US-12618466-B2 - System and method for calibrating transmission

Abstract

A method and system for automatically estimating clutch control parameters is described. In one example, a torque source is operated in a speed control mode so that changes in torque source torque output may be indicative of torque transfer through a clutch. Torque source torque output values may be a basis for estimating clutch fill time and clutch touch pressure.

Inventors

• Nicolas Lenaerts
• Christophe De Buyser
• Laurens DE BRUYNE

Assignees

• DANA BELGIUM N.V.

Dates

Publication Date

20260505

Application Date

20241227

Claims (20)

1. 1 . A method for determining a clutch fill time, comprising: adjusting a valve to flow a fluid to a clutch; and adjusting the clutch fill time based on an amount of time between adjusting the valve and a torque output of an electric machine increasing by more than a threshold amount of torque to maintain speed of the electric machine.
2. 2 . The method of claim 1 , further comprising operating the electric machine in a speed control mode while the torque output of the electric machine is variable.
3. 3 . The method of claim 2 , further comprising adjusting the valve when a transmission that includes the clutch is engaged in park or neutral.
4. 4 . The method of claim 1 , further comprising adjusting a clutch touch pressure in response to the torque output of the electric machine.
5. 5 . The method of claim 4 , where the clutch touch pressure is adjusted in response to the torque output of the electric machine being less than a minimum clutch touch pressure.
6. 6 . The method of claim 4 , where the clutch touch pressure is adjusted in response to the torque output of the electric machine being greater than a maximum clutch touch pressure.
7. 7 . The method of claim 4 , where the clutch touch pressure is a clutch pressure at which torque capacity of the clutch begins to increase from zero.
8. 8 . The method of claim 1 , further comprising operating the electric machine in a speed control mode prior to and during adjusting the valve to flow the fluid to the clutch.
9. 9 . A vehicle system, comprising: one or more torque sources; a transmission including a plurality of clutches and gears; a controller including executable instructions that cause the controller to operate one of the one or more torque sources in a speed control mode and perform an automatic clutch parameter determination sequence that generates a clutch fill time and a clutch touch pressure according to output torque of one of the one or more torque sources.
10. 10 . The vehicle system of claim 9 , further comprising additional instructions that cause the controller to increase a pressure in one of the plurality of clutches to a fill pressure while operating the one of the one or more torque sources in the speed control mode.
11. 11 . The vehicle system of claim 10 , further comprising additional instructions that cause the controller to decrease the pressure in one of the plurality of clutches such that torque output of the one of the one or more torque sources is greater than a drag torque and less than a touch torque.
12. 12 . The vehicle system of claim 11 , further comprising additional instructions that cause the controller to: decrease the pressure in one of the plurality of clutches to substantially zero pressure for a predetermined amount of time since the pressure in the one of the plurality of clutches caused torque output of the one or more torque sources to be greater than the drag torque and less than the touch torque.
13. 13 . The vehicle system of claim 9 , further comprising additional instructions that cause the controller to increase a pressure in one of the plurality of clutches to a fill pressure while operating the one of the one or more torque sources in the speed control mode and increase an amount of time the fill pressure is applied to the one of the plurality of clutches in response to electric machine torque being less than a touch torque.
14. 14 . The vehicle system of claim 9 , further comprising additional instructions that cause the controller to increase a pressure in one of the plurality of clutches to a fill pressure while operating the one of the one or more torque sources in the speed control mode and decrease an amount of time the fill pressure is applied to the one of the plurality of clutches in response to electric machine torque being greater than a touch torque.
15. 15 . The vehicle system of claim 9 , further comprising additional instructions that cause the controller to increase or decrease a pressure in one of the plurality of clutches after reducing the pressure in the one of the plurality of clutches from a fill pressure during the automatic clutch parameter determination sequence in response to electric machine torque.
16. 16 . A method for determining a clutch fill time, comprising: operating a torque source in a speed control mode and monitoring a torque output of the torque source while the torque source is operating in the speed control mode; increasing a clutch pressure from substantially zero pressure to a clutch fill pressure and maintaining the clutch pressure for an amount of time; and adjusting the amount of time according to the torque source torque output.
17. 17 . The method of claim 16 , further comprising decreasing the clutch pressure from the clutch fill pressure to a clutch touch pressure.
18. 18 . The method of claim 17 , further comprising adjusting the clutch touch pressure according to the torque source torque output.
19. 19 . The method of claim 16 , where adjusting the amount of time includes increasing the amount of time in response to the torque source torque output being less than a threshold torque.
20. 20 . The method of claim 16 , where adjusting the amount of time includes decreasing the amount of time in response to the torque source torque output being greater than a threshold torque.

Description

CROSS REFERENCE TO RELATED APPLICATION The present application claims priority to U.S. Provisional Application No. 63/558,966, entitled “SYSTEM AND METHOD FOR CALIBRATING TRANSMISSION”, and filed on Feb. 28, 2024. The entire contents of the above-listed application are hereby incorporated by reference for all purposes. TECHNICAL FIELD The present disclosure relates to automatically adjusting clutch control parameters for a transmission of a vehicle. The vehicle may include an electric propulsion source. BACKGROUND AND SUMMARY A transmission of a vehicle may include one or more clutches that allow different gears of the transmission to be engaged and disengaged. Operation of the clutches may be adjusted via a controller according to clutch control parameters. The clutch control parameters may be initially populated with default values that may be based on testing and/or simulations. However, there may be some part-to-part variability within the transmission that may result in the default control parameters being less effective than may be desired. Further, as the transmission ages and is subject to different applications, components within the transmission may wear such that the default control parameters may be less effective. For these reasons, it may be desirable for to adjust the initial or default control parameters so that transmission operation may be more repeatable as the transmission ages. The inventors herein have recognized the above-mentioned issues and have developed a method for determining a clutch fill time, comprising: adjusting a valve to flow a fluid to a clutch; and adjusting the clutch fill time based on an amount of time between adjusting the valve and a torque output of an electric machine increasing by more than a threshold amount of torque to maintain speed of the electric machine. By adjusting a valve to flow fluid to a clutch and adjusting a clutch fill time based on an amount of time between adjusting the valve and torque output of an electric machine increasing by more than a threshold amount, it may be possible to automatically (e.g., without human input) determine clutch control parameters. The clutch parameters may be determined when a transmission of the vehicle is engaged in park or neutral while a vehicle that includes the transmission is stationary. The approach may be performed at predetermined time or event intervals without a human request so that vehicle operation may not be interfered. The present description may provide several advantages. In particular, the approach may reduce driveline torque disturbances by providing smoother gear shifts. Further, the approach may reduce a possibility of clutch wear. In addition, the approach may be performed automatically without interfering with vehicle operation. It may be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not constrained to implementations that solve any disadvantages noted above or in any part of this disclosure. The accompanying drawings are incorporated herein as part of the specification. The drawings described herein illustrate embodiments of the presently disclosed subject matter, and are illustrative of selected principles and teachings of the present disclosure. However, the drawings do not illustrate all possible implementations of the presently disclosed subject matter, and are not intended to constrain the scope of the present disclosure in any way. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic diagram of an example vehicle powertrain that includes a transmission; FIGS. 2-4 show diagrams of example transmissions; FIG. 5 shows example phases of a desired sequence for determining clutch control parameters; FIGS. 6-9 show example clutch pressures and electric machine torques when determining clutch fill time; FIGS. 10-11 show example clutch pressures and electric machine torques when determining clutch touch pressure; and FIG. 12 shows a method for determining clutch control parameters. DETAILED DESCRIPTION The following description relates to systems and methods for automatically determining control parameters for a clutch. The control parameters include a clutch fill time (e.g., an amount of time that it takes for fluid to move clutch plates from a fully open clutch position to a position where the clutch's torque capacity begins to increase from zero or substantially zero (e.g., a value that is less than five percent of clutch torque capacity)) and a clutch touch pressure (e.g., a clutch pressure at which torque capacity of a clutch begins to increase from zero or substantially zero). The clutch torque capacity is an amount of torque that a clutch may transfer at the clutch's presen