Methods and systems for improving hybrid vehicle transmission shifting

• US 9,452,748 B2
• Filed: 07/31/2014
• Issued: 09/27/2016
• Est. Priority Date: 07/31/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Gibson, Alexander O'Connor, Doering, Jeffrey Allen, Lee, Seunghoon, Nedorezov, Felix
• Primary Examiner(s): Holmes, Justin
• Application Number:
  US14/448,944
• Publication Number:
  US 20160031432A1
• Time in Patent Office: 789 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B60K 2006/4825 Electric machine connected or connectable to gearbox input shaft
• CPC Class Codes: B60K 6/48 Parallel type
• 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 10/11 Stepped gearings
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 20/30 Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• CPC Class Codes: B60W 2510/081 Speed
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: F16H 61/0437 by using electrical signals F16H61/0403 and F16H61/061 take precedence
• CPC Class Codes: F16H 63/46 Signals to a clutch outside the gearbox
• CPC Class Codes: F16H 63/502 for smoothing gear shifts
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

Systems and methods for improving hybrid vehicle shifting are presented. Specifically, torque supplied to an input shaft of a transmission may be adjusted during torque and inertia phases of a transmission gear shift. The torque supplied to the transmission input shaft may be increased or decreased based on the shift and the shift phase.

Claims

1. A driveline method, comprising:

in response to a transmission gear shift request, increasing transmission input shaft torque via an electric machine when electric machine speed is less than a threshold speed during a torque phase of the transmission gear shift;

decreasing transmission input shaft torque via slipping a driveline disconnect clutch and reducing output torque of the electric machine during an inertia phase of the transmission gear shift; and

increasing transmission input shaft torque during the torque phase of the transmission gear shift via increasing engine speed and increasing slip of the driveline disconnect clutch at electric machine speeds greater than the threshold speed.

2. The method of claim 1, where the threshold speed is a speed where the electric machine transitions from providing a constant maximum torque to providing a constant maximum power.

3. The method of claim 1, where an engine is operated in a speed control mode during the torque phase of the transmission gear shift.

4. The method of claim 1, where the transmission gear shift is an upshift.

5. The method of claim 1, where the engine speed is increased and the driveline disconnect clutch is slipped in response to the electric machine having insufficient available torque to provide a desired transmission input shaft torque during the torque phase.

6. A driveline method, comprising:

in response to a transmission gear shift request, decreasing transmission input shaft torque via an electric machine without slipping a driveline disconnect clutch during a torque phase of the transmission gear shift; and

increasing transmission input shaft torque via decreasing a pressure of a driveline disconnect clutch and slipping the driveline disconnect clutch during an inertia phase of the transmission gear shift.

7. The method of claim 6, further comprising increasing an engine speed during the gear shift and increasing torque transferred via the driveline disconnect clutch during the inertia phase.

8. The method of claim 7, where an engine is operated in a speed control mode during the inertia phase.

9. The method of claim 6, further comprising decreasing the transmission input shaft torque via slipping the driveline disconnect clutch during the torque phase of the transmission shift.

10. The method of claim 6, further comprising increasing torque output from the electric machine during the inertia phase.

11. The method of claim 6, where the transmission shift is a downshift from a higher gear to a lower gear.

12. The method of claim 6, where the electric machine is mechanically coupled to the driveline disconnect clutch upstream of a transmission.

13. A driveline system, comprising:

an engine;

an electric machine;

a driveline disconnect clutch selectively coupling the engine and the electric machine;

a transmission mechanically coupled to the electric machine; and

a controller including executable instructions stored in non-transitory memory for decreasing a pressure of the driveline disconnect clutch and slipping the driveline disconnect clutch in response to entering an inertia phase of a gear shift of the transmission.

14. The driveline system of claim 13, further comprising additional instructions to slip the disconnect clutch in response to entering a torque phase of the gear shift.

15. The driveline system of claim 14, further comprising additional instructions to operate the engine in a speed control mode during the gear shift.

16. The driveline system of claim 15, further comprising additional instructions to increase torque supplied to an input shaft of the transmission during the inertia phase via the electric machine.

17. The driveline system of claim 14, further comprising additional instructions to increase torque supplied to an input shaft of the transmission via increasing engine speed.

18. The driveline system of claim 13, further comprising additional instructions to decrease torque supplied to an input shaft of the transmission via slipping the driveline disconnect clutch.

19. A driveline method, comprising:

in response to a transmission gear shift request, increasing transmission input shaft torque via an electric machine when electric machine speed is less than a threshold speed during a torque phase of the transmission gear shift;

decreasing transmission input shaft torque via slipping a driveline disconnect clutch and reducing output torque of the electric machine during an inertia phase of the transmission gear shift; and

increasing transmission input shaft torque via increasing engine speed and slipping the driveline disconnect clutch while increasing transmission input shaft torque via the electric machine.

20. A driveline method, comprising:

in response to a transmission gear shift request, increasing transmission input shaft torque via an electric machine when electric machine speed is less than a threshold speed during a torque phase of the transmission gear shift; and

decreasing transmission input shaft torque via slipping a driveline disconnect clutch and reducing output torque of the electric machine during an inertia phase of the transmission gear shift, where engine speed is increased and the driveline disconnect clutch is slipped in response to the electric machine having insufficient available torque to provide a desired transmission input shaft torque during the torque phase.