Engine Position Tracking at Shutdown

McDonald, Dennis L.

doi:10.4271/2005-01-0048

Cited by 11 publications

(5 citation statements)

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“…There are two strong assumptions underpinning this closure: first, that the government has a target deficit/surplus that is constant; second, that the change in the tax burden will be spread across all household groups in proportion to their current average income tax rates. See McDonald (2005).…”

Section: Discussionmentioning

confidence: 99%

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Agricultural Policy and Trade Reform

2006

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The OECD is a unique forum where the governments of 30 democracies work together to address the economic, social and environmental challenges of globalisation. The OECD is also at the forefront of efforts to understand and to help governments respond to new developments and concerns, such as corporate governance, the information economy and the challenges of an ageing population. The Organisation provides a setting where governments can compare policy experiences, seek answers to common problems, identify good practice and work to co-ordinate domestic and international policies.

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Section: Discussionmentioning

confidence: 99%

“…This SAM underpins a CGE, by identifying the agents in the economy and providing the database through which the model is calibrated. The CGE follows a standard structure proposed by McDonald (2005).…”

Section: Scope and Objectivesmentioning

confidence: 99%

Agricultural Policy and Trade Reform

2006

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“…Quando o cilindro se move na direção do ponto morto superior o eixo a compressão do ar oferece um torque negativo, quando o pistão passa do ponto superior, a energia armazenada no ar comprimido faz um torque positivo, avançando o eixo do motor; durante a parada do motor isso ocorre até que a energia cinética do motor em movimento é gasta e o motor para numa posição onde o torque é próximo de zero logo após a descompressão de um cilindro [4].…”

Section: Otimização Da Velocidade De Sincronizaçãounclassified

Roda Fônica Codificada

Filho¹

2014

Blucher Engineering Proceedings

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RESUMOA rápida detecção da posição do eixo do motor é importante em sistemas Stop/Start assistidos por combustão.Atualmente, os sistemas de controle motor usam uma roda fônica com 58 dentes, ou suas variantes, para se determinar o ângulo do motor e comandar os eventos de ignição, injeção de combustível, janela de detonação, etc.Essa roda tem 60 dentes igualmente espaçados, com 2 dentes faltando. Outras configurações existem, porém, normalmente usam a marca de referência em uma única posição.Esse conceito apresenta os problemas: 1) pode ser necessário até uma volta completa do motor para encontrar a marca de referência e 2) normalmente não se pode atribuir eventos síncronos na marca de referência.Se propõe uma roda fônica codificada onde a marca de referência está espalhada em toda a sua circunferência, e os dentes representam símbolos, p. ex. 0 e 1, identificáveis pela largura do dente. Um tipo de transição, p. ex. borda de subida, ocorre em intervalos regulares e é usada para se medir o ângulo do motor.O código usado tem propriedade ótima de auto sincronização, p. ex. T-Codes, que é largamente usado em algorítimos de compressão de imagens e texto. A sincronização é obtida em menos de 1/9 de volta do motor. INTRODUÇÃODesde que o motor de combustão teve os eventos de ignição, e posteriormente, injeção de combustível, controlados por um módulo de controle eletrônico, mesmo que analógico, houve a necessidade de se saber a posição do eixo motor de modo a se aplicar a ignição e/ou injeção nos momentos em que o desempenho do motor é otimizado.A posição do motor, também, é usada nas lógicas de controle de detonação, que normalmente analisam as vibrações do bloco do motor em regiões de ângulo motor específicas, de modo a se minimizar a interferência de ruídos, como, por exemplo, de abertura de fechamento de válvulas.

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“…At present, two injection methods are used during the cranking start phase. 9 (1) Simultaneous injection: since the initial piston position is not measured at the start of cranking, the engine control unit (ECU) triggers all injectors simultaneously after the detection of engine cranking. Simultaneous injection ignores the difference between each cylinder and, therefore, often leads to poor combustion and excessive amounts of HC emissions in some cylinders.…”

Section: Introductionmentioning

confidence: 99%

“…At present, it is difficult to identify the initial piston position because directional reversals are common when engine coasts to a stop and normal crankshaft sensors cannot detect engine reversals. However, this situation would change in the future with the development of engine position tracking algorithms 9,10 and the use of bidirectional crankshaft sensors. 11 With these new technologies, engine reversals can be distinguished, and the engine stop positions can be tracked.…”

Section: Introductionmentioning

confidence: 99%

Effects of injection timing and fuel pulse width on mixture preparation and hydrocarbon emissions of the first cranking cycle under different initial piston positions

Lan¹,

Deng²,

Wu³

2012

Proceedings of the Institution of Mechanical Engineers, Part D:

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A fuel-injection strategy has been developed to reduce the hydrocarbon emissions and improve the performance of the first cranking cycle. The strategy is to deliver fuel injection individually according to the initial piston position in each cylinder. It allows cylinders at different initial phases to obtain appropriate and similar air-fuel mixtures. The objective of this study is to investigate the effects of the injection timing and fuel pulse width on the mixture preparation and the hydrocarbon emissions when the piston is cranked to start from different initial positions. Experiments were conducted on cylinder No.1 of a four-cylinder port fuel injection engine in both the ambient mode and hot mode. For each initial position of the piston, different injection timings and fuel pulse widths were tested. The effects of the injection timing and fuel pulse width on the mixture and hydrocarbon emissions were evaluated by measuring the hydrocarbon concentrations of the in-cylinder mixture and exhaust gas after each injection. The experimental results show that, the effects of the injection timing and fuel pulse width depend largely on the initial position of the piston. For example, when the piston is cranked to start from the mid-intake, fuel injection can barely form an ignitable mixture under different injection timings and fuel pulse widths. In addition, the temperature of the coolant can also influence the effects of the injection timing and fuel pulse width. To formulate the independent injection strategy for each cylinder for the first cranking cycle, the initial phase of the piston and the coolant temperature must be taken into consideration.

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Engine Position Tracking at Shutdown

Cited by 11 publications

References 0 publications

Agricultural Policy and Trade Reform

Agricultural Policy and Trade Reform

Roda Fônica Codificada

Effects of injection timing and fuel pulse width on mixture preparation and hydrocarbon emissions of the first cranking cycle under different initial piston positions

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