• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.515-517
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• 2014

엔진 부조(engine hesitation)의 원인을 추적함에 있어 가장 효과적인 점검방법 중의 하나가 엔진파워 밸런스(engine power balance)를 점검하는 것이다. 본 연구에서는 공회전 상태에서 4개의 실린더 폭발의 압력 편차로 인한 엔진 부조를 점검하기 위해 엔진 파워 밸런스를 점검하는 방법을 사용한다. 엔진의 부조는 네 개의 실린더의 회전 밸런스가 틀어졌기 때문이므로 실린더의 회전 밸런스 정보를 수집 분석하는 방법이 필요하다. 본 연구에서는 실린더의 엔진 회전수를 계산하기 위해 OBD-II와 무선 시스템인 블루투스 모듈을 이용하여 실시간으로 CKP 센서 정보를 수집하는 방법과 밸런스가 틀어진 실린더를 찾는 알고리즘을 제시하여 엔진 파워 밸런스를 조절 관리하는 시스템을 스마트 폰에 구현하고자한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1677-1683
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• 2015

To cope with exhaust gas regulation, Diesel engine applied to electronic control system. As it accurately regulated the injected fuel mass and the fuel efficiency and the output are increased but the noise and the vibration are decreased. In order to keep the performance of Electronic Diesel Control System, it is important to accurately control the fuel pressure. However, when the regulator of fuel pressure is not controlled properly, the failure phenomenons(starting failure, staring delay, accelerated failure, engine mismatch et al.) occur because the fuel pressure is not stabilize. In this study, effects on a fuel pressure, engine rotating speed according to the control rate of fuel-pressure regulator are investigated in order to analyzed the performance variation with failure of fuel-pressure regulator. As a result, when the control rate of a fuel-pressure regulator is 4%~6% lower than that of standard condition, the variation of engine's rpm and return fuel flow is increased, and the abnormal condition was occurred. Besides, it is possible to diagnose the failures on fuel-pressure regulator under these conditions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.6
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• pp.624-629
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• 2014

The purpose of this study is to carry out the task of engine hesitation which occurred intermittently in driving due to the defective CKPS of LPI vehicles. As the result of the wrong data from the equipment of D-logger, the signal error of CKPS caused the engine hesitation. We performed a study in the followings to analyze and investigate the cause effectively. First, we have investigated the control wiring harness and connector pin contact defect inspection. Second, we have inspected the defection of CKPS separately. From this study, it was found that the engine hesitation were caused by the bad durability and we have showed how to diagnosis the fault of the engine hesitation intermittently while driving. Therefore, it is determined that we have to improve the durability of the CKPS through a strict quality control and to increase the reliability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1004-1011
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• 2006

In this study, we have performed a systematic case study on troubles and diagnoses of passenger car's engine based on OBD. We have acquired 1,242 data in order to analysis accurate troubles' causes and apposite diagnoses. 128 data of them are got using OBD apparatus, and the rest of them are collected on related website. As results, distribution on trouble cases shows bad idling(32%), poor acceleration(21%), stop in running(19%), faulty start(11%), inferior fuel economy(9%), and insufficient power(8%) in order of magnitude. And in the systematic cases, it is not difficult to detect troubles in a single part. But we know that special apparatus such as multichannel scanner is needed in complicated troubles. Furthermore we think that the survey is continued in various ways for more systematic case study on troubles and diagnoses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.15-21
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• 2021

Electrically powered airplanes can reduce CO₂ emissions from fossil fuel use and reduce airplane costs in the long run through efficient energy use. For this reason, advanced aviation countries such as the United States and the European Union are leading the development of innovative technologies to implement the full-electric airplane in the future. Currently, the research and development to convert existing two-seater engine airplanes to electric-powered airplanes are underway domestically. The airplane converted to electric propulsion is the KLA-100, which aims to carry out a 30-minute flight test with a battery pack installed using the engine mounting space and copilot space. The lithium-ion battery installed on the airplane converted to electric propulsion was designed with a specific power of 150Wh/kg, weight of 200kg, and a C-rate 3~4. This study confirmed the possibility of a 30-minute flight with a designed battery pack before conducting a flight test of a modified electrically propelled airplane. The battery performance was verified by dividing the 30-minute flight profile into start/run stage, take-off stage, climbing stage, cruise stage, descending stage, and landing/run stage. The final target of the 30-minute flight was evaluated by calculating the battery capacity required for each stage. Furthermore, the flight performance of the electrically propelled airplane was determined by calculating the flight availability time and navigation distance according to the flight speed.