The Analysis of Mean Value SI Engine Models

920682

02/01/1992

Event
International Congress & Exposition
Authors Abstract
Content
Mean value engine models (MVEMs) seek to predict dynamically the mean values of important SI engine variables such as the crank shaft speed, the manifold pressure and the theoretical air/fuel ratio (lambda). Previous work also shows that such models can be made quite accurate, both for stationary and transient operating modes. Because these models can be made mathematically simple and compact, they are also tractable for direct mathematical and physical analysis.
In this paper an analysis of a mean value engine model is carried out which reveals the underlying structure of the problems which face engine control system designers. In particular it is shown that an SI engine is extremely nonlinear and time dependent. Because of this, conventional control strategies using conventional sensors cannot be made to operate correctly in the transient regime. An “ideal” nonlinear compensator is also described for the fueling dynamics which works over a wide operating range.
Meta TagsDetails
DOI
https://doi.org/10.4271/920682
Pages
21
Citation
Hendricks, E., and Vesterholm, T., "The Analysis of Mean Value SI Engine Models," SAE Technical Paper 920682, 1992, https://doi.org/10.4271/920682.
Additional Details
Publisher
Published
Feb 1, 1992
Product Code
920682
Content Type
Technical Paper
Language
English