EGR Reference Allocation for Diesel Engine Air System Control Johannes Kepler University Linz

Format:

Conference/Event

Author/Creator:

Waschl, Waschl, author.

Contributor:

Alberer, Daniel

Kerschbaummayr, Andreas

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

The control of the engine air system is an essential part formeeting the emission levels of current and upcoming legislation. Upto now different strategies were presented in the literature andalso applied on real systems. Starting from simplesingle-input-single-output structures in combination withfeedforward parts leading to advanced multi-input-multi-outputapproaches. Nevertheless, independent of the used control approachfor each of them suitable references are necessary. Although itseems adequate to directly use the emission target quantities in aclosed loop air system control, a fast and accurate measurement isseldom available. An alternative is to use intermediate quantitiesas references, like fresh air mass flow or oxygen concentrations,which represent the state of the air system. However, for controlpurposes each of these quantities has to be determined, id est,measured or calculated. Moreover, it has to be considered that eachsensor has different dynamics and accuracy in dependency of thegiven range and furthermore also system dynamics can influence thesensor readouts.In this work a method for controlling the exhaust gasrecirculation valve of a diesel engine is proposed, where incontrary to standard approaches not only one but a combination ofdifferent reference quantities is used, with the aim to maintainpredefined tailpipe nitric oxides emissions. The idea is to useallocation techniques and to combine different measurements withrespect to their accuracy and dynamic properties, thus ensuringthat in each operating point and time instant the most accuratequantity with respect to NOx is used. The determinationof the static accuracy of each quantity was carried out by aNOx sensitivity analysis and the use of Gaussian errorpropagation. Considering the dynamic properties, response and risetimes of the different sensors and physical quantities were takeninto account. Finally, the control strategy was implemented andtested on simulation models and on an EU5 passenger car dieselengine on an engine testbed, showing satisfactory results

Notes:

Vendor supplied data

Publisher Number:

2012-01-0892

Access Restriction:

Restricted for use by site license