This content is not included in your SAE MOBILUS subscription, or you are not logged in.
A Model for Fuel Optimal Control of a Spark-Ignited Variable Compression Engine
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2006 by SAE International in United States
Annotation ability available
Variable compression engines are a mean to meet the demand on lower fuel consumptions. A high compression ratio results in high engine efficiency, but also increases the knock tendency. On conventional engines with fixed compression ratio, knock is avoided by retarding the ignition angle. The variable compression engine offers an extra dimension in knock control, since both ignition angle and compression ratio can be adjusted. A vital question is thus what combination of compression ratio and ignition angle should be used to achieve maximum engine efficiency.
Fuel optimal control of a variable compression engine is studied and it is shown that a crucial component is the model for the engine torque. A model for the produced work that captures the important effects of ignition and compression ratio is proposed and investigated. The main task for the model is to be a mean for determining the fuel optimal control signals, for each requested engine torque and speed. The contribution is a model suitable for finding this optimal combination. This model consists of well-known components, and the novelty lies in the compilation and validation of the control oriented efficiency model for a variable compression engine.
Despite the models simplicity, it describes the indicated work with good accuracy, and suits its purpose of finding optimal control signals. The evaluation shows that a fuel optimal controller based on the proposed model will miss the optimal IMEP with only 1.5%, and that the corresponding loss in engine efficiency is less than 0.5 percentage units.
CitationNilsson, Y., Eriksson, L., and Gunnarsson, M., "A Model for Fuel Optimal Control of a Spark-Ignited Variable Compression Engine," SAE Technical Paper 2006-01-0399, 2006, https://doi.org/10.4271/2006-01-0399.
Electronic Engine Controls 2006
Number: SP-2003; Published: 2006-04-03
Number: SP-2003; Published: 2006-04-03
- Stone R. Introduction to Internal Combustion Engines SAE International third 1999
- Fitton John Nates Roy Knock erosion in spark-ignition engines 1996
- Ushijima Kenshi Hiyoshi Ryousuke Takemura Shinichi Fujimoto Hiroya Moteki Katsuya Aoyama Shunichi Arai Takayuki A study of variable compression ratio system with a multi-link mechanism Number SAE Technical Paper Series No. 2003-01-0921 2003
- Drangel H. Reinmann R. The variable compression (SVC) and the combustion control (scc) - two ways to improve fuel economy and still comply with world-wide emission requirements SAE Technical Paper 2002-02-0996 2002
- Roberts Martyn Benefits and challenges of variable compression ratio Number SAE Technical Paper Series No. 2003-01-0398 2003
- Grandin Börje Knock in Gasoline Engines - the effect of mixture composition on knock onset and heat transfer Chalmers University of Technology 2001
- Kiencke Uwe Nielsen Lars Automotive Control Systems For Engine, Driveline, and Vehicle Springer-Verlag 2000
- Hendricks Elbert Chevalier Alain Jensen Michael Sorenson Spencer C. Trumpy Dave Asik Joe Modeling of the intake manifold filling dynamics SAE paper No. 960037 1996
- Eriksson Lars Nielsen Lars Brugård Jan Bergström Johan Pettersson Fredrik Andersson Per Modeling and simulation of a turbo charged SI engine Annual Reviews in Control 26 1 129 137 2002
- Moran Michael J. Shapiro Howard N. Fundamentals of engineering thermodynamics Johan Wiley & Sons third 1998
- Heywood J. B. Internal Combustion Engine Fundamentals McGraw-Hill series in mechanical engineering McGraw-Hill 1988
- Inhelder J. Verbrauchs- und Schadstoffoptimiertes Ottomotor-Aufladekonzept Swiss Federal Institute of Technology Zürich 1996
- Stöckli M. Reibleistung von 4-Takt Verbrennugnsmotoren Technical report, Internal report of the Laboratory of Internal Combustion Engines Swiss Federal Institute of Technology Zürich 1989