UP-SHIFT CONTROL IN AN AUTOMATIC TRANSMISSION WITH NEGATIVE INPUT TORQUE

• US 20090319143A1
• Filed: 12/16/2008
• Published: 12/24/2009
• Est. Priority Date: 06/23/2008
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Caldwell, Brett R., Runde, Jeffrey K., Merrion, Robert M., Kluemper, Kevin L.
• Granted Patent: US 8,489,295 B2
• Time in Patent Office: Days
• US Class Current: 701/60
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 2059/385 Turbine speed
• CPC Class Codes: F16H 61/061 using electric control means

Abstract

A transmission control module including a shift control module that generates an enable signal when an up-shift is requested and the engine torque is below a threshold torque value. A turbine speed profile determination module that selectively generates a desired turbine speed profile. The shift control module controls a clutch pressure of an off-going clutch based on a measured turbine speed and the desired turbine speed profile when the enable signal is generated.

Claims

1. A transmission control module comprising:

a shift control module that generates an enable signal when an up-shift is requested and engine torque is below a threshold torque value; and

a turbine speed profile determination module that selectively generates a desired turbine speed profile, wherein the shift control module controls a clutch pressure of an off-going clutch based on a measured turbine speed and the desired turbine speed profile when the enable signal is generated.

2. The transmission control module of claim 1 wherein the shift control module minimizes the difference between the measured turbine speed and the desired turbine speed profile after slip of the off-going clutch is detected.

3. The transmission control module of claim 2 wherein the shift control module decreases the clutch pressure at a predetermined rate until slip of the off-going clutch is detected.

4. The transmission control module of claim 2 wherein the shift control module detects slip of the off-going clutch based on a decrease in the measured turbine speed.

5. The transmission control module of claim 3 wherein the shift control module holds the clutch pressure for a predetermined period after detecting slip of the off-going clutch and before control based on the desired turbine speed profile begins.

6. The transmission control module of claim 1 further comprising an error control module that determines an offset value based on a difference between the desired turbine speed profile and the measured turbine speed, wherein the shift control module adjusts the clutch pressure based on the offset value.

7. The transmission control module of claim 6 wherein the offset value is a pressure value and the shift control module controls the clutch pressure based on a sum of the offset value and an open-loop pressure value.

8. The transmission control module of claim 1 wherein the requested up-shift is from a first gear to a second gear and wherein the shift control module decreases the clutch pressure at a predetermined rate after the measured turbine speed reaches a synchronization speed corresponding to the second gear.

9. The transmission control module of claim 1 wherein the threshold torque value is less than or equal to zero.

10. The transmission control module of claim 1 wherein the shift control module generates a control signal for a first solenoid to control the clutch pressure.

11. A method for controlling an up-shift in an automatic transmission, comprising:

generating an enable signal when an up-shift is requested and engine torque is below a threshold torque value; and

selectively generating a desired turbine speed profile, wherein the shift control module controls a clutch pressure of an off-going clutch based on a measured turbine speed and the desired turbine speed profile when the enable signal is generated.

12. The method of claim 11 wherein the shift control module minimizes the difference between the measured turbine speed and the desired turbine speed profile after slip of the off-going clutch is detected.

13. The method of claim 12 wherein the shift control module decreases the clutch pressure at a predetermined rate until slip of the off-going clutch is detected.

14. The method of claim 12 wherein the shift control module detects slip of the off-going clutch based on a decrease in the measured turbine speed.

15. The method of claim 13 wherein the shift control module holds the clutch pressure for a predetermined period after detecting slip of the off-going clutch and before control based on the desired turbine speed profile begins.

16. The method of claim 11 further comprising:

determining an offset value based on a difference between the desired turbine speed profile and the measured turbine speed, wherein the shift control module adjusts the clutch pressure based on the offset value.

17. The method of claim 16 wherein the offset value is a pressure value and the shift control module controls the clutch pressure based on a sum of the offset value and an open-loop pressure value.

18. The method of claim 11 wherein the requested up-shift is from a first gear to a second gear and wherein the shift control module decreases the clutch pressure at a predetermined rate after the measured turbine speed reaches a synchronization speed corresponding to the second gear.

19. The method of claim 11 wherein the threshold torque value is less than or equal to zero.

20. The method of claim 11 wherein the shift control module generates a control signal for a first solenoid to control the clutch pressure.