Method and system for improving hybrid vehicle shifting

• US 9,031,722 B2
• Filed: 12/10/2012
• Issued: 05/12/2015
• Est. Priority Date: 12/10/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Doering, Jeffrey Allen, Reed, Dennis Craig, Gibson, Alex O'Connor, Pietron, Gregory Michael, McCallum, James William Loch
• Primary Examiner(s): Algahaim, Helal A
• Assistant Examiner(s): Williams, Kelly D
• Application Number:
  US13/710,257
• Publication Number:
  US 20140163788A1
• Time in Patent Office: 883 Days
• Field of Search: None
• US Class Current: 701/22
• 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 10/11 Stepped gearings
• CPC Class Codes: B60W 10/115 with planetary gears
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• 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 2510/0266 Moment of inertia
• CPC Class Codes: B60W 2510/0695 Inertia
• CPC Class Codes: B60W 2510/088 Inertia
• CPC Class Codes: B60W 2710/027 Clutch torque
• CPC Class Codes: B60W 2710/1005 Transmission ratio engaged
• CPC Class Codes: B60W 30/19 Improvement of gear change, e.g. by synchronisation or smoothing gear shift
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

A method and a system for improving operation of a hybrid vehicle are presented. In one example, torque converter impeller torque from beginning to end of transmission shifting is adjusted in response to variable driveline inertia. The approach may improve transmission shifting and reduce driveline torque disturbances.

Claims

1. A method for operating a hybrid powertrain, comprising:

operating a drivetrain with a first inertia and adjusting a torque converter impeller torque during transmission gear shifting in response to the first inertia; and

operating the drivetrain with a second inertia and adjusting the torque converter impeller torque during transmission gear shifting in response to the second inertia;

wherein the first inertia includes an inertia of a driveline integrated starter/generator (DISG) and inertia of a portion of a driveline disconnect clutch, further comprising capturing a difference between a desired transmission torque when the driveline disconnect clutch is closed and a desired transmission torque when the driveline disconnect clutch is open and adjusting a torque source output based on the difference; and

wherein the first inertia does not include inertia of an engine and wherein the torque converter impeller torque is based on a final drive ratio and an offset that is related to driveline spin losses.

2. The method of claim 1, where the second inertia includes an inertia of an engine and the inertia of the DISG.

3. The method of claim 2, where the second inertia includes a total inertia of the driveline disconnect clutch.

4. The method of claim 1, where the driveline disconnect clutch is in an open state.

5. The method of claim 3, where the driveline disconnect clutch is in a closed state when the drivetrain is operated with the second inertia.

6. A method for operating a hybrid powertrain, comprising:

operating a drivetrain with a first inertia and adjusting a first torque converter impeller torque during transmission gear shifting in response to the first inertia;

capturing the first torque converter impeller torque in a controller memory in response to a request to close a driveline disconnect clutch;

transitioning from the first torque converter impeller torque to a second torque converter impeller torque; and

operating the drivetrain with a second inertia and adjusting the second torque converter impeller torque during transmission gear shifting in response to the second inertia after the request to close the driveline disconnect clutch;

wherein the first torque converter impeller torque is based on the first inertia, further comprising capturing a difference between a desired transmission torque when the driveline disconnect clutch is closed and a desired transmission torque when the driveline disconnect clutch is open, and adjusting a torque source based on the difference; and

wherein the second torque converter impeller torque is based on the second inertia, and where the second torque converter impeller torque is further based on a final drive ratio and an offset that is related to driveline spin losses.

7. The method of claim 6, where transitioning from the first torque converter impeller torque to the second torque converter impeller torque includes ramping the first torque converter impeller torque to the second torque converter impeller torque, and where the first torque converter impeller torque is based on an amount of the first inertia and where the second torque converter impeller torque is based on an amount of the second inertia.

8. The method of claim 6, where adjusting the second torque converter impeller torque during transmission gear shifting includes accounting for a change in transmission gear ratio.

9. The method of claim 6, further comprising providing the second torque converter impeller torque while a motor in the drivetrain is converting driveline torque into electrical energy.

10. The method of claim 6, where the second torque converter impeller torque is provided by an engine and a motor.