Methods and system for adapting operation of a transmission clutch

Patent metadata

Field	Value
Publication number	US-11077856-B2
Application number	US-201916424354-A
Country	US
Kind code	B2
Filing date	May 28, 2019
Priority date	May 28, 2019
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, an actual total number of transmission gear downshifts are counted to determine whether or not a transmission clutch characterization is immature. The transmission clutch characterization may be adjusted if it is determined to be immature.

First claim

The invention claimed is:

1. A powertrain operating method, comprising:
adjusting a torque threshold of an electric machine via a controller in response to a value of a clutch adaption counter being greater than a threshold;
adjusting a relationship between transmission clutch pressure and transmission clutch torque capacity via the controller in response to the value of the clutch adaption counter being greater than the threshold; and
applying or releasing a transmission clutch responsive to the relationship between transmission clutch pressure and transmission clutch torque capacity.

2. The method of claim 1 , where the torque threshold is a level of a regenerative braking torque that is not to be exceeded via the electric machine.

3. The method of claim 1 , further comprising adjusting the torque threshold of the electric machine via the controller in response to a vehicle traveling less than a threshold distance.

4. The method of claim 1 , further comprising counting an actual total number of vehicle decelerations where the relationship between transmission clutch pressure and transmission clutch torque capacity is not adjusted while a vehicle brake is applied and the transmission clutch is adjusted from a not applied state to an applied state.

5. The method of claim 1 , where adjusting the relationship between transmission clutch pressure and transmission clutch torque capacity includes determining a stroke pressure of the transmission clutch.

6. The method of claim 5 , where the stroke pressure is a pressure at which the transmission clutch begins to transfer torque across the transmission clutch.

7. The method of claim 1 , where adjusting the torque threshold of the electric machine includes reducing a magnitude of the torque threshold from a rated amount of torque.

8. A system, comprising:
an engine in a hybrid vehicle driveline;
an electric machine in the hybrid vehicle driveline;
a rotation ratio changing device positioned in a driveline between the engine and the electric machine; and
a controller including executable instructions stored in non-transitory memory that cause the controller to adjust a torque threshold of the electric machine via the controller in response a value of a clutch adaption counter being greater than a threshold, and additional instructions that cause the controller to adjust the torque threshold of the electric machine in response to a vehicle traveling less than a threshold distance.

9. The system of claim 8 , where adjusting the torque threshold includes decreasing a magnitude of the torque threshold from a rated amount of torque.

Assignees

• Ford Global Tech Llc

Inventors

• Choi Jaewon
• Zhang Jianping
• Cicala Steve Michael
• Morrison Kendrick
• Nickerson Kurt Howard

Classifications

• B60W30/025

  related to comfort of drivers or passengers · CPC title

• B60W2510/0216

  Clutch engagement rate · CPC title

• F16D2500/5018

  Calibration or recalibration of the actuator · CPC title

• F16D2500/3024

  Pressure · CPC title

• B60W2030/203

  related or induced by the clutch · CPC title