Method for operating a nitrogen oxide (nox) storage catalyst

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 method comprising the steps of:

• storing nitrogen oxides in said (NOx)-storage catalytic converter during a first operating phase thereof;
• during said first operating phase, determining the amount of nitrogen oxides stored in said (NOx)-storage catalytic converter;
• discharging the stored nitrogen oxides from said (NOx)-storage catalytic converter during a second operating phase thereof;
• during said second operating phase, determining a quantity characterizing the amount of nitrogen oxides discharged from said (NOx)-storage catalytic converter;
• comparing said quantity to the stored amount determined in said first operating phase;
• and,
• calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing paid quantity determined in said second operating phase,
• wherein the nitrogen oxides are discharged from said (NOx)-storage catalytic converter with the aid of a reducing agent and the amount of reducing agent, which is needed during the second operating phase, is determined as said quantity characterizing the discharged quantity of nitrogen oxides.

A control element, including a read-only-memory or a flash memory, for a control apparatus of an internal combustion engine including an internal combustion engine of a motor vehicle, the control element comprising a program stored thereon which is adapted to run on a computing apparatus including a microprocessor, and said program being suitable for carrying out 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 nitrogen oxides in said (NOx)-storage catalytic converter during a first operating phase thereof;
• during said first operating phase, determining the amount of nitrogen oxides stored in said (NOx)-storage catalytic converter;
• discharging the stored nitrogen oxides from said (NOx)-storage catalytic converter during a second operating phase thereof;
• during said second operating phase, determining a quantity characterizing the amount of nitrogen oxides discharged from said (NOx)-storage catalytic converter;
• comparing said quantity to the stored amount determined in said first operating phase;
• and,
• calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing said quantity determined in said second operating phase.

A control apparatus for an internal combustion engine including an internal combustion engine of a motor vehicle, said engine including an (NOx)-storage catalytic converter wherein nitrogen oxides are stored during a first operating phase and stored nitrogen oxides are discharged during a second operating phase, the control apparatus comprising:

• first means for determining the amount of nitrogen oxides stored during the first operating phase;
• second means for determining a quantity characterizing the amount of nitrogen oxides discharged during the second operating phase;
• third means for comparing the amount of stored nitrogen oxides determined during the first operating phase to the determined quantity characterizing the amount of nitrogen oxides discharged during said second operating phase;
• and,
• fourth means for calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing said quantity determined in said second operating phase.

An internal combustion engine including an internal combustion engine of a motor vehicle, the internal combustion engine comprising:

• an (NOx)-storage catalytic converter wherein nitrogen oxides are stored during a first operating phase and stored nitrogen oxides are discharged during a second operating phase;
• a control apparatus including:
• first means for determining the amount of nitrogen oxides stored during the first operating phase;
• second means for determining a quantity characterizing the amount of nitrogen oxides discharged during the second operating phase;
• third means for comparing the amount of stored nitrogen oxides determined during the first operating phase to the determined quantity characterizing the amount of nitrogen oxides discharged during said second operating phase;
• and,
• said internal combustion engine further including means for calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing said quantity determined in said second operating phase.

An internal combustion engine including an internal combustion engine of a motor vehicle, the internal combustion engine comprising:

• an (NOx)-storage catalytic converter wherein nitrogen oxides are stored during a first operating phase and stored nitrogen oxides are discharged during a second operating phase;
• a control apparatus including;
• first means for determining the amount of nitrogen oxides stored during the first operating phase;
• second means for determining a quantity characterizing the amount of nitrogen oxides discharged during the second operating phase;
• third means for comparing the amount of stored nitrogen oxides determined during the first operating phase to the determined quantity characterizing the amount of nitrogen oxides discharged during said second operating phase;
• and,
• said internal combustion engine further including means for calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing said quantity determined in said second operating phase,
• wherein said second means includes an integrator for determining a quantity of reducing agent, which is needed during the second operating phase, by integrating a reducing agent flow over time.

A control element, including a road-only-memory or a flash memory, for a control apparatus of an internal combustion engine including an internal combustion engine of a motor vehicle, the control element comprising a program stored thereon which is adapted to run on a computing apparatus including a microprocessor, and said program being suitable for carrying out 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 nitrogen oxides in said (NOx)-storage catalytic converter during a first operating phase thereof;
• during said first operating phase, determining the amount of nitrogen oxides stored in said (NOx)-storage catalytic converter;
• discharging the stored nitrogen oxides from said (NOx)-storage catalytic converter during a second operating phase thereof;
• during said second operating phase determining a quantity characterizing the amount of nitrogen oxide discharged from said (NOx)-storage catalytic converter;
• comparing said quantity to the stored amount determined in said first operating phase;
• and,
• calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing said quantity determined in said second operating phase,
• wherein the nitrogen oxides are discharged from said (NOx)-storage catalytic converter with the aid of a reducing agent and the amount of reducing agent, which is needed during the second operating phase, is determined as said quantity characterizing the discharged quantity of nitrogen oxides.

A control apparatus for an internal combustion engine including an internal combustion engine of a motor vehicle, said engine including an (NOx)-storage catalytic converter wherein nitrogen oxides are stored during a first operating phase and stored nitrogen oxides are discharged during a second operating phase, the control apparatus comprising:

• first means for determining the amount of nitrogen oxides stored during the first operating phase;
• second means for determining a quantity characterizing the amount of nitrogen oxides discharged during the second operating phase, said nitrogen oxides being discharged with the aid of a reducing agent;
• third means for determining the amount of reducing agent;
• fourth means for comparing the amount of stored nitrogen oxides determined during the first operating phase to the determined quantity characterizing the amount of nitrogen oxides discharged during said second operating phase;
• and,
• fifth means for calibrating an exhaust-gas sensor mounted downstream of said (NOx)-storage catalytic converter utilizing said quantity determined in said second operating phase.