The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 2013
Filed:
Aug. 13, 2008
Michael-rainer Busch, Ebersbach, DE;
Dirk Herbstritt, Durmersheim, DE;
Uwe Hofmann, Reichelsheim, DE;
Michael-Rainer Busch, Ebersbach, DE;
Dirk Herbstritt, Durmersheim, DE;
Uwe Hofmann, Reichelsheim, DE;
Daimler AG, Stuttgart, DE;
Abstract
In an operating and diagnostic method for an SCR exhaust gas aftertreatment system which has an SCR catalytic converter with ammonia storage capacity, a signal of an exhaust gas sensor that is sensitive to nitrogen oxide and ammonia and is arranged downstream of the SCR catalytic converter, is measured. In a normal operating mode, ammonia is supplied to the SCR catalytic converter corresponding to a filling level model for ammonia stored in the SCR catalytic converter, in such a way that the ammonia filling level of the SCR catalytic converter is held at least approximately at a predefinable nominal value (or value range). The normal operating mode is interrupted if an exhaust gas sensor signal that exceeds a predefinable first limit value, is registered, and the set urea dosing rate is increased by a predefinable degree in relation to the value provided in the normal operating mode. Thereafter, a return is made to the normal operating mode, or a switch is made to a diagnostic operating mode, as a function of the profile of the signal of the exhaust gas sensor.