Torque modelling for optimising fuel economy in variable compression engines Online publication date: Thu, 28-Aug-2008
by Ylva Nilsson, Lars Eriksson, Martin Gunnarsson
International Journal of Modelling, Identification and Control (IJMIC), Vol. 3, No. 3, 2008
Abstract: Fuel optimal control of a variable compression engine is studied and it is shown that a crucial component is the model for the engine torque. A model for the produced work that captures the important effects of ignition and compression ratio is proposed and investigated. The main task for the model is to be a mean for determining the fuel optimal control signals, for each requested engine torque and speed. The contribution is a model suitable for finding this optimal combination. This model consists of well-known components, and the novelty lies in the compilation and validation of the control-oriented efficiency model for a variable compression engine. The modelling and validation is performed on a multicylinder variable compression engine using two fuels with different octane rating. Despite the models simplicity, it describes the indicated work with good accuracy, and suits its purpose of finding optimal control signals. In the evaluation, it is shown that a fuel optimal controller based on the proposed model captures the optimal IMEP to within 1.2%. This corresponds to a loss in engine efficiency that is in the range of 0.5% units or less.
Online publication date: Thu, 28-Aug-2008
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Modelling, Identification and Control (IJMIC):
Login with your Inderscience username and password:
Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.
If you still need assistance, please email email@example.com