Methods and systems for transitioning between driveline braking modes

• US 9,296,387 B2
• Filed: 01/20/2015
• Issued: 03/29/2016
• 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, Banker, Adam Nathan, Oshinsky, David
• Primary Examiner(s): CAMBY, RICHARD M
• Application Number:
  US14/601,086
• Publication Number:
  US 20150133264A1
• Time in Patent Office: 434 Days
• Field of Search: 701/22, 701/36, 701/67, 701/102, 477 2- 9, 180 651- 6529
• US Class Current: 1/1
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 15/2081 for drive off on a slope
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/507 Operating parameters
• CPC Class Codes: B60L 2240/622 by satellite navigation
• CPC Class Codes: B60L 2240/72 Charging station selection relying on external data
• CPC Class Codes: B60L 2250/26 by pedal actuation
• CPC Class Codes: B60L 2260/52 drive range estimation, e.g. of estimation of available travel distance
• CPC Class Codes: B60L 2260/54 Energy consumption estimation
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/15 Preventing overcharging
• CPC Class Codes: B60L 7/18 Controlling the braking effect B60L7/12, B60L7/14, B60L7/16 take precedence
• CPC Class Codes: B60L 8/003 Converting light into electric energy, e.g. by using photo-voltaic systems
• CPC Class Codes: B60W 10/00 Conjoint control of vehicle sub-units of different type or different function for propulsion of purely electrically-propelled vehicles with power supplied within the vehicle B60L50/00 - B60L58/00
• CPC Class Codes: B60W 10/02 : including control of driveline 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 10/10 : including control of change-speed gearings
• CPC Class Codes: B60W 10/11 : Stepped gearings
• CPC Class Codes: B60W 10/115 : with planetary gears
• CPC Class Codes: B60W 10/196 : acting within the driveline, e.g. retarders
• CPC Class Codes: B60W 10/30 : including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• 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 20/12 : using control strategies taking into account route information estimation or calculation of non-directly measurable driving parameters B60W40/00
• CPC Class Codes: B60W 20/14 : in conjunction with braking regeneration
• CPC Class Codes: B60W 20/20 : Control strategies involving selection of hybrid configuration, e.g. selection between series or parallel configuration
• CPC Class Codes: B60W 20/30 : Control strategies involving selection of transmission gear ratio control of change speed gearings, together with other vehicle sub-units B60W10/10; HEV transmission gearing B60K6/36; gearings and control thereof F16H
• 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 2510/244 : Charge state
• CPC Class Codes: B60W 2552/15 : Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2710/06 : Combustion engines, Gas turbines
• CPC Class Codes: B60W 2710/08 : Electric propulsion units
• CPC Class Codes: B60W 30/00 : Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
• CPC Class Codes: B60W 30/18027 : Drive off, accelerating from standstill
• CPC Class Codes: B60W 30/18127 : Regenerative braking
• CPC Class Codes: B60W 30/18136 : Engine braking
• CPC Class Codes: B60Y 2400/216 : by solar panels
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility
• CPC Class Codes: Y02T 10/90 : Energy harvesting concepts as power supply for auxiliaries' energy consumption, e.g. photovoltaic sun-roof
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric 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 903/946 : Characterized by control of driveline clutch
• 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 engine braking is described.

Claims

1. A method for controlling driveline braking, comprising:

idling an engine combusting air and fuel with an open disconnect clutch; and

during a first condition,

stopping rotation of the engine;

providing driveline braking via an electric machine while rotation of the engine is stopped;

operating the electric machine in a speed control mode in response to a request to provide driveline braking via the engine;

starting the engine;

accelerating the engine to a speed of the electric machine; and

closing the open driveline disconnect clutch in response to engine speed substantially equaling electric machine speed.

2. The method of claim 1, wherein engine idling includes operating the engine without providing engine torque to a driveline in response to driver demanded torque being within a threshold range of an engine cranking torque.

3. The method of claim 2, where the engine is started via a starter other than the electric machine.

4. The method of claim 2, where the request to provide driveline braking via the engine is based on a state of charge of an energy storage device.

5. The method of claim 4, where the request to provide driveline braking via the engine is in response to the state of charge of the energy storage device being greater than a threshold amount of charge.

6. The method of claim 2, further comprising adjusting slip of a torque converter clutch in response to closing the open driveline disconnect clutch, where the slip of the torque converter clutch is increased.

7. The method of claim 1, further comprising, during a second condition, increasing engine speed from idle speed to a speed synchronous with the electric machine, and closing the disconnect clutch.

8. A method for controlling driveline braking, comprising:

stopping an engine with a disconnect clutch open;

providing driveline braking via an electric machine while engine rotation is stopped;

starting and rotating the engine;

injecting fuel to the engine;

accelerating the engine to a speed of the electric machine; and

discontinuing to inject fuel to the engine and providing driveline braking via the engine while the electric machine outputs less than a threshold amount of current.

9. The method of claim 8, further comprising closing the driveline disconnect clutch in response to engine speed substantially equaling electric machine speed.

10. The method of claim 9, further comprising operating the electric machine in a speed control mode during closing the driveline disconnect clutch.

11. The method of claim 9, further comprising increasing slip of a torque converter clutch during closing the driveline disconnect clutch.

12. The method of claim 8, where the engine is started in response to charge of an energy storage device exceeding a threshold charge.

13. The method of claim 12, where electric machine torque is reduced in response to engine braking torque increasing after discontinuing to inject fuel to the engine.

14. The method of claim 8, where the engine is started via a starter other than the electric machine.

15. A vehicle system, comprising:

an engine;

a dual mass flywheel (DMF) 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 starter other than the DISG including a base state where the starter is not engaged to the engine;

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

a controller including non-transitory instructions executable to idle the engine while the disconnect clutch is open, automatically stop the engine, provide driveline braking via the DISG while engine rotation is stopped, start the engine in response to a state of charge of an energy storage device, stop combustion in the engine while the engine is rotating, and provide driveline braking via the engine.

16. The vehicle system of claim 15, further comprising additional instructions to accelerate the engine to a speed of the DISG.

17. The vehicle system of claim 16, further comprising additional instructions to close the driveline disconnect clutch when engine speed is substantially equal to DISG speed, and wherein during idling, said engine is operated by the controller to perform combustion without providing engine torque to a driveline.

18. The vehicle system of claim 15, further comprising additional instructions for starting the engine via the starter other than the DISG.

19. The vehicle system of claim 18, further comprising additional instructions for stopping combustion in engine cylinders after starting the engine.

20. The vehicle system of claim 19, further comprising additional instructions for adjusting engine braking after stopping combustion in engine cylinders.