Methods and systems for operating a driveline disconnect clutch responsive to engine operating conditions

• US 9,260,107 B2
• Filed: 02/25/2013
• Issued: 02/16/2016
• Est. Priority Date: 05/04/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Doering, Jeffrey Allen, Gibson, Alex O'Connor, Reed, Dennis Craig, Pietron, Gregory Michael, Lee, Seung-Hoon
• Primary Examiner(s): Algahaim, Helal A
• Assistant Examiner(s): Han, Charles J
• Application Number:
  US13/776,290
• Publication Number:
  US 20130297115A1
• Time in Patent Office: 1,086 Days
• Field of Search: 477/74, 477/84, 477/5, 477/10, 701/67
• US Class Current: 1/1
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/023 Fluid clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/14 in conjunction with braking regeneration
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2030/203 related or induced by the clutch
• CPC Class Codes: B60W 2510/0275 Clutch torque
• CPC Class Codes: B60W 2510/083 Torque
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/902 Prime movers comprising electrical and internal combustion motors
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, a driveline disconnect clutch transfer function may be adapted in response to engine operating conditions during closing of the driveline disconnect clutch.

Claims

1. A method, comprising:

rotating an integrated starter/generator (ISG) at a first speed;

operating an engine at a second different speed while operating the ISG at the first speed in response to conditions for adapting a transfer function stored in memory;

revising the transfer function stored in memory while rotating the ISG at the first speed and the engine at the second speed in response to a difference between an engine torque estimate based on engine operating conditions and a torque estimate based on the transfer function; and

operating a driveline disconnect clutch responsive to the transfer function.

2. The method of claim 1, where a transmission input shaft is rotated via the ISG, and where the transfer function is revised based on rotating the transmission input shaft at the first speed while rotating the engine at the second speed.

3. The method of claim 1, where the second speed is greater than the first speed, and where the first speed is zero.

4. The method of claim 1, where the second speed is less than the first speed.

5. The method of claim 1, where the engine torque estimate is based on engine conditions including at least one of engine speed, engine load, fuel injection timing, exhaust gas recirculation amount, spark timing, engine temperature, engine valve timing, intake pressure, exhaust pressure, barometric pressure, and accessory load estimates.

6. The method of claim 1, further comprising commanding an increase in application force of a driveline disconnect clutch.

7. The method of claim 6, further comprising adjusting engine torque to maintain engine speed at the second speed while commanding the increase in application force of the driveline disconnect clutch.

8. A driveline disconnect clutch adaptation method, comprising:

rotating an integrated starter/generator at a first speed;

operating an engine at a second speed different from the first speed while rotating the integrated starter/generator at the first constant speed;

storing an engine torque output value while a driveline disconnect clutch is open;

incrementally closing the driveline disconnect clutch while rotating the engine at the second speed and the integrated starter/generator at the first speed; and

revising a transfer function stored in memory based on rotating the integrated starter/generator at the first speed and the engine at the second speed in response to a difference between an engine torque estimate based on engine operating conditions and a torque estimate based on the transfer function; and

operating the driveline disconnect clutch in response to the transfer function.

9. The driveline disconnect clutch adaptation method of claim 8, where the first speed is a speed where torque converter output torque is less than a threshold torque.

10. The driveline disconnect clutch adaptation method of claim 8, where the engine operating conditions include at least one of engine speed, engine load, fuel injection timing, exhaust gas recirculation amount, spark timing, engine temperature, engine valve timing, intake pressure, exhaust pressure, barometric pressure, and accessory load estimates.

11. The driveline disconnect clutch adaptation method of claim 8, where the torque estimate based on engine operating conditions is an engine torque minus engine torque stored while the driveline disconnect clutch is open.

12. The driveline disconnect clutch adaptation method of claim 8, where engine speed is adjusted via adjusting engine torque during the speed control mode.

13. The driveline disconnect clutch adaptation method of claim 8, where the integrated starter/generator is mechanically coupled to a transmission input shaft via a torque converter.

14. The driveline disconnect clutch adaptation method of claim 8, where the first speed is a speed that generates a threshold transmission oil pressure that holds a transmission clutch in an applied state.

15. The driveline disconnect clutch adaptation method of claim 8, where the integrated starter/generator rotates at a speed greater than a speed of a torque converter turbine.

16. A vehicle system, comprising:

an engine;

a dual mass flywheel including a first side mechanically coupled to the engine;

a driveline disconnect clutch mechanically including a first side coupled to a second side of the dual mass flywheel;

a driveline integrated starter/generator (DISG) including a first side coupled to a second side of the driveline disconnect clutch;

a transmission selectively coupled to the engine via the driveline disconnect clutch; and

a controller including executable instructions stored in non-transitory memory to, during a first mode, adjust an estimate of torque transferred through the driveline disconnect clutch in response to an engine torque estimate, and operate the driveline disconnect clutch in response to the estimate of torque transferred through the driveline disconnect clutch; and

during a second mode when the engine is not rotating and combusting, revising a transfer function stored in memory in response to incrementally closing the driveline disconnect clutch and rotating the DISG at a speed in a speed control mode and a difference between an engine torque estimate based on engine operating conditions and a torque estimate based on the transfer function.

17. The vehicle system of claim 16, where the engine torque estimate is based on engine speed and load.

18. The vehicle system of claim 16, further comprising additional instructions for rotating the DISG and the engine during the first mode at a speed below which a torque converter transfers less than a threshold percent of DISG torque to the transmission.

19. The vehicle system of claim 18, further comprising additional instructions for rotating the DISG at a speed that is less than a speed of engine rotation during the first mode.

20. The vehicle system of claim 16, further comprising additional instructions to perform closed loop engine speed control via adjusting engine torque while estimating the engine torque.