Diesel HCCI in Multi-cylinder Engines
Researchers: Maria Karlsson and Rolf Johansson in cooperation with Kent Ekholm, Prof. Bengt Johansson, Dr. Per Tunestål, Div. Combustion Engines, Lund University, and Johan Dahl, Petter Strandh, Stefan Strömberg, Volvo Powertrain, Inc.
Homogeneous Charge Compression Ignition (HCCI) is a hybrid of the spark ignition and compression ignition engine concepts. As in an SI engine, a homogeneous fuel-air mixture is created in the inlet system. During the compression stroke the temperature of the mixture increases and reaches the point of autoignition, just as in a CI engine. One challenge with HCCI engines is the need for good timing control of the combustion. Auto ignition of a homogeneous mixture is very sensitive to operating condition. Even small variations of the load can change the timing from too early to too late combustion. Thus, fast combustion timing control is necessary since it sets the performance limitation of the load control. This project deals with various approaches to feedback control of the HCCI engine for optimized fuel economy and low emissions. A 12-liter Volvo Diesel engine has been successfully converted to HCCI operation with feedback systems based upon feedback of measured cylinder pressure or ion current.
In the project, control strategies for different modes of combustion were studied. Both port-injected HCCI combustion, direct injected diesel combustion, and fumigation which combines both injection settings was investigated.
Among control methods successfully applied, linear quadratic Gaussian control and model-predictive control have been implemented and tested.
In the last part of the project, work focused on low-emission diesel combustion, a combustion mode between traditional diesel combustion and HCCI. Using relatively early fuel injection combined with a large amount of recycled exhaust gases (EGR), the combustion process is more homogeneous than in traditional diesel combustion, which has a large impact on emissions. Namely, NOx emissions are drastically decreased while soot emissions are increased.
In such a combustion mode, the engine controller must meet several objectives simultaneously - high efficiency, reliable combustion, and low emissions of both NOx and soot. Several actuators are available to meet the specifications, and multiple input multiple output (MIMO) control is necessary. In the project, model predictive control (MPC) has been investigated as a way to systematically go from high-level specifications on torque response, combustion timing, and emissions to a control algorithm. Particulary, we have investigated what can be achieved using direct on-line measurements of emissions for the controller instead of indirect measurements combined with empirical maps which is common practice today.
This project is financially supported by Volvo Powertrain, Inc., and the Vinnova PFF program (VINNOVA-PFF Ref. 2005-00180).
Publications
Maria Karlsson, Kent Ekholm, Petter Strandh, Rolf Johansson, Per Tunestål: "Multiple-Input Multiple-Output Model Predictive Control of a Diesel Engine". In Proc. Fifth IFAC Symposium on Advances in Automotive Control, Munich, Germany, July 2010.
Maria Karlsson, Kent Ekholm, Petter Strandh, Per Tunestål, Rolf Johansson: "Dynamic Mapping of Diesel Engine through System Identification". In 2010 American Control Conference, Baltimore, Maryland, USA, June 2010.
Rolf Johansson, Per Tunestål, Anders Widd: "Modeling and Model-based Control of Homogeneous Charge Compression Ignition (HCCI) Engine Dynamics". In L. del Re, F. Allgöwer, L. Glielmo, C. Guardiola, I. Kolmanovsky (Eds.) (Eds.): Automotive Model Predictive Control---Models, Methods and Applications, Springer-Verlag, Berlin-Heidelberg, May 2010.
Anders Widd: "Predictive Control of HCCI Engines using Physical Models". Licentiate Thesis ISRN LUTFD2/TFRT--3246--SE, Department of Automatic Control, Lund University, Sweden, May 2009.
Carl Wilhelmsson, Per Tunestål, Bengt Johansson, Anders Widd, Rolf Johansson: "A Physical Two-Zone NOx Model Intended for Embedded Implementation". In SAE Technical Papers 2009-01-1509, SAE World Congress & Exhibition, April 2009, Detroit, MI, USA, April 2009.
Kent Ekholm, Maria Karlsson, Per Tunestål, Rolf Johansson, Bengt Johansson, Petter Strandh: "Ethanol-Diesel Fumigation in a Multi-Cylinder Engine". SAE International Journal of Fuels and Lubricants, 1:1, pp. 26–36, April 2009.
Luca Benvenuti, Andrea Balluchi, Alberto Bemporad, S. Di Cairano, Bengt Johansson, Rolf Johansson, Alberto Sangiovanni-Vincentelli, Per Tunestål: "Chapter 15: Automotive Control". In (Eds.): Handbook of Hybrid Systems Control: Theory, Tools, Applications. In J. Lunze, F. Lamnabhi-Lagarrigue (Eds.), Cambridge University Press, Cambridge, 2009.
Maria Karlsson, Kent Ekholm, Petter Strandh, Rolf Johansson, Per Tunestål: "LQG Control for Minimization of Emissions in a Diesel Engine". In 2008 IEEE International Conference on Control Applications, September 2008.
Kent Ekholm, Maria Karlsson, Per Tunestål, Rolf Johansson, Bengt Johansson, Petter Strandh: "Ethanol-Diesel Fumigation in a Multi-Cylinder Engine". In SAE World Congress, SAE Technical Paper 2008-01-0033, Detroit, MI, April 2008.
Daniel Blom, Maria Karlsson, Kent Ekholm, Per Tunestål, Rolf Johansson: "HCCI Engine Modeling and Control Using Conservation Principles". In SAE World Congress, SAE Technical Paper 2008-01-0789, Detroit, MI, April 2008.
Maria Karlsson: "Control Structures for Low-Emission Combustion in Multi-Cylinder Engines". Licentiate Thesis ISRN LUTFD2/TFRT--3243--SE, Department of Automatic Control, Lund University, Sweden, March 2008.
Johan Bengtsson, Petter Strandh, Rolf Johansson, Per Tunestål, Bengt Johansson: "Hybrid Modelling of Homogeneous Charge Compression Ignition (HCCI) Engine Dynamic—A Survey". International Journal of Control, 80:11, pp. 1814–1848, November 2007.
Rolf Johansson, Anders Rantzer: "Editorial—Hybrid Systems in Automotive Control". International Journal of Control, 80:11, pp. 1699–1700, November 2007.
Maria Karlsson, Kent Ekholm, Petter Strandh, Rolf Johansson, Per Tunestål, Bengt Johansson: "Closed-Loop Control of Combustion Phasing in an HCCI Engine Using VVA and Variable EGR". In Fifth IFAC Symposion on Advances in Automotive Control, Monterey, USA, August 2007.
Johan Bengtsson, Petter Strandh, Rolf Johansson, Per Tunestål, Bengt Johansson: "Model Predictive Control of Homogeneous Charge Compression Ignition (HCCI) Engine Dynamics". In 2006 IEEE International Conference on Control Applications, Munich, Germany, October 2006.
Johan Bengtsson, Petter Strandh, Rolf Johansson, Per Tunestål, Bengt Johansson: "Hybrid Control of Homogeneous Charge Compression Ignition (HCCI) Engine Dynamics". International Journal of Control, 79:5, pp. 422–448, May 2006.
Johan Bengtsson, Petter Strandh, Rolf Johansson, Per Tunestål, Bengt Johansson: "Multi-Output Control of a Heavy-Duty HCCI Engine using Variable Valve Actuation and Model Predictive Control". SAE Paper 2006-01-0873, April 2006.
Petter Strandh, Johan Bengtsson, Rolf Johansson, Per Tunestål, Bengt Johansson: "Variable Valve Actuation for Timing Control of a Homogeneous Charge Compression Ignition Engine". In SAE Paper 2005-01-0147, March 2005.
2011-03-31