Automotive Powertrain Control — A Survey

This paper surveys recent and historical publications on automotive powertrain control. Control-oriented models of gasoline and diesel engines and their aftertreatment systems are reviewed, and challenging control problems for conventional engines, hybrid vehicles and fuel cell powertrains are discussed. Fundamentals are revisited and advancements are highlighted. A comprehensive list of references is provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72023/1/j.1934-6093.2006.tb00275.x.pd

Advanced Technologies for the Optimization of Internal Combustion Engines

This Special Issue puts together recent findings in advanced technologies for the optimization of internal combustion engines in order to help the scientific community address the efforts towards the development of higher-power engines with lower fuel consumption and pollutant emissions

ECU-oriented models for NOx prediction. Part 1: a mean value engine model for NOx prediction

The implantation of nitrogen oxide sensors in diesel engines was proposed in order to track the emissions at the engine exhaust, with applications to the control and diagnosis of the after-treatment devices. However, the use of models is still necessary since the output from these sensors is delayed and filtered. The present paper deals with the problem of nitrogen oxide estimation in turbocharged diesel engines combining the information provided by both models and sensors. In Part 1 of this paper, a control-oriented nitrogen oxide model is designed. The model is based on the mapping of the nitrogen oxide output and a set of corrections which account for the variations in the intake and ambient conditions, and it is designed for implementation in commercial electronic control units. The model is sensitive to variations in the engine's air path, which is solved through the engine volumetric efficiency and the first-principle equations but disregards the effect of variation in the injection settings. In order to consider the effect of the thermal transients on the in-cylinder temperature, the model introduces a dynamic factor. The model behaves well in both steady-state operation and transient operation, achieving a mean average error of 7% in the steady state and lower than 10% in an exigent sportive driving mountain profile cycle. The relatively low calibration effort and the model accuracy show the feasibility of the model for exhaust gas recirculation control as well as onboard diagnosis of the nitrogen oxide emissions.Guardiola, C.; Pla Moreno, B.; Blanco-Rodriguez, D.; Calendini, PO. (2015). ECU-oriented models for NOx prediction. Part 1: a mean value engine model for NOx prediction. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering. 229(8):992-1015. doi:10.1177/0954407014550191S9921015229

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

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

A Challenging Future for the IC Engine: New Technologies and the Control Role

[FR] Un challenge pour le futur du moteur a` combustion interne : nouvelles technologies et ro¿le du contro¿le moteur ¿ Les nouvelles normes sur les e¿missions, en particulier le CO2, pourraient re¿duire l¿utilisation du moteur a` combustion interne pour les ve¿hicules. Cet article pre¿sente une revue de diffe¿rentes technologies en cours de de¿veloppement afin de respecter ces normes, depuis de nouveaux concepts de combustion jusqu¿a` des syste`mes avance¿s de suralimentation ou de post-traitement. La plupart de ces technologies demande un contro¿le pre¿cis des conditions de fonctionnement et impose souvent de fortes contraintes lors de l¿inte¿gration des syste`mes. Dans ce contexte et en profitant des dernie`res avance¿es dans les mode`les, les me¿thodes et les capteurs, le contro¿le moteur jouera un ro¿le clef dans la mise en œuvre et le de¿veloppement de la prochaine ge¿ne¿ration de moteurs. De l¿avis des auteurs, le moteur a` combustion interne restera la technologie dominante pour les ve¿hicules des prochaines de¿cennies.[EN] New regulations on pollutants and, specially, on CO2 emissions could restrict the use of the internal combustion engine in automotive applications. This paper presents a review of different technologies under development for meeting such regulations, ranging from new combustion concepts to advanced boosting methods and after-treatment systems. Many of them need an accurate control of the operating conditions and, in many cases, they impose demanding requirements at a system integration level. In this framework, engine control disciplines will be key for the implementation and development of the next generation engines, taking profit of recent advancements in models, methods and sensors. According to authors¿ opinion, the internal combustion engine will still be the dominant technology in automotive applications for the next decades.F. Payri; Luján, JM.; Guardiola, C.; Pla Moreno, B. (2015). A Challenging Future for the IC Engine: New Technologies and the Control Role. Oil & Gas Science and Technology ¿ Revue d¿IFP Energies nouvelles. 70(1):15-30. doi:10.2516/ogst/2014002S153070

Powertrain Architectures and Technologies for New Emission and Fuel Consumption Standards

New powertrain design is highly influenced by CO2 and pollutant limits defined by legislations, the demand of fuel economy in for real conditions, high performances and acceptable cost. To reach the requirements coming from both end-users and legislations, several powertrain architectures and engine technologies are possible (e.g. SI or CI engines), with many new technologies, new fuels, and different degree of electrification. The benefits and costs given by the possible architectures and technology mix must be accurately evaluated by means of objective procedures and tools in order to choose among the best alternatives. This work presents a basic design methodology and a comparison at concept level of the main powertrain architectures and technologies that are currently being developed, considering technical benefits and their cost effectiveness. The analysis is carried out on the basis of studies from the technical literature, integrating missing data with evaluations performed by means of powertrain-vehicle simplified models, considering the most important powertrain architectures. Technology pathways for passenger cars up to 2025 and beyond have been defined. After that, with support of more detailed models and experimentations, the investigation has been focused on the more promising technologies to improve internal combustion engine, such as: water injection, low temperature combustions and heat recovery systems

Low-Pressure EGR in Spark-Ignition Engines: Combustion Effects, System Optimization, Transients & Estimation Algorithms

Low-displacement turbocharged spark-ignition engines have become the dominant choice of auto makers in the effort to meet the increasingly stringent emission regulations and fuel efficiency targets. Low-Pressure cooled Exhaust Gas Recirculation introduces important efficiency benefits and complements the shortcomings of highly boosted engines. The main drawback of these configurations is the long air-path which may cause over-dilution limitations during transient operation. The pulsating exhaust environment and the low available pressure differential to drive the recirculation impose additional challenges with respect to feed-forward EGR estimation accuracy. For these reasons, these systems are currently implemented through calibration with less-than-optimum EGR dilution in order to ensure stable operation under all conditions. However, this technique introduces efficiency penalties. Aiming to exploit the full potential of this technology, the goal is to address these challenges and allow operation with near-optimum EGR dilution. This study is focused on three major areas regarding the implementation of Low-Pressure EGR systems: Combustion effects, benefits and constraints System optimization and transient operation Estimation and adaptation Results from system optimization show that fuel efficiency benefits range from 2% – 3% over drive cycles through pumping and heat loss reduction, and up to 16% or more at higher loads through knock mitigation and fuel enrichment elimination. Soot emissions are also significantly reduced with cooled EGR. Regarding the transient challenges, a methodology that correlates experimental data with simulation results is developed to identify over-dilution limitations related to the engine’s dilution tolerance. Different strategies are proposed to mitigate these issues, including a Neural Network-actuated VVT that controls the internal residual and increases the over-dilution tolerance by 3% of absolute EGR. Physics-based estimation algorithms are also developed, including an exhaust pressure/temperature model which is validated through real-time transient experiments and eliminates the need for exhaust sensors. Furthermore, the installation of an intake oxygen sensor is investigated and an adaptation algorithm based on an Extended Kalman Filter is created. This algorithm delivers short-term and long-term corrections to feed-forward EGR models achieving a final estimation error of less than 1%. The combination of the proposed methodologies, strategies and algorithms allows the implementation of near-optimum EGR dilution and translates to fuel efficiency benefits ranging from 1% at low-load up to 10% at high-load operation over the current state-of-the-art

Reactivity controlled compression ignition engine: Pathways towards commercial viability

© 2020 Elsevier Ltd. All rights reserved. This manuscript is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Licence (http://creativecommons.org/licenses/by-nc-nd/4.0/).Reactivity-controlled compression ignition (RCCI) is a promising energy conversion strategy to increase fuel efficiency and reduce nitrogen oxide (NOx) and soot emissions through improved in-cylinder combustion process. Considering the significant amount of conducted research and development on RCCI concept, the majority of the work has been performed under steady-state conditions. However, most thermal propulsion systems in transportation applications require operation under transient conditions. In the RCCI concept, it is crucial to investigate transient behavior over entire load conditions in order to minimize the engine-out emissions and meet new real driving emissions (RDE) legislation. This would help further close the gap between steady-state and transient operation in order to implement the RCCI concept into mass production. This work provides a comprehensive review of the performance and emissions analyses of the RCCI engines with the consideration of transient effects and vehicular applications. For this purpose, various simulation and experimental studies have been reviewed implementing different control strategies like control-oriented models particularly in dual-mode operating conditions. In addition, the application of the RCCI strategy in hybrid electric vehicle platforms using renewable fuels is also discussed. The discussion of the present review paper provides important insights for future research on the RCCI concept as a commercially viable energy conversion strategy for automotive applications.Peer reviewe

Advancement in Understanding the Extreme Altitude and Ambient Temperature Impact on Diesel Engine and Aftertreatment Performance

[ES] El carácter cada vez más estricto de las normativas de emisiones ha provocado el desarrollo de motores de combustión más respetuosos con el medioambiente. La última normativa europea aplicada al sector del transporte ha ampliado el rango de condiciones de operación en el que se realizan las pruebas de homologación. Las variables de temperatura ambiente y altitud de conducción son ahora requisitos adicionales que deben tenerse en cuenta con la intención de reducir la diferencia entre el resultado de esas pruebas y en condiciones de conducción real. La comprensión del impacto de las condiciones ambientales sobre el funcionamiento del motor es algo fundamental para superar los inconvenientes que pueden representar la respuesta del motor y teniendo un gran impacto sobre las emisiones del mismo. Como consecuencia de la variación de la altitud y de la temperatura ambiente, las condiciones de contorno de los sistemas de postratamiento de los gases de escape (EATS) se modifican, comprometiendo su funcionamiento y repercutiendo en las emisiones liberadas a la atmosfera. En el caso concreto de los motores Diesel, los dos EATS más comunes son el catalizador de oxidación diesel (DOC) y el filtro de partículas diesel (DPF). En este contexto, la presente tesis doctoral propone diferentes enfoques a fin de comprender los principales efectos que las condiciones ambientales extremas provocan en el motor y en el funcionamiento del DOC y del DPF. Una parte importante de este trabajo ha consistido en la puesta en marcha de un banco de pruebas experimental equipado con un simulador de altitud y de una herramienta de modelización termo fluidodinámica unidimensional (1D) para un amplio análisis. Tras los resultados experimentales en condiciones de estado estacionario a baja temperatura, los mapas de contorno de las emisiones de CO y HC condujeron a la evaluación como las condiciones ambientales extremas repercuten en la temperatura de activación del DOC y en la eficiencia de conversión de las emisiones contaminantes. El análisis computacinal ayudó a elaborar directrices que determinan la contribución de las propiedades del flujo causadas por dichas condiciones. Asimismo, se ha abordado el efecto de la aplicación de soluciones computacionales de aislamiento térmico del escape sobre el DOC y la respuesta del motor. Por otro lado, se ha realizado experimentalmente la actuación de la turbina de geometría variable (VGT) sobre el proceso de regeneración del DPF. El impacto que la estrategia de presión de sobrealimentación tiene sobre la tasa de consumo de hollín durante la regeneración activa en función de la altitud de conducción se considera con la orientación de las herramientas de modelado. La discusión de la reducción de la tasa de regeneración en altitud con las estrategias de sobrealimentación estándar ha conducido a la reevaluación de la actuación de la de la turbina de geometría variable (VGT) para condiciones de altitud extrema. Por último, se ha analizado experimentalmente la sensibilidad de la posición del VGT y la tasa de EGR de baja presión (LP-EGR) sobre el comportamiento del motor a cargas parciales en un amplio rango de condiciones ambientales. Los resultados han conducido a la redefinición de la calibración del motor a fin de aumentar la temperatura de entrada del EATS al tiempo que se reduce el consumo específico de combustible.[CA] El caràcter cada vegada més estricte de les normatives d'emissions ha provocat el desenvolupament de motors de combustió més respectuosos amb el medi ambient. L'última normativa europea aplicada al sector del transport ha ampliat el rang de condicions d'operació en el qual es realitzen les proves d'homologació. Les variables de temperatura ambient i altitud de conducció són ara requisits addicionals que han de tindre's en compte amb la intenció de reduir la diferència entre el resultat d'aqueixes proves i en condicions de conducció real. La comprensió de l'impacte de les condicions ambientals en el compliment de la normativa pel motor es fonamental per a superar els inconvenients que poden representar per a la resposta del motor amb un ampli impacte en les emissions d'aquest. A conseqüència de la variació de l'altitud o de la temperatura ambient, els límits dels sistemes de posttractament dels gasos de fuita (EATS) es modifiquen, comprometent el seu funcionament i repercutint en les emissions alliberades a la atmosfera. En el cas concret dels motors Dièsel, els dos EATS més comuns són el catalitzador d'oxidació dièsel (DOC) i el filtre de partícules dièsel (DPF). En aquest context, aquesta tesi doctoral proposa diferents enfocaments per a entendre els principals factors que les condicions ambientals extremes imposen al motor i al funcionament del DOC i del DPF. Una part important d'aquest treball ha consistit en la posada en marxa d'un banc de proves experimental equipat amb un simulador d'altitud i d'una eina de modelització termo fluidodinámica unidimensional (1D) per a una ampla anàlisi. Després dels resultats experimentals en condicions d'estat estacionari a baixa temperatura, els mapes de contorn de les emissions de CO i HC ha conduí a l'avaluació de com les condicions ambientals extremes repercuteixen en la temperatura d'activació del DOC i en l'eficiència de conversió de les emissions contaminants. L'anàlisi computacinal ha ajudat a elaborar directrius que determinen la contribució de les propietats del flux causades per aquestes condicions. Així mateix, l'efecte de l'aplicació de solucions d'aïllament tèrmic del tubo d'escapament sobre el DOC i la resposta del motor. D'altra banda, s'ha realitzat experimentalment l'actuació de la turbina de geometria variable (VGT) sobre el procés de regeneració del DPF. L'impacte que l'estratègia de pressió de sobrealimentació té sobre la taxa de consum de sutge durant la regeneració activa en funció de l'altitud de conducció es considera amb l'orientació de les eines de modelatge. La discussió de la reducció de la taxa de regeneració en altitud amb les estratègies de sobrealimentació estàndard ha conduït a la reavaluació de l'actuació de la de la turbina de geometria variable (VGT) per a condicions d'altitud extrema. Finalment, s'ha analitzat experimentalment la sensibilitat de la posició del VGT i la taxa de EGR de baixa pressió (LP-EGR) sobre el comportament del motor a càrregues parcials en un ampli rang de condicions ambientals. Els resultats han conduït a la redefinició del calibratge del motor a fi d'augmentar la temperatura d'entrada del EATS al mateix temps que es redueix el consum específic de combustible.[EN] The increasingly stringent emission standards act as a guide for the development of cleaner vehicles in a context of climate change. The latest European regulations applied to the transportation sector widened the operation range where homologation tests are carried out. The variables of ambient temperature and driving altitude are now extra requirements that must be considered in a way to shorten the gap between those tests and real driving. The understanding of the ambient conditions impact on the engine response becomes fundamental to overcome the drawbacks represented by them, being determinant for the engine response with an extended impact on engine-out emissions. As a consequence of altitude or ambient temperature variation, the exhaust aftertreatment systems (EATS) boundaries are modified, compromising their operation and impacting on tailpipe emissions. In the specific case of Diesel engines, the two most common EATS are the diesel oxidation catalyst (DOC) and the diesel particulate filter (DPF). In this context, this doctoral thesis proposes different approaches to understand the main factors that extreme ambient conditions impose to the engine and to the DOC and DPF operation. An important part of this work consisted of the set up of an experimental test bench equipped with an altitude simulator and of a one-dimensional (1D) thermo-fluid dynamic modelling tool for a wide-ranging analysis. Following low temperature steady state conditions experimental outcomes, CO and HC emission contour maps led to the evaluation of how extreme ambient conditions impact on the DOC light-off and pollutant emissions conversion efficiency. The modelling analysis helped to build guidelines that determine the contribution of the flow properties caused by such conditions. Besides, the effect of applying computational exhaust line thermal insulation solutions on the DOC and engine response is additionally addressed. On the other hand, the variable geometry turbine (VGT) actuation on the DPF regeneration process is performed experimentally. The impact that the boost pressure strategy has on the rate of soot depletion during active regeneration as a function of the driving altitude is considered with the guidance of the modelling tools. The reduction of the regeneration rate in altitude with standard boosting strategies is discussed, leading to the re-evaluation of the VGT actuation for high altitude practices. Finally, the sensitivity of the VGT position and low pressure exhaust gases recirculation (LP-EGR) rate at a vast array of ambient conditions is experimentally analysed for regular engine operation at partial loads. The results led to the engine calibration redefinition based on EATS inlet temperature increase and the reduction of the specific fuel consumption.Diesel Costa, B. (2022). Advancement in Understanding the Extreme Altitude and Ambient Temperature Impact on Diesel Engine and Aftertreatment Performance [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181715TESI