Browse Publications Technical Papers 2003-01-1054
2003-03-03

An Algorithm for the Calibration of Wall-Wetting Model Parameters 2003-01-1054

Spark-ignited engines equipped by a three-way catalyst require a precise control of the air fuel ratio fed to the combustion chamber. A stoichiometric mixture is necessary for the proper working of the catalyst in order to meet the legislation requirement.
A critical part of the air fuel ratio control is the feed-forward compensation of the fuel dynamics. Conventional strategies are based on a simplified model of the wall-wetting phenomena whose parameters are stored in off-line computed look-up tables. Unfortunately, errors in the parameters calibration over the whole engine map deteriorate the control performances in terms of emissions.
In this paper an automatic procedure for a rapid and efficient identification of the wall-wetting parameters is presented. The whole procedure has been experimentally tested on a vehicle by using a test bench. Using the identified parameters values, a significant reduction in the air fuel ratio excursion has been achieved during rapid throttle transients with respect to the same vehicle equipped by a commercial ECU with resident engine maps computed by traditional calibration activity. Moreover, the algorithm can be also on-line used to improve air-fuel ratio control performances.

SAE MOBILUS

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

Access SAE MOBILUS »

Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.
X