Battery state of charge engine shut-off threshold based on predicted operation

• US 9,533,674 B2
• Filed: 02/23/2015
• Issued: 01/03/2017
• Est. Priority Date: 02/23/2015
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Miller, Kenneth James, Martin, Douglas Raymond, Perkins, William Paul
• Primary Examiner(s): BUTLER, RODNEY ALLEN
• Application Number:
  US14/628,973
• Publication Number:
  US 20160244044A1
• Time in Patent Office: 680 Days
• US Class Current: 1/1
• CPC Class Codes: B60K 6/48 Parallel type
• 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 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2050/0075 Automatic parameter input, automatic initialising or calibrating means
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2510/246 Temperature
• CPC Class Codes: B60W 2556/10 Historical data
• CPC Class Codes: B60W 2710/244 Charge state
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: B60W 50/0098 Details of control systems ensuring comfort, safety or stability not otherwise provided for
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/93 Conjoint control of different elements

Abstract

A vehicle includes an engine; a fraction battery; and a controller or a battery control system having a controller. The controller is programed to respond to a predicted duration of charge sustaining operation for a drive cycle and a speed of the vehicle. When the predicted duration is greater than a predetermined duration and the speed is less than a speed threshold, the controller increases a state of charge threshold of the traction battery associated with triggering shut offs of the engine to reduce cycling of the engine during the drive cycle.

Claims

1. A vehicle comprising:

an engine;

a fraction battery; and

a controller programed to, in response to a predicted duration of charge sustaining operation for a drive cycle being greater than a predetermined duration and a speed of the vehicle being less than a speed threshold, increase a state of charge threshold of the traction battery associated with triggering shut offs of the engine to reduce cycling of the engine during the drive cycle.

2. The vehicle of claim 1 wherein the state of charge threshold is greater than a sum of a predicted change in battery state of charge and a minimum state of charge.

3. The vehicle of claim 1, wherein the controller is further programmed to, while operating the engine to charge the traction battery, increase a fuel consumption of the engine to increase a current provided to the traction battery.

4. The vehicle of claim 1, wherein the state of charge threshold is based on a maximum capacity of the traction battery and an ambient temperature.

5. The vehicle of claim 1, wherein the controller is further programmed to increase the state of charge threshold by an amount based on losses associated with the engine.

6. The vehicle of claim 5, wherein the losses are based on a duration of the drive cycle.

7. A method of operating a hybrid electric vehicle comprising:

in response to a predicted duration of charge sustaining operation for a drive cycle being greater than a predetermined duration and a speed of the vehicle being less than a speed threshold, increasing by a controller a state of charge threshold of a traction battery associated with triggering shut offs of an engine to reduce cycling of the engine during the drive cycle.

8. The method of claim 7, wherein the state of charge threshold is greater than a sum of a predicted change in battery state of charge and a minimum state of charge.

9. The method of claim 7 further comprising, while operating the engine to charge the traction battery, increasing a fuel consumption of the engine to increase a current provided to the traction battery.

10. The method of claim 7, wherein the state of charge threshold is based on a maximum capacity of the traction battery and an ambient temperature.

11. The method of claim 7 further comprising increasing the state of charge threshold based on losses associated with the engine.

12. The method of claim 11, wherein the losses are based on a duration of the drive cycle.

13. A vehicle traction battery control system comprising:

a controller programed to, in response to a vehicle speed being less than a threshold speed and an expected duration of charge sustaining operation being greater than a predetermined duration, increase a traction battery state of charge threshold that, when exceeded while an engine is on, triggers a command to shut down the engine to reduce cycling of the engine.

14. The system of claim 13, wherein the expected duration is based on historical data including auxiliary electric load profiles, electric only operational profiles, vehicle speed profiles, vehicle power demand profiles, or battery power profiles.

15. The system of claim 13, wherein the controller is further programmed to, while operating the engine to charge a traction battery, increase a fuel consumption of the engine to increase a current provided to the traction battery.

16. The system of claim 13, wherein the traction battery state of charge threshold is based on ambient temperature.