Patent ID: 7886588
Filing Date: 2011-02-15
Classification: F01N,F02D,Y02T

Abstract:
1. A method for determining current oxygen loading of a 3-way catalytic converter of a lambda-controlled internal combustion engine, comprising: determining a pre-converter lambda value of the engine exhaust gas upstream of the catalytic converter by a linear pre-converter lambda probe; determining a lambda value of the engine exhaust gas downstream of the catalytic converter by a post-converter lambda probe; determining an intake air mass flow rate by an intake air mass flow rate measuring device; calculating a relative value for current oxygen loading of the catalytic converter from the pre-converter lambda value and the determine air mass flow rate through integration over time; initializing the current oxygen loading relative value using the post-converter lambda probe value at time intervals in order to obtain an absolute value for current oxygen loading; calculating a maximum oxygen storage capacity of the catalytic converter; and calculating a current oxygen quotient from a quotient of current oxygen loading and the maximum oxygen storage capacity of the catalytic converter to aid in the regulation of engine emission output.