Patent ID: 7028465
Filing Date: 2006-04-18
Classification: B01D,F01N,Y02T

Abstract:
1. A method for controlling an exhaust-gas aftertreatment system of an internal combustion engine, the exhaust-gas aftertreatment system having at least one catalytic converter, the method comprising: supplying a selected quantity of a reducing agent to the exhaust-gas aftertreatment system as a function of a state of at least one of the internal combustion engine and the exhaust-gas aftertreatment system; measuring a first measured quantity and a second measured quantity downstream of the exhaust-gas aftertreatment system; adjusting the quantity of the reducing agent supplied as a function of the first measured quantity and the second measured quantity, wherein the first measured quantity depends on at least one of the concentration of substances required for conversion of exhaust gas and the concentration of resulting undesired intermediate products, and wherein the second measured quantity depends on the concentration of substances that are one of not converted in the exhaust-gas aftertreatment system and only partially converted in the exhaust-gas aftertreatment system; wherein the quantity of the reducing agent is decreased when the first measured quantity exceeds a first upper threshold value; and wherein the quantity of the reducing agent is increased when the second measured quantity exceeds a second upper threshold value.