framework of the specialized learning architecture. It is proposed a learning controller consisting of two neural network-fuzzy based on independent reasoning and a connection net with fixed weights to simply the neural networks-fuzzy. The performance of the proposed controller is shown by performing the computer simulation for trajectory tracking of the speed and azimuth of a mobile robot driven by two independent wheels.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.317.1-317
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• 2002

In this paper, static analysis of eddy current brake′s frame, which is one of key structural components of brake system for high speed train, was performed in order to evaluate the design by computer simulation. Calculation was carried out in general for the driving modes "braking" and "frame in upper position(brakes inactive)". Several yield stress load cases and fatigue load cases were analysed fur each of the driving modes. (omitted)

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.364-369
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• 2012

The vehicle sound classified into driving sound due to power-train, operating sound due to electric motor like sunroof, door lock and electronic sound. These vehicle sound has various features depend on the characteristic of sound that user required. And it based on cultural and regional difference of user. In this study, the user required vehicle sound characteristics for luxury sedan was investigated in overall viewpoint. And virtual target sound was developed through the result of user preference investigation. Next, Jury test was carried out in Germany, USA and Korea for evaluating the target sound. And the regional and individual difference of preference was analyzed through the result of jury test. This result of research will be contributed to design of vehicle sound quality and target sound setting.