› › Evaluation Of Sensors And Strategies For Closed Loop Combustion Control Of A Gasoline Spark Ignition Turbocharged Direct Injection Engine

EVALUATION OF SENSORS AND STRATEGIES FOR CLOSED LOOP COMBUSTION CONTROL OF A GASOLINE SPARK-IGNITION TURBOCHARGED DIRECT INJECTION ENGINE

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Page : pages

File Size : 27,89 MB

Release : 2016

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Abstract : Fuel economy has become one of the top design parameters of modern passenger cars and light trucks. Recent CAFE regulations have required manufactures to push the fuel economy of US passenger vehicles under 8600 lb GVW beyond the limit of conventional technology [1]. In order to continue to meet the increasing requirements for fuel economy while still satisfying other design criteria including safety, tailpipe emissions, performance, and comfort, more expensive technology must be integrated into each vehicle specifically the powertrain. Diminishing returns of the payback period of fuel savings vs. higher initial vehicle cost has now become longer than the life of the vehicle. Because of this, the dollar per fuel economy benefit of each technology is being closely examined and investigated [1]. In this thesis, the potential fuel economy benefit of a technology was studied for feasibility and potential; the technology was on-board cylinder pressure sensors and the data available from them. Two low-cost cylinder pressure sensor types from two suppliers were evaluated and analyzed and compared to a laboratory sensor of known performance characteristics. Further the benefits from real-time cylinder pressure feedback capable of improving part load combustion phasing, combustion variability management were studied. Two areas of fuel consumption reduction which this thesis concentrates on are the improvement of locating spark advance through combustion duration feedback, and the extension of the dilute limit through combustion cycle stability measurement during transient operating conditions. By allowing the engine to run at more dilute conditions and locating spark advance to produce combustion durations closer to MBT, lower fuel consumption is possible. Vehicle EPA drive cycle data was used to examine areas of operation that were not operating at maximum efficiency to determine the fuel economy benefit that could be achieved through the availability of cylinder pressure data in terms of burn location and running dilute/lean. Methods to improve fuel economy in the engine such as dilution of air charge can have a negative effect on combustion stability [2]. In a laboratory environment combustion stability is measured during steady state operation using cylinder pressure data typically using a 100 cycle moving window for averaging. Transient engine operating conditions present in every drive cycle do not allow for calculating combustion stability in this way because it cannot be assumed that even two cycles are at the same operating conditions. If cylinder pressure sensor data were available on a production vehicle, the ability to measure combustion stability would exist but the transient measurement of combustion stability poses challenges which are discussed. A metric is developed to make comparable measurements in real time and the outcomes and benefits available from these measurements are evaluated.



A STUDY OF MODEL-BASED CONTROL STRATEGY FOR A GASOLINE TURBOCHARGED DIRECT INJECTION SPARK IGNITED ENGINE

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Page : pages

File Size : 14,61 MB

Release : 2020

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Abstract : To meet increasingly stringent fuel economy and emissions legislation, more advanced technologies have been added to spark-ignition (SI) engines, thus exponentially increase the complexity and calibration work of traditional map-based engine control. To achieve better engine performance without introducing significant calibration efforts and make the developed control system easily adapt to future engines upgrades and designs, this research proposes a model-based optimal control system for cycle-by-cycle Gasoline Turbocharged Direct Injection (GTDI) SI engine control, which aims to deliver the requested torque output and operate the engine to achieve the best achievable fuel economy and minimum emission under wide range of engine operating conditions. This research develops a model-based ignition timing prediction strategy for combustion phasing (crank angle of fifty percent of the fuel burned, CA50) control. A control-oriented combustion model is developed to predict burn duration from ignition timing to CA50. Using the predicted burn duration, the ignition timing needed for the upcoming cycle to track optimal target CA50 is calculated by a dynamic ignition timing prediction algorithm. A Recursive-Least-Square (RLS) with Variable Forgetting Factor (VFF) based adaptation algorithm is proposed to handle operating-point-dependent model errors caused by inherent errors resulting from modeling assumptions and limited calibration points, which helps to ensure the proper performance of model-based ignition timing prediction strategy throughout the entire engine lifetime. Using the adaptive combustion model, an Adaptive Extended Kalman Filter (AEKF) based CA50 observer is developed to provide filtered CA50 estimation from cyclic variations for the closed-loop combustion phasing control. An economic nonlinear model predictive controller (E-NMPC) based GTDI SI engine control system is developed to simultaneously achieve three objectives: tracking the requested net indicated mean effective pressure (IMEPn), minimizing the SFC, and reducing NOx emissions. The developed E-NMPC engine control system can achieve the above objectives by controlling throttle position, IVC timing, CA50, exhaust valve opening (EVO) timing, and wastegate position at the same time without violating engine operating constraints. A control-oriented engine model is developed and integrated into the E-NMPC to predict future engine behaviors. A high-fidelity 1-D GT-POWER engine model is developed and used as the plant model to tune and validate the developed control system. The performance of the entire model-based engine control system is examined through the software-in-the-loop (SIL) simulation using on-road vehicle test data.



Automotive Spark-Ignited Direct-Injection Gasoline Engines

Author : F. Zhao

Publisher : Elsevier

Page : 129 pages

File Size : 18,44 MB

Release : 2000-02-08

Category : Technology & Engineering

ISBN : 008055279X

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The process of fuel injection, spray atomization and vaporization, charge cooling, mixture preparation and the control of in-cylinder air motion are all being actively researched and this work is reviewed in detail and analyzed. The new technologies such as high-pressure, common-rail, gasoline injection systems and swirl-atomizing gasoline fuel injections are discussed in detail, as these technologies, along with computer control capabilities, have enabled the current new examination of an old objective; the direct-injection, stratified-charge (DISC), gasoline engine. The prior work on DISC engines that is relevant to current GDI engine development is also reviewed and discussed. The fuel economy and emission data for actual engine configurations have been obtained and assembled for all of the available GDI literature, and are reviewed and discussed in detail. The types of GDI engines are arranged in four classifications of decreasing complexity, and the advantages and disadvantages of each class are noted and explained. Emphasis is placed upon consensus trends and conclusions that are evident when taken as a whole; thus the GDI researcher is informed regarding the degree to which engine volumetric efficiency and compression ratio can be increased under optimized conditions, and as to the extent to which unburned hydrocarbon (UBHC), NOx and particulate emissions can be minimized for specific combustion strategies. The critical area of GDI fuel injector deposits and the associated effect on spray geometry and engine performance degradation are reviewed, and important system guidelines for minimizing deposition rates and deposit effects are presented. The capabilities and limitations of emission control techniques and after treatment hardware are reviewed in depth, and a compilation and discussion of areas of consensus on attaining European, Japanese and North American emission standards presented. All known research, prototype and production GDI engines worldwide are reviewed as to performance, emissions and fuel economy advantages, and for areas requiring further development. The engine schematics, control diagrams and specifications are compiled, and the emission control strategies are illustrated and discussed. The influence of lean-NOx catalysts on the development of late-injection, stratified-charge GDI engines is reviewed, and the relative merits of lean-burn, homogeneous, direct-injection engines as an option requiring less control complexity are analyzed.



Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Author : National Research Council

Publisher : National Academies Press

Page : 373 pages

File Size : 47,24 MB

Release : 2011-06-03

Category : Science

ISBN : 0309216389

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Various combinations of commercially available technologies could greatly reduce fuel consumption in passenger cars, sport-utility vehicles, minivans, and other light-duty vehicles without compromising vehicle performance or safety. Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy estimates the potential fuel savings and costs to consumers of available technology combinations for three types of engines: spark-ignition gasoline, compression-ignition diesel, and hybrid. According to its estimates, adopting the full combination of improved technologies in medium and large cars and pickup trucks with spark-ignition engines could reduce fuel consumption by 29 percent at an additional cost of $2,200 to the consumer. Replacing spark-ignition engines with diesel engines and components would yield fuel savings of about 37 percent at an added cost of approximately $5,900 per vehicle, and replacing spark-ignition engines with hybrid engines and components would reduce fuel consumption by 43 percent at an increase of $6,000 per vehicle. The book focuses on fuel consumption-the amount of fuel consumed in a given driving distance-because energy savings are directly related to the amount of fuel used. In contrast, fuel economy measures how far a vehicle will travel with a gallon of fuel. Because fuel consumption data indicate money saved on fuel purchases and reductions in carbon dioxide emissions, the book finds that vehicle stickers should provide consumers with fuel consumption data in addition to fuel economy information.





MODEL-BASED ENGINE-OUT EMISSIONS ANALYSIS FOR A GASOLINE TURBOCHARGED DIRECT INJECTION SPARK-IGNITED ENGINE IN ELEVATED HEV CRANKING SPEED

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Page : pages

File Size : 44,1 MB

Release : 2021

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Abstract : The in-cylinder trapped air, residual gas, and temperature are important dynamic parameters in Gasoline Direct Injection (GDI) Spark Ignition (SI) engines for fuel and combustion control. However, their real-time prediction for transient engine operations is complicated, especially when concerning variable valve timing. A dynamic cycle-by-cycle control-oriented discrete nonlinear model is proposed and developed in this thesis to estimate the in-cylinder mixture temperature and the mass of trapped air, and residual gas at the point of Intake Valve Closing (IVC). The developed model uses in-cylinder, intake, and exhaust pressures as the primary inputs. The exhaust gas backflow into the cylinder is estimated using a compressible ideal gas model that is designed for engines equipped with Variable Valve Timing (VVT). The designed model is integrated into a rapid-prototype control system for real-time operation. The model's dynamic behavior is validated using an engine dynamometer transient test cycle under real-time conditions. The cold crank-start phase significantly contributes to total engine-out emissions during the US Federal Test Procedure (FTP). The first three engine cycles of the cold crank-start for a Gasoline Direct Injection (GDI) engine in Hybrid Electric Vehicle (HEV) elevated cranking speed is investigated at 20°C. To this end, the impact of the operating strategy on the individual-cylinder engine-out emissions is analyzed quantitatively. For this purpose, a new dynamic method was developed to translate the engine-out emissions concentration measured at the exhaust manifold outlet to mass per cycle per cylinder. The HEV elevated cranking speed provides valve timing control, throttling, and increased fuel injection pressure from the first firings. This study concentrates on analyzing the cranking speed, spark timing, valve timing, and fuel injection strategy, and parameter effects on engine-out emissions. Design of Experiment (DOE) method is used to create a two-step multi-level fractional-factorial test plan with a minimum number of test points to evaluate the significant parameters affecting engine-out emissions during cold crank-start. The split injection parameters, including the Start of the first Injection (SOI), End of the second injection (EOI), and split ratio, in addition to the first cycle additive fuel factor, are investigated. Results show that using the high cranking speed with stabilized low intake Manifold Absolute Pressure (MAP), highly-retarded spark timing, high valve overlap, late intake first injection, 30 CAD bTDC firing EOI, and low first cycle fuel factor reduces the average first three cycles HC emission by 94\%.



Control Strategy for Hydrocarbon Emissions in Turbocharged Direct Injection Spark Ignition Engines During Cold-start

Author : Kevin David Cedrone

Publisher :

Page : 191 pages

File Size : 15,67 MB

Release : 2013

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Gasoline consumption and pollutant emissions from transportation are costly and have serious, demonstrated environmental and health impacts. Downsized, turbocharged direct-injection spark ignition (DISI) gasoline engines consume less fuel and achieve superior performance compared with conventional port fuel injected spark ignition (PFI-SI) engines. Although more efficient, turbocharged DISI engines have new emissions challenges during cold start. DISI fuel injection delivers more liquid fuel into the combustion chamber, increasing the emissions of unburned hydrocarbons. The turbocharger slows down activation (warm-up) of the catalytic exhaust after-treatment system. The objective of this research is to find a control strategy that: 1. Accelerates warm-up of the catalyst, and 2. Maintains low emissions of unburned hydrocarbons (UBHCs) during the catalyst warm-up process. This research includes a broad experimental survey of engine behaviour and emission response for a modern turbocharged DISI engine. The study focuses on the idle period during cold-start for which DISI engine emissions are worst. Engine experiments and simulations show that late and slow combustion lead to high exhaust gas temperatures and mass flow rate for fast warm-up. However, late and slow combustion increase the risk of partial-burn misfire. At the misfire limit for each parameter, the following conclusions are drawn: 1. Late ignition timing is the most effective way to increase exhaust enthalpy flow rate for fast catalyst warm-up. 2. By creating a favourable spatial fuel-air mixture stratification, split fuel injection can simultaneously retard and stabilize combustion to improve emissions and prevent partial-burn misfire. 3. Excessive trapped residuals from long valve overlap limit the potential for valve timing to reduce cold-start emissions. 4. Despite their more challenging evaporation characteristics, fuel blends with high ethanol content showed reasonable emissions behaviour and greater tolerance to late combustion than neat gasoline. 5. Higher exhaust back-pressure leads to high exhaust temperature during the exhaust stroke, leading to significantly more post-flame oxidation. 6. Post-flame oxidation in the combustion chamber and exhaust system play a critical role in decreasing the quantity of catalyst-in emissions due to hydrocarbons that escape primary (flame) combustion. A cold start strategy combining late ignition, 15% excess air, and high exhaust backpressure yielded the lowest cumulative hydrocarbon emissions during cold start.



Experimental root cause analysis of low-speed pre-ignition mechanisms on a turbocharged gasoline engine with direct-injection

Author : Thorsten Schweizer

Publisher : Logos Verlag Berlin GmbH

Page : 140 pages

File Size : 33,14 MB

Release : 2024-07-04

Category : Technology & Engineering

ISBN : 3832582428

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Book Description

The concept of increasing power density is a successful approach to improving the conflict between efficiency and emission behavior of spark-ignition engine drive units for light-duty vehicles. This leads to highly charged gasoline engines with direct injection and high specific torque and power densities, promoting a not yet fully understood combustion anomaly known as low-speed pre-ignition (LSPI). This unpredictable, multicyclic phenomenon limits the depictable in-cylinder pressures, further efficiency gains and engine reliability. Only with a holistic understanding of the LSPI root cause mechanisms and processes can targeted countermeasures be taken and further efficiency gains achieved. A novel methodology pathway for LSPI root cause analysis was developed to accompany the entire LSPI event emergence process path by means of a multi-experimental approach on a modern high efficiency engine. This includes the identification of key LSPI activity – engine parameter specification relations, minimally invasive high-speed endoscopic imaging and further LSPI key experiments. Only the accumulation of inorganic substances originating from lubricating oil additives enables specific deposits/particles to ignite the surrounding mixture over a multicyclic process due to the resulting increased oxidation reactivity. Through a final synthesis step of all results, a multi-cycle oxidation-reactivity-enhanced deposit/particle-driven LSPI root cause mechanism is established.



Robust Design Evolution and Impact of In-Cylinder Pressure Sensors to Combustion Control and Optimization

Author : Kamran Eftekhari Shahroudi

Publisher :

Page : 248 pages

File Size : 45,51 MB

Release : 2008

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ISBN :

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In-Cylinder Pressure Sensors (ICPS) today are close to satisfying the robustness, performance and cost requirements for application to closed loop control and monitoring of production automotive engines. Using the Robust Design framework as a compass, this thesis first checks the evidence for emergence followed by tracking the evolution of the sensor component itself and its application to robust closed loop control of the combustion process in internal combustion engines. After identifying the potential system level impact of the emerging ICPS technology, System Dynamic and Technology Strategy frameworks are used to find spillover triggers and to recommend a number of strategic options to generate and capture value for integrated system solution providers so that they can beat the very stable status quo that persists in the slow and mature prime mover industries. In addition, Chapter 2 gives a data driven method for identifying the Skills needed for suppliers to realize the above recommendations. This method is based on collective intelligence of 690 experienced professionals with 20 years of work experience on average from 40 targeted companies, representing a large body of engineering and managerial experience in battling complex engineering system hurdles. This approach is more effective than blindly copying the prominent integrated system solution providers or OEM's, because a side effect of long term incremental innovation in the mature prime mover industry is that the underlying reasons for their success is ingrained in their "tacit knowledge" and "organizational furniture" and hence not explicitly understood.



Injection Technologies and Mixture Formation Strategies For Spark Ignition and Dual-Fuel Engines

Author : Alessandro Ferrari

Publisher : SAE International

Page : 407 pages

File Size : 38,2 MB

Release : 2022-06-24

Category : Transportation

ISBN : 1468603116

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Book Description

Fuel injection systems and performance is fundamental to combustion engine performance in terms of power, noise, efficiency, and exhaust emissions. There is a move toward electric vehicles (EVs) to reduce carbon emissions, but this is unlikely to be a rapid transition, in part due to EV batteries: their size, cost, longevity, and charging capabilities as well as the scarcity of materials to produce them. Until these isssues are resolved, refining the spark-ignited engine is necessary address both sustainability and demand for affordable and reliable mobility. Even under policies oriented to smart sustainable mobility, spark-ignited engines remain strategic, because they can be applied to hybridized EVs or can be fueled with gasoline blended with bioethanol or bio-butanol to drastically reduce particulate matter emissions of direct injection engines in addition to lower CO2 emissions. In this book, Alessandro Ferrari and Pietro Pizzo provide a full review of spark-ignited engine fuel injection systems. The most popular typologies of fuel injection systems are considered, with special focus on state-of-the-art solutions. Dedicated sections on the methods for air mass evaluation, fuel delivery low-pressure modules, and the specific subsystems for idle, cold start, and warm-up control are also included. The authors pay special attention to mixture formation strategies, as they are a fundamental theme for SI engines. An exhaustive overview of fuel injection technologies is provided, and mixture formation strategies for spark ignited combustion engines are considered. Fuel Injection Systems illustrates the performance of these systems and will also serve as a reference for engineers who are active in the aftermarket, offering detailed information on fuel injection system solutions that are mounted in older vehicles.