Exhaust gas recirculation control systems and methods

• US 9,341,133 B2
• Filed: 03/06/2013
• Issued: 05/17/2016
• Est. Priority Date: 03/06/2013
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Naik, Sanjeev M., Ramappan, Vijay, Casetti, Martino
• Primary Examiner(s): DALLO, JOSEPH J
• Application Number:
  US13/786,944
• Publication Number:
  US 20140257673A1
• Time in Patent Office: 1,168 Days
• Field of Search: 701101-105, 701/108, 123/445, 123/299, 123/305, 123/568.21, 123/568.11, 123/568.14, 123/568.16, 123/672, 606/02, 606/052
• US Class Current: 1/1
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/0062 Estimating, calculating or determining the internal EGR rate, amount or flow
• CPC Class Codes: F02D 41/12 for deceleration F02D41/0005, F02D41/107 take precedence
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: F02D 41/30 Controlling fuel injection F02D41/182, F02D41/24 take precedence
• CPC Class Codes: F02D 41/402 Multiple injections
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A fuel control system of a vehicle includes an injection control module and a command module. The injection control module determines a first target amount of fuel for a combustion event of an engine. A command module selectively command the injection control module to provide two fuel injections when a torque request decreases. In response to the command, the injection control module: determines second and third target amounts of fuel based on the first target amount; provides a first fuel injection during the combustion event based on the second target amount; and provides a second fuel injection during a compression stroke of the combustion event based on the third target amount.

Claims

1. A fuel control system of a vehicle, comprising:

an injection control module that determines a first target amount of fuel for a combustion event of an engine; and

a command module that selectively command the injection control module to provide two fuel injections when a torque request decreases and that determines whether to command the injection control module to provide the two fuel injections based on a difference between an estimated mass fraction of recirculated exhaust gas in a gas charge of the combustion event and a target mass fraction of recirculated exhaust gas for the combustion event,

wherein, in response to the command, the injection control module;

determines second and third target amounts of fuel based on the first target amount;

provides a first one of the two fuel injections during the combustion event based on the second target amount; and

provides a second one of the two fuel injections during a compression stroke of the combustion event based on the third target amount.

2. The fuel control system of claim 1 further comprising an enabling/disabling module that disables the command module when a decrease in the torque request is less than a predetermined value.

3. The fuel control system of claim 1 further comprising an enabling/disabling module that disables the command module when a decrease in the target mass fraction of recirculated exhaust gas is less than a predetermined value.

4. The fuel control system of claim 1 wherein the command module commands the injection control module to provide the two fuel injections when the difference is greater than a predetermined value.

5. The fuel control system of claim 4 further comprising a threshold determination module that determines the predetermined value based on an engine speed.

6. The fuel control system of claim 4 further comprising a threshold determination module that determines the predetermined value based on an engine load.

7. The fuel control system of claim 1 wherein the injection control module begins and ends the second one of the two fuel injections during the compression stroke of the combustion event.

8. The fuel control system of claim 1 wherein the injection control module determines the second and third target amounts further based on a predetermined percentage.

9. The fuel control system of claim 8 wherein the injection control module determines the predetermined percentage based on at least one of an engine speed and an engine load.

10. A fuel control method for a vehicle, comprising:

determining a first target amount of fuel for a combustion event of an engine;

determining whether to command provision of two fuel injections based on a difference between an estimated mass fraction of recirculated exhaust gas in a gas charge of the combustion event and a target mass fraction of recirculated exhaust gas for the combustion event;

selectively commanding provision of the two fuel injections when a torque request decreases; and

in response to the command;

determining second and third target amounts of fuel based on the first target amount;

providing a first one of the two fuel injections during the combustion event based on the second target amount; and

providing a second one of the two fuel injections during a compression stroke of the combustion event based on the third target amount.

11. The fuel control method of claim 10 further comprising preventing the commanding when a decrease in the torque request is less than a predetermined value.

12. The fuel control method of claim 10 further comprising preventing the commanding when a decrease in the target mass fraction of recirculated exhaust gas is less than a predetermined value.

13. The fuel control method of claim 10 further comprising commanding provision of the two fuel injections when the difference is greater than a predetermined value.

14. The fuel control method of claim 13 further comprising determining the predetermined value based on an engine speed.

15. The fuel control method of claim 13 further comprising determining the predetermined value based on an engine load.

16. The fuel control method of claim 10 further comprising beginning and ending the second one of the two fuel injections during the compression stroke of the combustion event.

17. The fuel control method of claim 10 further comprising determining the second and third target amounts further based on a predetermined percentage.

18. The fuel control method of claim 17 further comprising determining the predetermined percentage based on at least one of an engine speed and an engine load.