Patent ID: 6889497
Filing Date: 2005-05-10
Classification: F01N,F02D

Abstract:
1. A method for operating a nitrogen oxide (NOx)-storage catalytic converter of an internal combustion engine including an internal combustion engine of a motor vehicle, the engine generating nitrogen oxides (NOx) and the method comprising the steps of: storing the nitrogen oxides generated by said engine during a first operating phase in said (NOx)-storage catalytic converter; discharging the nitrogen oxides stored in said NOx-storage catalytic converter in a second operating phase; detecting a first value of an (NOx) mass flow (msnonk_s) rearward of said (NOx)-storage catalytic converter; taking a second value of said (NOx) mass flow (msnonk_m) rearward of said NOx-storage catalytic converter from an NOx storing model; forming a difference of said first and second values of said NOx mass flows ( msnok_m−msnonk_s); correcting said NOx storing model in dependence upon said difference (msnonk_m−msnonk_s); modeling an NOx fill level (mnosp) of said NOx storage catalytic converter based on said (NOx) storing model; and determining the start of said second operating phase based on said (NOx) fill level (mnosp) of said NOx-storage catalytic converter.