• 한국결정성장학회지
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• 제25권6호
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• pp.294-298
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• 2015

일본 국토교토성이 책정한 <도로교 장수명화 수선계획사업>에 의하면, 주요 지역에 건설된 RC 상판의 심각한 손상 원인은 대형차량의 주행하중에 의한 피로열화와 재료의 경년열화 등으로 보고되어지고 있다. 따라서 이에 대한 대책으로 탄소섬유 시트를 이용한 하부 접착 보강공법이 많이 소개되어지고 있으나, 최근에는 CFS와 동등한 재료특성치를 보유하며, 시공성이 뛰어난 탄소섬유 스트랜드 시트가 새로운 보강재료로써 관심이 증폭되어지고 있다. 그러나 이러한 CFSS의 윤하중 피로실험을 통한 내피로성 평가는 현재 일부 연구기관에서만 그 성과가 보고되어지고 있는 실정이며, 국내에서는 아직까지 연구성과에 관한 보고 등이 거의 없는 실정이다. 따라서 본 연구에서는 RC 상판의 하부에 CFS를 전면접착 보강한 실험체와 CFSS를 격자형으로 보강한 실험체를 제작하여, 윤하중 피로실험을 실시하고 내피로성을 평가하였다.

• 대한전자공학회논문지SP
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• 제49권3호
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• pp.30-39
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• 2012

본 논문에서는 검출된 운전자의 얼굴영역에서 눈의 형태를 인식하여 졸음 상태를 감지하는 기법을 개발하고 감지 결과에 따라 위험 상태를 알려주는 경보 시스템을 구현하고자 한다. 먼저 얼굴 검출에는 Haar 변환 기법을 이용하고 실험실환경, 차량환경 및 적외선 영상을 획득하여 다양한 조명 환경에서도 강인하도록 전처리 및 후처리 과정을 적용한다. 눈 검출에는 보통 한국인이라는 가정하에 눈의 위치 및 크기의 비례 구조 특성 등을 이용하여 후보 영역을 제한하고 트리구조에 대한 실험 결과로 고속 알고리즘을 구현하였다. 또한 졸음 상태를 인식하기 위해서는 눈의 개폐 형태를 검출할 수 있는 Hough 변환을 이용한 기법과 눈의 계폐에 따른 눈의 형태 비율을 이용한 기법을 새로이 제안하며, 눈이 감겨있는 시간을 측정하여 졸음 여부를 판단한다. 1단계 졸음 상태로 판단될 경우 통합 모니터링 인터페이스에서 운전자에게 경고음을 울리며 2단계 졸음 상태로 판단될 경우에는 CAN(Controller Area Network)을 통하여 안전벨트를 진동하게 함으로써 운전자에게 경고를 하는 시스템을 구현한다. 본 논문에서 제안하는 기법은 기존의 기법들과 비교하여 실험실 환경에서 평균 83.64% 이상의 검출률을 달성 하였으며, 실제 차량환경에서도 실험 결과를 통하여 평균적으로 우수한 결과를 보였다.

• 자동차안전학회지
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• 제14권2호
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• pp.57-69
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• 2022

Recently, as interest in self-driving cars has increased worldwide, research and development on the Advanced Driver Assist System is actively underway. Among them, the purpose of Adaptive Cruise Control (ACC) is to minimize the driver's driving fatigue through the control of the vehicle's longitudinal speed and relative distance. In this study, for the research of the ACC test in the real environment, the real-road test was conducted based on domestic-road test scenario proposed in preceding study, considering ISO 15622 test method. In this case, the distance measurement method using the dual camera was verified by comparing and analyzing the result of using the dual camera and the result of using the measurement equipment. As a result of the comparison, two results could be derived. First, the relative distance after stabilizing the ACC was compared. As a result of the comparison, it was found that the minimum error rate was 0.251% in the first test of scenario 8 and the maximum error rate was 4.202% in the third test of scenario 9. Second, the result of the same time was compared. As a result of the comparison, it was found that the minimum error rate was 0.000% in the second test of scenario 10 and the maximum error rate was 9.945% in the second test of scenario 1. However, the average error rate for all scenarios was within 3%. It was determined that the representative cause of the maximum error occurred in the dual camera installed in the test vehicle. There were problems such as shaking caused by road surface vibration and air resistance during driving, changes in ambient brightness, and the process of focusing the video. Accordingly, it was determined that the result of calculating the distance to the preceding vehicle in the image where the problem occurred was incorrect. In the development stage of ADAS such as ACC, it is judged that only dual cameras can reduce the cost burden according to the above derivation of test results.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.952-957
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• 2015

Recently, the interior permanent magnet (IPM) motors for electric vehicle (EV) traction motor are being extensively researched because of its high energy density and high efficiency. The traction motor for EV requires high power and high efficiency at the wide driving region. Therefore, it is essential to fully consider the characteristics of the motor from low speed to high-speed driving regions. Especially, when the motor is driven at high speed, a significant centrifugal force is applied to the rotor. Thus, the rotor must be stably structured and be fully endured at the critical speed. In this paper, aims to examine the characteristics of the IPM motor by adjusting the width of air-barrier according to the permanent magnet position which is critical in designing an IPM motor for EV traction motors and to conduct a centrifugal force analysis for grasping mechanical safety.

• 한국소음진동공학회논문집
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• 제16권7호
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• pp.704-711
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• 2006

Vibration test on MAST(multi axial simulation table) system has several advantage over one-axial vibration test that could simulate 6-DOF, 3-axial translation and 3-axial moment, at the same time. Since field vibration motion can be fully represented with 6-DOF, multi-axial vibration test on vehicle component is widely conducted in technical leading companies to make sure its fatigue performance in vibration environment. On the way to fulfill the process, editing technique of obtained field data is key issue to success a reliable vibration testing with MAST system. Since the original signals are not only too large to fulfill it directly, but all of the measured data is not guarantee its convergency on generating its driving files, editing technique of the original signals are highly required to make some events that should meet the equal fatigue damage on the target component In this paper, key technique on editing a field data feasible for MAST system is described based on energy method in vibration fatigue. To explain its technique explicitly, author first introduced a process on field data acquisition of two vehicle component and then, representing events are produced to keep up with the editing strategy about a energy method. In the final chapter, a time information regarding a vibration test on MAST system is derived from the energy data which is critical information to perform a vibration test.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.764-769
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• 2006

Vibration test on MAST(multi axial simulation table) system has several advantage over one-axial vibration test that could simulate 6-DOF, 3-axial translation and 3-axial moment, at the same time. Since field vibration motion can be fully represented with 6-DOF, multi-axial vibration test on vehicle component is widely conducted in technical leading companies to make sure its fatigue performance in vibration environment. On the way to fulfill the process, editing technique of obtained field data is key issue to success a reliable vibration testing with MAST system. Since the original signals are not only too large to fulfill it directly, but all of the measured data is not guarantee its convergency on generating its driving files, editing technique of the original signals are highly required to make some events that should meet the equal fatigue damage on the target component In this paper, key technique on editing a field data feasible for MAST system is described based on energy method in vibration fatigue. To explain its technique explicitly, author first introduced a process on field data acquisition of two vehicle component and then, representing events are produced to keep up with the editing strategy about a energy method. In the final chapter, a time information regarding a vibration test on MAST system is derived from the energy data which is critical information to perform a vibration test.

• 한국융합학회논문지
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• 제6권5호
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• pp.85-90
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• 2015

본 논문은 ATV차량의 전면에 부착되는 범퍼의 구조적인 형상에 따른 수명평가를 피로해석을 토대로 연구하였다. 본 연구의 목적은 진동과 같이 반복적인 하중조건에 노출되는 범퍼의 특성의 파악하며, 여러 가지 피로 상황에서 발생되는 크랙의 위치를 사전에 파악하며 이를 보완하기 위함이다. 다목적 차량이 일반적인 포장도로가 아닌 비포장도로와 같은 험로를 주행하게끔 설계됨을 고려한다. 그리고 이러한 주행환경에 대한 수명평가 연구를 통해, 그 범퍼의 취약부위를 파악한다. 본 연구의 해석결과를 토대로 자동차 범퍼의 안전설계를 함으로서 내구성을 향상하고 설계에 있어 융합기술에 접목하여 그 미적인 감각을 나타낼 수 있다.

• 한국군사과학기술학회지
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• 제20권1호
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• pp.1-11
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• 2017

In this paper, design requirements of the large radar were investigated, and development was performed through the analysis and design. Large radar should be designed by bearing the 75 knot wind force and $20kg/m^2$ ice mass as operating conditions in order to meet structural stability, and driving torque and bearing load were calculated for securing the driving stability. Thermal dissipation analysis was performed considering TRM and DC-DC Converter's limitation temperature by $50^{\circ}C$ ambient temperature condition in order to attain thermal stability, and PSD and shock analysis were carried out by using MIL-STD-810G vibration and shock specification in order to transport and installation of the large radar. As a result, all components of large radar could secure the structural stability more than 2.8 factor of safety, and driving stability was also secured with adequate bearing fatigue life. Thermal stability was attained by allowable max temperature 88.7 C of the TRM, and structural stability for transportation and installation of the large radar was also secured more than 5 factor of safety. After it was transported and installed to the radar site, operating capability was finally verified by rotating the large radar.

• 한국자동차공학회논문집
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• 제19권3호
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• pp.57-64
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• 2011

In general, the durability performance of a large-sized military truck has been checked through a field durability test which required many man-hours and costs. To reduce these expenses, the durability analysis using a VTL(Virtual Test Lab) at an initial design stage was introduced recently. In this paper, the VTL with a multi-post testrig template for a large-sized truck was developed to compute the load histories transferred to cabin and chassis frame. The VTL consisted of trimmed FE models of cabin, chassis frame, and deck, dynamic models of front and rear suspensions, and a 8-post testrig template. The basic characteristics of the VTL were correlated with experimental results which had been extracted from actual driving test, modal test, and static weight test. The fatigue analysis using MSM(Modal Superposition Method) was applied to evaluate the durability performance of a large-sized military truck. From a series of analytic methods, it is shown that the fatigue analysis process using the VTL could be a useful tool to estimate the fatigue lives and weak areas of a large-sized military truck.

• 대한교통학회지
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• 제34권4호
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• pp.341-353
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• 2016

고속도로는 중 장거리 차량 통행을 담당하고 있으며, 공공기관들의 지방이전 등으로 인해 직장과 거주지 간의 거리가 멀어짐에 따라 운전자들의 통행거리는 증가 추세를 보이고 있다. 이러한 이유로 고속도로에서는 피로나 졸음으로 인한 운전자요인 사고의 비중이 매우 높다. 하지만 기존의 사고예측 연구에서는 주로 도로요인, 환경요인, 차량요인 등 외적인 조건만을 고려하였을 뿐 도로구간별 운전자의 통행행태를 고려하지 못하였다. 본 연구에서는 대용량 내비게이션 경로자료를 활용하여 통행행태기반의 사고지표(운전피로도지표)를 제안하고, 교통사고와의 관계를 살펴보았다. 분석결과 개발된 지표와 교통사고와는 높은 상관성을 보이는 것으로 나타났으며, 이를 통해 시설물 위주에서 통행행태기반으로 교통사고 예측연구의 패러다임 변화가 필요함을 확인할 수 있었다. 본 연구에서 제안한 지표는 다양한 분야에서 활용이 가능할 것이다. 교통사고(졸음, 부주의운전 등)를 사전에 방지하기 위한 정보제공, 고속도로 안전진단 핵심요소기술로의 활용, 휴게소 및 졸음쉼터 입지 우선순위 선정 시, 피로한 구간에 대하여 운전자에게 주의환기를 위한 방법(노면요철, 그루빙 등)을 적용해야하는 구간 선정 시 활용이 가능할 것이다.