• 한국자동차공학회논문집
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• 제16권5호
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• pp.44-48
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• 2008

This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.

• 유공압시스템학회논문집
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• 제5권4호
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• pp.17-25
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• 2008

This study presents an analytical model of the pneumatic circuit of an air suspension system to analyze the characteristics of vehicle height control. The analytical model was developed through the co-simulation of Simulink(air spring) and HyPneu(pneumatic circuit). Variant effective area of air spring and flow coefficients of pneumatic valves were estimated experimentally prior to the system test, and utilized in simulation. One-comer test apparatus was established using the components of commercial air suspension products. The results of simulation and experiment were so close that the proposed analytical model in this study was validated. However the frictional loss of conduit and heat dissipation which were ignored in this study need to be considered in future study. As an application example of proposed analytical model, an alternative pneumatic circuit of air suspension to conventional WABCO circuit was evaluated. The comparison of simulation results of WABCO circuit and alternative circuit show that proposed analytical model of co-simulation in this study is useful for the study of pneumatic system of automotive air suspension.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.193-203
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• 2012

This study analyzed regular transportation costs between port warehouses and processing plants and between processing plants and central distribution centers and further transportation costs relations according to empty transfer rates in each circulation by examining the distribution routes of imported grain including wheat, barley, corn, and soybean, namely port warehouses, processing plants, and central distribution centers. Based on the results, the study compared and reviewed the logistics transportation costs. The analysis results of the alternative model show that logistics operational costs could be considerably cut down by introducing a flexible vehicle transportation operational method, which is to change the vehicle loading parts for proper substitute transportation after unloading and transport them to other locations such as central distribution centers instead of returning empty, as an alternative to high operational costs deriving from empty vehicle operation in each circulation after unloading items in case of transportation of imported grain and processed items. The results allow for a more realistic approach to general problems with large-scale distribution network operation and provide a theoretical foundation to serve as a guide to establish policies for corporate operation of imported grain logistics systems.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.496-501
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• 2008

Recently, many automotive companies tend to apply an air quality system (AQS), which prevents polluted air such as smoke or dust by controlling air intake actuator of vehicle, to satisfy the consumer's need for agreeable in-vehicle environment. However, performance of the traditional AQS is not satisfactory because a polluted air may enter into the inside of vehicle through the breaks of windows. Especially, the commercial vehicles such as bus or truck need to be prevented polluted air from the breaks of vehicle. Hence, as an alternative to the traditional AQS, this paper presents the architecture of smart AQS for commercial vehicle and implementation of the smart AQS. Also, the performance of the suggested system is evaluated through an experimental testbed.

• 한국가스학회지
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• 제19권6호
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• pp.34-39
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• 2015

최근 차량용 에너지의 소비는 대부분 화석연료로부터 사용된다. 기존 화석 연료를 사용하는 자동차보다 친환경적이며 저렴하고 재생이 가능한 연료의 요구증대로 대체연료 자동차산업이 강조되고 있다. 오늘날 고옥탄가와 높은 자기발화온도 특징을 가지고 있는 천연가스는 저렴한 비용, 기존 화석연료보다 풍부한 매장으로 기존 스파크 점화엔진인 가솔린엔진의 대체에너지로 간주되고 있다. 본 연구는 기존 2리터 가솔린 엔진에 CNG 가스 분사시스템을 장착하여 전소 및 혼소 연료분사시스템을 설치하였다. 또한 CNG전소 및 가솔린/CNG 혼소차량의 ECU 제어전략을 최적화 하였다. 혼소차량에 대하여 NEDC모드 주행결과 가솔린 차량 대비 혼소차량의 CO2 저감율을 16%확인하였다. 또한 CO와 HC의 배기가스 배출량은 가솔린 차량과 동등한 수준을 확보하였다. 하지만 NOx의 배기가스 배출수준은 증가된 현상을 확인할 수 있었다.

• 오토저널
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• 제25권5호
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• pp.43-47
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• 2003

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2004년도 추계 학술발표회 논문집
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• pp.303-309
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• 2004

• 한국산업융합학회 논문집
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• 제4권1호
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• pp.41-49
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• 2001

This study developed signal optimization algorithm by analyzing vehicle arrival patterns. The major principle of signal optimization is dissipate all queueing vehicle in 1cycle and assign delay time uniformly for all approaches. For this, this study used optimal green time and surplus green time. Optimal green time calculated by estimated traffic volume from vehicle arrival model. Surplus green time defined as the gap of optimal green time and queue dissipated time. And alternative cycle has minimum surplus green time was selected as the optimal cycle. Finally, total delay and average delay per vehicle can be calculated by using queueing theory.

• 대한임베디드공학회논문지
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• 제12권2호
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• pp.113-120
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• 2017

In this paper, we present a night-time vehicle detection method using CNN (Convolutional Neural Network) classification. The camera based night-time vehicle detection plays an important role on various advanced driver assistance systems (ADAS) such as automatic head-lamp control system. The method consists mainly of thresholding, labeling and classification steps. The classification step is implemented by existing CIFAR-10 model CNN. Through the simulations tested on real road video, we show that CNN classification is a good alternative for night-time vehicle detection.

• 한국자동차공학회논문집
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• 제10권5호
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• pp.9-14
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• 2002

The durability prediction of emission control components, especially 02 sensor and catalytic converter, is getting more important as emission regulation is getting stricter and vehicle durability mileage requirement is also extended from 80,000 ㎞ to 160,000 km in Korean market. And the duration of vehicle mileage accumulation to get vehicle exhaust emission deterioration factor for certification is required to be shorter in order to reduce the vehicle development time. Since most of the vehicle emission development tests are done on chassis dynamometer and aging bench by using vehicle aging modes, real road condition and in-use driving patterns must be reflected into them to predict the vehicle emission level and to meet emission regulation especially at high mileage. In order to get the frequent driving pattern of vehicle and the aging characteristic of emission components, a vehicle was tested by changing drivers and driving roads around Seoul. Real road driving patterns were analyzed and compared with those of the certification modes which are well known in automotive industry.