METHOD AND APPARATUS TO PROTECT POWERTRAIN COMPONENTS FROM EXCESSIVE FORCE DAMAGE DUE TO WHEEL LOCKUP

• US 20120158224A1
• Filed: 12/17/2010
• Published: 06/21/2012
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Naqvi, Ali K., Gupta, Pinaki
• Granted Patent: US 8,682,551 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/38 characterised by the driveline clutches shift clutches within the gearing or transmission B60K6/36 , B60K6/54
• CPC Class Codes: B60W 10/023 Fluid clutches
• 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 30/1846 Preventing of breakage of drive line components, e.g. parts of the gearing
• CPC Class Codes: F16D 2500/50287 Torque control
• CPC Class Codes: F16D 2500/7044 Output shaft torque
• CPC Class Codes: F16D 48/06 Control by electric or electronic means, e.g. of fluid pressure

Abstract

An example vehicle includes an engine and a motor-generator configured to generate a torque in a first direction. A torque limiter clutch is configured to dissipate a torque in a second direction that opposes the first torque. The torque in the second direction may be caused by a force event. A control processor is configured to detect a possible force event and control the torque limiter clutch in response to detecting the possible force event. A method of controlling the torque limiter clutch includes detecting a possible force event, reducing fluid pressure to the torque limiter clutch in response to detecting the possible force event, confirming the possible force event, maintaining the reduced fluid pressure to the torque limiter clutch if the force event is confirmed, and increasing the fluid pressure to the torque limiter clutch if the force event is not confirmed.

Claims

1. A vehicle comprising:

an engine configured to generate a torque in a first direction;

a motor-generator configured to generate a torque in the first direction;

a torque limiter clutch configured to dissipate a torque in a second direction that opposes the first torque, wherein the torque in the second direction is caused by a force event;

a control processor configured to detect a possible force event and control the torque limiter clutch in response to detecting the possible force event.

2. A vehicle as set forth in claim 1, wherein the control processor is configured to confirm the possible force event.

3. A vehicle as set forth in claim 2, wherein the control processor is configured to engage the torque limiter clutch if the possible force event is not confirmed.

4. A vehicle as set forth in claim 2, wherein the control processor is configured to control engagement of the torque limiter clutch for a predetermined amount of time if the possible force event is confirmed.

5. A vehicle as set forth in claim 2, wherein the control processor is configured to control engagement of the torque limiter clutch for a duration of the force event if the possible force event is confirmed.

6. A vehicle as set forth in claim 1, further comprising a braking system configured to generate the torque in the second direction.

7. A vehicle as set forth in claim 1, wherein the possible force event includes a hard brake condition on a low friction surface.

8. A vehicle as set forth in claim 1, further comprising a valve body configured to provide fluid at a first pressure to the torque limiter clutch, wherein the torque limiter clutch is configured to engage upon receipt of fluid at the first fluid pressure.

9. A vehicle as set forth in claim 8, wherein the valve body is configured to provide fluid to the torque limiter clutch at a second fluid pressure to reduce the torque capacity of the torque limiter clutch, and wherein the torque limiter clutch is configured to slip during the force event when provided with fluid at the second fluid pressure.

10. A vehicle as set forth in claim 9, wherein the valve body is configured to provide fluid to the torque limiter clutch at the second fluid pressure for at least one of a predetermined amount of time and a duration of the force event.

11. A method of controlling a torque limiter clutch in a vehicle, the method comprising:

detecting a possible force event;

reducing fluid pressure to the torque limiter clutch in response to detecting the possible force event;

confirming the possible force event;

maintaining the reduced fluid pressure to the torque limiter clutch if the force event is confirmed; and

increasing the fluid pressure to the torque limiter clutch if the force event is not confirmed.

12. A method as set forth in claim 11, further comprising engaging the torque limiter clutch prior to detecting the possible force event.

13. A method as set forth in claim 12, wherein engaging the torque limiter clutch includes providing the torque limiter clutch with fluid at a first pressure.

14. A method as set forth in claim 13, wherein reducing the fluid pressure to the torque limiter clutch in response to detecting the possible force event includes providing the torque limiter clutch with fluid at a second pressure, wherein the second pressure is less than the first pressure.

15. A method as set forth in claim 14, wherein maintaining the reduced fluid pressure if the force event is confirmed includes maintaining the fluid at the second pressure for a duration of the force event.

16. A method as set forth in claim 14, wherein maintaining the reduced fluid pressure if the force event is confirmed includes maintaining the fluid at the second pressure for a predetermined amount of time.

17. A method as set forth in claim 13, wherein increasing the fluid pressure to the torque limiter clutch if the force event is not confirmed includes providing the torque limiter clutch with the first fluid pressure if the force event is not confirmed.

18. A method as set forth in claim 11, wherein detecting the possible force event includes detecting a hard brake condition on a low friction surface.

19. A method as set forth in claim 11, wherein reducing the fluid pressure to the torque limiter clutch includes:

selecting at least one clutch in the vehicle as the torque limiter clutch based at least in part on an operating mode of the vehicle; and

reducing the fluid pressure to the selected clutch.