• 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).

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.117-123
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• 2003

In a bi-fuel engine using gasoline and LPG fuel, with the current ignition timing for gasoline being used, the effective performance could not be taken in LPG fuel supply mode. The ignition timing in LPG fuel mode must be advanced much more than that of gasoline mode for the compensation of its lower flame speed, due to engine torque drop. This study aims to develop the control system for ignition spark timing conversion which is composed of hardwares and control algorithm for gasoline/LPG engine. We propose the control system which can advance the ignition spark timing in LPG fuel mode more than used in gasoline fuel mode. The advance of ignition timing is achieved by change of the ignition dwell time of coil igniter. The engine torque and F/E(Fuel-Economy) in LPG fuel mode are measured to evaluate the difference of engine performance between before and alter changing ignition spark timings. The engine torque and F/E are increased respectively, which proves the developed control system is effective so much for gasoline and LPG bi-fuel engine.

• Journal of the korean Society of Automotive Engineers
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• v.1 no.1
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• pp.17-20
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• 1979

Transistor식 점화장치는 자동차의 배기 공해대책, 연료저감대책 등의 방안으로 근래에 급속히 발전된 System이다. Transistor 점화장치로 요구되는 배경은 다음과 같다. [1] 화화출력이 커져서 Engine에 있어서 확실한 연소가 기대되고 배기정화책 연료저감책에 유 효하다. [2] 기계적인 접점이 없으므로 장기적으로 Engine의 성능을 일정하게 유지한다. [3] 저회전에서 고회전까지 높고 안정된 화화출력을 갖고 있기 때문에 시동특성 고속특성이 양 호하다. [4] 점화시기제어에 신기능부가가 용이 이와같은 목표를 달성하기 위하여 세계각국의 자동차 Maker는 각각의 독자적인 System 회로방식을 개발하여 Transistor점화장치를 실용화하고 있 으나 우리나라에서는 아직도 자동차에 기계식 점화장치를 사용하여 생산하고 있는 실정이다.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.122-129
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• 1996

The spark timing is one of major parameters to the engine performance and emissions. The ECU controls the spark timing based on preset values, which are functions of load and speed, in most of today's automotive SI engine. In this system, the preset spark timing can be different from optimum value due to the deviations from mass production, aging effects and so on. In the present study, a control logic is investigated for real time adaptation of spark timing to optimal value. It has been found that crank angle of miximum cylinder pressure is one of the appropriate parameters to estimate the optimum spark timing throught experiment. It has also been observed for spark timing convergence by variation of engineering model factors. The simulation program including engineering model for cycle by cycle variation of combustion is developed for surveying spark timing control logic. It is also shown that simulation results reflect experiment outputs and reasonableness of spark timing control logic for crank angle of maximum cylinder pressure.

• Journal of the KSME
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• v.32 no.10
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• pp.876-882
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• 1992

여기에서는 삼원촉매 장착엔진을 정밀하게 제어(연료 제어, 공회전 제어, 점화시기 제어, Purge Air 제어 등)하여 삼원촉매의 효율을 향상시키고, 그 결과 배기가스를 감소시킴과 더불어 운전성 및 동력성능을 향상시킨 엔진 전자 제어 시스템의 개요를 간단히 소개하였다. 앞으로도 북미지 역의 배기가스 관련법규가 더욱 강화될 것으로 예상되며, 이에 대응한 엔진 제어 시스템에 대한 지속적인 연구 개발이 필요하리라 생각된다.

• 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 the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.39-47
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• 2011

In a bi-fuel engine using gasoline and LPG fuel, with the current ignition timing for gasoline being used, the optimum performance could not be taken in LPG fuel supply mode. The ignition timing in LPG fuel mode must be advanced much more than that of gasoline mode for the compensation of its higher ignition temperature. The purpose of this study is to investigate how the ignition spark timing conversion influences the engine performance of LPG/Gasoline Bi-Fuel engine. In order to investigate the engine performance during combustion, engine performance are sampled by data acquisition system, for example cylinder pressure, pressure rise rate and heat release rate, while change of the rpm(1500, 2000, 2500) and the ignition timing advance($5^{\circ}$, $10^{\circ}$, $15^{\circ}$, $20^{\circ}$). As the result, between 1500rpm, 2000rpm and 2500rpm, the cylinder pressure and pressure rise rate was increased when the spark ignition was advanced but pressure rise rate at $20^{\circ}$ was smaller value.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.5
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• pp.15-21
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• 1980

An engine control system in which the conventional mechanical ignition system is studied. The contact point of the breaker is replaced by the contactless magnetic pick up sensor from which the information of the speed and the position of the crankshaft is extracted , and further an electronic High Energy Ignitim System Is designed, implemented and tested . The High Energy Igniticwl System increases the secondary spark voltage of the ignition coil from the conventional 10000~15000 volts to the 30000~40000 volts resulting in improving the combustion efficiency. Also, instead of the conventional advimce mechanism forigniliontiming control, a microprocessorbased timinng mechanisn is installed to determine the ignition timing data in response to the engine rpm and the intake manifold vacuum.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1433-1438
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• 2009

The purpose of this study is to investigate how the ignition spark timing conversion influences the engine performance of LPG/Gasoline Bi-Fuel engine. We propose the control system which can advance the ignition spark timing in LPG fuel mode more than used in gasoline fuel mode. In order to investigate the engine performance during combustion, engine performance are sampled by data acquisition system, for example cylinder pressure, pressure rise rate and heat release rate, while change of the rpm(1500, 2000) and the ignition timing advance($5^{\circ}$,$10^{\circ}$,$15^{\circ}$,$20^{\circ}$) As the result, between 1500rpm and 2000rpm, the cylinder pressure and pressure rise rate was increased when the spark ignition was advanced but pressure rise rate at $20^{\circ}$was smaller value. Also, the heat release rate at 1500rpm was increased but it was lower around $20^{\circ}$at 2000rpm.

• 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.