Patent ID: 6632764
Filing Date: 2003-10-14
Classification: F01N,F02D

Abstract:
A method for controlling a regeneration of an NOx storage converter that is disposed in an exhaust-gas system of an internal-combustion engine and that is operatable in an absorption mode and a regeneration mode, with operating parameters of the internal-combustion engine being changed as a function of an operating state of the NOx storage converter, comprising:measuring an NOx concentration in exhaust gas downstream of the NOx storage converter; determining the operating state of the NOx storage converter, including damage to the NOx storage converter, when the NOx storage converter switches from the absorption mode to the regeneration mode, by ascertaining, from the measured NOx concentration in the exhaust gas, values of characteristic features of an NOx desorption peak in a time curve of the Nox, comparing the ascertained values to predetermined test patterns, forming a comparison result, and determining from the comparison result a converter-state signal that characterizes the operating state of the NOx converter; and changing the operating parameters of the internal combustion engine by implementing a regeneration measure, as a function of the converter-state signal, for attaining a regeneration of the NOx storage converter, the regeneration measure including a desulfurization of the NOx storage converter.