Method for the load dependent reduction of fuel consumption following deceleration fuel cut out

Patent metadata

Field	Value
Publication number	US-9512765-B2
Application number	US-201414299869-A
Country	US
Kind code	B2
Filing date	Jun 9, 2014
Priority date	Jun 6, 2013
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A method for controlling a motor vehicle with an internal combustion engine and a catalytic converter is disclosed. The method includes: determining an oxygen storage value, which is a dimension for oxygen stored in the catalytic converter, detecting an engine load, carrying out a part evacuation of the oxygen from the catalytic converter with a fuel enrichment when the oxygen storage value exceeds a trigger evacuation threshold value and when the engine load is below a low-load threshold value.

First claim

The invention claimed is:

1. A method for controlling a motor vehicle with an internal combustion engine and a catalytic converter, the method configured to be performed by a processor, the processor configured to perform the method comprising the steps of:
determining an oxygen storage value for oxygen stored in the catalytic converter based on a deceleration fuel cut out,
detecting an engine load, and
carrying out a part evacuation of the oxygen from the catalytic converter with a fuel enrichment based on the oxygen storage value exceeding a trigger evacuation threshold value and the engine load being below a low-load threshold value;
adjusting an air/fuel ratio to a rich mixture based on the carrying out of the part evacuation of the oxygen from the catalytic converter; and
maintaining the air/fuel ratio at the rich mixture based on the oxygen storage value exceeding a lower evacuation threshold value and the engine load remaining less than a high-load threshold value,
wherein the low-load threshold is less than the high-load threshold, and the carrying out of the part evacuation of the oxygen from the catalytic converter with the fuel enrichment and the maintaining the air/fuel ratio at the rich mixture are each based on the determining of the deceleration fuel cut out.

2. The method according to claim 1 , wherein the first fuel enrichment is carried out at a lambda value from 0.8 to 0.99.

3. The method according to claim 1 , wherein the part evacuation is 0.1 to 3 seconds long.

4. The method according to claim 1 , wherein following the part evacuation a lambda value from 0.997 to 0.998 is adjusted via a post-cat probe which is arranged downstream of the catalytic converter until the oxygen storage value drops below the lower evacuation threshold value or the engine load exceeds the high-load threshold value.

5. The method according to claim 4 , wherein based on an engine load greater than the low-load threshold value, the catalytic converter is evacuated through a post-cat control.

6. The method according to claim 5 , further comprising detecting by the post-cat probe, oxygen in the exhaust gas after the catalytic converter and increasing a fuel supply to the internal combustion engine through the post-cat control to reduce the oxygen in the exhaust gas.

7. The method according to claim 1 wherein the oxygen storage value is modeled based on at least one of lambda control and engine parameters.

8. A motor vehicle, comprising:
an internal combustion engine including an exhaust tract having a catalytic converter;
a pre-cat probe in fluid communication with the exhaust tract upstream from the catalytic converter;
a post-cat probe downstream from the catalytic converter and in fluid communication with the catalytic converter; and
a control unit onboard the motor vehicle having a processor that, based on a deceleration fuel cut out:
determines an oxygen storage value for oxygen stored in the catalytic converter;
detects an engine load;
carries out a part evacuation of the oxygen from the catalytic converter with a fuel enrichment based on the oxygen storage value exceeding a trigger evacuation threshold value and the engine load being below a low-load threshold value;
adjusts an air/fuel ratio to a rich mixture based on the part evacuation of the oxygen from the catalytic converter; and
maintains the air/fuel ratio at the rich mixture based on the oxygen storage value exceeding a lower evacuation threshold value and the engine load remaining less than a high-load threshold value,
wherein the low-load threshold is less than the high-load threshold.

9. A computer program product for controlling a motor vehicle with an internal combustion engine and a catalytic converter, the computer program product including a tangible storage medium readable by a processor and storing instructions for execution by the processor for carrying out a method, the processor configured to perform the method comprising:
determining an oxygen storage value for oxygen stored in the catalytic converter based on a deceleration fuel cut out;
detecting an engine load of the internal combustion engine;
carrying out a part evacuation of the oxygen from the catalytic converter with a fuel enrichment based on the oxygen storage value exceeding a trigger evacuation threshold value and the engine load being below a low-load threshold value;
adjusting an air/fuel ratio to a rich mixture based on the carrying out of the part evacuation of the oxygen from the catalytic converter; and
maintaining the air/fuel ratio at the rich mixture based on the oxygen storage value exceeding a lower evacuation threshold value and the engine load remaining less than a high-load threshold value,
wherein the low-load threshold is less than the high-load threshold, and the carrying out of the part evacuation of the oxygen from the catalytic converter with the fuel enrichment and the maintaining the air/fuel ratio at the rich mixture are each based on the determining of the deceleration fuel cut out.

Assignees

• Gm Global Tech Operations Llc
• Gm Global Tech Operations Llc

Inventors

• Horst Stefan
• Schilly Arnaud

Classifications

• F01N3/101

  Three-way catalysts · CPC title

• F01N3/22 Primary

  Control of additional air supply only, e.g. using by-passes or variable air pump drives · CPC title

• F02D41/1441

  Plural sensors · CPC title

• F02D41/0295 Primary

  Control according to the amount of oxygen that is stored on the exhaust gas treating apparatus · CPC title

• Y02T10/22

  Cross-Sectional Technologies · mapped topic