Methods and systems for adapting clutches of a vehicle transmission

Patent metadata

Field	Value
Publication number	US-10604137-B2
Application number	US-201715794845-A
Country	US
Kind code	B2
Filing date	Oct 26, 2017
Priority date	Oct 31, 2016
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

Methods and systems are provided for controlling clutch capacity in a hybrid electric vehicle. In one example, a method includes adjusting values of a transfer function of a clutch of a dual clutch transmission in response to an operating condition of an engine and/or operating condition of an integrated starter/generator coupled to the engine while a vehicle is propelled via an electric machine coupled to the dual clutch transmission, and maintaining a driver demand wheel torque at vehicle wheels via adjusting torque of the electric machine in response to the operating condition of the engine and/or operating condition of the integrated starter generator. In this way the method may apply pressure to one of the clutches where engine speed is independently controlled to maintain positive or negative slip, thus enabling adaptation of positive and negative clutch transfer functions, which may improve driveline operation and shift quality.

First claim

The invention claimed is:

1. A driveline operating method, comprising:
adjusting values of a transfer function of a clutch of a dual clutch transmission in response to an operating condition of an engine and/or operating condition of an integrated starter/generator coupled to the engine while a vehicle is propelled via an electric machine coupled to the dual clutch transmission;
maintaining a driver demand wheel torque at vehicle wheels via adjusting torque of the electric machine in response to the operating condition of the engine and/or operating condition of the integrated starter/generator; and
shifting the dual clutch transmission to a gear that reduces driveline torque disturbances in response to a request to adjust values of the transfer function.

2. The method of claim 1 , where the operating condition is a torque output or a current input, and where the electric machine supplies the driver demand wheel torque, and further comprising:
applying the clutch according to the adjusted values of the transfer function.

3. The method of claim 1 , further comprising combusting air and fuel in the engine and commanding the engine to a constant torque while adjusting the values of the transfer function.

4. The method of claim 1 , further comprising increasing a clutch pressure while adjusting the values of the transfer function.

5. The method of claim 1 , further comprising operating the integrated starter/generator and/or the engine in a speed control mode and maintaining a substantially constant engine speed while adjusting the values of the transfer function.

6. The method of claim 1 , further comprising increasing and then decreasing a pressure of fluid supplied to the clutch.

7. The method of claim 1 , where the gear that reduces driveline torque disturbances is a highest gear of the dual clutch transmission.

8. A driveline operating method, comprising:
disconnecting an engine from an input shaft of a dual clutch transmission in response to a request to adapt a transfer function of a clutch of the dual clutch transmission;
operating the engine in a torque control mode after disengaging the engine from the dual clutch transmission while an electric machine provides a desired wheel torque; and
adjusting a clutch pressure of the transfer function in response to an operating condition of an integrated starter/generator coupled to the engine, where the transfer function is adjusted according to where the clutch begins to transfer torque after increasing a pressure of fluid supplied to the clutch.

9. The method of claim 8 , where the operating condition is a torque output or a current input, and further comprising:
operating the integrated starter/generator in a constant speed control mode.

10. The method of claim 9 , further comprising providing the desired wheel torque via adjusting torque output of the electric machine in response to a current or a torque output of the integrated starter/generator.

11. The method of claim 8 , further comprising shifting the dual clutch transmission to a gear that reduces driveline torque disturbances.

12. The method of claim 8 , further comprising adjusting the transfer function at clutch pressures greater than the clutch pressure where the clutch begins to transfer torque.

13. The method of claim 8 , where the clutch transfers torque from the engine and the integrated starter/generator to the electric machine.

14. The method of claim 8 , further comprising adjusting a pressure of fluid supplied to the clutch in response to the adapted transfer function.

15. A system, comprising:
an engine;
an integrated starter/generator coupled to the engine;
a dual clutch transmission coupled to the engine including a first clutch and a second clutch;
an electric machine coupled to the dual clutch transmission; and
a controller including executable instructions stored in non-transitory memory to adjust a transfer function of the first clutch while a desired wheel torque is provided via the electric machine, the transfer function adapted in response to a condition of the integrated starter/generator and a vehicle travel distance, and additional instructions to actuate the first clutch in response to the adapted transfer function.

16. The system of claim 15 , where the condition is an output torque or an input current, and further comprising:
additional instructions to open the first clutch or the second clutch in response to a request to adapt the transfer function.

17. The system of claim 15 , where the transfer function describes a relationship between a torque capacity of the first clutch and a pressure of fluid applied to the first clutch.

18. The system of claim 15 , further comprising additional instructions to communicate a request to adapt the transfer function to other controllers in a vehicle.

Assignees

• Ford Global Tech Llc

Inventors

• Doering Jeffrey Allen
• Meyer Jason
• Wang Xiaoyong

Classifications

• B60W10/02

  including control of driveline clutches · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W2510/1075

  fluid pressure, e.g. oil pressure · CPC title

• B60W2710/083

  Torque · CPC title

• B60W2510/1005

  Transmission ratio engaged · CPC title