• 한국자동차공학회논문집
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• 제20권3호
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• pp.113-118
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• 2012

Collision detection plays a key role in collision mitigation system. The malfunction of the collision mitigation system can result in another dangerous situation or unexpected feeling to driver and passenger. To prevent this situation, the collision time, offset, and collision decision should be determined from the appropriate collision detection algorithm. This study focuses on a method to determine the time to collision (TTC) and frontal offset (FO) between the ego vehicle and the target object. The path prediction method using the ego vehicle information is proposed to improve the accuracy of TTC and FO. The path prediction method utilizes the ego vehicle motion data for better prediction performance. The proposed algorithm is developed based on laser scanner. The performance of the proposed detection algorithm is validated in simulations and experiments.

• 한국소음진동공학회논문집
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• 제25권3호
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• pp.141-149
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• 2015

In this study, there is an investigation about the sound quality of automotive horn that attached to luxury sedans. In order to define a questionnaire of horn sound quality the factor analysis is conducted. Ten automotive horns are selected for this research and ten passenger cars(nine is luxury sedan and one economy class car). Luxury is used for the questionnaire as an attribute for the sound quality of car horn. The interior noises for ten test cars are recorded and used for the subjective analysis of car horn sound. In the paper, new sound metric for the car horn sound is presented. The new sound metric is used for the objective sound index for the prediction of subjective sound quality of car horn.

• 한국자동차공학회논문집
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• 제22권3호
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• pp.12-18
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• 2014

This paper describes about the development of new concept's rear wheel guards for the reduction of Road Noise in the passenger vehicle using test. The new wheel guards are proposed by various frequency chamber concept and different textile layers concept. Two wheel guards were verified by small cabin resonance test and vehicle test. Through new developing process without vehicle test, Result of road noise will be expected when new concepts and materials of wheel guard is applied into automotive vehicle. As a result of the application of Aimed Helmholtz and Multi-layers concept, this paper classifies the road noise, cost and weight are reduced by new concepts and the solutions are adopted into the 2 cars.

• 자동차안전학회지
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• 제12권1호
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• pp.33-38
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• 2020

Since a diesel vehicle scandal related to the 'A' automobile company was issued in the United States in 2015, many countries have been interested in emission defeat devices. Being embedded in some diesel passenger cars sold in Korea, a defeat device for exhaust gas may have influence on both fuel economy and NOx emissions. In order to examine such effects, we carried out laboratory indoor tests as well as real road driving tests using four models of 'A' automobile company which may employ defeat devices. Those tests were performed observing the test modes of FTP-75, HWFET, and NEDC. Although fuel economy and NOx emissions according to indoor tests comply with the suggested tolerance, the findings in the real road driving tests do not satisfy the tolerance. Along with the results provided in this study, further evaluation may be necessary to investigate the noticeable difference between the indoor and real road tests.

• 한국재난정보학회 논문집
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• 제17권4호
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• pp.733-746
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• 2021

연구목적: 본 연구는 철도차량 내 승객 이상행동 및 위험상황 중 중요한 위험요소를 도출하기 위하여 승객 및 운용기관 종사자의 의견을 조사하고 분석을 하였다. 연구방법: 일반국민 20~60대 성인남녀 1,000명 및 전국 11개 기관의 종사자 429명에게 설문조사를 수행하였다. 일반국민에게는 지하철, 일반철도, 고속철도 등으로 구분하여 철도차량 내 발생 가능한 위험 상황에 대한 설문을 조사하였으며 운영기관 종사자들에게는 지하철 내의 위험 상황에 대한 설문을 조사하였다. 연구결과: 승객위험요소 발생에 대한 빈도 및 중요도를 판단근거로 선정된 철도차량내 승객 위험요소(이상행동 및 위험 상황) 중 주요 위험요소로 '차량 문끼임', '성추행', '주취행동', '싸움/폭행', '배회'. '마스크 미착용'으로 선정하였다. 결론: 승객에게 영향을 미치는 주요 위험요소는 일반 국민 및 철도운영기관의 종사자들의 설문조사를 통하여 선정되었다. 본 연구에서 얻은 결과인 철도차량내 주요 위험요소 발생시 신속하며 지속적으로 감지할 수 있는 AI 기술이 적용된 CCTV 감지 시스템이 개발될 예정이다.

• 자동차안전학회지
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• 제8권4호
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• pp.12-17
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• 2016

NHTSA (National Highway Traffic Safety Administration) has offered consumers the vehicle safety information on their car since 1978. NHTSA believes that they contribute auto makers to develop safer vehicle for customers, which will result in even lower numbers of deaths and injuries resulting from motor vehicle crashes. NHTSA has been studied why people are still dying in frontal test despite of the use of many restraints system and they understand that current test does not reflect real world crash data such as oblique and corner impact test. As a result, NHTSA announced that a new test method will be introduced to use of enhanced biofidelic dummy and new crash avoidance technology evaluation from 2019. New and refined injury criteria will be applied to Head / Neck / Chest / Lower Leg. BrIC(Brain Injury Criterion)value in NHTSA test results using THOR dummy from 2014 to 2015 was average 0.91 and 1.24 in driver and passenger dummies. IIHS 64kph SOF test is the most likely to new frontal oblique test in an aspect of offset impact which is being studied by NHTSA. In this paper, we focused on head injury, especially brain injury - BrIC and conducted IIHS 64kph SOF (Small Offset Front) test with Hybrid III dummy to evaluate the injury for BrIC. Based on the test results, these data can be predicted BrIC level and US NCAP rating with current vehicle.

• International Journal of Automotive Technology
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• 제6권1호
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• pp.23-28
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• 2005

The presented investigation of shift clonk in a vehicle with front-wheel drive shows how a detailed analysis of the complete acoustic system with respect to excitation, transfer and radiation foremost enables possibilities of noise reduction to be worked out. One of the most important basics for the shift clonk analysis was a synchronous measurement of both, torsional vibrations in the drive train on the excitation side as well as airborne and structure-borne noise signals on the transfer and radiation side. Thus, root causes could be identified and improvement measures of the internal shift system could be worked out. An analysis of the transfer paths by means of airborne and structure borne noise measurements made evident that the side shafts were responsible for the disturbing frequencies in the transfer paths. With the help of the FE-simulation it was possible to develop measures of structure optimisation for the side shaft system. The realisation of these measures clearly reduced the shift-noises in the vehicle interior.

• International Journal of Automotive Technology
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• 제6권1호
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• pp.29-35
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• 2005

The structural integrity of either a passenger car or a light truck is one of the basic requirements for a full vehicle engineering and development program. The results of the vehicle product performance are measured in terms of ride and handling, durability, Noise/Vibration/Harshness (NVH), crashworthiness, and occupant safety. The level of performance of a vehicle directly affects the marketability, profitability and, most importantly, the future of the automobile manufacturer. In this study, the Virtual Proving Ground (VPG) approach has been developed to simulate dynamic nonlinear events as applied to automotive ride & handling. The finite element analysis technique provides a unique method to create and analyze vehicle system models, capable of including vehicle suspensions, powertrains, and body structures in a single simulation. Through the development of this methodology, event-based simulations of vehicle performance over a given three-dimensional road surface can be performed. To verify the predicted dynamic results, a single lane change test was performed. The predicted results were compared with the experimental test results, and the feasibility of the integrated CAE analysis methodology was verified.

• The Journal of the Acoustical Society of Korea
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• 제18권3E호
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• pp.3-8
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• 1999

In speech recognition for real-world applications, the performance degradation due to the mismatch introduced between training and testing environments should be overcome. In this paper, to reduce this mismatch, we provide a hybrid method of spectral subtraction and residual noise masking. We also employ multiple model approach to obtain improved robustness over various noise environments. In this approach, multiple model sets are made according to several noise masking levels and then a model set appropriate for the estimated noise level is selected automatically in recognition phase. According to speaker independent isolated word recognition experiments in car noise environments, the proposed method using model sets with only two masking levels reduced average word error rate by 60% in comparison with spectral subtraction method.

• 한국자동차공학회논문집
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• 제19권2호
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• pp.12-19
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• 2011

Real-world accident cases were investigated to understand injury characteristics of the elderly driver. A total 10 cases of car-to-car frontal crash accidents from passenger car including SUV claimed to domestic car insurance company were reviewed. The injury characteristics of the elderly were analyzed from personal information (gender, age), medical treatment record (medical certificate, curative days), vehicle information (model, air-bag, seatbelt) and damage information. This study showed that elderly driver has higher possibility of thorax injury than non-elderly's. Moreover, Injury type and severity were more severe than non-elderly driver at similar type accident conditions. Also, elderly driver's medical treatment period needs 3 times more than non-elderly driver's.