Model Identification for the A/F Path of an SI Engine

Paper #:
  • 970612

Published:
  • 1997-02-24
Citation:
Onder, C., Roduner, C., and Geering, H., "Model Identification for the A/F Path of an SI Engine," SAE Technical Paper 970612, 1997, https://doi.org/10.4271/970612.
Pages:
11
Abstract:
Modern model-based control schemes and their application on different engines need mathematical models for the various dynamic subsystems of interest. Here, the fuel path of an SI engine is investigated. When the engine speed and the throttle angle are kept constant, the fuel path is excited only by the fuel injected. Taking the NO concentration of the exhaust gas as a measure for the air/fuel ratio, models are derived for the wall-wetting dynamics, the gas mixture, as well as for the air/fuel ratio sensor. When only the spark advance is excited, the gas flow dynamics can be studied.A very fast NO measurement device is used as reference. Its time constant is below the segment time of one single cylinder (180° crank angle for a 4-cylinder engine), therefore its dynamics are much faster than the time constants of the systems investigated.A model structure considering the muliplexing effects of the discrete operation of an engine is given for the fuel path of a BMW 1.8 liter engine. The exhaust system of this engine is specially designed such that all distances from each exhaust valve to the confluence point are equal.
Access
Now
SAE MOBILUS Subscriber? You may already have access.
Buy
Select
Price
List
Download
$27.00
Mail
$27.00
Members save up to 40% off list price.
Share
HTML for Linking to Page
Page URL

Related Items

Technical Paper / Journal Article
2010-10-25