• 실천공학교육논문지
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• 제8권2호
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• pp.91-94
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• 2016

요즈음 자동차 전기장치의 입출력 요소별 설계와 작동원리, 제어로직 등의 정성 및 정량적인 내용을 체계적으로 이해하면서 종합 진단기와 데이터 통신이 가능하고 동작 상태에서 시스템의 회로를 학습할 수 있는 시뮬레이터가 활발하게 연구되고 있다. 이에 본 연구의 목적은 회로수리 능력을 정의하고, 회로수리 준비 능력, 탈부착 능력, 회로분석능력, 점검 및 측정능력, 수리(문제해결)능력, 정리능력의 함양을 통해 전기장치 정비에 대한 이해를 높이고 회로수리능력의 향상을 검증하는 데 있다. 본 논문에서는 자동차 등화장치 시뮬레이터 장치를 연구 개발하여 자동차 전기장치의 점검과 자동차 회로의 수리 및 점검, 전기계측 내용의 이해에 도움을 주고자 했다. 자동차 전기 장치는 눈에 보이지 않는 부분에 대한 이해가 필요하고, 기본점검 및 측정, 수리를 위해서 다양한 기호와 복잡한 회로에 대한 이해가 필수적으로 요구된다. 이러한 필수적인 부분에 대해 어려움을 느끼는 학생들에게 전기장치에 대한 흥미를 높이고, 자동차 전기실습에 필요한 기본적인 지식의 함양과 다양한 전기장치 고장진단에 필요한 기초능력을 습득할 수 있도록 하였다.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.39-44
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• 2013

자동차 부품 중 승차감이나 안전에 직접적으로 관련된 부분은 시트이다. 또한 이러한 여건을 만족시키면서 승객의 안전을 보장하는 충분한 강성과 강도를 가져야 한다. 자동차 시트는 3D 모델링 되었고, 전후 유격, 측면 유격 및 전후 모멘트 강도의 3가지 실험에 대하여 시뮬레이션으로서 구조해석을 하였다. 해석 결과, 전후 유격 시험에서는 $0.038^{\circ}$의 변형 각도의 값과 측면 유격 시험에서는 $0.04^{\circ}$의 변형 각도의 값이 각각 나타났다. 또한 전후 모멘트 강도시험에서는 전방 및 후방 하중 시에 최대의 전변형량 값이 각각 0.18946mm 및 3.2482mm로 나타났다. 본 연구결과는 자동차 시트 프레임의 과도한 변형 및 파괴가 없음으로서 승객의 안전을 보장하는 충분한 강성과 강도를 검증할 수 있었다.

• 디지털융복합연구
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• 제10권6호
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• pp.275-281
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• 2012

본 연구는 태스크 온톨로지를 이용한 자동차부품 추천시스템 개발 방법을 제안하였다. 제안한 지능형 추천 시스템은 자동차 부품 조립과정을 학습하도록 하였으며, 자동차부품 추천을 위하여 부품들을 온톨로지 방법으로 구축하였다. is-a Relationship 기반 hierarchical Taxonomy를 이용하여 자동차 엔진을 구성하고 있는 각각의 부품들 사이의 관계를 설정하였다. 각각의 부품은 자동차 전문가의 지식에 의해 각기 다른 가중치 값을 가지고 있게 된다. 가중치는 자동차 추천시스템의 사용자들이 직접 사용하면서 선택한 횟수와 가중치의 곱 연산을 이용한 결과 값을 시스템 내에서 기록하여 순서를 작성하고 결과적으로 우선순위(priority)가 높은 순서부터 사용자에게 출력함으로써 어느 부품의 어느 요소가 중요한지 쉽게 파악할 수 있도록 하였다. 자동차부품 지능형 추천시스템은 사용자가 쉽게 접근하기 어려운 자동차 부품관련 부분을 생성된 데이터를 바탕으로 임의의 부품을 선택했을 때 해당 부품과 밀접한 관계를 가진 부품을 표현하여 특별히 전문적인 지식 없이도 손쉽게 자동차 부품의 조립 및 쓰임새와 중요성을 알 수 있게 해주는 시스템이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.552-557
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• 2004

This paper presents a disturbance observer based on an $H_{\infty}$ controller synthesis for the trajectory control of a hydraulic excavator. Compared to conventional robot manipulators driven by electrical motors, the hydraulic excavator has more nonlinear and coupled dynamics. In particular, the interactions between an excavation tool and the materials being excavated are unstructured and complex. In addition, its operating modes depend on working conditions, which make it difficult to not only derive the exact mathematical model but also design a controller systematically. In this study, the approximated linear model obtained through off-line system identification is used as nominal plant model for a disturbance observer. A disturbance observer based tracking controller which considers the effect of disturbance and model uncertainty is synthesized in $H_{\infty}$ frameworks. Simulation results are used to demonstrate the applicability of the proposed control scheme.

• 한국자동차공학회논문집
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• 제21권4호
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• pp.33-42
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• 2013

This paper describes a multiple vehicle tracking algorithm using an integrated probabilistic data association filter (IPDAF) in urban environments. The algorithm consists of two parts; a pre-processing stage and an IPDA tracker. In the pre-processing stage, measurements are generated by a feature extraction method that manipulates raw data into predefined geometric features of vehicles as lines and boxes. After that, the measurements are divided into two different objects, dynamic and static objects, by using information of ego-vehicle motion. The IPDA tracker estimates not only states of tracks but also existence probability recursively. The existence probability greatly assists reliable initiation and termination of track in cluttered environment. The algorithm was validated by using experimental data which is collected in urban environment by using single laser scanner.

• 한국기계가공학회지
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• 제17권3호
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• pp.39-44
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• 2018

The automotive headrest is intended to provide comfort, safety, convenience and durability to a vehicle's passengers and driver. In this study, impact and fatigue analyses were carried out for three headrest shape models-A, B and C. These models have the same material properties and the same force was applied to them. Impact and fatigue analyses demonstrated that all of the models obtained almost the exact same result values. This study found that all models had similar equivalent stress, deformation, fatigue life and main damage parts due to the fact that the shared same material properties. Better safety and fatigue life can be anticipated by changing the material of the headrest in order to secure more stable safety. An automotive headrest optimized for safety and durability is thought to have been developed through the impact and fatigue analyses of this study.

• 한국자동차공학회논문집
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• 제23권5호
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• pp.502-507
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• 2015

In this paper, we built a three-dimensional model by applying reverse engineering techniques on targeting the intake port of 2900cc class diesel engine before that three-dimensional design technique is applied. The performance of the intake port is predicted and analysed using the computational flow analysis. Flow Coefficient and Swirl Ratio have been analyzed for two intake port models. One is the intake port for the diesel engine with plunger-type fuel system, and the other is for the diesel engine with CRDI fuel system. Computational result shows that the Flow Coefficient of the intake port with CRDI fuel system is increased upto 10 percentage compared with that with plunger-type. Also, the intake port with plunger-type has high Swirl Ratio at high valve lift, and the intake port with CRDI fuel system has high Swirl Ratio at relatively low valve lift. It is believed that because of high performance of the fuel injector, the intake port with CRDI fuel system is designed for more air amount and not much swirl flow at high valve lift. However, high swirl flow is required at low valve lift for initial fuel and air mixing. The result of this study may be useful for the re-manufacturing industry of automotive parts.

• 한국자동차공학회논문집
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• 제16권4호
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• pp.165-172
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• 2008

Urea-SCR, the selective catalytic reduction using urea as reducing agent, has been investigated for about 10 years in detail and today is a well established technique for deNOx of stationary diesel engines. In the case of the SCR-catalyst a non-uniform velocity and $NH_3$ profile will cause an inhomogeneous conversion of the reducing agent $NH_3$, resulting in a local breakthrough of $NH_3$ or increasing NOx emissions. Therefore, this work investigates the effect of flow and $NH_3$ non-uniformities on the deNOx performance and $NH_3$ slip in a Urea-SCR exhaust system. From the results of this study, it is found that flow and $NH_3$ distribution within SCR monolith is strongly related with deNOx performance of SCR catalyst. It is also found that multi-hole injector shows better $NH_3$ uniformity at the face of SCR monolith face than one hole injector.

• 소성∙가공
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• 제20권7호
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• pp.485-490
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• 2011

The application of helical gears in crucial parts of automotive transmissions has been steadily increasing due to their higher power transfer performance compared to spur gears. However, the traditional gear manufacturing methods such as hobbing and deburring require large cycle times with expensive production lines so that there have been intensive efforts trying to manufacture gears via forging processes. Although forging processes for spur and bevel type gears have been developed on the practical level, the manufacturing of helical gears is still dependent on the traditional cutting process. Therefore, this paper seeks to develop a cold forward extrusion process for the helical gear with the pitch diameter of 43.5mm and a helix angle of $18.4^{\circ}$. A forward extrusion process was used due to the relatively small diameter of the target geometry. The material deforming behavior influenced by the die geometry was examined by using CAE analysis. Finally, it was found that the helical gear manufactured by the developed extrusion process satisfied the dimensional accuracy and mechanical characteristics for automotive transmissions.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.353-354
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• 2006

The automatic inspection system is developed for the formed end part of automotive fuel pipe. The developed system has functions of outer diameter and formed end length measurement by LVDT(linear variable differential transformer) together with burr cleaning of automotive fuel pipe. The measured data are managed and controlled in real time by embedded SPC(statistical process control) program. The system is composed of mechanical part, electronic part and developed software system. These three parts operate automatically by mutual communication with each other. The developed system showed good results in finding inferior goods and efficiency improvement of the fuel pipe production line. It also eliminated the unreliable manual inspection processes and improved the confidence of product quality.