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Wavelet Filtering of Cylinder Pressure Signal for Improved Polytropic Exponents, Reduced Variation in Heat Release Calculations and Improved Prediction of Motoring Pressure & Temperature
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2018 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Recent advancements in the combustion control of new generation engines can benefit from real time, precise sensing of the cylinder pressure profile to facilitate successful combustion feedback. Currently, even laboratory-grade pressure sensors can deliver pressure traces with insufficient signal-to-noise quality due to electrical or combustion-induced signal interference. Consequently, for example, calculation of compression and expansion polytropic indices may require statistical averaging over several cycles to deliver required information. This lag in the resultant feedback may become a concern when the calculated combustion metric is used for feedback control, especially in the case of transients. The method described in this paper involves a special digital filter offering excellent performance which facilitates reduced-error calculation of individual polytropic indices. This enables precise calculation of individual combustion event heat release estimates, delivering information needed to effect the necessary correction in combustion-defining input parameters (e.g. intake pressure, injection timing, etc.), as calculated by the engine controller for use on subsequent combustion cycles. The pressure filter construction is based on pattern recognition techniques and guarantees equal performance regardless of engine rotational speed. The signal processing technique requires only invariant numbers of samples per combustion cycle to deliver excellent results in the angular span covering -180 thru +90 degrees with TDC firing being located at zero degrees. The performance of the technique is illustrated with experimental results involving calibration and testing of a Gasoline Direct Injection Compression Ignition (GDCI) engine.
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CitationMalaczynski, G. and Foster, M., "Wavelet Filtering of Cylinder Pressure Signal for Improved Polytropic Exponents, Reduced Variation in Heat Release Calculations and Improved Prediction of Motoring Pressure & Temperature," SAE Technical Paper 2018-01-1150, 2018, https://doi.org/10.4271/2018-01-1150.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
- Schten, K., Ripley, G., Punater, A., and Erickson, C., “Design of an Automotive Grade Controller for In-Cylinder Pressure Based Engine Control Development,” SAE Technical Paper 2007-01-0774, doi:https://doi.org/10.4271/2007-01-0774.
- Livengood, J.C. and Wu, P.C., “Correlation of Autoignition Phenomena in Integral Combustion Engines and rapid Compression Machines,” Symp. Int. Combust347-356, 1955.
- Swan, K., Shahbakhti, M., and Koch, C.R., “Predicting Start of Combustion Using a Modified Knock Integral Method for an HCCI Engine,” SAE Technical Paper 2006-01-1086, doi:10.4271/2006-01-1086.
- Yates, A. and Viljoen, C.L., “An Improved Empirical Model for Describing Auto-Ignition,” SAE Technical Paper 2008-01-1629, doi:https://doi.org/10.4271/2008-01-1629.
- Iqbal, A., Selamet, A., Reese, R., and Vick, R., “Ignition Delay Correlation for Predicting Autoignition of a Toluene Reference Fuel Blend in Spark Ignition Engines,” SAE Technical Paper 2011-01-0338, doi:10.4271/2011-01-0338.
- Pan, J., Zhao, P., Law, C.K., and Wei, H., “A Predictive Livengood-Wu Correlation for Two-Stage Ignition,” International Journal of Engine Research1-11, 2015.
- “Introduction to Signals and Systems,” Chapter 5 - FIR Filters, University of Colorado, Colorado Springs, ECE 2619, November 12, 2015
- “Cylinder Pressure Development Controller User’s Manual,” Delphi Part Numbers:DK233841 (GEN1) & DK246668 (GEN2), May 11, 2009.
- Donoho, D.L. and Johnstone, I.M., “Adapting to Unknown Smoothness Via Wavelet Shrinkage,” Journal of the American Statistical Association1200-1224, 1995.
- Strang, G. and Nguyen, T., “Wavelets and Filter Banks,” (Wellesley-Cambridge Press, 1997).
- Smith, S.W., “Digital Signal Processing,” (Elsevier, 2003).