Clutch torque trajectory correction to provide torque hole filling during a ratio upshift

Patent metadata

Field	Value
Publication number	US-9260102-B2
Application number	US-201414295411-A
Country	US
Kind code	B2
Filing date	Jun 4, 2014
Priority date	Jun 8, 2011
Publication date	Feb 16, 2016
Grant date	Feb 16, 2016

Abstract

A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided. Measured torque values are used during a torque phase of the upshift to correct an estimated oncoming friction element target torque so that transient torque disturbances at an oncoming clutch are avoided and torque transients at the output shaft are reduced.

First claim

What is claimed is:

1. A powertrain comprising:
a multiple-ratio transmission with oncoming and off-going clutches for effecting a ratio-upshift;
a torque sensor for measuring an actual measured torque value for one of the off-going and oncoming clutches;
a shift controller configured for:
adjusting an estimated oncoming clutch torque in response to the actual measured torque value during a torque phase; and
releasing the off-going clutch if measured off-going clutch torque is less than a threshold.

2. The powertrain set forth in claim 1 , wherein the shift controller, during the torque phase of the upshift, is further configured for:
increasing torque input at a controlled rate during a torque phase of the ratio-upshift;
estimating oncoming clutch torque during the torque phase of the ratio-upshift; and
controlling torque input to achieve a desired amount of slip in the off-going clutch.

3. The powertrain set forth in claim 1 wherein the shift controller, during the torque phase of the upshift, is further configured for:
controlling torque input and pressure of the off-going clutch to achieve a desired amount of slip in the off-going clutch.

4. The powertrain set forth in claim 1 wherein the controller is configured further for:
repeating adjusting the oncoming clutch torque if the off-going clutch torque is not less than the threshold.

5. The powertrain set forth in claim 1 further comprising at least two torque sensors for measuring friction torque values for off-going and oncoming clutches, one torque sensor being adapted to measure actual input torque and the other torque sensor being adapted to measure clutch torque of one of the clutches.

6. The powertrain set forth in claim 5 wherein the controller has memory registers with a stored transfer function for each clutch;
the transfer function is precalibrated with a functional relationship between a sensor actuator displacement and clutch torque;
the one torque sensor is adapted to measure a sum of torque input for each clutch; and
the other torque sensor being is adapted to measure torque output of one of the clutches, whereby torque output of the other clutch is equal to a difference between torque measured by the one torque sensor and the torque measured by the other torque sensor.

7. The powertrain set forth in claim 1 wherein the shift controller, during a torque phase of the upshift, is further configured for:
increasing a transmission input torque;
choosing a desired output shaft torque and a desired off-going clutch torque;
controlling input torque to achieve desired off-going clutch slip;
measuring oncoming and off-going clutch torque; and
calculating an oncoming feed-forward clutch torque as a function of the desired output shaft torque and measured off-going clutch torque followed by an inertia phase of the upshift.

8. The powertrain set forth in claim 1 wherein the shift controller, during the torque phase of the upshift, is further configured for:
controlling an engine to achieve an increasing torque input and a controlled slip of the off-going clutch.

9. The powertrain set forth in claim 1 wherein the shift controller, during the torque phase of the upshift, is further configured for:
choosing a desired output shaft torque and a desired input shaft slip torque;
calculating a target input torque during a torque phase of an upshift based on the desired output shaft torque and the desired input shaft slip torque;
calculating an oncoming clutch torque target as a function of a change in off-going clutch torque during the torque phase and a change in torque of the input shaft and ramping oncoming clutch torque to the torque target;
measuring actual oncoming clutch torque during the torque phase and calculating a feedback correction based on a measured oncoming clutch torque; and
ramping input torque toward the target input torque.

10. A method for controlling oncoming and off-going clutches in a multiple-ratio transmission comprising:
increasing torque input at a controlled rate during a torque phase of a ratio-upshift;
controlling torque input to achieve a desired off-going clutch slip;
measuring oncoming and off-going clutch torques; and
setting an oncoming feed-forward clutch torque as a function of chosen output shaft torque and a measured off-going clutch torque, followed by an inertia phase of the upshift.

11. The method set forth in claim 10 wherein the desired off-going clutch slip is based on a desired output shaft torque and a desired off-going clutch torque.

12. The method set forth in claim 10 wherein increasing torque input comprises:
controlling an engine to achieve an increasing torque input and a controlled slip of the off-going clutch during the torque phase.

13. The method set forth in claim 10 further comprising:
correcting an estimated oncoming clutch torque if a measured torque of the off-going clutch is less than a predetermined threshold and releasing the off-going clutch if the measured off-going clutch torque is less than the threshold, and
repeating the steps for correcting an estimated oncoming clutch torque if the off-going clutch torque is greater than the threshold.

14. The method set forth in claim 13 wherein the step of correcting estimated oncoming clutch torque includes computing a correction in a closed loop fashion using measured off-going clutch torque as a feedback variable.

15. The method set forth in claim 10 wherein least two torque sensors are included for measuring friction torque values for off-going and oncoming clutches.

16. A method for controlling oncoming and off-going clutches in a multiple-ratio transmission comprising: setting a target input torque during a torque phase of an upshift based on a desired output shaft torque and a desired input shaft slip torque;
calculating an oncoming clutch torque target as a function of a change in off-going clutch torque during the torque phase and a change in torque of the input shaft;
ramping the oncoming clutch torque to the torque target;
measuring an actual oncoming clutch torque during the torque phase;
adjusting the target input torque based on the actual measured oncoming clutch torque; and
ramping input torque toward the adjusted target input torque.

17. The method set forth in claim 16 further comprising at least two torque sensors for measuring friction torque values, one torque sensor being adapted to measure actual input torque and the other torque sensor being adapted to measure clutch torque of one of the clutches.

18. The method set forth in claim 16 further comprising at least one torque sensor for measuring the actual oncoming clutch torque.

19. The method set forth in claim 18 wherein a shift controller includes memory registers with a stored transfer function for each clutch, the transfer function being precalibrated with a functional relationship between a sensor actuator displacement and a clutch torque.

20. The method set forth in claim 16 comprising at least two torque sensors for providing the measured the actual oncoming clutch torque, one torque sensor being adapted to provide a measured torque input for each clutch, the other torque sensor being adapted to provide a measured torque output of one of the clutches, whereby a torque output of the other clutch is equal to a difference between the measured torque output and the measured torque input.

Assignees

• Ford Global Tech Llc

Inventors

• Teslak Christopher John
• Pietron Gregory Michael
• Tseng Hongtei Eric
• Fujii Yuji
• Fodor Michael Glenn
• Yanakiev Diana
• Lee Seung-Hoon

Classifications

• F16H59/16 Primary

  Dynamometric measurement of torque · CPC title

• B60W10/02

  including control of driveline clutches · CPC title

• F16H61/061

  using electric control means · CPC title

• B60W10/115 Primary

  with planetary gears · CPC title

• F16H2061/0462

  by controlling slip rate during gear shift transition · CPC title