Transient Fueling Controller Identification for Spark Ignition Engines

2005 ◽  
Vol 128 (3) ◽  
pp. 499-509 ◽  
Author(s):  
Matthew A. Franchek ◽  
Jackie Mohrfeld ◽  
Andy Osburn

Presented in this paper is a feedforward fueling controller identification methodology for the transient fueling control of spark ignition (SI) engines. The hypothesis of this work is that the feedforward fueling control of SI engines can be separated into steady state and transient phenomena and that the majority of the nonlinear behavior associated with engine fueling can be captured with nonlinear steady state models. The proposed transient controller identification process is built from standard nonparametric identification techniques followed by parametric model recovery. Crank angle serves as the independent variable for these models. Two separate system identification problems are solved to identify the air path dynamics and the fueling path dynamics. The transient feedforward controller is then calculated as the ratio of the air path-over-the fueling path dynamics thereby coordinating the engine fueling with the air path dynamics. It will be shown that a linear transient feedforward-fueling controller operating in tandem with a nonlinear steady state fueling controller can achieve air-fuel ratio regulation comparable to the production fueling controller without the extensive controller calibration process. The engine used in this investigation is a 1999 Ford 4.6L V-8 fuel injected engine.

Author(s):  
Matthew A. Franchek ◽  
Jackie Mohrfeld ◽  
Andy Osburn

Presented in this paper is a feedforward fueling controller identification methodology for the transient fueling control of spark ignition (SI) engines. The proposed transient feedforward controller is identified and executed in the crank angle domain, and operates in tandem with a steady state fueling controller. The hypothesis is that the feedforward fueling control of SI engines can be separated into steady state and transient phenomena, and that the majority of the nonlinear behavior associated with engine fueling can be captured with nonlinear steady state compensation. The proposed transient controller identification process is built from standard nonparametric identification techniques using spectral density functions where crank angle serves as the independent variable. Two separate system identification problems are solved to identify the air path dynamics and the fuel path dynamics. The transient feedforward controller is then calculated as the ratio of the air path-over-the fuel path dynamics so that the fuel path dynamics match the air path dynamics. Consequently fueling is coordinated with the fresh air charge during transient conditions. It will be shown that a linear transient feedforward-fueling controller operating in tandem with a nonlinear steady state fueling controller can achieve air-fuel ratio (AFR) regulation comparable to a production controller without the extensive controller calibration process. The engine used in this investigation is a 1999 Ford 4.6L V-8 fuel injected engine.


2016 ◽  
Vol 819 ◽  
pp. 272-276 ◽  
Author(s):  
Ali Ghanaati ◽  
Mohd Farid Muhamad Said ◽  
Intan Zaurah Mat Darus ◽  
Amin Mahmoudzadeh Andwari

The performance of Spark Ignition (SI) engines in terms of thermal efficiency can be restricted by knock. Although it is common for all SI engines to exhibit knock from compressed end-gas, knocks from surface ignition remains a more serious problem due to its effect on combustion stability and its obscurity to detect. This paper focuses on predicting the occurrence of knocks from surface ignition by monitoring exhaust gas temperature (EGT). EGT measured during an engine cycle without the spark plug firing. Therefore, EGT rises illustrated any combustion made by surface ignition. Modelling and simulation of a one-dimensional engine combustion done by using GT-Power. The new approach reduces the complexity as EGT monitoring does not require high computational demands, and the EGT signals are robust to noise. The method is validated against a variety of fuel properties and across engine conditions. A new approach is proposed as a measure to predict and detect the knock events.


Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4131
Author(s):  
George M. Kosmadakis ◽  
Constantine D. Rakopoulos

A methodology for determining the cyclic variability in spark-ignition (SI) engines has been developed recently, with the use of an in-house computational fluid dynamics (CFD) code. The simulation of a large number of engine cycles is required for the coefficient of variation (COV) of the indicated mean effective pressure (IMEP) to converge, usually more than 50 cycles. This is valid for any CFD methodology applied for this kind of simulation activity. In order to reduce the total computational time, but without reducing the accuracy of the calculations, the methodology is expanded here by simulating just five representative cycles and calculating their main parameters of concern, such as the IMEP, peak pressure, and NO and CO emissions. A regression analysis then follows for producing fitted correlations for each parameter as a function of the key variable that affects cyclic variability as has been identified by the authors so far, namely, the relative location of the local turbulent eddy with the spark plug. The application of these fitted correlations for a large number of engine cycles then leads to a fast estimation of the key parameters. This methodology is applied here for a methane-fueled SI engine, while future activities will examine cyclic variations in SI engines when fueled with different fuels and their mixtures, such as methane/hydrogen blends, and their associated pollutant emissions.


Author(s):  
Zhe Wang ◽  
Qilun Zhu ◽  
Robert Prucka ◽  
Michael Prucka ◽  
Hussein Dourra

Spark-ignition engine in-cylinder air charge estimation is important for air-to-fuel ratio (AFR) control, maintaining high after-treatment efficiency, and determination of current engine torque. Current cylinder air charge estimation methodologies generally depend upon either a mass air flow (MAF) sensor or a manifold absolute pressure (MAP) sensor individually. Methods based on either sensor have their own advantages and disadvantages. Some production vehicles are equipped with both MAF and MAP sensors to offer air charge estimation and other benefits. This research proposes several observer-based cylinder air charge estimation methods that take advantage of both MAF and MAP sensors to potentially reduce calibration work while providing acceptable transient and steady-state accuracy with low computational load. This research also compares several common air estimation methods with the proposed observer-based algorithms using steady-state and transient dynamometer tests and a rapid-prototype engine controller. With appropriate tuning, the proposed observer-based methods are able to estimate cylinder air charge mass under different engine operating conditions based on the manifold model and available sensors. Methods are validated and compared based on a continuous tip-in tip-out operating condition.


2000 ◽  
Author(s):  
David J. Stroh ◽  
Matthew A. Franchek ◽  
James M. Kerns

Abstract Presented in this paper is an adaptive, model based, fueling control system for spark ignition-internal combustion engines. Since the fueling control system is model based, the engine maps currently used in engine fueling control are eliminated. This proposed fueling control system is modular and can therefore accommodate changes in the engine sensor set such as replacing the mass-air flow sensor with a manifold air pressure sensor. The fueling algorithm can operate with either a switching type O2 sensor or a linear O2 sensor. The fueling control system is also parceled into steady state fueling compensation and transient fueling compensation. This feature provides the distinction between fueling control adaptation for transient fueling and steady state fueling. The steady state feedforward controller is comprised of two nonlinear models. These models are adapted via a recursive least squares method to accommodate product variability, engine aging, and changes in the operating environment. The transient fueling compensation also utilizes a feedforward controller that captures the essential dynamic characteristics of the transient fueling operation. This controller is measured using a frequency domain system identification approach. This proposed fueling control system is demonstrated on a Ford 4.6L V-8 fuel injected engine.


2016 ◽  
Vol 822 ◽  
pp. 190-197
Author(s):  
Obeid Zuhair H. Obeid ◽  
Constantin Pana ◽  
Niculae Negurescu ◽  
Alexandru Cernat ◽  
Iulius Bondoc

The use of bioethanol as alternative fuel for automotive supercharged spark ignition engines is required especially for to respect the pollutant norms which become more and more severe, especially for NOx emissions.The general objective of the researches is improving of a automotive supercharged spark ignition engine efficiency, improving performance of power and torque and decreasing of the emissions level by the use of bioethanol. Bioethanol is so a very good alternative fuel for SI engines because of its better combustion proprieties comparative to the gasoline as a good cooling agent of the intake air due to its high vaporization heat.The paper presents results of some theoretical and experimental investigations on a 1.5 L supercharged SI engine fuelled with gasoline-bioethanol blends. The investigations show that the improvement of the combustion process by use the bioethanol at the supercharged spark ignition engine leads to the reduction of BSFC, to the accentuated reduction CO and HC due to a lower C content and better combustion properties of the bioethanol. In same time, the NOx emissions level significantly decreases because of the local cooling effect produced by bioethanol vaporization.


Author(s):  
Sebastian Grasreiner ◽  
Jens Neumann ◽  
Michael Wensing ◽  
Christian Hasse

Quasi-dimensional (QD) modeling of combustion in spark-ignition (SI) engines allows to describe the most relevant processes of heat release. Here, a submodel for the ignition delay is introduced and applied. The start of combustion is considered from ignition to the crank angle of 5% burned gas fraction. The introduced physical approach identifies the turbulent propagation velocity of the initiated kernel by taking into account early flame expansion and geometric restrictions of the flame propagation. The model is applied to stationary operation within an entire engine map of a turbocharged direct injection SI engine with fully variable valvetrain. Based on provided cycle-averaged input data, the model delivers good results within the margins of measured cycle-to-cycle fluctuations. Thus, it contributes to the assessment of the interplay between engine, engine control unit, drivetrain, and vehicle dynamics, hence making a step toward optimization and virtual engine calibration.


2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Saket Verma ◽  
L. M. Das

In-cylinder pressure-based combustion descriptors have been widely used for engine combustion control and spark advance scheduling. Although these combustion descriptors have been extensively studied for gasoline-fueled spark ignition (SI) engines, adequate literature is not available on use of alternative fuels in SI engines. In an attempt to partially address this gap, present work focuses on spark advance modeling of hydrogen-fueled SI engines based on combustion descriptors. In this study, two such combustion descriptors, namely, position of the pressure peak (PPP) and 50% mass fraction burned (MFB) have been used to evaluate the efficiency of the combustion. With a view to achieve this objective, numerical simulation of engine processes was carried out in computational fluid dynamics (CFD) software ANSYS fluent and simulation data were subsequently validated with the experimental results. In view of typical combustion characteristics of hydrogen fuel, spark advance plays a very crucial role in the system development. Based on these numerical simulation results, it was observed that the empirical rules used for combustion descriptors (PPP and 50% MFB) for the best spark advance in conventional gasoline fueled engines do not hold good for hydrogen engines. This work suggests revised empirical rules as: PPP is 8–9 deg after piston top dead center (ATDC) and position of 50% MFB is 0–1 deg ATDC for the maximum brake torque (MBT) conditions. This range may vary slightly with engine design but remains almost constant for a particular engine configuration. Furthermore, using these empirical rules, spark advance timings for the engine are presented for its working range.


Author(s):  
A Kowalewicz

A review and analysis of recent literature data on the use of methanol as an alternative fuel for internal combustion engines have been performed. The properties of methanol have been analysed from the point of view of its application to spark ignition (SI) and compression ignition (CI) engines. From this analysis it may be concluded that fewer modifications to the engine are expected when methanol is used in SI engines than in CI engines. Neat methanol is the most suitable, because all the positive properties of methanol as a fuel can be utilized. In the case of SI engines, only minor modifications of the fuel system and/or addition of ignition improver to the fuel are required. Use of methanol-gasoline blends of up to 15 per cent methanol (by volume) and diesel oil-methanol blends of up to 20 per cent methanol require only minor engine modifications. However, miscibility of methanol and conventional fuels is poor; in order to avoid fuel separation, mixtures of these fuels require fuel additives. Methanol engines burn cleaner and more efficiently, but have higher emissions of aldehydes, which increase with increasing mileage of the vehicle. In the presence of an oxidation catalyst unburned methanol can be converted to formaldehyde and simultaneously nitrous oxide to nitrogen dioxide. The advantage of engine fuelling with reformed methanol (CO + H2) is shown. The reasons for better efficiency, performance and less emissions (except of aldehydes) of methanol-fuelled SI engines in comparison with gasoline- and diesel oil-fuelled engines respectively have been analysed. Technical aspects of using methanol as an automotive fuel that have not yet been satisfactorily solved are pointed out. The feasibility of the widespread use of methanol as a transportation fuel for SI engines is discussed from technical, economic and ecological points of view. The need for further research and development work on problems related to methanol as a fuel for SI engines is also discussed.


2011 ◽  
Vol 180 ◽  
pp. 323-330 ◽  
Author(s):  
Józef Małecki

This paper describes mathematical models of propeller thrust and torque. The models are traditionally based on steady state thrust and torque characteristics. These characteristics usually are obtained in model towing tanks. Often experimental results are showed that these quasi steady state models do not accurately describe the transient phenomena in a thruster of the marine mechatronic system. Nowadays papers published in conference proceedings includes dynamic models usually was based on the experimental observations. Describing zero advance speed conditions accurately, this model however does not work for a marine vehicle at nonzero relative water speed. This paper derives a dynamic model of propeller that includes the effects of transients in the flow over a wide range of sea operation. The results of this trials are essential for accurate thrust control in precise control of marine vehicle.


Sign in / Sign up

Export Citation Format

Share Document