• 한국자동차공학회논문집
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• 제17권4호
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• pp.10-15
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• 2009

Emission regulations on greenhouse gas(GHG) in automobiles have been stringent because of global warming effect. Over 90% of total GHG emission are carbon dioxides and about 20% of this $CO_2$ emission are emitted from automobiles. In this study, 110 vehicles were tested on a chassis dynamometer and $CO_2$ emissions and fuel economy were measured in order to investigate the characteristics of $CO_2$ emission factor from passenger vehicles which are the most dominant vehicle type in Korea. The characteristics of emissions in accordance with displacements, gross vehicle weight, NIER and CVS-75 speed mode were discussed. It was found that vehicles having larger displacement, heavier gross vehicle weight, automatic transmission and specially at cold start emitted more $CO_2$ emissions. From these results, correlation between $CO_2$ emission and fuel economy was also obtained. This study may contribute to evaluate domestic greenhouse gas emissions and establish national policies on climate changes in future.

• 한국자동차공학회논문집
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• 제18권6호
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• pp.130-137
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• 2010

Due to test facility and specialty, it is physically difficult to conduct the modal tests of large-sized structures such as truck, bus and airplane. So, in case of a large-sized truck, the mode analysis on a full vehicle model comprised of reliable cabin, frame, and deck has been generally performed. However, the reliability of overall vibrational characteristics of the analytic model has not been fairly guaranteed by the testified models of each subsystem owing to the existence of cab suspension and the nonlinear mounting between a chassis frame and a special deck system. In this paper, a method to find out the modal characteristics of a large-sized military truck is presented. New modal test equipment is developed to set the boundary conditions of three military truck variants as close as a free-free condition. And the mode analysis method using coupled structure and dynamic models is established to consider the above-mentioned dynamic non-linearities of the vehicle itself. The usefulness of the suggested method is verified by comparing with the modal test results. Finally, the modal parameters of the final variant are extracted using the proved analytic method.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.967-976
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• 2012

본 논문은 자동차 환경규제에 따른 CO2 감소 및 연비향상을 위하여 Stop&Go 기능을 적용한 소형 승용차에 대한 파워트레인 마운트 (Powertrain Mount) 의 진동 소음 최적화 방향을 제시하였다. 이를 위해 현재 "A" 차량에 적용중인 파워트레인 마운트 시스템을 분석한 후 다구찌 기법을 활용하여 파워트레인 마운트에 적용된 고무 동특성에 대한 다양한 변수를 제시하였고, 고무의 동특성 변수에 의해 만들어진 테스트 제품을 AHP(Analytic Hierarchy Process)기법을 적용하여 Stop&Go 기능에 적합한 진동 소음의 최적화 정도를 검증하였다. 이와 같은 시스템을 파워트레인 마운트의 초기 디자인 검증에 적용함으로써, 파워트레인 마운트의 고무 동특성에 대한 엔지니어링 노하우 (Engineering Know-How) 없이도 엔진의 움직임으로 야기되는 진동 소음의 문제점을 파악하고 이를 효과적으로 제어하는데 큰 역할을 할 것으로 예상된다.

• 한국대기환경학회지
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• 제24권3호
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• pp.275-283
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• 2008

Since mobile source is a major source of VOCs, quantifying emissions from motor vehicles is an important factor to control VOCs in atmosphere. In this study, in order to evaluate tailpipe VOCs emissions from motor vehicles, mass emissions of non-methane volatile organic compounds from 45 vehicles were determined. Measurements were made on a chassis dynamometer using CVS-75 mode and speed specific drive modes. Target VOCs are 53 compounds determined as the volatile ozone precursors. The individual VOCs composition of vehicle emission and emission rates were also determined. In case of gasoline vehicles, VOCs emission from over 80,000 km vehicles were about 46% larger than less 80,000 km vehicles. The difference in benzene and toluene according to driving mileage was 44% and 26% respectively. The composition of VOCs were different by fuel type. The order of VOCs composition was paraffins>aromatics>olefins in gasoline vehicle emissions, paraffins>olefins>aromatics in light duty diesel vehicle emissions. The VOCs emissions were decreased as vehicle speed increasing. These results will be used to calculate total VOCs emissions from automobiles in the future.

• 전자공학회논문지S
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• 제35S권9호
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• pp.43-52
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• 1998

본 논문에서는 능동형 샤시 시스템이 정착된 차량의 안정성(Stability), 조종성(Handling) 및 승차감(Ridecomfort)을 향상시키기 위한 새로운 통합제어기를 설계한다. 하이브리드 퍼지논리 제어기는 퍼지논리 제어기, 스카이 훅 제어기, 자세 제어기 및 롤 모멘트 분포 제어기로 이루어지며, 차량의 주행상태에 기초한 통합제어로직을 이용하여 위와 같은 제어기들을 적절히 결합시켜 사용한다. 또한 MATRIXx/SYSTEMBBUILD 소프트웨어를 이용하여 16자유도 차량모델에 대하여 시뮬레이션을 수행함으로써 차량의 승차감, 조종성 및 능동적 안전도가 향상됨을 확인한다.

• KIEAE Journal
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• 제8권4호
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• pp.63-69
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• 2008

The thesis is a comparative analysis of Infill Technologies between Korea's long-life Mock-up House, a study driven by 'Durability and Flexibility of Long-life Housing Technology Development' of R&D, and Japan's KSI experimental house, the major example of Japan's long-llfe housing. In terms of the domestic Mock-up House, a system of building the floor first was applied. The floor material of each housing unit required a development of dry heating component that is partially substitutable in order to avoid conflict with the finishing. Also, a development of a floor system that can counteract against the construction inaccuracy was required. In the Case of an outer wall, need to make the wall with the chassis. In the case of ceiling, need to develop the double ceiling system which is good for sound insulation. Also, in comparison to KSI experimental house in Japan, it would require to develop a wiring system of the ceiling which can react to the movement of the wall. Especially, to assure the flexible nature of an internal wall, it would desperately require the research and development of the products related to components and flexible system of mechanical/electrical/communication parts as well as supporting institutionalized system for this development. Furthermore, for KSI experimental house in Japan, it would be necessary to formulate a construction manual as well as a systematic and practical planning guide to invent a new interface rule which will secure simplicity of assembling, dismantling, installation and replacement of architectural components for which research development is quite insignificant at the moment. This effort will have to continue to give a solid direction for better application of such reference manual during construction and development of long life span apartment by public sector as well as private corporations.

• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.634-639
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• 2012

The contribution levels of emissions from the heavy-duty vehicles have been continuously increased. Among the exhaust emissions, NOx (nitric oxides) have a ratio of 73.2% and particle matters have a proportion of 61.8% in the heavy-duty vehicles. Also, natural gas vehicles have the 78.9% of total registered local buses in Korea. Therefore, the investigation on emission characteristics of heavy-duty vehicles using CNG and diesel fuel according to the various driving cycles was carried out in this study. In order to analyze the emission characteristics, the five kinds of buses by using CNG and diesel fuels with a after-treatment devices (DPF, p-DPF) was used and five test driving schedules were applied for analysis of emission characteristics in a chassis dynamometer. To analyze the exhaust emission, the exhaust emission and PM analyzers were used. From this study, it is revealed that diesel buses with after-treatment had reduced emission of CO, HC, PM but NOx. Also, NMHC emission of CNG bus have a higher level and NOx level was similar with diesel buses. In addition, emissions in NIER06 with slow average speed shows lowest levels compared to other test modes.

• 대한기계학회논문집B
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• 제36권5호
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• pp.503-508
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• 2012

최근에 들어서 이산화탄소가 지구온난화의 원인으로 알려져 있기 때문에 온실가스 문제는 이슈화 되어 왔다. 본 연구는 한국에서 운행 중인 차량에서 이산화탄소 배출가스 영향인자 특성을 파악하고자 했다. 가솔린 자동차 129대, 디젤자동차 100대, LPG 자동차 34대 차량을 차대 동력계에서 시험했다. 시험과정에서 이산화탄소, 일산화탄소 그리고 연료저감율을 측정했다. 실험모드는 현재 한국에서 경차의 배출가스를 규제하기 위해서 배출계수를 산정하기 위해 개발된 CVS-75 모드에서 이루어졌다. 실험 결과 배기량, 연료소비율, 연료 종류, 주행패턴, 마일수 그리고 이산화탄소 사이의 관련성이 조사되었다.

• 대한기계학회논문집A
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• 제37권5호
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• pp.673-678
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• 2013

크립 그론 소음은 자동차 브레이크에서 제동압 제거 초기나 제동 말기에 발생하는 저주파 소음 현상이다. 이러한 현상은 브레이크 시스템에 국한되는 문제가 아니라 샤시의 진동특성에도 영향을 받는 것으로 예측되고 있기 때문에 그 특성 파악이 어려운 것으로 알려져 있다. 때문에 현재까지의 연구는 마찰재를 통한 개선이 대부분이었다. 그래서 실차를 이용한 실험은 여전히 어려운 과제로 남겨져 있다. 이번 연구는 환경에 민감한 크립 그론 소음의 특성과 샤시 진동특성의 영향을 실차와 NVH 전용 샤시 다이나모를 이용한 여러 가지 실험을 통해 알아 보았다. 이를 통해 실차에서의 새로운 크립 그론 소음 평가시 중요한 통제변수를 제시하고 차량 시스템 측면에서 소음 저감 대책 연구에 대한 가능성을 확인할 수 있었다.

• 한국수소및신에너지학회논문집
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• 제28권3호
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• pp.287-294
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• 2017

EVs manufacturers typically target a range of 300 km on a fully charged battery. Many studies have been conducted to improve these disadvantages. As a results, the mileage of EVs is expected to increase significantly. However, as the distance traveled by EVs increases, current test method (SCT) have many difficulties. The biggest problem is that it takes a lot of time to test an EVs and greatly increases the error rate during the test period. In order to solve these problems, this paper discusses the fuel economy test method of EVs for energy efficiency and mileage. The comparison of test methods was achieved by chassis dynamometer test about EVs. These review of test methods are intended to both improve testing efficiency and provide a practical testing methodology that can be easily adapted to accommodate future testing enhancements. In conclusion, the results of MCT mode and SCT mode comparison show similar results within 3 %, confirming that the test method is appropriate. Also, as the CSCM distance becomes shorter in the MCT mode, the mileage becomes longer and the fuel economy becomes lower. As a result, the error from the SCT test results is expected to increase. In order to minimize the error of SCT measurement fuel economy, it is recommended to maximize the CSCM driving distance. However, since the timing of the EOT is not clearly known, it is reasonable to define the allowable range of the CSCE to be within 20 % of the MCT total mileage.