• 대한임베디드공학회논문지
• /
• 제14권3호
• /
• pp.143-150
• /
• 2019

In this paper, we have developed a module that prevents a driver from using mobile phone while driving. The module is equipped with a vibration sensor to determine if the vehicle is running, a BLE module to transmit the status of the module and a speaker to transmit audible/unaudible sound to the mobile terminal where GUI application is installed. If the vehicle is judged to be moving, the application is activated and the touch function of the mobile phone is blocked. Other data are also transmitted depending on the state of the module, which informs forced module removal, battery failure, or sleep mode of the module.

• 대한교통학회지
• /
• 제26권5호
• /
• pp.195-204
• /
• 2008

운전자가 도로를 주행하면서 안내표지판을 인지하고 원하는 목적지로 잘 도착할 수 있도록 하기 위해서는 인적요소, 표지판의 요소, 기하구조 등 여러 가지 원인이 잘 조화되어 운전자를 이끌어야 한다. 본 연구의 목적은 운전자가 표지판을 정확하게 인지하고 다음 목적지로 갔는지를 알아보기 위해서 성공여부(성공0, 실패1)의 개념을 사용하여 도로표지의 지명 판독과정에서 영향을 미치는 인자를 규명하는 것이다. 운전자의 인적요소, 표지판 요소 등을 고려하였으며, 도로주행시뮬레이터(driving simulator)를 이용하여 도로표지의 지명 판독과정에서 안전운행에 영향을 미치는 인자에 대한 통계 분석을 실시하였다. 통계적 분석은 선정된 변수를 토대로 Logistic Model을 이용하여 성공여부에 대한 확률식을 제시하였다. 본 연구의 결과는 도로표지 설계 및 설치에 있어서 도로 이용자에게 보다 좋은 시설이 될 수 있도록 하는데 기초자료로 활용될 수 있을 것이다.

• 대한기계학회논문집A
• /
• 제24권1호
• /
• pp.38-51
• /
• 2000

The study on the mechanical behavior of a spot-welded specimen is largely divided into the quasi-static overload failure analysis and the fatigue failure prediction. The main issue in an overload analysis is to examine the critical loads, thereby providing a generalized overload failure criterion. As the welding spot forms a singular geometry of an external crack type, fatigue failure of spot-welded specimens can be evaluated by means of a fracture parameter. In this study, we first present the limit loads of 4 representative types of single spot-welded specimens in terms of the base metal yield strength and specimen geometries. Recasting the load vs. fatigue life relationships experimentally, obtained here, we then predict the fatigue life of spot-weld specimens with a single parameter denoted the equivalent stress intensity factor. This crack driving parameter is demonstrated to successfully describe the effects of specimen geometry and loading type in a comprehensive manner. The suggested fatigue life formula for a single spot weld can play a key, role in the design and assessment of spot-welded panel structures, in that the fatigue strength of multi-spots is eventually determined by the fatigue strength of each single spot.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.811-818
• /
• 2005

Stability analyses on the 17 railroad cut-off soil slopes were carried out. The influences of rainfall infiltration on the slope stabilities were taken into account by seepage analyses using finite element method and by assuming ground water tables to be located adjacent to soil surface. The validity of those analyses were evaluated by comparing the slope failure characteristics between analysis results and the past failure records. The analyses were not appropriate to estimate the failure surface and the method considering only the increase of pore-water pressure (reduction of matric suction) as the influence of rainfall cannot appropriately estimate the surficial failures that occurred most of the cut-off soil slopes. For the better estimation of the surficial failure, the influence of water flows over slope surface which erode soil mass and/or increase driving force, should be evaluated and considered.

• 드라이브 ㆍ 컨트롤
• /
• 제20권3호
• /
• pp.9-14
• /
• 2023

In this paper, the selection of a reliable accelerated life test code for a 2-ton forklift was accomplished by choosing the driving resistance coefficient failure-free test time based on a 10,000-hour B₁₀ life. The overall life and average equivalent load of the vehicle were then calculated based on actual driving test conditions using the selected driving resistance coefficient. The gear train's accelerated life test code was selected by adjusting the equivalent load to a torque and rotation speed that did not exceed 125%(about 75HP) of the vehicle rated power. The safety of the test standards was validated by conducting an actual accelerated life test utilizing the proposed test method in this study and comparing the test result with the corresponding theoretical value. It is anticipated that the reliability of the accelerated life test in this paper will be enhanced, by incorporating actual driving performance data collected directly from the forklift and adjusting the conditions used in developing the accelerated life test code.

• 한국철도학회논문집
• /
• 제15권6호
• /
• pp.550-557
• /
• 2012

일반적으로 FMECA는 시스템에 치명적인 영향을 줄 수 있는 장치나 고장모드를 파악하고 우선순위를 판단하여 이를 설계나 시스템 유지보수에 반영할 때 사용할 수 있는 기법이다. 본 논문은 도시철도차량의 차상 신호설비인 ATC/ATO 시스템에 FMECA를 이용하여 도시철도차량의 운전장애 현상을 정량적으로 분석하고 위험요소를 도출한 다음 이를 제거하여 도시철도차량의 운전환경을 개선할 수 있도록 하는데 목적을 두었다. 이를 위해 본 연구에서는 FMECA를 활용한 분석을 통해 ADU 개선방안과 사례를 제시하였다.

• 한국도로학회논문집
• /
• 제18권3호
• /
• pp.127-134
• /
• 2016

PURPOSES : Low visibility caused by dark surroundings at nighttime affects the likelihood of accidents, and various efforts, such as installing road safety facilities, have been made to reduce accidents at night. Despite these efforts, the nighttime severity index (SI) in Korea was higher than the daytime SI during 2011-2014. This study determined the factors affecting daytime and nighttime accident severity through a discriminant analysis. METHODS : Discriminant analysis. RESULTS : First, drowsiness, lack of attention, and lighting facilities affected both daytime and nighttime accident severity. Accidents were found to be caused by a low ability to recognize the driving conditions and a low obstacle avoidance capability. Second, road conditions and speeding affected only the daytime accident severity. Third, failure to maintain a safe distance significantly affected daytime accident severity and nonsignificantly affected nighttime accident severity. The majority of such accidents were caused by rear-end collisions of vehicles driving in the same direction; given the low relative speed difference in such cases, the shock imparted by the accidents was minimal. CONCLUSIONS : Accidents caused by a failure to maintain a safe distance has lower severity than do accidents caused by other factors.

• 한국자동차공학회논문집
• /
• 제22권4호
• /
• pp.145-151
• /
• 2014

Modern vehicle has a lot of ECU(Electronic Control Unit) products to control many parts such as engine, transmission, brake, body and so on. ECU quality is one of important factors related to vehicle quality and driver's safety. Based on Bath-tub curve which presents failure rate during product lifetime, we designed and applied Accelerated Run-in Test into manufacturing line by simulating stress amount to ECU and developing the required software and efficient test equipment for mass production. This test makes ECU products stressed through electrical and thermal stresses under excessive driving condition, which induce potential initial failure of components in the ECU during production. The outcome until these days proved that Acceleration Run-in Test have reduced initial failure rates and increased quality of ECU products in the field outstandingly.

• 한국기계가공학회지
• /
• 제21권9호
• /
• pp.105-109
• /
• 2022

In this study, the cause of the acceleration failure of Hyundai Motor's 2.0-liter CRDi engine was analyzed. We tried to find problems through MDA (Measuring Data Analyzer) based on data such as vehicle speed, air intake, and air-fuel ratio obtained during the actual driving process. As a result, it was analyzed that the failure of the EGR valve exceeded the NOx emission standard and caused a decrease in engine output. Through this study, it is possible to reduce the time and cost of unnecessary maintenance and repair, and it is expected that a rapid cause analysis will be possible in the case of new failure diagnosis in the future.

• 한국ITS학회 논문지
• /
• 제21권5호
• /
• pp.218-232
• /
• 2022

차량의 물체 인식에 사용되던 센서인 레이더 센서를 위치 추정에 사용하기 위한 연구들이 진행되고 있다. 특히 레이더 센서에서 출력되는 도플러 속도를 이용하여 동적 물체와 정적 물체를 분류하고, 정적 물체만을 이용하여 에고 모션을 계산하는 방법이 연구되었다. 기존의 동적 물체 분류에서는 RANSAC을 사용한 방법이 제시되었는데, 단 한 번의 알고리즘 실패가 큰 영향을 미치는 위치 추정의 특성상 더 높은 성능을 가진 분류 방법이 필요하다. 본 논문에서는 동적 물체의 추적 및 필터링을 통해 기존 방법보다 분류 성능을 높이는 방법에 대해 제안한다. 추가적으로 GMPHD 필터를 사용하여 추적 성능을 최대로 향상시킨다. 제안된 방법은 기존의 방법과 비교하여 분류 정확도에서 더 높은 성능을 보였으며, 특히 알고리즘의 실패를 방지할 수 있다는 것을 보인다.