Methods and systems providing driveline braking

• US 9,174,633 B2
• Filed: 02/25/2013
• Issued: 11/03/2015
• 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: Lee, Seung-Hoon, Pietron, Gregory Michael, Doering, Jeffrey Allen, Gibson, Alex O'Connor, Reed, Dennis Craig
• Primary Examiner(s): Nguyen, John Q
• Assistant Examiner(s): Sood, Anshul
• Application Number:
  US13/776,296
• Publication Number:
  US 20130297117A1
• Time in Patent Office: 981 Days
• Field of Search: 701/22
• 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, driveline braking may transition from regenerative braking to engine braking to reduce the possibility of battery degradation.

Claims

1. A method for controlling driveline braking in a hybrid vehicle, comprising:

providing driveline braking via a first electric machine while rotation of an engine internal combustion is stopped; and

starting rotation of the engine after the engine is stopped in response to a battery state of charge exceeding a threshold that is indicative of a fully charged battery, where the starting of rotation of the engine is performed via a second electric machine.

2. The method of claim 1, where the second electric machine is not coupled to the engine before engine rotation is commanded.

3. The method of claim 1, where the first electric machine is not mechanically coupled to the engine while engine rotation is stopped.

4. The method of claim 1, where the second electric machine is disengaged from the engine after engine speed reaches a threshold speed.

5. The method of claim 4, further comprising closing a driveline disconnect clutch when engine speed is substantially equal to a speed of the first electric machine.

6. The method of claim 5, further comprising increasing torque converter clutch slip during closing the driveline disconnect clutch.

7. The method of claim 1, where a power output capacity of the second electric machine is lower than a power output capacity of the first electric machine.

8. A vehicle system, comprising:

an internal combustion 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 DMF;

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, and rotate a stopped engine via the starter other than the DISG when the DISG is providing driveline braking and when battery state of charge is greater than a threshold level that is indicative of a fully charged battery.

9. The vehicle system of claim 8, further comprising additional instructions to increase slip of a torque converter clutch when the driveline disconnect clutch is at least partially closed.

10. The vehicle system of claim 9, further comprising closing the driveline disconnect clutch after the engine is started.

11. The vehicle system of claim 10, where the DISG has a power output capacity greater than the starter other than the DISG.

12. The vehicle system of claim 11, further comprising the torque converter clutch and additional instructions for increasing the slip of the torque converter clutch during closing the driveline disconnect clutch.

13. The vehicle system of claim 12, where the DISG is supplying charge to an energy storage device when providing driveline braking.