• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2361-2370
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• 2000

The introduction of inexpensive cylinder pressure sensors provides new opportunities for precise engine control. This paper presents a control strategy of spark advance based upon cylinder pressure of spark ignition engines. A location of peak pressure(LPP) is the major parameter for controlling the spark timing, and also the UP is estimated, using a multi-layer feedforward neural network, which needs only five pressure sensor output voltage samples at -40˚, -20˚, 0˚, 20˚, 40˚ after top dead center. The neural network plays an important role in mitigating the A/D conversion load of an electronic engine controller by increasing the sampling interval from 10 crank angle(CA) to 20˚ CA. A proposed control algorithm does not need a sensor calibration and pegging(bias calculation) procedure because the neural network estimates the UP from the raw sensor output voltage. The estimated LPP can be regarded as a good index for combustion phasing, and can also be used as an MBT control parameter. The feasibility of this methodology is closely examined through steady and transient engine operations to control individual cylinder spark advance. The experimental results have revealed a favorable agreement of individual cylinder optimal combustion phasing.

• Journal of Biosystems Engineering
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• v.12 no.1
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• pp.45-52
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• 1987

In order to improve the thermal efficiency of an internal combustion engine, various ignition timing control systems were examined and the best one was chosen. The parts used for the systems were a microcomputer system with DAS, 8 bit output port (D-FLIP FLOP), three types of isolation circuit, two types of ignition timing pulse generator, three types of switching circuit and two types of high voltage ignition circuit. Most systems did not operate well due to the effects of electromagnetic waves and surge currents occurring when the ignition began or ended with resulting high voltage. The best ignition timing control system was found to be the combination of (microcomputer system)-(ignition timing pulse generator using step motor position control pick-up)-(switching circuit using TR logic)-(high voltage ignition circuit using CDI).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.6
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• pp.607-614
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• 2013

Nowadays, automotive manufacturers have developed various technologies to improve fuel economy and reduce harmful emissions. The ultra-lean direct injection engine is a promising technology because it has the advantage of improving thermal efficiency through the deliberate control of fuel and ignition. This study aims to investigate the development of a spray-guided-type lean-burn LPG direct injection engine through the redesign of the combustion system. This engine uses a central-injection-type cylinder head in which the injector is installed adjacent to the spark plug. Fuel consumption and combustion stability were estimated depending on the ignition timing and injection timing at various air-fuel ratios. The optimal injection timing and ignition timing were based on the best fuel consumption and combustion stability.

• Journal of Energy Engineering
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• v.24 no.4
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• pp.166-174
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• 2015

This study examined combustion characteristics by selecting the fuel which have a different physical properties compared to gasoline in order to examine the effects of vehicle performance and environment depending on the physical properties. The experiment examined the combustion characteristic in the optimum ignition timing according to the physical properties change and the lean burn by performing control about ignition timing and air-fuel ratio for each fuel, and it was also evaluated the exhaust gas according to the experiment. We used a single-cylinder engine for the experiment, and tested for gasoline properties change by selecting a fake fuel that beyond the fuel quality standards in 석대법. As a result, in the case of the selected fuel showed a difference in Octane and distillation characteristics, vapor pressure and it was also found to unstable combustion, and leads to a large amount of harmful exhaust gas.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.63-68
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• 2003

The purpose of this study was to investigate reduction of exhaust gas temperature in LPG conversion engine from diesel. A conventional diesel engine was modified to a LPG(Liquified Petroleum Gas) engine that diesel fuel injection pump was replaced by the LPG fuel system. The research was peformed with measurement of exhaust gas temperature by varying spark ignition timing, air-fuel ratio, compression ratio, EGR ratio and different compositions of butane and propane. The major conclusion of this work were followed. (i) Exhaust gas temperature was decreased and power was increased with the advanced spark ignition timing. (ii) Exhaust gas temperature was decreased with lean and rich air-fuel ratio. (iii)Exhaust gas temperature was decreased and power was increased with the higher compression ratio. (iv) Engine power and exhaust temperature were not influenced by varied butane/propane fuel compositions. (v) Finally, one of the important parameters in reduction of exhaust gas temperature is spark ignition timing among the parameters in this study.

• Journal of Power System Engineering
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• v.12 no.4
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• pp.12-17
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• 2008

The purpose of this study is to analyse and compare the fuel combustion characteristics between LPG and gasoline on SI engine. Pressures of combustion chamber were measured on the state that engine speed was 2000rpm and BMEP was 2.0bar And we measured pressures of combustion chamber regarding variation of the MBT We could know that the combustion pressure of LPG fuel use engine is appeared lower than that of gasoline fuel use engine. At the lean mixture ratio area we could blow that Ignition timings are pulled very forward, and ignition timing of LPG fuel is advanced to $5\sim12^{\circ}$ CA than gasoline fuel. We learned that the value of coefficient of variation of LPG fuel is higher than gasoline fuel.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1203-1205
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• 1987

가솔린 엔진용 전자 제어 에뮬레이션 시스템은 엔진의 운전 상태를 알려 주는 각종 센서로 감지한 정보를 A/D변환기를 통해 마이크로프로세서에 입력시키고, 이 정보를 이용하여 운전 상태를 분석한 후 엔진이 푤요로 하는 연료량, 점화시기, 배기가스의 재순환량, 공회전수 등을 전자적으로 제어하여 엔진의 최적제어를 실현시킴으로서 연료소비율 및 배기가스 중 공해물질 함량을 감소시키기 위한 장치이다.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.3
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• pp.644-654
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• 2001

In this paper, an electronic control unit of the automobile engine for optimal fuel injection an spark timing control has been designed and developed. This system includes hardware and software for a precise control of fuel injection and ignition timing. Especially, the crank angle sensor provides two separate signals: One is the position signal (POS) which indicates 180 degree pulses per revolution, and the other is the reference signal (REF) that represents each cylinder individually. Consequently, the developed engine control system has been able to control fuel injection and ignition timing more quickly and accurately. Through the experiment, it has been found that the fuel injection duration and the position of MBT have been influenced by coolant temperature, air flow rate and engine speed.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.2
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• pp.129-136
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• 2004

환경문제와 석유자원의 고갈이 많은 연구자들을 기존 탄화수소연료를 대체할수 있는 재생 가능한 연료를 구하는데 많은 노력을 기울이고 있다. 수소연료는 유해배기물질이 없는 연소와 또한 연소후에 재생 가능한 물성분만 배출하는 속성으로 미래의 청정에너지로 각광을 받고 있다. 이러한 이유로 수소연료는 수송기계의 연료로도 주목을 받고 있다. 따라서 수소연료기관 개발은 21세기에도 지속적으로 진행될 것이다. 이에대한 초기연구로 기체 LPG 연료가 아닌 액체 LPG 연료를 흡기관에 분사하여 기화된 LPG 연료를 엔진으로 흡입하는 LPi엔진에 수소연료를 과급하여 엔진에 성능을 연구하고자 하였다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.242-247
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• 2003

An experimental study presents characteristics of combustion in a combustion chamber by port deactivation valve for economy and emissions standards. In order to use combustion properties data it is necessary to build some data base, which use cylinder pressure sensor, etc. Port deactivation valve has been developed to satisfy requirement of achieving sufficient swirl generation to improve the combustion. A feasibility and necessity of combustion pressure based cylinder spark timing control has been examined. So, this was obtained the Coefficient of Variation(COV) and the mass-burned(MFB). The characteristics of pressure ratio fraction is similar to that of mass-burned fraction. Using the results of the test, the effects of the combustion chamber can be improved combustion stability by port deactivation.