This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Intake and ECM Submodel Improvements for Dynamic SI Engine Models: Examination of Tip-In/Tip-Out
Annotation ability available
Sector:
Language:
English
Abstract
Improved submodels for use in a dynamic engine/vehicle model have been developed and the resulting code has been used to analyze the tip-in, tip-out behavior of a computer-controlled port fuel injected SI engine. This code consists of four submodels. The intake simulation submodel is similar to prior intake models, but some refinements have been made to the fuel flow model to more properly simulate a timed port injection system, and it is believed that these refinements may be of general interest. A general purpose engine simulation code has been used as a subroutine for the cycle simulation submodel. A conventional vehicle simulation submodel is also included in the model formulation. Perhaps most importantly, a submodel has been developed that explicitly simulates the response of the on-board computer (ECM) control system. Within this ECM submodel, calculations are performed to determine the requested equivalence ratio, the delivered equivalence ratio, the duration of combustion, and the spark advance. Analytical techniques for predicting the combustion efficiency and CO emissions are also presented. The predicted trends for the combustion efficiency, CO emissions, spark advance, and duration of combustion are physically reasonable and thus these modeling techniques may be of general interest. It is concluded that three characteristic delays are responsible for unwanted air/fuel ratio excursions during tip-in and tip-out. These are the time delay of the computer control system, a physical delay in air delivery due to storage of mass in the intake manifold, and a physical delay of the fuel flow which results from the finite rate of evaporation of the fuel film on the intake manifold walls (which is important during the first few cycles of tip-in and tip-out due to the large change of mass of fuel injected). The physical delay in the air flow is more significant during tip-in, the physical delay of the fuel evaporation process is more significant during tip-out, and the ECM delay is equally important during both tip-in and tip-out.
Recommended Content
Authors
Topic
Citation
Matthews, R., Dongre, S., and Beaman, J., "Intake and ECM Submodel Improvements for Dynamic SI Engine Models: Examination of Tip-In/Tip-Out," SAE Technical Paper 910074, 1991, https://doi.org/10.4271/910074.Also In
References
- Chiu, J. 1988 “Control of air/fuel ratio during rapid transients of a computer-controlled engine” The University of Texas at Austin, Department of Mechanical Engineering May 1988
- Fozo, S.R. Aquino C.F. 1988 “Transient A/F characteristics for cold operation of a 1.6 liter engine with sequential fuel injection” SAE Paper 880691
- Nishiyama, R. Ohkubo S. Washino S. 1989 “An analysis of controlled factors improving transient A/F control characteristics” SAE Paper 890761 , in: Engine Management and Driveline Controls 99 111
- Tanaka, M. Durbin E. 1977 “Transient response of a carburetor engine” SAE Technical Paper 770076
- Powell, B.K. 1979 “A dynamic model for automotive engine control analysis” Proceedings of the 18th IEEE Conference on Decision and Control 120 126
- Dobner, D.J. 1980 “A mathematical engine model for development of dynamic engine control” SAE Technical Paper 800054
- DeLosh, R.G. Brewer K.J. Buch L.H. Ferguson T.F.W. Tobler W.E. 1981 “Dynamic computer simulation of a vehicle with electronic engine control” SAE Technical Paper 810447
- Morris, R.L. Hopkins H.G. Borcherts R.H. 1981 “An identification approach to throttle-torque modeling” SAE Technical Paper 810448
- Powell, B.K. Cook J.A. 1987 “Nonlinear low frequency phenomenological engine modeling and analysis” Proceedings of the 1987 American Control Conference 332 340
- Hendricks, E. Sorenson S.C. 1990 “Mean value modeling of spark ignition engines” SAE Technical Paper 900616
- Baruah, P.C. 1990 “A simulation model for transient operation of spark ignition engines” SAE Technical Paper 900682
- Powell, B.K. Powers W.F. 1981 “Linear quadratic control design for nonlinear IC engine systems” Proc. Int. Soc. of Automotive Technology and Automation
- Dongre, S.K. 1990 “Development of an improved dynamic engine/vehicle model and application to examination of air/fuel ratio control during rapid transients” The University of Texas at Austin, Department of Mechanical Engineering December 1990
- Boam, D.J. Finlay I.C. Martins J.J.G. 1989 “A model for predicting engine torque response during rapid throttle transients in port-injected spark ignition engines” SAE Technical Paper 890565
- Heywood, J.B. 1988 Internal Combustion Engine Fundamentals McGraw-Hill, New York 375
- Chin, Y-W. Matthews R.D. Nichols S.P. Kiehne T.M. 1989 “Use of fractal geometry to model turbulent combustion in SI engines” Combustion Science & Technology
- Chin, Y-W. Matthews R.D. Nichols S.P. Kiehne T.M. 1990 “Continued development of an SI engine model using fractal geometry” Diagnostics and Modeling of Combustion in Internal Combustion Engines JSME Tokyo 81 86
- Matthews, R.D. Chin Y-W. 1991 “A fractal-based engine model: comparisons of predictions with experimental data” 1991 SAE International Congress
- Liou, D. North, G.L., Santavicca D.A. 1990 “A fractal model of turbulent flame kernel growth” SAE Technical Paper 900024
- Metghalchi, M Keck J.C. 1982 “Burning velocities of mixtures of air with methanol, iso-octane, and indolene at high pressure and temperature” Combustion & Flame 48 191 210
- Miao, S. Matthews R.D. 1987 “Combustion efficiency of spark ignition engines,” Int. J. Vehicle Design 8 3 345 354
- Koeroghlian, M.M. Chin Y-W. Matthews R.D. 1988 “Development of a computationally fast equilibrium-equivalent 4-stroke SI engine model” SAE Technical Paper 880130
- Mentjies, K. 1987 “A user's guide for the GM engine-simulation program” General Motors Research Publication
- Bishop, I.N. 1964 “Effects of design variables on friction and economy” SAE Paper 812A 1964 SAE Trans.73: 334-358 1965
- Heywood, J.B. 1988 Internal Combustion Engine Fundamentals McGraw-Hill, New York 592