Methods and systems for adjusting driveline operation during an accelerator tip-out

• US 9,321,452 B2
• Filed: 07/14/2014
• 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: Reed, Dennis Craig, Gibson, Alex O'Connor, Doering, Jeffrey Allen, Banker, Adam Nathan, Lee, Seung-Hoon
• Primary Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US14/331,136
• Publication Number:
  US 20140323266A1
• Time in Patent Office: 652 Days
• Field of Search: 701/22, 180/65.265, 903/903, 903/947, 477/174.5, 477/174, 477/5
• US Class Current: 1/1
• 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, an engine may be operated at an idle speed while a driveline disconnect clutch separating the engine from a driveline is open in response to a reduction in driver demand torque. Engine torque may be applied to the driveline by simply closing the driveline disconnect clutch.

Claims

1. A driveline operating method, comprising:

providing torque from an engine to a driveline coupled to wheels via at least a transmission and torque converter;

operating the engine at an idle speed and decoupling the engine from the driveline in response to a reduced driver demand torque; and

providing a constant vehicle deceleration rate during the reduced driver demand torque.

2. The method of claim 1, further comprising during another deceleration condition, stopping rotation of the engine and providing regenerative braking via a driveline integrated starter/generator.

3. The method of claim 2, further comprising during the another deceleration condition, 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.

4. The method of claim 3, further comprising opening a driveline disconnect clutch in response to the reduced driver demand torque.

5. The method of claim 1, where a driveline integrated starter/generator provides a negative torque to provide the constant vehicle deceleration rate.

6. The method of claim 1, where the idle speed is a first idle speed, and where the first idle speed is lower than a second idle speed, the engine operated at the second idle speed when the engine is coupled to the driveline.

7. The method of claim 1, where the engine is operated at the idle speed in response to the reduced driver demand torque being less than a driveline integrated starter/generator threshold torque.

8. The method of claim 7, where the driveline integrated starter/generator threshold torque is greater than 75% of a rated driveline integrated starter/generator torque.

9. The method of claim 1, where the torque provided from the engine is a positive torque.

10. A driveline operating method, comprising:

providing torque from an engine to a driveline coupled to wheels via at least a transmission and torque converter;

operating the engine at idle speed and decoupling the engine from the driveline in response to a reduced driver demand torque;

providing a constant vehicle deceleration rate at the reduced driver demand torque; and

accelerating the engine to a speed in response to an increase in driver demand torque after operating the engine at the idle speed.

11. The method of claim 10, where the speed is a driveline integrated starter/generator speed.

12. The method of claim 11, further comprising closing a driveline disconnect clutch in response to the speed reaching the driveline integrated starter/generator speed.

13. The method of claim 10, where the constant vehicle deceleration rate is provided via a driveline integrated starter/generator.

14. The method of claim 13, where the driveline integrated starter/generator is operated in a regeneration mode charging a battery.

15. The method of claim 10, where the idle speed is a first idle speed, and where the first idle speed is lower than a second idle speed, the engine operated at the second idle speed when the engine is coupled to the driveline.

16. The method of claim 10, where the engine is operated at the idle speed in response to the reduced driver demand torque being less than a driveline integrated starter/generator threshold torque.

17. 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 torque converter with a torque converter clutch; and

a controller including executable instructions stored in non-transitory memory to provide a constant vehicle deceleration rate while idling the engine at a sailing mode idle speed, and to further adjust torque converter slip across the clutch responsive to vehicle operating conditions.

18. The vehicle system of claim 17, where the sailing mode idle speed is a speed less than a base idle speed, the base idle speed provided when the engine is coupled to the DISG.

19. The vehicle system of claim 17, further comprising additional instructions to open the driveline disconnect clutch in response to a decreasing driver demand torque.

20. The vehicle system of claim 17, further comprising additional instructions to exit sailing mode idle speed in response to an increasing driver demand torque.

21. The vehicle system of claim 17, further comprising additional instructions to increase engine speed from sailing mode idle speed in response to an increasing driver demand torque.

22. The vehicle system of claim 19, where the constant vehicle deceleration rate is provided via the DISG.