• 품질경영학회지
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• 제51권2호
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• pp.283-296
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• 2023

Purpose: The purpose of this study is to actually implement and verify whether welding defects can be detected in real time by utilizing deep learning AI solutions in the welding process of electric vehicle hairpin winding motors. Methods: AI's function and technological elements using synthetic neural network were applied to existing electric vehicle hairpin winding motor laser welding process by making special hardware for detecting electric vehicle hairpin motor laser welding defect. Results: As a result of the test applied to the welding process of the electric vehicle hairpin winding motor, it was confirmed that defects in the welding part were detected in real time. The accuracy of detection of welds was achieved at 0.99 based on mAP@95, and the accuracy of detection of defective parts was 1.18 based on FB-Score 1.5, which fell short of the target, so it will be supplemented by introducing additional lighting and camera settings and enhancement techniques in the future. Conclusion: This study is significant in that it improves the welding quality of hairpin winding motors of electric vehicles by applying domestic artificial intelligence solutions to laser welding operations of hairpin winding motors of electric vehicles. Defects of a manufacturing line can be corrected immediately through automatic welding inspection after laser welding of an electric vehicle hairpin winding motor, thus reducing waste throughput caused by welding failure in the final stage, reducing input costs and increasing product production.

• 한국자동차공학회논문집
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• 제12권2호
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• pp.148-159
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• 2004

This paper discusses vibration mode of the drivesystem considered the vehicle body's dynamic characteristics to study the influence of the vehicle body's dynamic characteristics on the vibration mode of the engine mount system and the ride quality of a vehicle. The simulation model consists of the engine mount system, the powertrain and the rigid or elastic vehicle body. Variables used in this study are the stiffnesses of an engine mount system and the excitation forces. The Goals of the study are analyzing both the vibration transmitted to the vehicle body including the drivesystem and the influence of the vehicle body's dynamic characteristics on the engine mount system. The mode of drivesystems with a rigid and a elastic vehicle body was compared. From the result of the forced vibration analysis for the drivesystem with a elastic vehicle body, it is shown that the vehicle body's dynamic characteristics influence on the engine mount system reciprocally.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.187-192
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• 2003

of the road would be a key index judged for a safety at the vehicle driving on the road. In Korea, as seen through a lot of documents, the vehicle driving speed is much faster compared with the design speed. The vehicle driving speed is an important element to get to know the vehicle driving characteristics. However, it is not easy to obtain the vehicle driving speed relating to vehicles' consecutive movements just merely through the presently used methods of vehicle driving speed. In consequence, this study has conducted photographing vehicle movements by use of digital moving images. Based on digital moving Images pictured, we have obtained a certain time interval frame and extracted out vehicles' coordinates and calculated vehicle speed from the firstly rectified image and the secondly rectified image. We could obtain comparatively exact results in the calculation of vehicle driving speed as errors of about 4%, as a result of comparison and verification of vehicle speed calculated from the digital moving images and the speed obtained from DGPS.

• 한국디지털정책학회:학술대회논문집
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• 한국디지털정책학회 2004년도 International Conference on Digital Policy & Management
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• pp.185-202
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• 2004

Recent development in wireless computing and GPS technology cause the active development in the application system of location information in real-time environment such as transportation vehicle management, air traffic control and location based system. Especially, study about vehicle location tracking system, which monitors the vehicle's position in a control center, is appeared to be a representative application system. However, the current vehicle location tracking system can not provide vehicle position information that is not stored in a database at a specific time to users. We designed a vehicle location tracking system that could track vehicle location using mobile interface such as PDA. The proposed system consist of a vehicle location retrieving server and a mobile interface. It is provide not only the moving vehicle's current location but also the position at a past and future time which is not stored in database for users.

• Journal of Mechanical Science and Technology
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• 제16권9호
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• pp.1166-1174
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• 2002

This paper presents the implementation and vehicle tests of a vehicle longitudinal control scheme for Stop and Go cruise control. The control scheme consists of a vehicle-to-vehicle distance control algorithm and throttle/brake control algorithm for acceleration tracking. The desired acceleration of a vehicle for vehicle-to-vehicle distance control has been designed using Linear Quadratic optimal control theory. Performance of the control algorithm has been investigated via vehicle tests. A millimeter wave radar sensor has been used for distance measurement. A stepper motor and an electronic vacuum booster have been used for throttle/brake actuators, respectively. It has been shown that the proposed control algorithm can provide satisfactory performance.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.303-310
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• 2007

The vehicle noise is classified into interior and radiated exterior noise. And it influences on consumer‘s vehicle decision and traffic noise environment very much. In case of the vehicle exterior noise, it is related with traffic noise and in case of the interior noise, it is related with driver’s and passenger‘s sensitivity quality. Because these influenced on drivers and traffic environment, so standards are restricted by the laws and regulated for the measurement. But, the existence standards measuring the only sound pressure level are limit to reflect consumer’s sensitive aspects. Therefore in this study, the recent standards and laws were searched about domestic and abroad papers and the testing mode for the sound quality (SQ) evaluation was constructed about the vehicle interior noise. Finally, we aimed at the standard establishment to evaluate the vehicle interior SQ using statistics method.

• 센서학회지
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• 제14권6호
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• pp.409-414
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• 2005

For an intelligent vehicle driving which uses magnetic markers and magnetic sensors, we can get every kind of road information while moving the vehicle if we use the code that is encoded with N, S pole direction of markers. If we make it an only aim to move the vehicle, it becomes easy to control the vehicle the more we put markers close. By the way, to recognize the direction of a marker pole it is much better that the markers have no effect each other. To get road informations and move the vehicle autonomously we propose the methods of arranging magnetic sensors and algorithm of recognizing the position of the vehicle with those sensors. We verified the effectiveness of the methods with computer simulation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.659-664
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• 2000

Fuel-consumption and catalyst-out emissions of a parallel hybrid electric vehicle are affected by operating region of an engine. In many researches, It is generally known that it is profitable in fuel- consumption to operate engine in OOL(Optimal Operating Line). We established the mathematical model of a parallel hybrid electric vehicle, which is linear time-invariant. To operate an engine in OOL, we applied RHC(Receding Horizon Control) to the driving control of a parallel hybrid electric vehicle. And it is known that the RHC has advantages such as good tracking performance under state and control constraints. This RHC is obtained by using linear matrix inequality (LMI) optimization. In this paper, there are three main topics. First, without state and control constraints, the optimal tracking of OOL was simulated. Second, with state and control constraints by engine and motor performances, the optimal tracking of OOL was simulated. In the last, we studied on the optimal gear ratio. That is to say, we combined the RHC and the iterative simulation to extract the optimal gear ratio. In this simulation, the vehicle is commanded to track the reference vehicle trajectory and the engine is operated in the optimal operating region which is made by the state constraints.

• 한국소음진동공학회논문집
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• 제17권12호
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• pp.1230-1237
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• 2007

The vehicle noise is classified into interior and radiated exterior noise. And it influences on consumer's vehicle decision and traffic noise environment very much. In case of the vehicle exterior noise, it is related with traffic noise and in case of the interior noise, it is related with driver's and passenger's sensitivity quality. Because these influenced on drivers and traffic environment, so standards are restricted by the laws and regulated for the measurement. But, the existence standards measuring the only sound pressure level are limit to reflect consumer's sensitive aspects. Therefore in this study, the recent standards and laws were searched about domestic and abroad papers and the testing mode for the sound quality(SQ) evaluation was constructed about the vehicle interior noise. Finally, we aimed at the standard establishment to evaluate the vehicle interior SQ using statistics method.

• 조명전기설비학회논문지
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• 제14권2호
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• pp.31-35
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• 2000

본 논문에서는 차량의 추종 주행 제어기를 비선형 상태관측자를 이용하여 설계한다. i 번째 차량(추종차량}과 i-1 번째 차량(선행차량) 간의 거리(상대거리)만을 측정하여 아는 것으로 간주 한다. 선행차량의 속도 및 가속도를 추정하기 위한 비션형 상태관측자를 설계하여 추종차량의 추종 주행 제어기에 이용할 수 있도록 한다. 본 논문에서 제안하는 방법이 차간 통신이 필요 없음을 수학적으로 증명한다. 또한 비선형 상태관측자를 이용하여 추정한 선행 차량간의 상대속도 및 상대가속도 오차가 '0' 으로 수렴함을 증명한다. 제안한 방법의 타당성은 수학적인 증명과 더불어 컴퓨터 시뮬레이션을 통하여 검증한다.