Method for setting a predetermined oxygen filling value of an oxygen storage reservoir of a catalytic converter

• US 8,291,693 B2
• Filed: 12/11/2008
• Issued: 10/23/2012
• Est. Priority Date: 12/14/2007
• Status: Active Grant

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Odendall, Bodo
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): TRAN, DIEM T
• Application Number:
  US12/332,434
• Publication Number:
  US 20090151324A1
• Time in Patent Office: 1,412 Days
• Field of Search: 602/74, 602/76, 602/77, 602/85, 701/103, 701/109
• US Class Current: 60/285
• CPC Class Codes: F01N 3/0864 Oxygen
• CPC Class Codes: F02D 2200/0814 Oxygen storage amount
• CPC Class Codes: F02D 41/0295 Control according to the amount of oxygen that is stored on the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/1445 the characteristics being related to the exhaust flow

Abstract

A method for setting a predetermined oxygen filling value of an oxygen storage reservoir of a catalytic converter for a motor vehicle, the oxygen filling value being set with consideration of a combustion air ratio which has been determined depending on the raw emission values which have been determined or which are to be determined for the exhaust gas components which are to be oxidized and reduced by the catalytic converter.

Claims

1. A method comprising

setting a predetermined oxygen filling value of an oxygen storage reservoir of a catalytic converter for a motor vehicle;

collecting raw emissions data during operation of the motor vehicle,

wherein the exhaust gas data comprises information about pollutants in an exhaust gas stream of the motor vehicle,

wherein the pollutants are components which are to be oxidized or reduced by the catalytic converter;

differentiating the raw emissions data by pollutant to obtain pollutant-differentiated raw emissions data;

determining a combustion air ratio based on the pollutant-differentiated raw emissions data converted to a change of the oxygen filling value of an oxygen storage reservoir of the catalytic converter as a function of a mass flow of exhaust gas,

detecting an oxygen storage behavior and an oxygen discharge behavior of the catalytic converter;

wherein oxygen entry into and oxygen discharge out of the oxygen storage reservoir of the catalytic converter are corrected based on

the oxygen storage behavior of the catalytic converter,

the oxygen discharge behavior of the catalytic converter, and

the converted raw emissions data for each of a plurality of individual pollutants;

resetting the predetermined oxygen filling value based on the combustion air ratio.

2. The method according to claim 1 wherein raw emission values are determined for at least one of

hydrocarbons and carbon monoxide as the exhaust gas components which are to be oxidized and

nitrogen oxides and oxygen as the exhaust gas components which are to be reduced.

3. The method according to claim 1, wherein balancing of at least one of

oxygen entry into the catalytic converter and

oxygen discharge from the catalytic converter is weighted by way of the relative oxygen filling of the catalytic converter such that at least one of

the reaction rate of oxygen entry rises with a decrease of the relative oxygen filling,

the reaction rate of oxygen discharge drops as the relative oxygen filling decreases,

the reaction rate of oxygen entry declines with an increase of relative oxygen filling, and

the reaction rate of oxygen discharge increases with the increase of the relative oxygen filling.

4. The method according to claim 1, wherein the combustion air ratio is determined as a function of values of an oxygen storage curve and an oxygen discharge curve of an oxygen storage reservoir of the catalytic converter, which values are assigned to a predetermined oxygen filling value.

5. The method according to claim 1, wherein an oxygen filling value is set for a catalytic converter which is in an equilibrium state.

6. The method according to claim 1, wherein the method is carried out when there are large masses of exhaust gas.

7. A device comprising

means for setting a predetermined oxygen filling value of an oxygen storage reservoir of a catalytic converter for a motor vehicle;

means for collecting raw emissions data during operation of the motor vehicle,

wherein the exhaust gas data comprises information about pollutants in an exhaust gas stream of the motor vehicle,

wherein the pollutants are components which are to be oxidized or reduced by the catalytic converter;

means for differentiating the raw emissions data by pollutant to obtain pollutant-differentiated raw emissions data;

means for determining a combustion air ratio based on the pollutant-differentiated raw emissions data converted to a change of the oxygen filling value of an oxygen storage reservoir of the catalytic converter as a function of a mass flow of exhaust gas,

means for detecting an oxygen storage behavior and an oxygen discharge behavior of the catalytic converter;

wherein oxygen entry into and oxygen discharge out of the oxygen storage reservoir of the catalytic converter are corrected based on

the oxygen storage behavior of the catalytic converter,

the oxygen discharge behavior of the catalytic converter, and

the converted raw emissions data for each of a plurality of individual pollutants;

means for resetting the predetermined oxygen filling value based on the combustion air ratio.

8. A motor vehicle including a device as set forth in claim 7.