METHOD TO ADJUST FUEL ECONOMY READINGS FOR STORED ENERGY

• US 20150302670A1
• Filed: 04/21/2014
• Published: 10/22/2015
• Est. Priority Date: 04/21/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Ulrey, Joseph Norman, Pursifull, Ross Dykstra, Ruona, William Charles
• Granted Patent: US 9,367,972 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60K 2360/174 Economic driving
• CPC Class Codes: B60K 35/28 characterised by the type of the output information, e.g. video entertainment or vehicle dynamics information; characterised by the purpose of the output information, e.g. for attracting the attention of the driver
• CPC Class Codes: B60K 35/60 Instruments characterised by their location or relative disposition in or on vehicles arrangements of lighting devices on dashboards B60Q3/10
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2552/25 Road altitude
• CPC Class Codes: B60W 40/00 Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
• CPC Class Codes: G01F 9/023 with electric, electro-mechanic or electronic means
• CPC Class Codes: G07C 5/0816 Indicating performance data, e.g. occurrence of a malfunction
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

Methods and systems are provided for compensating an instantaneous fuel economy reading for stored energy. One method comprises, when a vehicle undergoes a sufficient change in one or more of square of vehicle speed and vehicle altitude, estimating a conversion factor for fuel due to stored vehicle energy and adjusting the instantaneous fuel economy reading by the estimated conversion factor. The adjusted instantaneous fuel economy reading may be displayed to an operator of the vehicle.

Claims

1. A method for a vehicle, comprising:

when the vehicle undergoes a sufficient change in square of vehicle speed and/or a sufficient change in vehicle altitude;

estimating a conversion factor for fuel due to stored vehicle energy; and

adjusting a fuel economy reading by the estimated conversion factor.

2. The method of claim 1, wherein the sufficient change in square of vehicle speed is a positive change in the square of vehicle speed that is higher than a vehicle speed threshold and wherein the sufficient change in vehicle altitude is a positive change in vehicle altitude that is greater than a vehicle altitude threshold.

3. The method of claim 2, wherein the conversion factor is directly proportional to fuel flow due to stored vehicle energy and is inversely proportional to each of the change in square of vehicle speed and the change in vehicle altitude.

4. The method of claim 3, wherein the fuel flow due to stored vehicle energy is estimated in a vehicle controller by subtracting a fuel flow rate determined during steady state driving conditions from an existing fuel flow rate.

5. The method of claim 4, wherein steady state driving conditions include conditions when changes in each of a square of vehicle speed and vehicle altitude are below their respective thresholds.

6. The method of claim 1, wherein the adjusted fuel economy reading is displayed to an operator of the vehicle at periodic intervals.

7. The method of claim 1, wherein stored vehicle energy is one or both of potential energy and kinetic energy, and wherein potential energy is directly proportional to vehicle altitude, and kinetic energy is directly proportional to square of vehicle speed.

8. The method of claim 1, wherein the change in vehicle altitude is estimated based on grade readings from an inclinometer and vehicle speed.

9. The method of claim 8, wherein the grade readings from the inclinometer are corrected for offset error by comparison with readings from a barometric pressure sensor.

10. A method for an engine in a vehicle, comprising:

determining a fuel economy at steady state driving conditions;

estimating a conversion factor for stored vehicle energy based on the fuel economy at steady state driving conditions; and

displaying a fuel economy reading to an operator of the vehicle based on fuel consumed by the engine adjusted for stored vehicle energy with the conversion factor.

11. The method of claim 10, wherein steady state driving conditions include conditions when changes in each of square of vehicle speed and vehicle altitude are below their respective thresholds.

12. The method of claim 10, wherein the conversion factor for stored vehicle energy is determined when one or both of square of vehicle speed and vehicle altitude undergo a sufficient increase.

13. The method of claim 12 wherein the sufficient increase in square of vehicle speed is higher than a vehicle speed threshold and the sufficient increase in vehicle altitude is higher than a vehicle altitude threshold.

14. The method of claim 10, wherein the conversion factor for stored vehicle energy is directly proportional to fuel flow due to stored vehicle energy and inversely proportional to each of a change in square of vehicle speed and change in vehicle altitude, the change in vehicle altitude measured by an inclinometer and corrected for offset error.

15. The method of claim 14, wherein the fuel flow due to stored vehicle energy is determined by subtracting a fuel flow rate based on the fuel economy at steady state driving conditions from an existing fuel flow rate.

16. The method of claim 10, wherein the conversion factor for stored vehicle energy and fuel economy at steady state driving conditions are determined after engine warm up.

17. The method of claim 10, wherein the conversion factor for stored vehicle energy and fuel economy at steady state driving conditions are not determined during transmission shifts.

18. The method of claim 10, wherein the conversion factor for stored vehicle energy and fuel economy at steady state driving conditions are not determined during vehicle braking conditions.

19. A system in a vehicle comprising:

an engine; and

a controller configured with computer readable instructions stored in non-transitory memory to;

during a first mode,

determine a fuel economy reading;

during a second mode,

determine a conversion factor for stored vehicle energy based on the fuel economy reading determined in the first mode; and

display instantaneous fuel economy readings, which are compensated for stored vehicle energy by using the conversion factor, to an operator of the vehicle.

20. The system of claim 19, wherein the first mode includes steady state driving conditions, and wherein the second mode includes only conditions when an increase in square of vehicle speed is higher than a vehicle speed threshold and/or when an increase in vehicle altitude is higher than a vehicle altitude threshold.