Browse Publications Technical Papers 2002-01-1667
2002-05-06

Estimation of Air Fuel Ratio of a SI Engine from Exhaust Gas Temperature at Cold Start Condition 2002-01-1667

Wall wetting of injected fuel onto the intake manifold and cylinder wall causes unpredictable transient behavior of air-fuel mixing which results in a significant emission of unburned hydrocarbon (HC) emission during cold start operation. Heated exhaust gas oxygen (HEGO) sensors cannot measure the air-fuel ratio (A/F) of exhaust gas during cold start condition. Precise and fast estimation of air/fuel ratio of the exhaust gas is required to elucidate the wall wetting phenomena and subsequent HC formation. Refined A/F estimation can enable the control of fuel injection minimizing HC emissions during cold start conditions so that HC emissions can be minimized.
A new estimator for A/F of the exhaust gas has been developed. The A/F estimator described in this study utilizes measured exhaust gas temperature and general engine parameters such as engine speed, airflow, coolant temperature, etc. A fast response, fine-wire thermocouple was used to measure exhaust gas temperatures and a fast response flame ionization detector was used to measure HC emissions during the cold start period. A Generalized Regression Neural Network Function Approximation (GRNN) was used to estimate the A/F of exhaust gas. The A/F traces generated by the GRNN algorithm agree very well with measurements.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Preview Document Add to Cart
Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Experimental Validation of a Neural Network Based A/F Virtual Sensor for SI Engine Control

2006-01-1351

View Details

TECHNICAL PAPER

AFR Control on a Single Cylinder Engine Using the Ionization Current

980203

View Details

TECHNICAL PAPER

Analysis of SI Combustion Diagnostics Methods Using Ion-Current Sensing Techniques

2006-01-1345

View Details

X