METHODS AND SYSTEMS FOR DRIVELINE MODE TRANSITIONS

• US 20130297121A1
• Filed: 02/25/2013
• Published: 11/07/2013
• 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: Reed, Dennis Craig, Gibson, Alex O'Connor, Doering, Jeffrey Allen, Banker, Adam Nathan, Lee, Seung-Hoon
• Granted Patent: US 8,924,062 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60W 10/02 including control of driveline clutches
• CPC Class Codes: B60W 10/023 Fluid clutches
• CPC Class Codes: B60W 10/026 of lock-up clutches
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• 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 2030/1809 Without torque flow between driveshaft and engine, e.g. with clutch disengaged or transmission in neutral
• CPC Class Codes: B60W 2030/206 related or induced by the engine
• CPC Class Codes: B60W 30/18118 Hill holding
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: B60W 30/20 Reducing vibrations in the driveline
• CPC Class Codes: F02D 41/0032 Controlling the purging of the canister as a function of the engine operating conditions
• CPC Class Codes: F02P 5/1508 with particular means during idling
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect
• 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
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking

Abstract

Systems and methods for improving operation of a hybrid vehicle are presented. In one example, a method for transitioning between regenerative braking and providing positive torque to a driveline is presented.

Claims

1. A method for operating a driveline, comprising:

stopping rotation of an engine and providing regenerative braking via a driveline;

transitioning from the regenerative braking to providing positive torque to the driveline; and

operating a driveline integrated starter/generator in a speed control mode during the transition.

2. The method of claim 1, where the driveline integrated starter/generator is operated in a torque control mode before and after operating the driveline integrated starter/generator in the speed control mode.

3. The method of claim 1, where the driveline integrated starter/generator is adjusted to a speed based on a speed of a torque converter turbine.

4. The method of claim 1, further comprising opening a driveline disconnect clutch when the engine is stopped.

5. The method of claim 1, further comprising closing a driveline disconnect clutch to start the engine after operating the driveline integrated starter/generator in the speed control mode.

6. The method of claim 1, where the regenerative braking is provided when a state of charge of an energy storage device is less than a threshold charge.

7. The method of claim 1, further comprising increasing slip of a torque converter clutch during the transitioning from the regenerative braking to providing positive torque to the driveline.

8. A method for operating a driveline, comprising:

stopping rotation of an engine and providing regenerative braking via a driveline integrated starter/generator;

transitioning the driveline integrated starter/generator from providing the regenerative braking to providing positive torque to the driveline; and

adjusting slip of a torque converter clutch in response to the transition from providing regenerative braking to providing positive torque to the driveline.

9. The method of claim 8, further comprising operating the driveline integrated starter/generator in a speed control mode during transitioning the driveline integrated starter/generator from providing the regenerative braking to providing positive torque to the driveline.

10. The method of claim 9, where the driveline integrated starter/generator is operated at a speed that is a predetermined speed greater than a torque converter turbine speed.

11. The method of claim 10, further comprising increasing the speed in response to a reduction in gear lash.

12. The method of claim 8, where adjusting slip of the torque converter includes increasing torque converter slip.

13. The method of claim 8, where transitioning the driveline integrated starter/generator from providing the regenerative braking to providing positive torque to the driveline is in response to an increasing torque demand.

14. The method of claim 8, further comprising starting the engine via closing a driveline disconnect clutch while adjusting slip of the torque converter clutch.

15. A vehicle system, comprising:

an engine;

an electric machine;

a driveline disconnect clutch positioned in a driveline between the engine and the electric machine;

a transmission a torque converter positioned in the driveline between the electric machine and the transmission; and

a controller including executable instructions stored in non-transitory memory for reducing gear lash in the transmission via operating the electric machine in a speed control mode and adjusting a speed of the electric machine.

16. The vehicle system of claim 15, further comprising a torque converter clutch and additional executable instructions to slip the torque converter clutch when the electric machine is operated in the speed control mode.

17. The vehicle system of claim 15, further comprising additional executable instructions to operate the electric machine at a predetermined speed that is greater than a speed of a turbine of the torque converter.

18. The vehicle system of claim 17, further comprising additional executable instructions to increase a speed of the electric machine after operating the electric machine at the predetermined speed.

19. The vehicle system of claim 15, further comprising additional executable instructions to provide driveline brake torque via the electric machine.

20. The vehicle system of claim 19, further comprising additional executable instructions to reduce driveline brake torque toward zero torque before operating the electric machine in the speed control mode.