SIMPLIFIED MODELS OF ENGINE HC EMISSIONS, EXHAUST TEMPERATURE AND CATALYST TEMPERATURE FOR AUTOMOTIVE COLDSTART

Abstract The initial 1-2 minutes of operation of an automotive spark-ignition engine, commonly called as the “coldstart” period, produces more than 75-80 % of the hydrocarbon (HC) emissions in a typical drive cycle. Model-based controller development requires accurate, yet simple, models that can run in realtime. Simple, intuitive models are developed to predict both tailpipe hydrocarbon (HC) emissions and exhaust temperature during coldstart. Each of the models is chosen to be sum of first order linear systems based on the observation of experimental data and on the notion that such structure is suitable for controller synthesis. Inputs to these models are AFR , spark timing and engine crankshaft speed. A reduced order thermodynamic model for the catalyst temperature is also developed. The parameters are identified using least squares technique. The model estimates for the coldstart are compared with the experimental results with good agreement. Submitted to Fifth IFAC Symposium on Advances in Automotive Control

[1]  Richard A. Jackson,et al.  A Simplified Model for the Dynamics of a Three-Way Catalytic Converter , 2000 .

[2]  Yanying Wang,et al.  Dynamic modeling of a three-way catalyst for SI engine exhaust emission control , 2000, IEEE Trans. Control. Syst. Technol..

[3]  B. Powell,et al.  A dynamic model for automotive engine control analysis , 1979, 1979 18th IEEE Conference on Decision and Control including the Symposium on Adaptive Processes.

[4]  Byron T. Shaw,et al.  A simplified coldstart catalyst thermal model to reduce hydrocarbon emissions , 2002 .

[5]  J. Karl Hedrick,et al.  Automotive Engine Modeling for Real Time Control Application , 1987, 1987 American Control Conference.

[6]  S. Chan,et al.  Modeling of Catalytic Conversion of CO/HC in Gasoline Exhaust at Engine Cold-Start , 1999 .

[7]  J. Karl Hedrick,et al.  Cylinder Air/Fuel Ratio Estimation Using Net Heat Release Data , 2001 .

[8]  J. K. Hedrick,et al.  Automotive Powertrain Modeling for Control , 1989 .

[9]  Luigi Glielmo,et al.  Control oriented models for TWC-equipped spark ignition engines during the warm-up phase , 2002, Proceedings of the 2002 American Control Conference (IEEE Cat. No.CH37301).

[10]  Karl Hedrick,et al.  Fuel Dynamics Model for Engine Coldstart , 2006 .

[11]  Grigorios C. Koltsakis,et al.  Thermal Response of Close-Coupled Catalysts During Light-Off , 2003 .

[12]  Shinji Kojima,et al.  Numerical Prediction of Transient Conversion Characteristics in a Three-Way Catalytic Converter , 1998 .

[13]  Tariq Shamim,et al.  An Investigation of Catalytic Converter Performances during Cold Starts , 1999 .

[14]  J. K. Hedrick,et al.  Automotive engine hybrid modelling and control for reduction of hydrocarbon emissions , 2006 .

[15]  C. Pinello,et al.  Mixed models of computation in the design of automotive engine control , 2001, Proceedings of the 40th IEEE Conference on Decision and Control (Cat. No.01CH37228).

[16]  Byron T. Shaw,et al.  COLDSTART ENGINE COMBUSTION MODELLING TO CONTROL HYDROCARBON EMISSIONS , 2002 .