Vehicle rollback control systems and methods

• US 8,694,231 B2
• Filed: 07/14/2010
• Issued: 04/08/2014
• Est. Priority Date: 06/01/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Ma, Qi, Shafto, Robert Douglas
• Primary Examiner(s): SOLIS, ERICK R
• Application Number:
  US12/835,856
• Publication Number:
  US 20110290216A1
• Time in Patent Office: 1,364 Days
• Field of Search: 180/65.265, 180/65.28, 123/179.4, 123/339.11, 123/339.15, 123/339.16, 701/54, 701/113
• US Class Current: 701/113
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/062 for starting F02D41/061 takes precedence
• CPC Class Codes: F02N 11/0833 Vehicle conditions F02N11/0822, F02N11/0825 take precedence
• CPC Class Codes: F02N 2200/0802 Transmission state, e.g. gear ratio or neutral state
• CPC Class Codes: F02N 2200/124 Information about road conditions, e.g. road inclination or surface
• CPC Class Codes: F02N 2300/102 Control of the starter motor speed; Control of the engine speed during cranking
• CPC Class Codes: F02P 5/1506 with particular means during starting
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A control system for an auto-stop/start vehicle includes a transmission load module, a target engine speed module, and an actuator control module. The transmission load module determines a load imposed on an engine through a transmission. The target engine speed module selectively determines a target engine speed during an engine startup event based on the load. The actuator control module controls at least one engine actuator based on the target engine speed during the engine startup event.

Claims

1. A control system for an auto-stop/start vehicle, comprising:

a transmission load module that determines a load imposed on an engine through a transmission based on a vehicle weight and a grade of a road;

a target engine speed module that selectively determines a target engine speed during an engine startup event based on the load; and

an actuator control module that controls at least one engine actuator based on the target engine speed during the engine startup event.

2. The control system of claim 1 further comprising:

an auto-stop/start module that selectively shuts down the engine between a first time when a vehicle startup command is received and a second time when a vehicle shutdown command is received and that selectively initiates the engine startup event between the first and second times; and

an auto-stop/start disabling module that disables the auto-stop/start module when the load is greater than a predetermined load.

3. The control system of claim 2 wherein the actuator control module selectively applies mechanical brakes during the engine startup event when the load is greater than a second predetermined load, and

wherein the second predetermined load is less than the predetermined load.

4. The control system of claim 3 wherein the actuator control module controls the application of the mechanical brakes based on the load.

5. The control system of claim 3 wherein the target engine speed module determines the target engine speed based on whether the load is greater than the second predetermined load.

6. The control system of claim 5 wherein the target engine speed module determines the target engine speed based on a first predetermined profile when the load is greater than the second predetermined load and determines the target engine speed based on a second predetermined profile when the load is greater than zero and one of less than and equal to the second predetermined profile,

wherein the first and second predetermined profiles are different.

7. The control system of claim 6 wherein the first predetermined profile approaches a predetermined speed at a greater slope during the engine startup event than the second predetermined profile.

8. The control system of claim 1 further comprising:

a correction determination module that determines a spark timing correction based on a difference between the target engine speed and a measured engine speed; and

a spark timing adjustment module that determines an adjusted spark timing based on the spark timing correction and a target spark timing and that controls spark during the engine startup event based on the adjusted spark timing.

9. A control method for an auto-stop/start vehicle, comprising:

determining a load imposed on an engine through a transmission based on a vehicle weight and a grade of a road;

selectively determining a target engine speed during an engine startup event based on the load; and

controlling at least one engine actuator based on the target engine speed during the engine startup event.

10. The control method of claim 9 further comprising:

selectively shutting down the engine between a first time when a vehicle startup command is received and a second time when a vehicle shutdown command is received;

selectively initiating the engine startup event between the first and second times; and

preventing the selective shut down when the load is greater than a predetermined load.

11. The control method of claim 10 further comprising selectively applying mechanical brakes during the engine startup event when the load is greater than a second predetermined load, and

wherein the second predetermined load is less than the predetermined load.

12. The control method of claim 11 further comprising controlling the application of the mechanical brakes based on the load.

13. The control method of claim 11 further comprising determining the target engine speed based on whether the load is greater than the second predetermined load.

14. The control method of claim 13 further comprising:

determining the target engine speed based on a first predetermined profile when the load is greater than the second predetermined load; and

determining the target engine speed based on a second predetermined profile when the load is greater than zero and one of less than and equal to the second predetermined profile,

wherein the first and second predetermined profiles are different.

15. The control method of claim 14 wherein the first predetermined profile approaches a predetermined speed at a greater slope during the engine startup event than the second predetermined profile.

16. The control method of claim 9 further comprising:

determining a spark timing correction based on a difference between the target engine speed and a measured engine speed;

determining an adjusted spark timing based on the spark timing correction and a target spark timing; and

controlling spark during the engine startup event based on the adjusted spark timing.

17. A control system for an auto-stop/start vehicle, comprising:

a transmission load module that determines a load imposed on an engine through a transmission;

a target engine speed module that selectively determines a target engine speed during an engine startup event based on the load;

an actuator control module that controls at least one engine actuator based on the target engine speed during the engine startup event;

an auto-stop/start module that selectively shuts down the engine between a first time when a vehicle startup command is received and a second time when a vehicle shutdown command is received and that selectively initiates the engine startup event between the first and second times; and

an auto-stop/start disabling module that disables the auto-stop/start module when the load is greater than a predetermined load.

18. The control system of claim 17 wherein the actuator control module selectively applies mechanical brakes during the engine startup event when the load is greater than a second predetermined load, and

wherein the second predetermined load is less than the predetermined load.

19. The control system of claim 18 wherein the actuator control module controls the application of the mechanical brakes based on the load.

20. The control system of claim 18 wherein the target engine speed module determines the target engine speed based on whether the load is greater than the second predetermined load.

21. The control system of claim 20 wherein the target engine speed module determines the target engine speed based on a first predetermined profile when the load is greater than the second predetermined load and determines the target engine speed based on a second predetermined profile when the load is greater than zero and one of less than and equal to the second predetermined profile,

wherein the first and second predetermined profiles are different.

22. A control method for an auto-stop/start vehicle, comprising:

determining a load imposed on an engine through a transmission;

selectively determining a target engine speed during an engine startup event based on the load;

controlling at least one engine actuator based on the target engine speed during the engine startup event;

selectively shutting down the engine between a first time when a vehicle startup command is received and a second time when a vehicle shutdown command is received;

selectively initiating the engine startup event between the first and second times; and

preventing the selective shut down when the load is greater than a predetermined load.

23. The control method of claim 22 further comprising selectively applying mechanical brakes during the engine startup event when the load is greater than a second predetermined load, and

wherein the second predetermined load is less than the predetermined load.

24. The control method of claim 23 further comprising controlling the application of the mechanical brakes based on the load.

25. The control method of claim 23 further comprising determining the target engine speed based on whether the load is greater than the second predetermined load.

26. The control method of claim 25 further comprising:

determining the target engine speed based on a first predetermined profile when the load is greater than the second predetermined load; and

determining the target engine speed based on a second predetermined profile when the load is greater than zero and one of less than and equal to the second predetermined profile,

wherein the first and second predetermined profiles are different.