Electric current based engine auto stop inhibit algorithm and system implementing same

• US 10,480,477 B2
• Filed: 07/11/2011
• Issued: 11/19/2019
• Est. Priority Date: 07/11/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Sangameswaran, Sangeetha, Harpenau, Kevin Roy, Pebley, Kirk, Celinske, David, Rademacher, Eric Michael
• Primary Examiner(s): Vilakazi, Sizo B
• Assistant Examiner(s): Kirby, Brian R
• Application Number:
  US13/179,747
• Publication Number:
  US 20130018569A1
• Time in Patent Office: 3,053 Days
• Field of Search: 1231794, 123198 D, 123198 DB, 123198 DC, 701 41, 701112, 701113
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0825 related to prevention of engine restart failure, e.g. disabling automatic stop at low battery state
• CPC Class Codes: F02N 2200/062 Battery current
• CPC Class Codes: F02N 2200/0809 Electrical loads
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A vehicle includes an engine and at least one controller. The at least one controller periodically determines an estimated current to be demanded by vehicle electrical loads during an auto stop of the engine, compares the estimated current with a threshold current, and inhibits an auto stop of the engine if the estimated current is greater than the threshold current for a predetermined period of time.

Claims

1. A vehicle comprising:

an engine; and

at least one controller configured to inhibit an auto stop of the engine in response to expected increases and decreases to currents consumed by climate system accessory loads or power steering system accessory loads once the engine has been auto stopped resulting in an estimated current to be demanded by the vehicle accessory loads during an auto stop of the engine being greater than a threshold current.

2. The vehicle of claim 1 wherein inhibiting an auto stop of the engine includes preventing the engine from stopping.

3. The vehicle of claim 1 wherein the at least one controller is further configured to allow an auto stop of the engine in response to the estimated current being less than the threshold current.

4. A vehicle comprising:

an engine; and

a controller configured to detect an engine auto stop inhibit condition responsive to expected increases and decreases to currents consumed by vehicle accessory fan loads or vehicle accessory pump loads once the engine has been auto stopped resulting in an estimate of current to be demanded by the vehicle accessory loads during an auto stop of the engine being greater than a threshold current, and to prevent the engine from auto stopping.

5. The vehicle of claim 4 wherein the at least one controller is further configured to detect an engine auto stop permit condition responsive to the estimate of current being less than the threshold current, and to allow the engine to auto stop.

6. A method for controlling a vehicle engine comprising:

inhibiting an auto stop of the engine responsive to expected changes to currents consumed by climate system accessory loads or power steering system accessory loads once the engine has been auto stopped resulting in an estimated current to be demanded by the vehicle accessory loads being greater than a threshold current; and

allowing an auto stop of the engine responsive to the estimated current being less than the threshold current.

7. The method of claim 6 further comprising controlling the vehicle accessory loads during an auto stop of the engine such that the vehicle accessory loads consume an amount of current not greater than the estimated current.

8. The method of claim 6 wherein inhibiting an auto stop of the engine includes preventing the engine from stopping.