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

• US 10,099,675 B2
• Filed: 12/03/2014
• Issued: 10/16/2018
• Est. Priority Date: 10/27/2014
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Shafto, Robert Douglas, Burleigh, Darrell W.
• Primary Examiner(s): Huynh, Hai
• Assistant Examiner(s): Laguarda, Gonzalo
• Application Number:
  US14/559,003
• Publication Number:
  US 20160115932A1
• Time in Patent Office: 1,413 Days
• Field of Search: 1231794, 123481, 123320, 123325, 123332, 123436, 701110, 701112
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2030/1809 Without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60Y 2300/18083 without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: F01N 11/007 the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2200/602 Pedal position
• CPC Class Codes: F02D 41/0215 in relation with elements of the transmission
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02D 41/1495 Detection of abnormalities in the air/fuel ratio feedback system
• CPC Class Codes: F02N 11/0822 related to action of the driver
• CPC Class Codes: F02N 11/0829 related to special engine control, e.g. giving priority to engine warming-up or learning
• CPC Class Codes: F02N 11/0844 with means for restarting the engine directly after an engine stop request, e.g. caused by change of driver mind
• CPC Class Codes: F02N 2200/022 Engine speed
• CPC Class Codes: F02N 2200/0801 Vehicle speed
• CPC Class Codes: F02N 2200/101 : Accelerator pedal position
• CPC Class Codes: F16H 2312/14 : Going to, or coming from standby operation, e.g. for engine start-stop operation at traffic lights
• CPC Class Codes: F16H 61/00 : Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
• CPC Class Codes: Y02T 10/40 : Engine management systems

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.

Claims

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.

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.

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.

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.