Modelling and operational testing of pulse-width modulation at injection time for a spark-ignition engine

Danas, kada govorimo o bilo kojem polju moramo uključiti upravljanje računalom. Zbog prednosti njegovog binarnog sustava, ono može upravljati signalima iz uređaja i kontrolirati ih u vrlo kratkom vremenu. U ovom radu smo željeli predstaviti studije i istraživanja tehnologije PWM (Pulse Width Modulation - modulacije širine impulsa). Današnji motori su opskrbljeni s elektronički upravljanim sustavom ubrizgavanja. Tijekom istraživanja uspostavili smo vezu između nekoliko parametara koji su uključeni u povećanje performansi motora. PWM, najčešće korištena tehnika za kontroliranje snage inercijskih električnih uređaja, korištena je za predstavljanje prednosti kontrole vremena ubrizgavanja, s vrlo dobrim rezultatima u sustavu upravljanja motorom. Uzeli smo u obzir neke parametre, kao tlak, napon baterije, lambda signale, količinu goriva i zraka, itd., a sve to u vremenskom razvoju s ECU pomoćnim upravljanjem. Korištenje MATLAB/Simulink softvera uspjeli smo upravljati, počevši od referentnih brzina, položaja regulacije i drugih parametara, potrebnih podataka iz ispitivanog vozila, Dacia Logan 1.4 MPI (pokretanog Renaultom), razvojem vremena ubrizgavanja uporabom modulacije širine impulsa. Stvaranjem PWM signala možemo točno kontrolirati vrijeme ubrizgavanja.Nowadays, the computer control has to be taken into account in any field of study. Due to the advantage of its binary system, it can very quickly control the signals from devices. This paper is focused on the analysis of some studies carried out on the PWM (Pulse Width Modulation) technologies. The engines used nowadays are provided with an electronic injection system. During our research, we have made a connection between a few parameters which contribute to the increase of the engine performance. Our team has used the PWM, a common technique employed for controlling power to inertial electrical devices, in order to show the benefits of the injection time control; the results regarding the engine management have been very good. We have taken into account a few parameters such as pressure, battery voltage, lambda signals, fuel and air amount, etc., as well as their time evolution, with the help of the ECU control. Using the MATLAB/Simulink software, we have managed to control, by using the pulse width modulation, the reference speed, the throttle position, as well as other parameters and data collected from the tests carried out on Dacia Logan 1.4 MPI (powered by Renault), and the evolution of the injection time. By creating a PWM signal, we can precisely control the injection time

Modelling and operational testing of pulse-width modulation at injection time for a spark-ignition engine

Danas, kada govorimo o bilo kojem polju moramo uključiti upravljanje računalom. Zbog prednosti njegovog binarnog sustava, ono može upravljati signalima iz uređaja i kontrolirati ih u vrlo kratkom vremenu. U ovom radu smo željeli predstaviti studije i istraživanja tehnologije PWM (Pulse Width Modulation - modulacije širine impulsa). Današnji motori su opskrbljeni s elektronički upravljanim sustavom ubrizgavanja. Tijekom istraživanja uspostavili smo vezu između nekoliko parametara koji su uključeni u povećanje performansi motora. PWM, najčešće korištena tehnika za kontroliranje snage inercijskih električnih uređaja, korištena je za predstavljanje prednosti kontrole vremena ubrizgavanja, s vrlo dobrim rezultatima u sustavu upravljanja motorom. Uzeli smo u obzir neke parametre, kao tlak, napon baterije, lambda signale, količinu goriva i zraka, itd., a sve to u vremenskom razvoju s ECU pomoćnim upravljanjem. Korištenje MATLAB/Simulink softvera uspjeli smo upravljati, počevši od referentnih brzina, položaja regulacije i drugih parametara, potrebnih podataka iz ispitivanog vozila, Dacia Logan 1.4 MPI (pokretanog Renaultom), razvojem vremena ubrizgavanja uporabom modulacije širine impulsa. Stvaranjem PWM signala možemo točno kontrolirati vrijeme ubrizgavanja.Nowadays, the computer control has to be taken into account in any field of study. Due to the advantage of its binary system, it can very quickly control the signals from devices. This paper is focused on the analysis of some studies carried out on the PWM (Pulse Width Modulation) technologies. The engines used nowadays are provided with an electronic injection system. During our research, we have made a connection between a few parameters which contribute to the increase of the engine performance. Our team has used the PWM, a common technique employed for controlling power to inertial electrical devices, in order to show the benefits of the injection time control; the results regarding the engine management have been very good. We have taken into account a few parameters such as pressure, battery voltage, lambda signals, fuel and air amount, etc., as well as their time evolution, with the help of the ECU control. Using the MATLAB/Simulink software, we have managed to control, by using the pulse width modulation, the reference speed, the throttle position, as well as other parameters and data collected from the tests carried out on Dacia Logan 1.4 MPI (powered by Renault), and the evolution of the injection time. By creating a PWM signal, we can precisely control the injection time

Investigation of Gasoline Partially Premixed Combustion with External Exhaust Gas Recirculation

The stringent emission regulations for Internal Combustion Engines (ICEs) spawned a great amount of research in the field of innovative combustion approaches characterized by high efficiency and low emissions. Previous research demonstrate that such promising techniques, named Low-Temperature Combustion (LTC), combine the benefits of Compression Ignition (CI) engines, such as high compression ratio and unthrottled lean mixture, with low engine-out emissions using a properly premixed air-fuel mixture. Due to longer ignition delay and high volatility compared to diesel, gasoline-like fuels show good potential for the generation of a highly premixed charge, which is needed to reach LTC characteristics. In this scenario, gasoline Partially Premixed Combustion (PPC), characterized by the high-pressure direct injection of gasoline, showed good potential for the simultaneous reduction of pollutants and emissions in CI engines. However, previous research on gasoline CI highlight that a key factor for the optimization of both efficiency and pollutants is the proper management of Exhaust Gas Recirculation (EGR). This work presents the experimental investigation performed running a light-duty CI engine, operated with gasoline PPC, and varying the mass of recirculated gases trapped in the combustion chamber. To guarantee the stability of gasoline autoignition in all the tested conditions, a specific experimental layout has been developed to accurately quantify the amount of trapped residual gases due to the internal and external EGR. The obtained results clearly highlight the impact of EGR on the combustion process and emissions, demonstrating that optimization of charge dilution with EGR is fundamental to guarantee the optimal compromise between efficiency and emissions over the whole operating range

Review of combustion indexes remote sensing applied to different combustion types

This paper summarizes the main studies carried out by the authors for the development of indexes for remote combustion sensing applicable to different combustion types, i.e. conventional gasoline and diesel combustions, diesel PCCI and dual fuel gasoline-diesel RCCI. It is well-known that the continuous development of modern Internal Combustion Engine (ICE) management systems is mainly aimed at complying with upcoming increasingly stringent regulations throughout the world, both for pollutants and CO2 emissions. Performing an efficient combustion control is crucial for efficiency increase and pollutant emissions reduction. Over the past years, the authors of this paper have developed several techniques to estimate the most important combustion indexes for combustion control, without using additional cylinder pressure sensors but only using the engine speed sensor (always available on board) and accelerometers (usually available on-board for gasoline engines). In addition, a low-cost sensor based on acoustic sensing can be integrated to support combustion indexes evaluation and other engine relevant information. The real-time calculation of combustion indexes is even more crucial for innovative Low Temperature Combustions (such as diesel PCCI or dual fuel gasoline-diesel RCCI), mainly due to the high instability and the high sensitivity to slight variations of the injection parameters that characterize this kind of combustions. Therefore, the authors of this paper have applied the developed techniques not only to conventional engines (gasoline and diesel combustion), but also to engines modified for Low Temperature Combustions, with promising results in terms of validation and applicability for real-time combustion control. The developed methodologies have been tested and validated through a large amount of experimental tests. To run the estimation algorithms in real-time, they have been all implemented in a specifically designed rapid control prototyping system, the goal being to quantify the accuracy of the estimations and optimize the strategy implementations for the extensive use (in the near future) in modern Engine Control Modules (ECM)

Machine Learning Techniques for High Performance Engine Calibration

Ever since the advent of electronic fuel injection, auto manufacturers have been able to increase fuel efficiency and power production, and to meet stricter emission standards. Most of these systems use engine sensors (Speed, Throttle Position, etc.) in concert with look-up tables to determine the correct amount of fuel to inject. While these systems work well, it is time and labor intensive to fine tune the parameters for these look-up tables. In general, automobile manufacturers are able to absorb the cost of this calibration since the variation between engines in a new model line is often small enough as to be inconsequential for a specific calibration. However, a growing number of drivers are interested in modifying their vehicles with the intent of improving performance. While some aftermarket performance upgrades can be accounted for by the original manufacturer equipped (OEM) electronic control unit (ECU), other more significant changes, such as adding a turbocharger or installing larger fuel injectors, require more drastic accommodations. These modifications often require an entirely new ECU calibration or an aftermarket ECU to properly control the upgraded engine. The problem is now that the driver becomes responsible for the calibration of the ECU for this "new" engine. However, most drivers are unable to devote the resources required to achieve a calibration of the same quality as the original manufacturers. At best, this results in reduced fuel economy and performance, and at worst, unsafe and possibly destructive operation of the engine. The purpose of this thesis is to design and develop--using machine learning techniques--an approximate predictive model from current engine data logs, which can be used to rapidly and incrementally improve the calibration of the engine. While there has been research into novel control methods for engine air-fuel ratio control, these methods are inaccessible to the majority of end users, either due to cost or the required expertise with engine calibration. This study shows that there is a great deal of promise in applying machine learning techniques to engine calibration and that the process of engine calibration can be expedited by the application of these techniques

Development of an electronic control unit for the T63 gas turbine

Includes bibliographical references.Fundamental research has been undertaken at the SASOL Advanced Fuels Laboratory to investigate the effects of the chemistry and physical properties of both conventional and synthetic jet fuels on threshold combustion. This research was undertaken using a purpose built low pressure continuous combustion test facility. Researchers at the laboratory now wish to examine these effects on an aviation gas turbine in service for which “off-map” scheduling of fuel to the engine would be required. A two phase project was thus proposed to develop this capability; the work of this thesis embodies Phase I of that project

Model Based Combustion Phasing Control for High Degree of Freedom Spark-Ignition Engines

With more restrictive engine emissions regulations and higher energy prices, the modern engine is equipped with an increasing number of actuators to meet the fuel economy, drivability and emissions requirements. Although map-based engine control and calibration routines are state of the art, they become burdensome when the number of control degrees of freedom increases significantly. The increased system complexity motivates the use of model-based methods to minimize product development time and ensure calibration flexibility when the engine is altered during the design process. Model-based control has the potential to significantly reduce the labor, time and expense of engine calibration, as compared to state-of-the-art experimentally based methods. In this research, physics-based models designed for real-time SI engine combustion phasing prediction and control are proposed. To realize real-time implementation of this system several models are derived; (1) a physics based internal residual gas mass prediction model, (2) a real-time cylinder pressure calculation model, (3) a two-step physics based turbulence intensity model, (4) a flame kernel development prediction model, and (5) a spark selection algorithm are subsequently developed. The complete physical models based combustion phasing prediction and control system are implemented into a rapid prototype ECU to realize real-time engine tests. Steady-state and transient engine test results show that the proposed system can accurately predict key variables and control the SI engine combustion phasing in real-time. The root-mean-square-error (RMSE) of the combustion phasing control over a wide range of operating conditions is 2-3 crank angle degrees

The Optimization of Data Acquisition, Fuel Flow, and Spark Timing Control for a Synthesis Gas-Engine-Generator System

As climate change drives the exploration into new and alternative fuels, biodiesel has emerged as a promising alternative to traditional diesel fuel. To further increase the viability of biodiesel, a unique system at the University of Kansas utilizes glycerin, the primary byproduct of biodiesel production, for power generation. This system converts glycerin into a hydrogen-rich gas (syngas) that is sent to an engine-generator system in one continuous flow process. This thesis details the implementation and troubleshooting of recent upgrades to the system, the experimental optimization of propane fuel and spark control for the engine, and directions for future research involving this setup. Chapter Two describes recent changes in the Syngas Rig including the renovation and replacement of various components to enhance the efficiency of the system and to resolve encountered issues. For instance, a recently installed water pump (Berkeley Model S39533) in the cooling system replaced the stock mechanical pump to eliminate an engine overheating issue. Moreover, additional safety measures were implemented in the fuel system in order to prevent any unintentional activation of fuel flow. All of the rig’s operating paths now require the activation of both mechanical and electric switches by wiring in a series instead of through parallel circuits. This chapter also includes troubleshooting guidelines to aid future students in utilizing the system. The third chapter discusses upgrades in pure propane operation that help by preheating the engine prior to syngas operation and establishing the baseline energy requirement for fueling the system. In addition, an upgrade to the fuel system incorporates an electric fuel valve (EFV) as a replacement for a gaseous propane carburetor, providing the ability for air-to-fuel ratio (AFR) adjustment of the engine at different generator loads. Moreover, spark timing optimization accompanies the new fuel control in order to enhance engine performance and maximize fuel economy. Additionally, in-cylinder pressure traces and associated performance parameters are reviewed and discussed in order to analyze the operation of the new EFV-based system. Finally, the fourth chapter provides a thorough discussion of the thesis efforts along with suggested directions for future research

Investigation of the Performance and Emissions Characteristics of Dual Fuel Combustion in a Single Cylinder IDI Diesel Engine

Restrictions in the allowable exhaust gas emissions of diesel engines has become a driving factor in the design, development, and implementation of internal combustion (IC) engines. A dual fuel research engine concept was developed and implemented in an indirect injected engine in order to research combustion characteristics and emissions for non-road applications. The experimental engine was operated at a constant speed and load 2400 rpm and 5.5 bar indicated mean effective pressure (IMEP). n-Butanol was port fuel injected at 10%, 20%, 30%, and 40% by mass fraction with neat ultra-low sulfur diesel (ULSD#2). Peak pressure, maximum pressure rise rates, and heat release rates all increased with the increasing concentration of n-Butanol. MPRR increased by 127% and AHRR increased by 30.5% as a result of the shorter ignition delay and combustion duration. Ignition delay and combustion duration were reduced by 3.6% and 31.6% respectively. This occurred despite the lower cetane number of n-Butanol as a result of increased mixing due to the port fuel injection of the alcohol. NOx and soot were simultaneously reduced by 21% and 80% respectively. Carbon monoxide and unburned hydrocarbons emissions were increased for the dual fuel combustion strategies due to valve overlap. Results display large emission reductions of harmful pollutants, such as NOx and soot

Safe operation of dual-fuel engines using constrained stochastic control

This is the author¿s version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087420985109[EN] Premixed combustion strategies have the potential to achieve high thermal efficiency and to lower the engine-out emissions such as NOx. However, the combustion is initiated at several kernels which create high pressure gradients inside the cylinder. Similarly to knock in spark ignition engines, these gradients might be responsible of important pressure oscillations with a harmful potential for the engine. This work aims to analyze the in-cylinder pressure oscillations in a dual-fuel combustion engine and to determine the feedback variables, control actuators, and control approach for a safe engine operation. Three combustion modes were examined: fully, highly, and partially premixed, and three indexes were analyzed to characterize the safe operation of the engine: the maximum pressure rise rate, the ringing intensity, and the maximum amplitude of pressure oscillations (MAPO). Results show that operation constraints exclusively based on indicators such as the pressure rise rate are not sufficient for a proper limitation of the in-cylinder pressure oscillations. This paper explores the use of a knock-like controller for maintaining the resonance index magnitude under a predefined limit where the gasoline fraction and the main injection timing were selected as control variables. The proposed strategy shows the ability to maintain the percentage of cycles exceeding the specified limit at a desired threshold at each combustion mode in all the cylinders.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was financially support by the Programa Operativo del Fondo Social Europeo (FSE) de la Comunitat Valenciana 2014-2020 through grant ACIF/2018/141.Guardiola, C.; Pla Moreno, B.; Bares-Moreno, P.; Barbier, ARS. (2022). Safe operation of dual-fuel engines using constrained stochastic control. International Journal of Engine Research. 23(2):285-299. https://doi.org/10.1177/146808742098510928529923