Torque converter clutch slip control

• US 20080058161A1
• Filed: 09/01/2006
• Published: 03/06/2008
• Est. Priority Date: 09/01/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Casteran, Regis, Sieffert, Jean
• Granted Patent: US 7,513,851 B2
• Time in Patent Office: Days
• US Class Current: 477/176
• CPC Class Codes: F16H 2061/145 for controlling slip, e.g. approaching target slip value
• CPC Class Codes: F16H 2306/30 characterised by the way or trajectory to a new ratio, e.g. by performing shift according to a particular algorithm or function
• CPC Class Codes: F16H 61/143 using electric control means

Abstract

A method and system for regulating engagement of a torque converter clutch (TCC) in a vehicle incorporating a transmission that is driven by an engine through a torque converter includes determining a non-linear slip profile based on vehicle operating parameters, calculating an actual TCC slip, calculating a TCC ramp pressure based on the non-linear slip profile and the actual TCC slip and regulating a TCC engagement pressure based on the TCC ramp pressure.

Claims

1. A method of regulating engagement of a torque converter clutch (TCC) in a vehicle incorporating a transmission that is driven by an engine through a torque converter, comprising:

determining a non-linear slip profile based on vehicle operating parameters;

calculating an actual TCC slip;

calculating a TCC ramp pressure based on said non-linear slip profile and said actual TCC slip; and

regulating a TCC engagement pressure based on said TCC ramp pressure.

2. The method of claim 1 further comprising determining said TCC engagement pressure based on a base pressure and said TCC ramp pressure.

3. The method of claim 1 wherein said TCC ramp pressure is determined based on a TCC delta ramp pressure.

4. The method of claim 1 wherein said TCC ramp pressure is determined based on a slip delta correction term and a slip error correction term.

5. The method of claim 4 wherein said slip delta correction term is determined based on a vehicle operating parameter, a TCC slip target and a TCC slip reference.

6. The method of claim 5 wherein said TCC slip reference is a fixed value.

7. The method of claim 4 wherein said slip error correction term is determined based on a vehicle operating parameter and said actual TCC slip.

8. The method of claim 1 wherein said actual TCC slip is determined as a difference between an engine speed and a turbine speed of said torque converter.

9. A method of regulating engagement of a torque converter clutch (TCC) in a vehicle incorporating a transmission that is driven by an engine through a torque converter, comprising:

initiating an electronic clutch control (ECC) on mode;

determining an engine torque and a turbine speed of said torque converter;

determining a non-linear slip profile based on said engine torque and said turbine speed;

determining an actual TCC slip;

calculating a TCC ramp pressure based on said non-linear slip profile and said actual TCC slip; and

regulating a TCC engagement pressure based on said TCC ramp pressure.

10. The method of claim 9 further comprising determining said TCC engagement pressure based on a base pressure and said TCC ramp pressure.

11. The method of claim 9 wherein said TCC ramp pressure is determined based on a TCC delta ramp pressure.

12. The method of claim 9 wherein said TCC ramp pressure is determined based on a slip delta correction term and a slip error correction term.

13. The method of claim 12 wherein said slip delta correction term is determined based on said engine torque, a TCC slip target and a TCC slip reference.

14. The method of claim 13 wherein said TCC slip reference is a fixed value.

15. The method of claim 12 wherein said slip error correction term is determined based on said engine torque and said actual TCC slip.

16. The method of claim 9 wherein said actual TCC slip is determined as a difference between an engine speed and said turbine speed.

17. A torque converter clutch (TCC) regulation system in a vehicle incorporating a transmission that is driven by an engine through a torque converter, comprising:

a first module that determines a non-linear slip profile based on vehicle operating parameters;

a second module that calculating an actual TCC slip;

a third module that calculates a TCC ramp pressure based on said non-linear slip profile and said actual TCC slip; and

a fourth module that regulates a TCC engagement pressure based on said TCC ramp pressure.

18. The TCC regulation system of claim 17 wherein said third module determines said TCC engagement pressure based on a base pressure and said TCC ramp pressure.

19. The TCC regulation system of claim 17 wherein said TCC ramp pressure is determined based on a TCC delta ramp pressure.

20. The TCC regulation system of claim 17 wherein said TCC ramp pressure is determined based on a slip delta correction term and a slip error correction term.

21. The TCC regulation system of claim 20 wherein said slip delta correction term is determined based on a vehicle operating parameter, a TCC slip target and a TCC slip reference.

22. The TCC regulation system of claim 21 wherein said TCC slip reference is a fixed value.

23. The TCC regulation system of claim 20 wherein said slip error correction term is determined based on a vehicle operating parameter and said actual TCC slip.

24. The TCC regulation system of claim 17 wherein said actual TCC slip is determined as a difference between an engine speed and a turbine speed of said torque converter.