Further analysis of a compression-expansion machine for a Brayton Waste Heat Recovery cycle on an IC engine

[EN] In order to comply with the legislation, car manufacturers are looking for a way to lower the CO2 emission by improving engine efficiency. About one third of the fuel combustion energy is wasted through exhaust gasses. Waste Heat Recovery (WHR) could improve engine efficiency by recovering a part of exhaust gasses energy. In this study, the potential use of an open loop Brayton cycle with a volumetric compression expansion machine for exhaust gas waste heat recovery was investigated. The use of the Brayton cycle system with only two main elements, a heat exchanger and a volumetric machine, could be very interesting due to its compactness and versatility. However, the publications on this subject are scarce. The present paper aims at bridging this knowledge gap by studying the cycle viability for passenger car application characterized by low temperatures, variable working conditions and several restrictions of available space and weight. The simulated vehicle was a Ford Mondeo family car with an Ecoboost 2.0 engine. The main components of the Brayton cycle WHR system model were a heat exchanger and an alternating piston machine that was used both as a compressor and as an expander. Theoretical studies were conducted in the compression-expansion machine model in order to determine the main parameters that influence the cycle and optimize those parameters in order to obtain the maximum recuperated power. The conclusion was that the cycle viability is not clear because cycle losses are in the same order of magnitude as the recuperated power. Considering future improvements of the compression-expansion machine and the heat exchanger, the recuperated power could be positive. Nevertheless, it is hard to expect that recuperated power would be sufficient to justify the application of this WHR system in the vehicle. (C) 2017 Elsevier Ltd. All rights reserved.Galindo, J.; Guardiola, C.; Dolz, V.; Kleut, P. (2018). Further analysis of a compression-expansion machine for a Brayton Waste Heat Recovery cycle on an IC engine. Applied Thermal Engineering. 128:345-356. https://doi.org/10.1016/j.applthermaleng.2017.09.012S34535612

Optimal control as a method for diesel engine efficiency assessment including pressure and NOx constraints

[EN] The present paper studies the optimal heat release law in a Diesel engine to maximise the indicated efficiency subject to different constraints, namely: maximum cylinder pressure, maximum cylinder pressure derivative, and NOx emission restrictions. With this objective, a simple but also representative model of the combustion process has been implemented. The model consists of a OD energy balance model aimed to provide the pressure and temperature evolutions in the high pressure loop of the engine thermodynamic cycle from the gas conditions at the intake valve closing and the heat release law. The gas pressure and temperature evolutions allow to compute the engine efficiency and NOx emissions. The comparison between model and experimental results shows that despite the model simplicity, it is able to reproduce the engine efficiency and NOx emissions. After the model identification and validation, the optimal control problem is posed and solved by means of Dynamic Programming (DP). Also, if only pressure constraints are considered, the paper proposes a solution that reduces the computation cost of the DP strategy in two orders of magnitude for the case being analysed. The solution provides a target heat release law to define injection strategies but also a more realistic maximum efficiency boundary than the ideal thermodynamic cycles usually employed to estimate the maximum engine efficiency. (C) 2017 Elsevier Ltd. All rights reserved.Thanks are due to the Ministerio de Economia y Competitividad by its financial support through project mu-Balance (TRA2013-41348-R).Guardiola, C.; Climent, H.; Plá Moreno, B.; Reig, A. (2017). Optimal control as a method for diesel engine efficiency assessment including pressure and NOx constraints. Applied Thermal Engineering. 117:452-461. https://doi.org/10.1016/j.applthermaleng.2017.02.056S45246111

Control-oriented modelling of three-way catalytic converter for fuel-to-air ratio regulation in spark ignited engines

[EN] The purpose of this paper is to introduce a grey-box model of three-way catalytic converter, which is capable of estimating the oxygen storage level to aid the fuel-to-air ratio control in spark ignited engines. As it is well-known, the prime parameter that drives the transient dynamics in current three-way catalytic converter is their capability to store a certain amount of oxygen, then allowing to oxidize some pollutant species such as carbon monoxide or hydrocarbons even at rich conditions during short periods of time. Since oxygen storage level is considered a good indicator of the catalyst state but it cannot be directly measured, a model based real-time capable estimation like the one proposed in this paper could be valuable. The model accounts for oxygen storing as well as oxidation and reduction of the main species involved, taking as inputs fuel-to-air equivalence ratio, air mass flow, temperature and gas composition at three-way catalyst inlet. From these inputs, oxygen storage level and brick temperature are calculated as model states, which finally provide the gas composition downstream of the catalyst as output. In addition, a simplified model of narrowband lambda sensor is included, it provides a voltage from gas composition at the outlet of the catalyst and allows to assess the model behaviour by comparison with the on-board lambda sensor measurements. Finally, the validation of the model performance by means of experimental test as well as different practical cases, where the benefits of oxygen storage level estimation plays a key role, are introduced.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge the support of Spanish Ministerio de Economía, Industria y Competitividad through project TRA2016-78717-R.Guardiola, C.; Climent, H.; Pla Moreno, B.; Real, M. (2019). Control-oriented modelling of three-way catalytic converter for fuel-to-air ratio regulation in spark ignited engines. Proceedings of the Institution of Mechanical Engineers Part D Journal of Automobile Engineering. 233(14):3758-3774. https://doi.org/10.1177/0954407019833822S3758377423314Auckenthaler, T. S., Onder, C. H., & Geering, H. P. (2004). Aspects of Dynamic Three-Way Catalyst Behaviour Including Oxygen Storage. IFAC Proceedings Volumes, 37(22), 331-336. doi:10.1016/s1474-6670(17)30365-8Yang, H., Shu, G., Tian, H., Ma, X., Chen, T., & Liu, P. (2018). Optimization of thermoelectric generator (TEG) integrated with three-way catalytic converter (TWC) for harvesting engine’s exhaust waste heat. Applied Thermal Engineering, 144, 628-638. doi:10.1016/j.applthermaleng.2018.07.091Koltsakis, G. C., Konstantinidis, P. A., & Stamatelos, A. M. (1997). Development and application range of mathematical models for 3-way catalytic converters. Applied Catalysis B: Environmental, 12(2-3), 161-191. doi:10.1016/s0926-3373(96)00073-2Zygourakis, K. (1989). Transient operation of monolith catalytic converters: a two-dimensional reactor model and the effects of radially nonuniform flow distributions. Chemical Engineering Science, 44(9), 2075-2086. doi:10.1016/0009-2509(89)85143-7Coxeter, H. S. M. (1993). Cyclotomic integers, nondiscrete tessellations, and quasicrystals. Indagationes Mathematicae, 4(1), 27-38. doi:10.1016/0019-3577(93)90049-5Konstantas, G., & Stamatelos, A. M. (2007). Modelling three-way catalytic converters: An effort to predict the effect of precious metal loading. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 221(3), 355-373. doi:10.1243/09544070jauto329Pontikakis, G. N., Konstantas, G. S., & Stamatelos, A. M. (2004). Three-Way Catalytic Converter Modeling as a Modern Engineering Design Tool. Journal of Engineering for Gas Turbines and Power, 126(4), 906-923. doi:10.1115/1.1787506Kumar, P., Gu, T., Grigoriadis, K., Franchek, M., & Balakotaiah, V. (2014). Spatio-temporal dynamics of oxygen storage and release in a three-way catalytic converter. Chemical Engineering Science, 111, 180-190. doi:10.1016/j.ces.2014.02.014Auckenthaler, T. S., Onder, C. H., Geering, H. P., & Frauhammer, J. (2004). Modeling of a Three-Way Catalytic Converter with Respect to Fast Transients of λ-Sensor Relevant Exhaust Gas Components. Industrial & Engineering Chemistry Research, 43(16), 4780-4788. doi:10.1021/ie034242uNievergeld, A. J. L., Selow, E. R. v., Hoebink, J. H. B. J., & Marin, G. B. (1997). Simulation of a catalytic converter of automotive exhaust gas under dynamic conditions. Dynamics of Surfaces and Reaction Kinetics in Heterogeneous Catalysis, Proceedings of the International Symposium, 449-458. doi:10.1016/s0167-2991(97)80431-4Oh, S. H., & Cavendish, J. C. (1982). Transients of monolithic catalytic converters. Response to step changes in feedstream temperature as related to controlling automobile emissions. Industrial & Engineering Chemistry Product Research and Development, 21(1), 29-37. doi:10.1021/i300005a006Chan, S. H., & Hoang, D. L. (1999). Heat transfer and chemical reactions in exhaust system of a cold-start engine. International Journal of Heat and Mass Transfer, 42(22), 4165-4183. doi:10.1016/s0017-9310(99)00064-2Sabatini, S., Gelmini, S., Hoffman, M. A., & Onori, S. (2017). Design and experimental validation of a physics-based oxygen storage — thermal model for three way catalyst including aging. Control Engineering Practice, 68, 89-101. doi:10.1016/j.conengprac.2017.07.007Schürholz, K., Brückner, D., Gresser, M., & Abel, D. (2018). Modeling of the Three-way Catalytic Converter by Recurrent Neural Networks. IFAC-PapersOnLine, 51(15), 742-747. doi:10.1016/j.ifacol.2018.09.166Brandt, E. P., Yanying Wang, & Grizzle, J. W. (2000). Dynamic modeling of a three-way catalyst for SI engine exhaust emission control. IEEE Transactions on Control Systems Technology, 8(5), 767-776. doi:10.1109/87.865850Shaw, B. T., Fischer, G. D., & Hedrick, J. K. (2002). A SIMPLIFIED COLDSTART CATALYST THERMAL MODEL TO REDUCE HYDROCARBON EMISSIONS. IFAC Proceedings Volumes, 35(1), 307-312. doi:10.3182/20020721-6-es-1901.01519Bickel, J., Odendall, B., Eigenberger, G., & Nieken, U. (2017). Oxygen storage dominated three-way catalyst modeling for fresh catalysts. Chemical Engineering Science, 160, 34-53. doi:10.1016/j.ces.2016.11.016Kiwitz, P., Onder, C., & Guzzella, L. (2012). Control-oriented modeling of a three-way catalytic converter with observation of the relative oxygen level profile. Journal of Process Control, 22(6), 984-994. doi:10.1016/j.jprocont.2012.04.014Kumar, P., Makki, I., Kerns, J., Grigoriadis, K., Franchek, M., & Balakotaiah, V. (2012). A low-dimensional model for describing the oxygen storage capacity and transient behavior of a three-way catalytic converter. Chemical Engineering Science, 73, 373-387. doi:10.1016/j.ces.2011.12.001Gong, J., Wang, D., Li, J., Currier, N., & Yezerets, A. (2017). Dynamic oxygen storage modeling in a three-way catalyst for natural gas engines: A dual-site and shrinking-core diffusion approach. Applied Catalysis B: Environmental, 203, 936-945. doi:10.1016/j.apcatb.2016.11.005Ramanathan, K., & Sharma, C. S. (2011). Kinetic Parameters Estimation for Three Way Catalyst Modeling. Industrial & Engineering Chemistry Research, 50(17), 9960-9979. doi:10.1021/ie200726jOlsson, L., & Andersson, B. (2004). Kinetic Modelling in Automotive Catalysis. Topics in Catalysis, 28(1-4), 89-98. doi:10.1023/b:toca.0000024337.50617.8eMöller, R., Votsmeier, M., Onder, C., Guzzella, L., & Gieshoff, J. (2009). Is oxygen storage in three-way catalysts an equilibrium controlled process? Applied Catalysis B: Environmental, 91(1-2), 30-38. doi:10.1016/j.apcatb.2009.05.003Rink, J., Meister, N., Herbst, F., & Votsmeier, M. (2017). Oxygen storage in three-way-catalysts is an equilibrium controlled process: Experimental investigation of the redox thermodynamics. Applied Catalysis B: Environmental, 206, 104-114. doi:10.1016/j.apcatb.2016.12.052Auckenthaler, T. S., Onder, C. H., & Geering, H. P. (2002). CONTROL-ORIENTED INVESTIGATION OF SWITCH-TYPE AIR/FUEL RATIO SENSORS. IFAC Proceedings Volumes, 35(1), 331-336. doi:10.3182/20020721-6-es-1901.0152

A new knock event definition for knock detection and control optimization

[EN] In this paper, the knock phenomenon is studied and characterized in the time-frequency domain. From the analysis results, a new knock event definition is proposed, which compares the excitation of the cylinder resonance produced by the autoignition of the end gas to that associated with the combustion. The new definition permits a more consistent differentiation between knocking and not knocking cycles than the classical approach in the literature, thus allowing the improvement of the knock control strategies. The new knock index proposed analyses the frequency spectrum of the pressure signal in two locations, i.e. near the maximum heat release and near the end of combustion, by using the fast Fourier transform and a window function, and it is compared with the classical MAPO definition, which consists on finding the maximum pressure oscillation in the time domain. Both indices have been implemented online in a four-stroke SI engine and its performance is illustrated by using a classical knock control strategy. Results obtained under different operating conditions demonstrate that the improved knock index definition can substantially reduce the variability of the spark advance angle control, avoiding strong knocking events and reducing engine vibration.Bares-Moreno, P.; Selmanaj, D.; Guardiola, C.; Onder, C. (2018). A new knock event definition for knock detection and control optimization. Applied Thermal Engineering. 131:80-88. https://doi.org/10.1016/j.applthermaleng.2017.11.138S808813

Knock probability estimation through an in-cylinder temperature model with exogenous noise

[EN] This paper presents a new knock model which combines a deterministic knock model based on the in-cylinder temperature and an exogenous noise disturbing this temperature. The autoignition of the end-gas is modelled by an Arrhenius-like function and the knock probability is estimated by propagating a virtual error probability distribution. Results show that the random nature of knock can be explained by uncertainties at the in cylinder temperature estimation. The model only has one parameter for calibration and thus can be easily adapted online. In order to reduce the measurement uncertainties associated with the air mass flow sensor, the trapped mass is derived from the in-cylinder pressure resonance, which improves the knock probability estimation and reduces the number of sensors needed for the model. A four stroke SI engine was used for model validation. By varying the intake temperature, the engine speed, the injected fuel mass, and the spark advance, specific tests were conducted, which furnished data with various knock intensities and probabilities. The new model is able to predict the knock probability within a sufficient range at various operating conditions. The trapped mass obtained by the acoustical model was compared in steady conditions by using a fuel balance and a lambda sensor and differences below 1% were found. (C) 2017 Elsevier Ltd. All rights reserved.Bares-Moreno, P.; Selmanaj, D.; Guardiola, C.; Onder, C. (2018). Knock probability estimation through an in-cylinder temperature model with exogenous noise. Mechanical Systems and Signal Processing. 98:756-769. https://doi.org/10.1016/j.ymssp.2017.05.033S7567699

Adaptive calibration for reduced fuel consumption and emissions

This paper presents a model-based approach for continuously adapting an engine calibration to the traffic and changing pollutant emission limits. The proposed strategy does not need additional experimental tests beyond those required by the traditional calibration approach. The method utilises information currently available in the engine control unit to adapt the engine control to the particular driving patterns of a given driver. Additional information about the emissions limits should be provided by an external structure if an adaptation to the pollutant immission is required. The proposed strategy has been implemented in a light-duty diesel engine, and showed a good potential to keep NOx emissions around a defined limit.Guardiola, C.; Pla Moreno, B.; Bares-Moreno, P.; Waschl, H. (2016). Adaptive calibration for reduced fuel consumption and emissions. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering. 230(14):2002-2014. doi:10.1177/0954407016636977S200220142301

Optimal control of a turbocharged direct injection diesel engine by direct method optimization

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/10.1177/1468087418772231[EN] This work studies the effect and performance of an optimal control strategy on engine fuel efficiency and pollutant emissions. An accurate mean value control-oriented engine model has been developed and experimental validation on a wide range of operating conditions was carried out. A direct optimization method based on Euler's collocation scheme is used in combination with the above model in order to address the optimal control of the engine. This optimization method provides the optimal trajectories of engine controls (fueling rate, exhaust gas recirculation valve position, variable turbine geometry position and start of injection) to reproduce a predefined route (speed trajectory including variable road grade), minimizing fuel consumption with limited NOx emissions and a low soot stamp. This optimization procedure is performed for a set of different NOx emission limits in order to analyze the trade-off between optimal fuel consumption and minimum emissions. Optimal control strategies are validated in an engine test bench and compared against engine factory calibration. Experimental results show that significant improvements in both fuel efficiency and emissions reduction can be achieved with optimal control strategy. Fuel savings at about 4% and less than half of the factory NOx emissions were measured in the actual engine, while soot generation was still low. Experimental results and optimal control trajectories are thoroughly analyzed, identifying the different strategies that allowed those performance improvements.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Ministerio de Economia y Competitividad through project TRA2016-78717-R.Luján, JM.; Guardiola, C.; Pla Moreno, B.; Reig, A. (2019). Optimal control of a turbocharged direct injection diesel engine by direct method optimization. International Journal of Engine Research. 20(6):640-652. https://doi.org/10.1177/1468087418772231S640652206Payri, F., Luján, J., Guardiola, C., & Pla, B. (2014). 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/2014002Hagelauer, P., & Mora-Camino, F. (1998). A soft dynamic programming approach for on-line aircraft 4D-trajectory optimization. European Journal of Operational Research, 107(1), 87-95. doi:10.1016/s0377-2217(97)00221-xHiggins, A., Kozan, E., & Ferreira, L. (1996). Optimal scheduling of trains on a single line track. Transportation Research Part B: Methodological, 30(2), 147-161. doi:10.1016/0191-2615(95)00022-4Darby, C. L., & Rao, A. V. (2011). Minimum-Fuel Low-Earth Orbit Aeroassisted Orbital Transfer of Small Spacecraft. Journal of Spacecraft and Rockets, 48(4), 618-628. doi:10.2514/1.a32011Nilsson, T., Froberg, A., & Aslund, J. (2012). Optimal Operation of a Turbocharged Diesel Engine during Transients. SAE International Journal of Engines, 5(2), 571-578. doi:10.4271/2012-01-0711Asprion, J., Chinellato, O., & Guzzella, L. (2014). Optimal Control of Diesel Engines: Numerical Methods, Applications, and Experimental Validation. Mathematical Problems in Engineering, 2014, 1-21. doi:10.1155/2014/286538Guardiola, C., Pla, B., Bares, P., & Waschl, H. (2016). Adaptive calibration for reduced fuel consumption and emissions. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 230(14), 2002-2014. doi:10.1177/0954407016636977Luján, J. M., Guardiola, C., Pla, B., & Reig, A. (2015). Switching strategy between HP (high pressure)- and LPEGR (low pressure exhaust gas recirculation) systems for reduced fuel consumption and emissions. Energy, 90, 1790-1798. doi:10.1016/j.energy.2015.06.138Guardiola, C., Pla, B., Blanco-Rodríguez, D., & Reig, A. (2013). Modelling driving behaviour and its impact on the energy management problem in hybrid electric vehicles. International Journal of Computer Mathematics, 91(1), 147-156. doi:10.1080/00207160.2013.829567Asprion, J., Chinellato, O., & Guzzella, L. (2013). Optimisation-oriented modelling of the NOx emissions of a Diesel engine. 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Proceedings of the National Academy of Sciences, 42(10), 767-769. doi:10.1073/pnas.42.10.767Diehl, M., Bock, H. G., Diedam, H., & Wieber, P.-B. (s. f.). Fast Direct Multiple Shooting Algorithms for Optimal Robot Control. Fast Motions in Biomechanics and Robotics, 65-93. doi:10.1007/978-3-540-36119-0_4Wächter, A., & Biegler, L. T. (2005). On the implementation of an interior-point filter line-search algorithm for large-scale nonlinear programming. Mathematical Programming, 106(1), 25-57. doi:10.1007/s10107-004-0559-yNocedal, J. (1980). Updating quasi-Newton matrices with limited storage. Mathematics of Computation, 35(151), 773-773. doi:10.1090/s0025-5718-1980-0572855-

An on-board method to estimate the light-off temperature of diesel oxidation catalysts

[EN] Current diesel engine regulations include on-board diagnostic requirements so that after-treatment systems need on-board methods to detect their aging state through the available measurements. In a state-of-the-art diesel exhaust line, two temperature and lambda measurements can be found upstream and downstream of the diesel oxidation catalyst. Thus, the strategy presented in this article makes use of these measurements to estimate the light-off temperature, which has been widely studied as a characteristic of diesel oxidation catalyst aging. The light-off temperature estimation potential is evaluated first under dynamic engine operating conditions, in which lambda measurements are proved to be precise enough to detect oxidation. However, dynamic conditions make the association of a representative temperature with an oxidation event difficult. Therefore, the method makes use of more controlled conditions at idle, during which the exhaust temperature decreases avoiding dynamics of normal driving conditions. During the idle, post-injection pulses are applied to determine whether oxidation occurs at a representative temperature measured by the upstream temperature sensor. The result of each pulse is used to generate a database. Then, after a long enough time window, the database generated will allow characterizing non-oxidation and oxidation temperatures, with an intermediate interval of indefinition. This article shows how the temperatures of these ranges increase as the light-off temperature increases, thereby validating the proposed method for light-off temperature estimation.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge the support of Spanish Ministerio de Econom¿¿a, Industria y Competitividad through project TRA2016-78717-R.Guardiola, C.; Pla Moreno, B.; Bares-Moreno, P.; Mora, J. (2020). An on-board method to estimate the light-off temperature of diesel oxidation catalysts. International Journal of Engine Research. 21(8):1480-1492. https://doi.org/10.1177/146808741881796514801492218Guardiola, C., Pla, B., Piqueras, P., Mora, J., & Lefebvre, D. (2017). Model-based passive and active diagnostics strategies for diesel oxidation catalysts. Applied Thermal Engineering, 110, 962-971. doi:10.1016/j.applthermaleng.2016.08.207Blanco-Rodriguez, D., Vagnoni, G., & Holderbaum, B. (2016). EU6 C-Segment Diesel vehicles, a challenging segment to meet RDE and WLTP requirements. IFAC-PapersOnLine, 49(11), 649-656. doi:10.1016/j.ifacol.2016.08.094Ye, S., Yap, Y. H., Kolaczkowski, S. T., Robinson, K., & Lukyanov, D. (2012). Catalyst ‘light-off’ experiments on a diesel oxidation catalyst connected to a diesel engine—Methodology and techniques. Chemical Engineering Research and Design, 90(6), 834-845. doi:10.1016/j.cherd.2011.10.003Li, J., Szailer, T., Watts, A., Currier, N., & Yezerets, A. (2012). Investigation of the Impact of Real-World Aging on Diesel Oxidation Catalysts. SAE International Journal of Engines, 5(3), 985-994. doi:10.4271/2012-01-1094Wiebenga, M. H., Kim, C. H., Schmieg, S. J., Oh, S. H., Brown, D. B., Kim, D. H., … Peden, C. H. F. (2012). Deactivation mechanisms of Pt/Pd-based diesel oxidation catalysts. Catalysis Today, 184(1), 197-204. doi:10.1016/j.cattod.2011.11.014Mallamo, F., Longhi, S., Millo, F., & Rolando, L. (2013). Modeling of diesel oxidation catalysts for calibration and control purpose. International Journal of Engine Research, 15(8), 965-979. doi:10.1177/1468087413492526Mohammadpour, J., Franchek, M., & Grigoriadis, K. (2011). A survey on diagnostic methods for automotive engines. International Journal of Engine Research, 13(1), 41-64. doi:10.1177/1468087411422851Tourlonias, P., & Koltsakis, G. (2011). Model-based comparative study of Euro 6 diesel aftertreatment concepts, focusing on fuel consumption. International Journal of Engine Research, 12(3), 238-251. doi:10.1177/1468087411405104Guardiola, C., Pla, B., Blanco-Rodriguez, D., Mazer, A., & Hayat, O. (2013). A bias correction method for fast fuel-to-air ratio estimation in diesel engines. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 227(8), 1099-1111. doi:10.1177/0954407012473415Guardiola, C., Dolz, V., Pla, B., & Mora, J. (2016). Fast estimation of diesel oxidation catalysts inlet gas temperature. Control Engineering Practice, 56, 148-156. doi:10.1016/j.conengprac.2016.08.02

Cylinder charge composition observation based on in-cylinder pressure measurement

[EN] Accurate cylinder charge and composition estimation is crucial for proper combustion control, however, current sensors and models show different issues for transient estimation. The work presented in this paper combines a novel technique for trapped mass estimation, which relies on the in-cylinder pressure resonance, with on-board engine sensors by taking into account the intake manifold dynamics with a closed-loop observer. The resonance method provides a measurement of trapped mass with one cycle resolution. This measurement feeds a Kalman filter to improve the transient and steady response of the intake charge and composition estimation. The observer was validated in a four stroke heavy-duty engine, showing fast transient capabilities and an adequate steady-state accuracy.This work was partially supported by Ministerio de Economia y Competitividad through Project TRA2016-78717-R. C. Guardiola research has been partially financed by the Fulbright Commission and the Spanish Ministerio de Educacion, Cultura y Deporte through grant PRX14/00274.Guardiola, C.; Pla Moreno, B.; Bares-Moreno, P.; Stefanopoulou, A. (2019). Cylinder charge composition observation based on in-cylinder pressure measurement. Measurement. 131:559-568. https://doi.org/10.1016/j.measurement.2018.08.024S55956813