This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Individual Cylinder Air-Fuel Ratio Control Part I: L3 and V6 Engine Applications
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 12, 2011 by SAE International in United States
Annotation ability available
A frequency-domain approach to balancing of air-fuel ratio (A/F) in a multi-cylinder engine is described. The technique utilizes information from a single Wide-Range Air-Fuel ratio (WRAF) or a single switching (production) O₂ sensor installed in the exhaust manifold of an internal combustion engine to eliminate the imbalances. At the core of the proposed approach is the development of a simple novel method for the characterization of A/F imbalances among the cylinders. The proposed approach provides a direct objective metric for the characterization of the degree of A/F imbalances for diagnostic purposes as well as a methodology for the control of A/F imbalances among various cylinders. The fundamental computational requirement is based on the calculation of a Discrete Fourier Transform (DFT) of the A/F signal as measured by a WRAF or a switching O₂ sensor. For real-time applications, the approach is iterative in nature and the intended goal of A/F balancing is achieved quite accurately and fast in around 1-2 seconds. Experimental results for 3-cylinder and 6-cylinder applications are provided and the advantages and limitations of the technique including the effect of blind spots pointed out. Application of the technique will result in lower tailpipe emissions on FTP and US06 driving cycles as well as tangible (but minor) fuel economy gains. Clearly, in extreme cases of cylinder A/F maldistributions, the impact on the maintenance of good driveability is of paramount importance and achieved automatically using the technique on-board the vehicle in its real-world operation.
CitationJavaherian, H., Brown, A., and Nolan, M., "Individual Cylinder Air-Fuel Ratio Control Part I: L3 and V6 Engine Applications," SAE Technical Paper 2011-01-0695, 2011, https://doi.org/10.4271/2011-01-0695.
- Hosaka, A. Yamaguchi, H. Feedback Air Fuel Ratio Control System and Method US Patent No. 4,483,300 Nov. 20 1984
- Cook, J. A. Grizzle, J. Individual Cylinder Air/Fuel Ratio Feedback control System US Patent No. 4,962,741 Oct. 16 1990
- Grizzle, J. Dobbins, K. L. Cook, J. “Individual Cylinder Air-Fuel Ratio with a Single EGO Sensor,” IEEE Trans. Veh. Tech. 40 1 Feb. 1991
- Moraal, P. Cook, J. A. Grizzle, J. W. “Single Sensor Individual Cylinder Air-Fuel Ratio Control of an Eight Cylinder Engine with Exhaust Gas Mixing,” Proc. American Control Conf. 1761 1767 San Francisco June 1993
- Bush, K. J. Adams, N. J. Dua, S. Markyvech, C.R. “Automatic Control of Cylinder by Cylinder Air-Fuel Mixture Using a Proportional Exhaust Gas Sensor,” SAE Technical Paper 940149 1994 10.4271/940149
- Hasegawa, Y. Akazaki, S. Komoriya, I. Maki, H. et al. “Individual Cylinder Air-Fuel Ratio Feedback Control Using an Observer,” SAE Technical Paper 940376 1994 10.4271/940376
- Fantini, J. Chamaillard, Y. Gouy, F. Peron, L. “Determination of a Nonlinear, Unified and Robust Individual Cylinder Air Fuel Ratio Estimator,” SAE Technical Paper 2000-01-0262 2000 10.4271/2000-01-0262
- Kainz, J.L. Smith, J.C. “Individual Cylinder Fuel Control with a Switching Oxygen Sensor,” SAE Technical Paper 1999-01-0546 1999 10.4271/1999-01-0546
- Turin, R.C. Naik, S.M. Individual Cylinder Fuel Control Method US Patent No. 6,314,952 Nov. 13 2001
- Benvenuti, L. Di Benedetto, M. D. Gennaro, S. Sangiovanni-Vincenetelli, A. “Individual Cylinder Characteristic Estimation for a Spark Injection Engine,” Automatica 39 1157 1169 2003
- Javaherian, H. Individual Cylinder Controller for Three-Cylinder Engine US Patent No. 6,668,812 Dec 30 2003
- Cavina, N. “Fast Algorithm for Individual Cylinder Air-Fuel Ratio Control,” SAE Technical Paper 2005-01-3759 2005 10.4271/2005-01-3759
- Javaherian, H. Brown, A. W. Individual Cylinder Controller for Four-Cylinder Engine US Patent No. 7,027,910 Apr. 11 2006
- Smith, J.C. Schulte, C.W. Cabush, D.D. “Individual Cylinder Fuel Control for Imbalance Diagnosis,” SAE Int. J. Engines 3 1 28 34 2010 10.4271/2010-01-0157