METHOD AND APPARATUS FOR REMEDIATION OF AND RECOVERY FROM A CLUTCH SLIP EVENT IN A HYBRID POWERTRAIN SYSTEM

• US 20090112427A1
• Filed: 10/08/2008
• Published: 04/30/2009
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG, Daimler AG (Mercedes-Benz Group AG), Chrysler Group LLC (Stellantis NV)
• Original Assignee: BMW AG (Bayerische Motoren Werke AG), Daimler AG (Mercedes-Benz Group AG), GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust), Chrysler LLC (Stellantis NV)
• Inventors: Heap, Anthony H., Sah, Jy-Jen F., Kaminsky, Lawrence A.
• Granted Patent: US 8,335,623 B2
• Time in Patent Office: Days
• US Class Current: 701/67
• CPC Class Codes: B60K 1/02 comprising more than one electric motor
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/365 with the gears having orbital motion
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2050/0042 Transfer function lag; delays
• CPC Class Codes: B60W 2510/0241 Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 2510/104 Output speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2540/12 : Brake pedal position
• CPC Class Codes: B60W 2710/025 : Clutch slip, i.e. difference between input and output speeds
• CPC Class Codes: B60W 2710/0666 : Engine torque
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 2710/1022 : Input torque
• CPC Class Codes: B60W 30/1846 : Preventing of breakage of drive line components, e.g. parts of the gearing
• CPC Class Codes: B60W 30/20 : Reducing vibrations in the driveline
• CPC Class Codes: F16H 2037/0866 : Power split variators with distributing differentials, with the output of the CVT connected or connectable to the output shaft
• CPC Class Codes: F16H 2037/102 : the input or output shaft of the transmission is connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/104 : Power split variators with one end of the CVT connected or connectable to two or more differentials
• CPC Class Codes: F16H 2037/106 : with switching means to provide two variator modes or ranges
• CPC Class Codes: F16H 3/728 : with means to change ratio in the mechanical gearing
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility

Abstract

A method for operating a powertrain, including an electro-mechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine, includes monitoring slip across a selectively applied clutch within the transmission to indicate a clutch slip event, and if the monitoring indicates the clutch slip event decreasing a load across the selectively applied clutch by reducing torque of at least one of the engine and the electric machine, in order to reduce the slip, thereby ending the clutch slip event.

Claims

1. A method for operating a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an internal combustion engine and an electric machine adapted to selectively transmit mechanical power to an output member, the method comprising:

monitoring slip across a selectively applied clutch within said transmission to indicate a clutch slip event; and

if said monitoring indicates said clutch slip event, decreasing a load across said selectively applied clutch by reducing at least one of a magnitude of torque permitted from said engine and a magnitude of torque permitted from said electric machine, in order to reduce said slip, thereby ending said clutch slip event.

2. The method of claim 1, further comprising monitoring slip across a plurality of selectively applied clutches.

3. The method of claim 1, wherein said monitoring slip comprises comparing a measured clutch clip speed to a threshold slip speed and indicating said clutch slip event if said measured clutch clip speed exceeds said threshold slip speed.

4. The method of claim 1, wherein said monitoring slip comprises comparing a measured clutch clip speed to a threshold slip speed and indicating said clutch slip event if said measured clutch clip speed exceeds said threshold slip speed throughout a slip detection period.

5. The method of claim 1, wherein said decreasing said load further comprises reducing a magnitude of torque permitted from a second electric machine.

6. The method of claim 1, wherein said decreasing said load across said selectively applied clutch includes delaying said reducing said magnitude of torque permitted from said electric machine in comparison to said reducing a magnitude of torque permitted from said engine, anticipating greater response lag in said engine, so as to effect said decreasing with substantially contemporaneous engine and electric machine torque reductions.

7. The method of claim 1, wherein said reducing said magnitude of torque permitted from said engine comprises:

initially reducing said magnitude of torque permitted from said engine to a magnitude of a calculated reactive clutch torque; and

progressively reducing said magnitude of torque permitted from said engine.

8. The method of claim 1, wherein said reducing said magnitude of torque permitted from said electric machine comprises:

initially reducing said magnitude of torque permitted from said electric machine to said magnitude of said calculated reactive clutch torque; and

progressively reducing said magnitude of torque permitted from said electric machine.

9. The method of claim 1, further comprising reapplying load across the selectively applied clutch when said monitoring indicates an end to said clutch slip event.

10. The method of claim 9, wherein said monitoring indicating an end to said clutch slip event comprises comparing a measured clutch clip speed to a threshold slip speed and indicating said end to said clutch slip event if said measured clutch clip speed is less than said threshold slip speed.

11. The method of claim 9, wherein said monitoring indicating an end to said slip event comprises comparing a measured clutch clip speed to a threshold slip speed and indicating said end to said clutch slip event if said measured clutch clip speed is less than said threshold slip speed through a slip recovery period.

12. The method of claim 9, wherein said reapplying load across the selectively applied clutch comprises:

initially maintaining said load across said selectively applied clutch; and

progressively increasing said load until a normal load across said clutch is achieved.

13. A method for operating a powertrain comprising an electro-mechanical transmission adapted to selectively transmit mechanical power to an output member through selective application of a plurality of clutches, wherein said transmission is mechanically-operatively coupled to an internal combustion engine and a plurality of electric motors, the method comprising:

monitoring clutch slip across each selectively applied clutch; and

if said monitoring indicates clutch slip in excess of a threshold clutch slip level through a slip detection period, limiting a magnitude of torque permitted from said engine transmitted through said clutches and limiting a magnitude of torque permitted from said electric motors transmitted through said clutches.

14. The method of claim 13, wherein said limiting said magnitude of torque permitted from said electric motors includes a delay in comparison to said limiting a magnitude of torque permitted from said engine, anticipating greater response lag in said engine, so as to effect both said limiting engine and electric motor torques substantially contemporaneously.

15. The method of claim 13,

wherein said limiting said magnitude of torque permitted from said engine comprises

initially constraining said magnitude of torque permitted from said engine to a magnitude of a calculated clutch reactive torque, and

progressively constraining said magnitude of torque permitted from said engine;

and

wherein said limiting a magnitude of torque permitted from said electric motors comprises

initially constraining said magnitude of torque permitted from said electric motors to said magnitude of said calculated clutch reactive torque, and

progressively constraining said magnitude of torque permitted from said electric motors.

16. Apparatus for operating a powertrain comprising an electro-mechanical transmission adapted to selectively transmit mechanical power to an output member through selective application of a plurality of clutches, wherein said transmission is mechanically-operatively coupled to an internal combustion engine and a plurality of electric machines, the apparatus comprising:

a control system monitoring slip across said clutches and including logic diagnosing excessive slip in each clutch and imposing torque constraints upon said engine and said electric machines based upon said diagnosis, said constraints being effective to reduce a load upon said clutch and eliminate said excessive slip.

17. The apparatus of claim 16, wherein said logic imposing torque constraints upon said engine issues control commands comprising:

a command initially limiting a magnitude of torque permitted from said engine to a magnitude of a calculated clutch reactive torque; and

subsequent commands progressively constraining said magnitude of torque permitted from said engine.

18. The apparatus of claim 16, wherein said logic imposing torque constraints upon said electric machines issues control commands comprising:

a command initially limiting a magnitude of torque permitted from said electric machines to a magnitude of a calculated clutch reactive torque; and

subsequent commands progressively constraining said magnitude of torque permitted from said electric machines.

19. The apparatus of claim 16,

wherein said logic diagnosing excessive slip in each clutch further diagnoses an end to said excessive slip;

and

wherein said logic imposing torque constraints upon said engine and said electric machines based upon said diagnosis, upon diagnosing said end to said excessive slip, issues control commands comprising

a command initially maintaining a load across said selectively applied clutch, and

subsequent commands progressively increasing said load until a normal load across said clutch is achieved.