Methods and systems for operating a driveline disconnect clutch

• US 9,321,457 B2
• Filed: 08/24/2015
• Issued: 04/26/2016
• 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: Gibson, Alexander O'Connor, Nedorezov, Felix, Doering, Jeffrey Allen, Jiang, Hong, Lee, Seung-Hoon, McCallum, James William Loch, Pietron, Gregory Michael, Fujii, Yuji
• Primary Examiner(s): CAMBY, RICHARD M
• Application Number:
  US14/834,339
• Publication Number:
  US 20150360683A1
• Time in Patent Office: 246 Days
• Field of Search: 701/22, 701/36, 701 51- 55, 701/67, 701/102, 180 651- 6529
• 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 10/026 of lock-up clutches
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• 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 2030/206 related or induced by the engine
• CPC Class Codes: B60W 2510/02 Clutches
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/1015 Input shaft speed, e.g. turbine speed
• CPC Class Codes: B60W 2710/021 Clutch engagement state
• CPC Class Codes: B60W 2710/027 Clutch torque
• CPC Class Codes: B60W 2710/06 Combustion engines, Gas turbines
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2710/081 Speed
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: B60Y 2200/92 Hybrid vehicles
• CPC Class Codes: B60Y 2300/18083 without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60Y 2300/49 Engine push start or restart by use of vehicle kinetic energy
• CPC Class Codes: B60Y 2400/426 Hydrodynamic couplings, e.g. torque converters
• CPC Class Codes: F02N 11/00 Starting of engines by means of electric motors
• CPC Class Codes: F02N 11/0851 : characterised by means for controlling the engagement or disengagement between engine and starter, e.g. meshing of pinion and engine gear
• 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 903/903 : having energy storing means, e.g. battery, capacitor

Abstract

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, application of a driveline disconnect clutch to start an engine is described. The approach applies the driveline disconnect clutch to rotate an engine and at least partially disengages the driveline disconnect clutch to reduce the possibility of a reduction in torque applied to vehicle wheels.

Claims

1. A method of operating a hybrid vehicle driveline, comprising:

automatically stopping an engine and opening a driveline disconnect clutch in response to an engine stop request;

automatically starting the engine in response to an engine start request, wherein automatically starting the engine includes partially closing the driveline disconnect clutch; and

adjusting a driveline integrated starter/generator (DISG) speed in response to a desired torque converter impeller speed.

2. The method of claim 1, wherein the at least partially closing the disconnect clutch rotates the engine at a cranking speed.

3. The method of claim 2, wherein the method further comprises at least partially opening the driveline disconnect clutch in response to a combustion event.

4. The method of claim 3, wherein the combustion event is a first combustion event since engine stop.

5. The method of claim 4, further comprising counting a number of combustion events since engine stop.

6. The method of claim 4, further comprising fully closing the driveline disconnect clutch in response to engine speed being within a range of a speed of a driveline integrated starter generator.

7. The method of claim 6, where the range of speed begins at a speed below the speed of the driveline integrated starter generator.

8. The method of claim 7, where the range of speed extends to a speed greater than the speed of the driveline integrated starter generator.

9. The method of claim 3, where the combustion event is a combustion event that accelerates the engine, and where the combustion event is deemed to have occurred in response to a change in engine speed.

10. A method of operating a hybrid vehicle driveline, comprising:

automatically stopping an engine and opening a driveline disconnect clutch in response to an engine stop request;

automatically starting the engine in response to an engine start request, wherein automatically starting the engine includes partially closing the driveline disconnect clutch to rotate the engine at a cranking speed and at least partially opening the driveline disconnect clutch in response to an anticipated event; and

adjusting a driveline integrated starter/generator (DISG) speed in response to a desired torque converter impeller speed.

11. The method of claim 10, where the anticipated event is an event that is based on engine position and engine rotation.

12. The method of claim 11, where the anticipated event is a change in state of a poppet valve of a cylinder.

13. The method of claim 11, where the anticipated event is a cylinder combustion event.

14. The method of claim 10, further comprising closing the driveline disconnect clutch in response to engine speed being within a speed range of a speed of a DISG.

15. The method of claim 14, where the engine is rotated at the cranking speed via torque supplied by the DISG.

16. The method of claim 10, further comprising adjusting a torque converter clutch capacity to a constant value in response to the engine start request.

17. A hybrid vehicle driveline system, comprising:

a torque converter;

a driveline integrated starter/generator (DISG);

an engine;

a transmission selectively coupled to the engine;

a driveline disconnect clutch positioned in a driveline between the engine and the DISG; and

a controller including executable non-transitory instructions for operating the DISG in a speed control mode in response to an engine start request, instructions for closing the driveline disconnect clutch to rotate the engine at a cranking speed, and instructions for at least partially opening the driveline disconnect clutch in response to an engine rotation based event, the controller further including instructions to adjust an estimate of torque transferred through the driveline disconnect clutch in response to a torque sensor output.

18. The hybrid vehicle driveline system of claim 17, where the engine rotation based event is a change in a state of a poppet valve, wherein the driveline disconnect clutch is ramped open.

19. The hybrid vehicle driveline system of claim 17, where the engine rotation based event is a predetermined combustion event number since stop of engine rotation.