System and method for learning driveline disconnect clutch liftoff

Patent metadata

Field	Value
Publication number	US-11970153-B2
Application number	US-202217823812-A
Country	US
Kind code	B2
Filing date	Aug 31, 2022
Priority date	Aug 31, 2022
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch liftoff pressure is estimated according to a derivative of a driveline disconnect clutch pressure when a driveline disconnect clutch is being de-stroked. The driveline disconnect clutch may be prepositioned in anticipation of driveline disconnect closing based on the estimated driveline disconnect clutch liftoff pressure.

First claim

The invention claimed is:

1. A method for operating a vehicle, comprising:
via one or more controllers, during de-stroking of a driveline disconnect clutch, monitoring a driveline disconnect clutch pressure and generating an estimated driveline disconnect clutch liftoff pressure via the driveline disconnect clutch pressure;
adjusting a commanded driveline disconnect clutch pressure based on the estimated driveline disconnect clutch liftoff pressure;
generating a derivative of the driveline disconnect clutch pressure; and
generating the estimated driveline disconnect clutch liftoff pressure according to the driveline disconnect clutch pressure after the derivative of the driveline disconnect clutch is less than a threshold value for longer than a threshold time duration.

2. The method of claim 1 , where the de-stroking includes adjusting the commanded driveline disconnect clutch pressure to substantially zero pressure.

3. The method of claim 1 , where the estimated driveline disconnect clutch liftoff pressure is based on the driveline disconnect clutch pressure.

4. The method of claim 1 , where the estimated driveline disconnect clutch liftoff pressure is based on the derivative.

5. The method of claim 1 , further comprising generating the estimated driveline disconnect clutch liftoff pressure according to the driveline disconnect clutch pressure when the derivative of the driveline disconnect clutch pressure exceeds the threshold value.

6. A system, comprising:
an internal combustion engine;
an integrated starter/generator;
a driveline disconnect clutch positioned in a driveline between the internal combustion engine and the integrated starter/generator;
a transmission included in the driveline; and
a controller including executable instructions stored in non-transitory memory that cause the controller to command a driveline disconnect clutch pressure in response to an estimate of a driveline disconnect clutch liftoff pressure, where the driveline disconnect clutch liftoff pressure is a pressure at which a driveline disconnect clutch drag begins to increase from a substantially constant value, additional executable instructions that cause the controller to generate a derivative of the driveline disconnect clutch pressure, and additional executable instructions that cause the controller to generate the estimate of the driveline disconnect clutch liftoff pressure in response to the derivative exceeding a threshold value.

7. The system of claim 6 , where driveline disconnect clutch drag is internal forces within the driveline disconnect clutch that resist rotation of the driveline disconnect clutch when the driveline disconnect clutch is open.

8. The system of claim 6 , where commanding the driveline disconnect clutch pressure includes adjusting the driveline disconnect clutch pressure to a stroke pressure.

9. The system of claim 8 , where the stroke pressure is where driveline disconnect clutch plates begin to touch each other.

10. The system of claim 6 , further comprising additional executable instructions that cause the controller to de-stroke the driveline disconnect clutch.

11. The system of claim 10 , further comprising additional executable instructions that cause the controller to generate the estimate of the driveline disconnect clutch liftoff pressure based on the driveline disconnect clutch pressure during de-stroking the driveline disconnect clutch.

12. A method for operating a vehicle, comprising:
via one or more controllers, during de-stroking of a driveline disconnect clutch, sensing a driveline disconnect clutch pressure and generating an estimated driveline disconnect clutch liftoff pressure via the driveline disconnect clutch pressure;
adjusting a driveline disconnect clutch liftoff pressure correction in response to the estimated driveline disconnect clutch liftoff pressure, where the estimated driveline disconnect clutch liftoff pressure is based on a derivative of the driveline disconnect clutch pressure where the derivative exceeds a threshold value; and
adjusting a commanded driveline disconnect clutch pressure based on the driveline disconnect clutch liftoff pressure correction.

13. The method of claim 12 , where de-stroking the driveline disconnect clutch includes de-stroking the driveline disconnect clutch from a fully closed state.

14. The method of claim 12 , where the driveline disconnect clutch liftoff pressure correction is added to a baseline driveline disconnect clutch liftoff pressure.

Assignees

• Ford Global Tech Llc

Inventors

• Bichkar Akshay
• Blue Corey James
• Glauber Samuel Melville
• Kucharski Joseph
• Riedle Bradley Dean

Classifications

• F16D2500/50245

  Calibration or recalibration of the clutch touch-point · CPC title

• F16D2500/50254

  Brake actuated · CPC title

• F16D2500/5026

  Gear engaged · CPC title

• F16D2500/70424

  Outputting a clutch engaged-disengaged signal · CPC title

• F16D2500/30401

  On-off signal indicating the engage or disengaged position of the clutch · CPC title