Abstract: A method of controlling a reducing agent generation system of an internal combustion engine includes generating a reagent substance in a form of pulses and delivered to an exhaust gas duct of the internal combustion engine upstream of an SCR-catalytic converter for the selective catalytic reduction of the nitrogen oxides contained in an exhaust gas. A catalytic converter model is used to model a reagent substance fill level of the SCR-catalytic converter and a closed-loop feedback control system compares the modeled reagent substance fill level with a storage set point. A reagent substance demand signal is generated that at least releases a reagent substance pulse when a difference between the storage set point and the reagent substance fill level exceeds a specified threshold value.

Abstract: The invention concerns a procedure to control a reducing agent generation system of an internal combustion engine, in which the reagent substance is generated in the form of pulses by the reducing agent generation system and is delivered to an exhaust gas duct of the internal combustion engine in front of a SCR-catalytic converter for the selective reduction of the nitrogen oxides contained in the exhaust gas, with a catalytic converter model, in which the reagent substance fill level of the SCR-catalytic converter is modeled and with a closed-loop feedback control system, in which the modeled reagent substance fill level is compared with a storage set point.