• 한국자동차공학회논문집
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• 제22권5호
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• pp.91-101
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• 2014

In this study, we presented a timing verification method for a passenger car diesel engine management system (EMS) using measurement-based worst-case execution time (WCET) analysis. In order to cope with AUTOSAR-compliant software architecture, a development process model is proposed. In the process model, a runnable is regarded as a test unit and its temporal behavior (i.e. maximum observed execution time, MOET) is obtained along with on-target functionality evaluation results during online unit test. Furthermore, a cost-effective framework for online unit test is proposed. Because the runtime environment layer and the standard calibration environment are utilized to implement test interface, additional resource consumption of the target processor is minimized. Using the proposed development process model and unit test framework, the MOETs of 86 runnables for diesel EMS are obtained with 213 unit test cases. Using the obtained MOETs of runnables, the WCETs of tasks are estimated and the schedulability is evaluated. From the schedulability analysis results, the problems of the initially designed schedule table is recognized and it is fixed by redesigning of the runnable mapping and task offset. Through the various test scenarios, the proposed method is validated.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.315-318
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• 2007

MATLAB/$SIMULINK^{TM}$ 환경 기반에서 일반적인 터보 축 엔진의 천이상태 및 시동 특성 해석을 위한 동적 시뮬레이션을 수행하였다. 터보축 엔진 구성품을 열역학 및 로터 동역학적인 관계식을 이용하여 모델을 구성하였다. 엔진 시동 특성은 보조동력장치에서 발생한 축력을 엔진 터빈에 전달시켜 엔진 각 구성품에서의 압력, 온도 및 축력의 변화 등에 대한 해석을 수행하였으며, 정상상태에서 작동 중인 모델엔진의 연료유량 변화에 대한 엔진 작동상황을 모사해 봄으로써 엔진 천이 특성에 대한 해석을 수행하였다. 향후, 엔진 제어기능을 기본 모델에 추가함으로써 보다 다양한 엔진 성능 시뮬레이션이 가능할 것으로 사료된다.

• 한국추진공학회지
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• 제25권5호
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• pp.1-9
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• 2021

국내 소형 가스터빈엔진 상용화 시장의 저변화를 위하여 상용 소형 가스터빈엔진의 시동 및 정상운용구간에서의 제어로직을 파악하고자 하였다. 이를 통하여 시동 및 정상운용구간에서 엔진의 점화 및 정상작동을 위하여 엔진의 점화기, 시동모터, 연료펌프 및 연료밸브가 어떻게 제어되는지 파악하였고, 확보된 제어로직을 실제 상용화 연구가 진행되고 있는 소형 가스터빈엔진의 지상용 제어기에 활용하였다. 해당 엔진은 비행용 엔진 제어기를 제작 중이며, 제작 완료 후 항우연에서 보유하고 있는 고도시험설비를 활용한 고도시험을 통해 비행시험 전에 고도에서의 운용성능을 확인할 예정이다.

• Journal of Advanced Marine Engineering and Technology
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• 제21권5호
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• pp.579-583
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• 1997

A diesel Engine rotates vibratively because of alternative explosion strokes. Traditional measurement of a diesel engine speed is carried out by measuring output voltage of FV convertor from input signals of MPU(magnetic pickup unit) or of DC tachometer. Because these measurement include also vibrative rotation of a diesel engine, an analog filter is often used to eliminate high frequency noises due to periodic explosion stroke. But by this method these high frequency noises do not eliminated effectively because noise frequencies are changed according to diesel engine speed. In this paper, author proposes a new measurement method of a diesel engine revolution which read digital signal directly from MPU and prove the utility of proposed method through the real experiment.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.187-190
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• 2012

An experimental study was performed to provide the effect of PM reduction and the improvement of diesel alternative ratio utilizing diesel-natural gas dual-fuel combustion mode in a retrofit 3.4-liter diesel engine. In order to achieve the same power as the original diesel engine, engine control unit (ECU) of the dual-fuel engine was calibrated. As a result, diesel alternative ratio was found that the maximum value of diesel alternative ratio was about 96%. Finally PM emission experiment was performed in C1-8 mode cycle and it was shown PM emission was extremely reduced down to $7.42{\ast}10^{-7}g/kWh$ comparing with mechanical diesel engine.

• 한국정밀공학회지
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• 제22권6호
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• pp.192-198
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• 2005

Recently, Automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile. This reason is increasingly strict environmental regulations to lower fuel consumption and reduce emission. Designing more efficient and low emission control exhaust system results in more efficient Performance, reduced back Pressure and higher convert efficiency. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate, higher conversion efficiency demand information of pressure fraction and heat characteristics. To be able to determine these factor fur we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency, lower back pressure and optimal performance. This study furnish basic data for engineers, technicians.

• 한국자동차공학회논문집
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• 제21권2호
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• pp.159-165
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• 2013

ESD damage by Charged Cable Model (CCM) is introduced. Due to its own impedance characteristic unlike Human Body Model (HBM) or Machine Model (MM) electric component can be destroyed even though it is located after typical protection circuit. Possible mechanism of ESD damage to automotive electric control unit (ECU) in vehicle environment by CCM discharge was investigated. Based on investigation, field-returned vehicle whose ECU is expected to be damaged by CCM discharge was tested to reproduce it and similar electric component destruction inside ECU was observed. Suggestions to reduce the possibility of ESD damage by CCM are introduced.

• 제어로봇시스템학회논문지
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• 제7권11호
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• pp.912-917
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• 2001

In this study, we define the measuring method of crank angle precisely using an event and perform a study on the hardware structure and software algorithms which is applicable for the commercial engine. Also we developed a Computer-ECU(Personal computer based electronic control unit) using a computer and a microprocessor, for performing the ignition at a desire position(angle) and for controlling a duty ratio a pulse for ISC(Idle speed control). We applied these algorithms to the modeling which is induced a concept of event and got a better result than a conventional ECU in the state of transient as a result of performing air fuel ratio control in a commercial engine. This technique can be used for the back to improve ECU performance. It the present type of Hybrid I. C voltage regulator is altered to the new type of regulator, we will be surely able to reduce the production cost as well as simplify the design of alternator\`s rear bracket and rectifier part because of the removal of trio diode. Experiment is taken by MS-R004.

• 오토저널
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• 제16권6호
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• pp.9-15
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• 1994

• 한국자동차공학회논문집
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• 제9권1호
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• pp.63-74
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• 2001

In this study, a cycle simulation program of a Unit-Injection(UI) system was developed to estimate the injection performance of newly designed injection system. A fundamental theory of the simulation program is based on the conservation law of mass. Loss of fuel mass in the system due to leakage, compressibility effect of the liquid fuel and friction loss in the control volume was considered in the algorithm f the program. For the evaluation of the simulation program developed, the experimental result which was offered by the Technical Research Center of Doowon Precision Industry Co. was incorporated. Two main parameters; the maximum pressure in the plunger chamber and total fuel mass(kg) injected into the engine cylinder per cycle, were measured and compared with the simulation results. It was found that the maximum error rate of the simulation result to the experimental output was less than 3% in the rated rotational speed (rpm) range of the plunger cam.