Method and device for controlling an exhaust treatment system

A device for controlling an exhaust-gas aftertreatment system of an internal combustion engine, the exhaust-gas aftertreatment system having at least one catalytic converter, the device comprising:

• an arrangement for 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;
• an arrangement for measuring a first measured quantity downstream of the exhaust-gas aftertreatment system;
• an arrangement for measuring a second measured quantity downstream of the exhaust-gas aftertreatment system;
• and
• an arrangement for 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.

A computer-readable medium having stored thereon instructions for execution on a computer for controlling an internal combustion engine having an exhaust-gas aftertreatment system, the instructions, upon execution on the computer, performing:

• control of a supply of 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;
• control of measuring a first measured quantity and a second measured quantity downstream of the exhaust-gas aftertreatment system;
• and
• control of 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.

A computer-readable data storage element for storing a computer program having a plurality of instruction codes executable by a computer for controlling an internal combustion engine having an exhaust-gas aftertreatment system, the instruction codes performing:

• control of a supply of 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;
• control of measuring a first measured quantity and a second measured quantity downstream of the exhaust-gas aftertreatment system;
• and
• control of 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.