Vehicle transmission clutch engagement control system

Patent metadata

Field	Value
Publication number	US-10451125-B2
Application number	US-201715674788-A
Country	US
Kind code	B2
Filing date	Aug 11, 2017
Priority date	Aug 11, 2017
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A vehicle includes a transmission and a controller. The transmission has clutches that are configured to establish multiple speed ratios, including a first clutch. The first clutch has a measured drag torque distribution. The measured drag torque distribution has a median and a standard deviation. The controller is programmed to increase a pressure at a rate to engage the first clutch and to increase the rate in response to a measured first clutch torque exceeding the median by a predetermined multiple of the standard deviation.

First claim

What is claimed is:

1. A vehicle comprising:
a transmission having clutches configured to establish multiple speed ratios, including a first clutch having a measured drag torque distribution with a median and a standard deviation; and
a controller programmed to increase a pressure at a rate to engage the first clutch and to increase the rate in response to a measured first clutch torque exceeding the median by a predetermined multiple of the standard deviation.

2. The vehicle of claim 1 , wherein the multiple of the deviation ranges between two and four standard deviations of a normal distribution.

3. The vehicle of claim 1 , wherein the median is non-zero.

4. The vehicle of claim 1 , wherein the transmission includes a second clutch having a second measured drag torque distribution with a second median and a second standard deviation, and where the controller is further programmed to, decrease a pressure at a second rate to disengage the second clutch and to decrease the second rate in response to a measured second clutch torque decreasing below a predetermined multiple of the second standard deviation.

5. The vehicle of claim 1 , wherein the engagement of the first clutch corresponds to an upshift of the transmission.

6. The vehicle of claim 1 , wherein the engagement of the first clutch corresponds to a downshift of the transmission.

7. The vehicle of claim 1 , wherein the engagement of the first clutch corresponds to a transition of the transmission from a neutral mode into a mode that transmits power to an output of the transmission.

8. The vehicle of claim 1 , wherein the controller is further programmed to, in response to the measured first clutch torque decreasing below the median by the predetermined multiple of the standard deviation, issue a notification that the transmission is operating in an error state.

9. A vehicle transmission comprising:
an oncoming clutch having a measured fluctuating torque when disengaged, the fluctuating torque having a non-zero median value and a standard deviation; and
a controller programmed to, in response to a torque of the oncoming clutch increasing at a first rate during an engagement and surpassing the non-zero median value by a multiple of the standard deviation, increase the torque at a second rate that is greater than the first rate.

10. The transmission of claim 9 , wherein the multiple of the standard deviation ranges between two and four standard deviations of a normal distribution.

11. The transmission of claim 9 , further comprising an off-going clutch having a second fluctuating torque when disengaged, the second fluctuating torque having a second non-zero median value and a second standard deviation, and wherein the controller is further programmed to, in response to a torque of the off-going clutch during the engagement decreasing below a multiple of the second standard deviation, increase a rate at which the torque of the off-going clutch decreases.

12. The transmission of claim 9 , wherein the engagement is an upshift of the transmission.

13. The transmission of claim 9 , wherein the engagement is a downshift of the transmission.

14. The transmission of claim 9 , wherein the engagement is a transition of the transmission from a neutral mode into a mode that transmits power to an output of the transmission.

15. The transmission of claim 9 , wherein the engagement is a transition of the transmission from a neutral mode to a drive mode.

16. The transmission of claim 9 , wherein the engagement is a transition of the transmission from a neutral mode to a reverse mode.

17. A method comprising:
providing an oncoming clutch for a vehicle transmission, the oncoming clutch having a measured fluctuating disengaged torque that has a median value and a standard deviation; and
increasing a rate at which torque of the oncoming clutch increases during an engagement in response to the torque of the oncoming clutch surpassing the median value by predetermined a multiple of the standard deviation.

18. The method of claim 17 , wherein the multiple of the standard deviation ranges between two and four standard deviations of a normal distribution.

19. The method of claim 17 , wherein the median value of the measured disengaged torque is non-zero.

20. The method of claim 17 , further comprising the steps of:
providing an off-going clutch for the vehicle transmission, the off-going clutch having a second measured fluctuating disengaged torque that has a second median value and a second standard deviation; and
increasing a rate at which torque of the off-going clutch decreases during the engagement in response to the torque of the off-going clutch decreasing below a multiple of the second standard deviation.

Assignees

• Ford Global Tech Llc

Inventors

• Pietron Gregory Michael
• Wang Qi
• Fujii Yuji
• Hippalgaonkar Rohit
• Kucharski Joseph F
• Meyer Jason
• Ford Stuart N

Classifications

• F16D2500/30421

  Torque of the output shaft · CPC title

• F16D2021/0692

  with two clutches arranged axially without radial overlap · CPC title

• F16D2500/3027

  Torque · CPC title

• F16D2500/5029

  Reducing drag torque · CPC title

• F16D2500/1085

  Automatic transmission · CPC title