Methods and systems for hybrid driveline control

• US 9,067,594 B2
• Filed: 09/03/2013
• Issued: 06/30/2015
• Est. Priority Date: 09/03/2013
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wang, Xiaoyong, Liang, Wei, Johri, Rajit, Connolly, Francis Thomas, Colvin, Daniel, Kuang, Ming Lang, McGee, Ryan Abraham
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): BERNS, MICHAEL ANDREW
• Application Number:
  US14/016,938
• Publication Number:
  US 20150066264A1
• Time in Patent Office: 665 Days
• Field of Search: 701/22
• US Class Current: 1/1
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• 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 10/023 Fluid clutches
• CPC Class Codes: B60W 10/026 of lock-up 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 10/115 with planetary gears
• CPC Class Codes: B60W 20/14 in conjunction with braking regeneration
• 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 2050/0091 of control inputs
• CPC Class Codes: B60W 2510/0233 of torque converter lock-up clutch
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2510/108 pressure of control fluid
• CPC Class Codes: B60W 2510/1085 pressure of working fluid
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2540/10 Accelerator pedal position
• CPC Class Codes: B60W 2710/027 Clutch torque
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 2710/083 : Torque
• CPC Class Codes: B60W 30/18136 : Engine braking
• CPC Class Codes: B60W 30/20 : Reducing vibrations in the driveline
• CPC Class Codes: B60Y 2400/426 : Hydrodynamic couplings, e.g. torque converters
• CPC Class Codes: F16H 61/143 : using electric control means
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y10S 903/902 : Prime movers comprising electrical and internal combustion motors
• CPC Class Codes: Y10S 903/93 : Conjoint control of different elements

Abstract

Systems and methods for operating and hybrid driveline are presented. In one example, driver demand torque may be supplied to vehicle wheels via a hydraulic torque path and a friction torque path. Torque is distributed between the friction torque path and the hydraulic torque path in a way that ensures that driver demand torque is met and the friction torque path transfers torque up to its capacity.

Claims

1. A method for operating a driveline, comprising:

operating an electric machine in a torque control mode in response to a torque converter clutch torque capacity available at a transmission line pressure being greater than a driver demand torque; and

operating the electric machine in a speed control mode in response to the torque converter clutch torque capacity available at the transmission line pressure being less than the driver demand torque.

2. The method of claim 1, where the electric machine is a driveline integrated starter/generator, and where the electric machine is operated in the speed control mode during an engine start.

3. The method of claim 1, further comprising adjusting a torque converter impeller speed in response to a torque converter turbine speed and a difference between driver demand torque and torque transferred across a torque converter via a torque converter clutch.

4. The method of claim 1, further comprising operating the electric machine in the torque control mode instead of the speed control mode in response to the driveline operating in a regenerative braking mode.

5. The method of claim 4, where the transmission line pressure is a regulated transmission pump outlet pressure, and further comprising adjusting a torque of the electric machine in response to a lesser of a driver demand braking torque and the torque converter clutch torque capacity.

6. The method of claim 1, where the transmission line pressure is applied to a torque converter clutch, and further comprising adjusting torque converter clutch torque to equal the driver demand torque.

7. The method of claim 1, further comprising adjusting a speed of the electric machine in response to driver demand torque while operating the electric machine in the speed control mode.

8. A method for operating a driveline, comprising:

adjusting a torque converter clutch to transfer a first portion of a driver demand torque to vehicle wheels; and

adjusting speed of a torque converter impeller in response to a difference in the driver demand torque and the first portion of the driver demand torque.

9. The method of claim 8, where a torque delivered across a converter clutch and a torque transferred between the torque converter impeller and a torque converter turbine equal the driver demand torque.

10. The method of claim 8, further comprising adjusting torque converter slip to be maintained above a minimum threshold amount of slip during engine starting when torque transferable across a torque converter via the torque converter clutch is greater than the driver demand torque.

11. The method of claim 10, where torque transferable across the torque converter via the torque converter clutch is estimated based on transmission line pressure, and where the first portion of driver demand torque is based on torque converter clutch capacity at a transmission line pressure at a time of adjusting the torque converter clutch.

12. The method of claim 8, where the torque converter clutch is adjusted to transfer the driver demand torque across a torque converter in response to transmission line pressure.

13. The method of claim 8, where the speed of the torque converter impeller is further adjusted in response to torque converter turbine speed.

14. The method of claim 8, where the torque converter impeller speed is adjusted via a driveline integrated starter/generator.

15. A vehicle system, comprising:

an electric machine;

a torque converter in mechanical communication with the electric machine, the torque converter including a torque converter clutch; and

a controller including non-transitory instructions executable to schedule torque converter clutch torque transfer capacity in response to a driver demand torque and a transmission line pressure.

16. The vehicle system of claim 15, further comprising adjusting torque transferred between a torque converter impeller and a torque converter turbine in response to driver demand torque and the scheduled torque converter clutch torque transfer capacity.

17. The vehicle system of claim 16, further comprising a driveline integrated starter/generator in mechanical communication with the torque converter, and where adjusting torque transferred between the torque converter impeller and the torque converter turbine includes adjusting a speed of the driveline integrated starter/generator.

18. The vehicle system of claim 15, further comprising determining torque transferred via a hydraulic torque path between a torque converter impeller and a torque converter turbine in response to the driver demand torque and torque converter clutch torque transfer capacity.

19. The vehicle system of claim 15, further comprising additional instructions to operate the electric machine in a speed control mode in response to torque converter clutch capacity being less than the driver demand torque.

20. The vehicle system of claim 19, further comprising additional instructions to operate the electric machine in a torque control mode in response to torque converter clutch capacity being greater than the driver demand torque.