Methods and systems for providing uniform driveline braking

• US 9,327,717 B2
• Filed: 11/13/2014
• Issued: 05/03/2016
• 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, Pietron, Gregory Michael
• Primary Examiner(s): Black, Thomas G
• Assistant Examiner(s): PAIGE, TYLER D
• Application Number:
  US14/540,871
• Publication Number:
  US 20150073644A1
• Time in Patent Office: 537 Days
• Field of Search: 701/22, 180/65.25, 475/5
• 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, negative torque of an electric machine is adjusted to mimic negative torque of an engine during engine braking so that the vehicle may transition from regenerative braking to engine braking in a seamless manner.

Claims

1. A method for controlling driveline braking, comprising:

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

adjusting a torque of the electric machine while the engine is stopped in response to an estimated engine brake torque, where the torque of the electric machine is varied as a condition of the engine varies;

restarting the engine and operating the engine at an idle speed in a speed control mode; and

accelerating the engine in the speed control mode to electric machine speed in response to a desired torque.

2. The method of claim 1, where the condition of the engine is an oil temperature.

3. The method of claim 1, where the condition of the engine is a valve timing of the engine, where the idle speed is a sailing mode idle speed, and where the sailing mode idle speed is a lower speed than a base engine idle speed.

4. The method of claim 3, further comprising reducing an engine air amount while the engine operates in the sailing mode idle speed with respect to engine air amount while operating the engine at the base engine idle speed.

5. The method of claim 1, where the driveline braking is provided via operating the electric machine in a generator mode.

6. The method of claim 1, where the engine is restarted via a second electric machine.

7. A method for controlling driveline braking, comprising:

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

adjusting a torque of the electric machine based on a braking torque of the engine, the torque of the electric machine adjusted while rotation of the engine is stopped, the braking torque of the engine estimated based on a speed of the electric machine, where the braking torque of the engine is a deceleration fuel shut-off braking torque; and

restarting the engine via the electric machine in response to driver demand torque being less than a threshold torque.

8. The method of claim 7, where the braking torque of the engine is estimated based on an engine oil temperature.

9. The method of claim 7, further comprising restarting the engine via a second electric machine in response to driver demand torque being greater than the threshold torque.

10. The method of claim 7, where the torque of the electric machine is a negative torque.

11. The method of claim 10, where the electric machine is in a generator mode.

12. The method of claim 7, where the braking torque of the engine is estimated based on a position of a throttle.

13. 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 automatically stop the engine, provide driveline braking via the DISG while engine rotation is stopped, adjust a torque of the DISG while the engine is stopped to an engine brake torque occurring when the engine is rotated without being fueled, and restart the engine via the DISG or the starter other than the DISG, and additional instructions to stop combustion in engine cylinders after restarting the engine.

14. The vehicle system of claim 13, further comprising additional instructions to accelerate the engine to a speed of the DISG.

15. The vehicle system of claim 13, further comprising additional instructions to restart the engine via the DISG in response to driver demand torque being less than a threshold torque.

16. The vehicle system of claim 13, further comprising additional instructions to restart the engine via the starter other than the DISG in response to driver demand torque being greater than a threshold torque.

17. The vehicle system of claim 13, further comprising additional instructions for adjusting engine braking after stopping combustion in engine cylinders.