System and method for improving fuel economy and reducing emissions when a vehicle is decelerating

Patent metadata

Field	Value
Publication number	US-10099675-B2
Application number	US-201414559003-A
Country	US
Kind code	B2
Filing date	Dec 3, 2014
Priority date	Oct 27, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A system according to the principles of the present disclosure includes a fuel control module, a transmission control module, and a starter control module. The fuel control module selectively stops fuel delivery to cylinders of an engine while the engine is coupled to a transmission of a vehicle when an accelerator pedal is not depressed. The transmission control module selectively decouples the engine from the transmission while fuel delivery to the cylinders is stopped. The fuel control module selectively allows the engine to stop while the vehicle is moving by not resuming fuel delivery to the cylinders when the engine is decoupled from the engine. The starter control module controls a starter to automatically restart the engine when the accelerator pedal is depressed after fuel delivery to the cylinders is stopped and the engine is decoupled from the engine.

First claim

What is claimed is:

1. A system comprising:
a fuel control module that, when an accelerator pedal is not depressed, selectively stops fuel delivery to cylinders of an engine while an ignition switch is on and the engine is coupled to a transmission of a vehicle;
a transmission control module that controls a torque converter to selectively decouple the engine from the transmission before controlling the transmission to perform a downshift from one forward gear to another forward gear that is lower than the one forward gear while fuel delivery to the cylinders is stopped, wherein the fuel control module selectively allows the engine to stop while the vehicle is moving by not resuming fuel delivery to the cylinders when the engine is decoupled from the transmission while the transmission performs the downshift; and
a starter control module that controls a starter to automatically restart the engine when the accelerator pedal is depressed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

2. The system of claim 1 wherein, when the accelerator pedal is depressed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission, the starter control module controls the starter to increase the speed of the engine and the fuel control module resumes fuel delivery to the cylinders.

3. The system of claim 1 wherein the fuel control module allows the engine to stop when the engine is decoupled from the transmission independent of whether a brake pedal is depressed.

4. The system of claim 1 wherein, while the speed of the vehicle remains greater than zero after fuel delivery to the cylinders is stopped, the starter control module controls the starter to automatically restart the engine when at least one of:
the speed of the engine is greater than or equal to a first predetermined speed; and
the vehicle speed is greater than or equal to a second predetermined speed, wherein the first and second predetermined speeds are greater than zero.

5. The system of claim 1 wherein, after fuel delivery to the cylinders is stopped and the speed of the vehicle has decreased to zero, the starter control module controls the starter to automatically restart the engine when at least one of:
a brake pedal is not depressed; and
the vehicle speed is greater than zero.

6. The system of claim 1 further comprising a diagnostic module that performs a diagnostic on a component of the vehicle, wherein the fuel control module does not allow the engine to stop while the diagnostic is performed.

7. The system of claim 6 wherein the fuel control module allows the engine to stop when the engine is decoupled from the transmission and the diagnostic is complete.

8. The system of claim 1 further comprising a valve control module that adjusts intake and exhaust valves of the engine to a desired position for an engine start when the speed of the vehicle is less than a predetermined speed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

9. The system of claim 1 further comprising a spark control module that stops spark generation in the engine when the speed of the vehicle is less than a predetermined speed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

10. A method comprising:
when an accelerator pedal is not depressed, selectively stopping fuel delivery to cylinders of an engine while an ignition switch is on and the engine is coupled to a transmission of a vehicle;
selectively controlling a torque converter to decouple the engine from the transmission before controlling the transmission to perform a downshift from one forward gear to another forward gear that is lower than the one forward gear while fuel delivery to the cylinders is stopped;
selectively allowing the engine to stop while the vehicle is moving by not resuming fuel delivery to the cylinders when the engine is decoupled from the transmission while the transmission performs the downshift; and
controlling a starter to automatically restart the engine when the accelerator pedal is depressed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

11. The method of claim 10 further comprising controlling the starter to increase the speed of the engine and resuming fuel delivery to the cylinders when the accelerator pedal is depressed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

12. The method of claim 10 further comprising allowing the engine to stop when the engine is decoupled from the transmission independent of whether a brake pedal is depressed.

13. The method of claim 10 further comprising, while the speed of the vehicle remains greater than zero after fuel delivery to the cylinders is stopped, controlling the starter to automatically restart the engine when at least one of:
the speed of the engine is greater than or equal to a first predetermined speed; and
the vehicle speed is greater than or equal to a second predetermined speed, wherein the first and second predetermined speeds are greater than zero.

14. The method of claim 10 wherein, after fuel delivery to the cylinders is stopped and the speed of the vehicle has decreased to zero, controlling the starter to automatically restart the engine when at least one of:
a brake pedal is not depressed; and
the vehicle speed is greater than zero.

15. The method of claim 10 further comprising:
performing a diagnostic on a component of the vehicle; and
not allowing the engine to stop while the diagnostic is performed.

16. The method of claim 15 allowing the engine to stop when the engine is decoupled from the transmission and the diagnostic is complete.

17. The method of claim 10 further comprising adjusting intake and exhaust valves of the engine to a desired position for an engine start when the speed of the vehicle is less than a predetermined speed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

18. The method of claim 10 further comprising stopping spark generation in the engine when the speed of the vehicle is less than a predetermined speed after fuel delivery to the cylinders is stopped and the engine is decoupled from the transmission.

19. The system of claim 1 wherein the system does not use an electric motor to rotate the engine when the transmission performs the downshift.

20. The system of claim 1 wherein the engine is the only device configured to provide direct motive power to wheels of the vehicle.

21. The method of claim 10 further comprising not using an electric motor to rotate the engine when the transmission performs the downshift.

22. The method of claim 10 wherein the engine is the only device configured to provide direct motive power to wheels of the vehicle.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Shafto Robert Douglas
• Burleigh Darrell W

Classifications

• F02D2200/602

  Pedal position · CPC title

• B60W10/04 Primary

  including control of propulsion units · CPC title

• F01N11/007

  the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus · CPC title

• F02D41/1495

  Detection of abnormalities in the air/fuel ratio feedback system · CPC title

• F02D41/123

  the fuel injection being cut-off · CPC title