Abstract:
Methods for adapting system variation for an engine system having an after-treatment system. Measured characteristics of the after-treatment system may be used to predict a model value(s) that is compared to a measured value(s) of the after-treatment system to provide a comparison value. Information relating to high frequency uncertainties in characteristics of the after-treatment system are removed from the comparison value to provide an estimated system variation value. The estimated system variation value may then be used to adapt a system command of a controller. Further, information relating to high frequency uncertainties in characteristics of the after-treatment system may be used by a feed-back controller to determine high frequency adaptation values that may also be used to adjust the system command. The inclusion of the estimated system variation may eliminate reliance on the feed-back controller to provide system adjustments for both high and low frequency uncertainties.
Abstract:
According to one representative embodiment, an apparatus for controlling reductant dosing in an SCR catalyst system (150) having a reductant injection system (151) configured to inject reductant (170) into an exhaust gas stream (144) includes a controller (130), an actual reductant dosing rate module (210), and a reductant doser compensation module (230). The controller is configured to determine a reductant dosing rate command (202) representing a desired reductant dosing rate. The actual reductant dosing rate module is configured to determine a predicted actual reductant dosing rate (220) based at least partially on the reductant dosing rate command. The reductant doser compensation module is configured to determine a modified reductant dosing rate command (240) based at least partially on the predicted actual reductant dosing rate. The reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.
Abstract:
According to one representative embodiment, an apparatus for controlling reductant dosing in an SCR catalyst system (150) having a reductant injection system (151) configured to inject reductant (170) into an exhaust gas stream (144) includes a controller (130), an actual reductant dosing rate module (210), and a reductant doser compensation module (230). The controller is configured to determine a reductant dosing rate command (202) representing a desired reductant dosing rate. The actual reductant dosing rate module is configured to determine a predicted actual reductant dosing rate (220) based at least partially on the reductant dosing rate command. The reductant doser compensation module is configured to determine a modified reductant dosing rate command (240) based at least partially on the predicted actual reductant dosing rate. The reductant injection system injects reductant into the exhaust gas stream at a rate corresponding to the modified reductant dosing rate command.
Abstract:
Die Erfindung betrifft ein Verfahren zum Betreiben einer Abgasreinigungsanlage mit einem SCR-Katalysator (5) zur Reinigung eines Abgases eines Kraftfahrzeug- Verbrennungsmotors (1), bei welchem von einer durch eine Steuereinheit ansteuerbaren Dosiereinheit (27) ein Ammoniak enthaltendes Reduktionsmittel mit einer einstellbaren Dosierrate dem Abgas zudosiert wird und dem SCR-Katalysator (5) ein entsprechend der Zudosierung mit Ammoniak angereichertes Abgas zugeführt wird. Ein Rechenmodell berechnet einen Ammoniak-Füllstandswert (F) für einen Füllstand von im SCR- Katalysator (5) gespeichertem Ammoniak und eine Modell-Dosierrate (D) für die Zudosierung des Reduktionsmittels ins Abgas, mit der ein durch das Rechenmodell vorgegebener Soll-Füllstand von im SCR-Katalysator (5) gespeichertem Ammoniak und/oder ein durch das Rechenmodell vorgegebener Soll-Wirkungsgrad (η) für einen Stickoxid-Umsatz (U NOx ) mit im SCR-Katalysator (5) gespeichertem und/oder dem SCR- Katalysator (5) zugeführtem Ammoniak wenigstens annähernd erreicht werden. Erfindungsgemäß werden in Abhängigkeit vorbestimmter Werte für bestimmte Betriebsgrößen wie beispielsweise eine Temperatur des Abgases oder des SCR- Katalysators (5) entweder eine modellbasierte Füllstandsregelung zur Erreichung des Soll-Füllstands oder eine modellbasierte Wirkungsgradsteuerung zur Erreichung des Soll- Wirkungsgrads (η) durchgeführt.
Abstract:
L'invention concerne un moteur à combustion de véhicule automobile configuré pour sélectionner une règle de calcul utilisée par le module de détermination (10) de la consigne de richesse à la sonde et/ou par le module de régulation (9) parmi une première règle et une deuxième règle de calcul en fonction d'au moins une valeur (d) d'un paramètre de fonctionnement du moteur.
Abstract:
A method includes raising a temperature of an SCR catalyst for a predetermined time period while dosing urea. The method further includes maintaining the temperature of the SCR catalyst without dosing urea for a second predetermined time period. The method further includes filtering out at least low frequency data from a first NO x sensor upstream of the SCR catalyst and from a second NO x sensor downstream of the SCR catalyst, and comparing the filtered data from the first NO x sensor and the second NO x sensor without dosing urea over a third predetermined time period. The method further includes providing a NO x sensor condition index for at least one of the first NOx sensor and the second NO x sensor in response to the comparing.
Abstract:
The invention relates to a method and an arrangement for monitoring the functioning of an exhaust gas aftertreatment system (2) of a motor vehicle based on a measuring signal from a sensor (11) as to the magnitude of a parameter related to exhaust gases flowing out of an exhaust gas aftertreatment appliance (5), for instance in the form of a catalyst or a filter, included in the exhaust gas aftertreatment system (2). A frequency analysis of the measuring signal supplied by the sensor (11) during a certain period of time is performed so as to establish an evaluation value that reflects the character of a frequency part of the measuring signal supplied by the sensor during this period of time. Information regarding the functioning of the exhaust gas aftertreatment system (2) is generated based on this evaluation value.