• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권12호
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• pp.5842-5861
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• 2019

A current autonomous vehicle determines its driving strategy by considering only external factors (Pedestrians, road conditions, etc.) without considering the interior condition of the vehicle. To solve the problem, this paper proposes "An Optimal Driving Support Strategy(ODSS) based on an Genetic Algorithm for Autonomous Vehicles" which determines the optimal strategy of an autonomous vehicle by analyzing not only the external factors, but also the internal factors of the vehicle(consumable conditions, RPM levels etc.). The proposed ODSS consists of 4 modules. The first module is a Data Communication Module (DCM) which converts CAN, FlexRay, and HSCAN messages of vehicles into WAVE messages and sends the converted messages to the Cloud and receives the analyzed result from the Cloud using V2X. The second module is a Data Management Module (DMM) that classifies the converted WAVE messages and stores the classified messages in a road state table, a sensor message table, and a vehicle state table. The third module is a Data Analysis Module (DAM) which learns a genetic algorithm using sensor data from vehicles stored in the cloud and determines the optimal driving strategy of an autonomous vehicle. The fourth module is a Data Visualization Module (DVM) which displays the optimal driving strategy and the current driving conditions on a vehicle monitor. This paper compared the DCM with existing vehicle gateways and the DAM with the MLP and RF neural network models to validate the ODSS. In the experiment, the DCM improved a loss rate approximately by 5%, compared with existing vehicle gateways. In addition, because the DAM improved computation time by 40% and 20% separately, compared with the MLP and RF, it determined RPM, speed, steering angle and lane changes faster than them.

• 전기전자학회논문지
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• 제26권4호
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• pp.671-680
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• 2022

본 논문에서는 현재 출시되어 있는 전기차의 구동모터 사양을 대부분 포괄하는 200kW급 구동용 모터드라이버를 개발하였다. 고효율ㆍ고전력밀도를 달성하기 위해 기존 전력반도체(Insulated-gate bipolar transistor, IGBT)대신에 차세대 전력반도체(Silicon carbide, SiC)를 적용하였으며 SiC를 최적사용하기 위해 하드웨어에 대한 분석을 통해, 예상되는 효율 및 방열특성을 구하여 최적 설계를 하였다. 전기차 구동모터에 대부분 활용되는 매입형 영구자석 동기모터(Interior permanent-magnet synchronous machine, IPMSM)를 위한 벡터 제어 알고리즘을 DSP를 활용하여 구현하였다. 본 논문에서는 SiC기반 전기차 구동용 모터드라이버 시작품을 설계ㆍ제작하였으며 실험을 통해 성능을 검증하였다.

• 서비스연구
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• 제11권3호
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• pp.43-54
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• 2021

본 연구는 자율주행시대에 적합한 차량 실내 인테리어 디자인 중에서 실내 공간, 편의장치를 중심으로 진행하였으며 STEEP 분석법을 적용하여 미래 자동차 실내디자인 모델을 제시하였다. 서비스디자인 방법론을 적용하여 레이아웃의 재배치와 운전자 중심의 정보 제공 목적으로 설치되었던 디스플레이 장치의 변화를 다루고 있다. 커넥티드, 인포테인먼트 등 다양한 목적을 위한 디스플레이의 종류와 설치 위치에 대한 변화가 예상된다. 특히, 이런 분석을 통해 미래 자율주행 자동차에서 지내게 되는 실내 인테리어 연구를 통한 트렌드와 경험을 연구함으로서 이후 후속연구에서는 실제 개발과 응용을 위한 기초 자료로써 활용될 것이다. 5단계로 진행한 연구 과제를 STEEP과 연계하는 미래트렌드 도출과 FGI를 통한 전문가들의 자문을 거쳐 핵심동인을 추출 하였다. 이를 통해 이후 실내디자인에 하나의 방향으로 제시했다. 사용자 중심의 참여형 디자인 방법을 통해 자율주행차에서 기대 할 수 있는 체험과 경험을 위주로 감성적인 키워드 도출법을 사용하였다, 도출된 동인을 미래사회 5대 트렌드와 묶어서 요약정리 하였고 각 도출된 동인들에는 해당되는 기술 분야를 함께 고려할 수 있도록 그룹핑을 했으며, 자율주행 Level에 따라 수요자가 경험할 수 있는 요소를 더하기도 했다. 이는 미래 자율주행차 산업은 개인적 성향뿐만 아니라 다양한 사회적 이슈와 관점에서 바라본 실내 레이아웃, 편의장치 등의 서비스디자인 트렌드에 대한 연구가 이어져서 보다 다양한 연구가 진행되어야 할 것이다.

• 한국자동차공학회논문집
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• 제2권2호
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• pp.24-32
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• 1994

This paper is the experimental study on the vibration reduction of the 4WD vehicle through the change of the engine mounting conditions.(4 stroke diesel engine) The engine mounting conditions are changed to reduce the transmitted vibrations of the engine to the frame at the idle speed. Under the assumption that the Powertrain(Engine Transmission and Transfer Case) is a rigid body, the inertia properties of the powertrain are obtained by experimental modal analysis. And then the changed mounting conditions are studied by the decoupled vibration theory and analytical model of six degree of freedom. Though the mounting conditions are changed to improve the vibration isolation at idle speed, the vibration and the interior noise of the vehicle are reduced significantly at driving speed as well as idle speed. From the indirect endurance test of the front engine mounts, the changed mounting conditions are desirable to endurance as well as vibration reduction of the 4WD vehicle.

• 대한안전경영과학회지
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• 제14권3호
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• pp.67-75
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• 2012

Because recently(July 14, 2011) fire occurred in the engine room of a moving taxi under Namsan Tunnel 1, 51 vehicles' driver and more than 250 passengers in the road tunnel were urgently evacuated with abandoned vehicles. Vehicle fires in Namsan Tunnel that day, Sufferers struggled to escape quickly difficult to escape the two-way by abandoned vehicles on the road and to fear many casualties by using vehicle fuel and combustible interior and the driver who is ignorant of vehicle accident continuous entered in the road tunnel had accessibility the site of fire department was more difficult. In this study, It is to investigate structure and basic materials, such as fire extinguish equipment and facilities for damage prevention and to analyze the problems and to plan improvement method of fire extinguish equipment, facilities for damage prevention and transportation facilities(Large traffic signs, Breaker, etc.) on the Namsan Tunnel that in the long-term plan is prepared to strengthen for accessibility of the site of fire department in case of Vehicle's fire.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.125-129
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• 2003

The identification of location and strength distribution of extended noise sources is important in the practical noise control engineering, especially in the viewpoint of dealing with the inherent nature of noise problem in question. For noise source ranking inside an automotive vehicle, the window method has been mainly used due to its simplicity. However, time and cost drawbacks in the measurement and inaccuracy due to low-frequency tunneling and lack of phase information have been a serious problem in using this method. In this study, the inverse FRF method was employed to carry out the noise source ranking inside an automotive vehicle and it was also used to predict the interior sound pressure with the change of sound insulation materials. As a result, it was found that the source contribution of vehicle panels could be successfully identified in comparison with the window method. The sound pressure at driver's ear position was predicted based on the obtained data and was compared with the measured data. The agreement in spectral trends was acceptable and their difference in level was within 3㏈ above 500㎐.

• 한국자동차공학회논문집
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• 제2권6호
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• pp.29-37
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• 1994

Active noise control of random noise which propatate in the vehicle cabin as a form of spherical wave is the target of this study. In the previous study, the adaptive algorithm for adaptive controller is presented for the application in active noise control system. And for the preliminary study of adaptive active noise control in vehicle cabin as a real system, a computer simulation is performed on the effectiveness of the adaptive algorithm in the amplitude of the pressure fluctuation. This work studies the implementation of multi-channel feedforward adaptive algorithm for the reduction of the noise inside a vehicle cabin using a number of secondary sources derived by adaptive filtering of reference noise source. Multi-channel adaptive feedforward algorithm are verified in numerical simulation and semi-experimental justification of developed system is made on a domestic passenger car. In the results of semi-experimental study, the noise of specific region in the interior of automobile are reduced for the appreciabe sound pressure level in the operating engine rpm and finally this study suggests the capabilities of the real time active noise control in 3 dimensional acoustic fields.

• 자동차안전학회지
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• 제16권1호
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• pp.55-61
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• 2024

The advancement of autonomous driving technology is expected to transform cars beyond mere transportation into multifunctional spaces for relaxation and entertainment. As autonomous driving technology becomes more sophisticated, with no need for direct driver control, the interior space of vehicles is anticipated to be utilized for various purposes. Consequently, the importance of car seats, the component most frequently interacted with by passengers during travel, is expected to significantly rise. However, existing car seats are designed according to a seated posture, necessitating verification for passenger safety and seat structure considerations in the context of autonomous driving, where comfortable postures may differ. For these reasons, it is anticipated that the seats of future autonomous vehicles will evolve with the incorporation of additional safety and convenience features. In this study, a three-axis car simulator was employed to investigate seat angles for comfortable postures of passengers in autonomous driving scenarios. Representative postures were identified to enhance passenger convenience. Furthermore, functional design factors contributing to passenger comfort were applied to conduct seat design, seat structure, and collision analysis, with an analysis of the interrelationships among design factors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.694-698
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• 2006

This paper presents an optimal design process using beads on a body panel to improve interior noise of a passenger vehicle. Except modification of structural members, it is difficult to find effective countermeasures that can work for the intermediate frequency range from 100 Hz to 300 Hz which lies between the booming and low medium frequency. In this study, it is a major goal to find additional counter-measures for this intermediate frequency range by performing optimal design of beads on body panels. The proposed method for design optimization consists of 4 sub-steps, that is, a) problem definition, b) cause analysis, c) countermeasure development and d) validation. The objective function is minimization of interior noise level. The major design variables are the geometrical shape of a bead and combination of beads on the critical panels. Sensitivity analysis and optimization are performed according to the predefined process for an optimal design. It is verified that the proposed design decreases the level of noise transfer function above 5 dB.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.857_858
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• 2009

On account of small size and light weight, a high-speed machine is regarded as a key technology for many future applications of drive systems. In high-speed applications, permanent magnet (PM) synchronous motors have a number of merits such as high efficiency and high power density. Accordingly, they are suitable for driving the air-blower of a fuel cell electric vehicle (FCEV) where space and energy savings are critical. Particularly, a surface-mounted PM motor of them is mainly used as a high-speed machine. However, the motor has a fatal flaw owing to a retaining can to maintain the mechanical integrity of a rotor assembly. The can results in the increase of magnetic air-gap length in the surface-mounted PM motor. Thus, in this paper, an interior PM motor is designed in order to drive the air-blower of FCEV instead of the surface-mounted PM motor, and the experimental results of two models are compared to verify the capability of the interior PM motor for a high-speed machine.