US5578748A
Expired / Lapsed
US
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Method and system for calculating effective fuel economy
Assignee: Ford Global Technologies LLC
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Filing: 1995-09-25
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Granted: 1996-11-26
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Expires: 2015-09-25
Abstract
Abstract A method and system for calculating the effective fuel economy of a fuel-consuming engine in a vehicle are disclosed. The effective fuel economy is calculated taking into consideration the chemical energy contained in the fuel and the change in kinetic energy of the vehicle (42). The effective fuel economy is also calculated by further considering the change in potential energy of the vehicle (60). The chemical energy contained in the fuel is determined by sensing the mass flow rate of fuel (52). The kinetic energy (56) is determined by sensing the change in the speed of the vehicle and the mass of the vehicle (50). The potential energy (58) is determined by sensing the change in elevation of the vehicle (50). The effective fuel economy is displayed to the operator of the vehicle (64).
Inventors
- 👤 Diana D. Brehob
- 👤 Todd A. Kappauf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:01
CPC Classifications
G; G01; G01F; G01F9/00; G01F9/02; G01F9/023; G01G; G01G19/00; G01G19/40; G01G19/413; G01G19/414
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
208 words
A method for determining and displaying on a visual display the effective fuel economy (MPG eff ) of a fuel consuming engine during a time interval Δ t in a vehicle, the method comprising: providing a vehicle having a mass and said fuel consuming engine; determining an enthalpy of reaction (ΔH R ) of the fuel, which represents the energy released per unit mass by combustion following actual injection of fuel into the engine; determining an amount of chemical energy (E f ) contained in the fuel based on the enthalpy of reaction of the fuel; sensing a vehicle speed at predetermined periods of time during the time interval and generating corresponding velocity signals (v i , v i-1 ); determining a change in kinetic energy (ΔE KE ) of the vehicle during the time interval based solely on the velocity signals and the mass of the vehicle; determining a change in potential energy (ΔE PE ) of the vehicle; determining the effective fuel economy of the vehicle based on the chemical energy, the change in kinetic energy and the change in potential energy; generating an electrical signal for receipt by the visual display corresponding to the determined effective fuel economy; and displaying the determined effective fuel economy.
Claim 2
Independent Claim
208 words
A method for determining and displaying on a visual display the effective fuel economy (MPG eff ) of a fuel consuming engine during a time interval Δ t in a vehicle, the method comprising: providing a vehicle having a mass and said fuel consuming engine; determining an enthalpy of reaction (ΔH R ) of the fuel, which represents the energy released per unit mass by combustion following actual injection of fuel into the engine; determining an amount of chemical energy (E f ) contained in the fuel based on the enthalpy of reaction of the fuel; sensing a vehicle speed at predetermined periods of time during the time interval and generating corresponding velocity signals (v i , v i-1 ); determining a change in kinetic energy (ΔE KE ) of the vehicle during the time interval based solely on the velocity signals and the mass of the vehicle; determining a change in potential energy (ΔE PE ) of the vehicle; determining the effective fuel economy of the vehicle based on the chemical energy, the change in kinetic energy and the change in potential energy; generating an electrical signal for receipt by the visual display corresponding to the determined effective fuel economy; and displaying the determined effective fuel economy.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the mass of the vehicle is a preselected value.
Claim 4
Dependent Claim
64 words
The method of claim 1, wherein the step of determining ΔH R comprises: determining a mass fraction of alcohol contained in the fuel (X alcohol ); determining an enthalpy of reaction of alcohol (ΔH R , alcohol); determining an enthalpy of reaction of gasoline (ΔH R , gasoline); and determining ΔH R in accordance with the formula: ΔH.sub.R ={X.sub.alcohol ×ΔH.sub.R, alcohol }+{(1-X.sub.alcohol) ×ΔH.sub.R,gasoline }.
Claim 5
Dependent Claim
72 words
The method of claim 1 wherein the step of determining the change in the potential energy includes the step of determining a pitch of the vehicle (.O slashed.) with respect to a horizontal and wherein the change in potential energy is determined in accordance with the formula: ΔE.sub.PE =m×g×v.sub.avg ×Δ.sub.t ×sin .O slashed., where g is acceleration due to gravity and v avg is an average vehicle speed during the time interval.
Claim 6
Dependent Claim
53 words
The method as recited in claim 1 wherein the step of determining the amount of chemical energy contained in the fuel includes the step of determining a mass flow rate (m f ) of the fuel and wherein the amount of chemical energy is determined in accordance with the formula: E.sub.f =m.sub.f ×ΔH.sub.R.
Claim 7
Dependent Claim
54 words
The method as recited in claim 5 wherein the vehicle includes fuel injector values which open and close to allow fuel to flow into the engine, and wherein the step of determining the mass flow rate of fuel includes the step of determining a duration of time when the fuel injector values are opened.
Claim 8
Dependent Claim
67 words
The method as recited in claim 1 wherein the step of determining the change in the potential energy includes the step of determining a change in height (h i -h i-1 ) of the vehicle above a datum plane during the time interval and wherein the change in potential energy is determined in accordance with the formula: ΔE.sub.PE =m×g×(h.sub.i -h.sub.i-1), where g is acceleration due to gravity.
Claim 9
Dependent Claim
45 words
The method as recited in claim 1 further comprising the step of determining a density (D) of the fuel, and wherein the effective fuel economy is determined in accordance with the formula: ##EQU9## where v avg is an average vehicle speed during the time interval.
Claim 10
Dependent Claim
24 words
The method as recited in claim 1 wherein the step of providing the vehicle includes the step of sensing the mass of the vehicle.
Claim 11
Dependent Claim
199 words
For use with a vehicle having a mass and a fuel consuming engine, a system for determining and displaying the effective fuel economy of the fuel consuming engine during a time interval, the system comprising: means for determining an enthalpy of reaction (ΔH R ) of the fuel, which represents the energy released per unit mass by combustion following actual injection of fuel into the engine; means for determining an amount of chemical energy contained in the fuel based on the enthalpy of reaction of fuel; a first sensor for sensing a vehicle speed at predetermined periods of time during the time interval and for generating corresponding velocity signals; means for determining a change in kinetic energy of the vehicle during the time interval based solely on the velocity signals and the mass of the vehicle; means for determining a change in potential energy of the vehicle; means for determining the effective fuel economy based on the amount of chemical energy, the change in kinetic energy and the change in potential energy; means for generating an electrical signal corresponding to the effective fuel economy; and a display for displaying the effective fuel economy upon receipt of the electrical signal.
Claim 12
Dependent Claim
199 words
For use with a vehicle having a mass and a fuel consuming engine, a system for determining and displaying the effective fuel economy of the fuel consuming engine during a time interval, the system comprising: means for determining an enthalpy of reaction (ΔH R ) of the fuel, which represents the energy released per unit mass by combustion following actual injection of fuel into the engine; means for determining an amount of chemical energy contained in the fuel based on the enthalpy of reaction of fuel; a first sensor for sensing a vehicle speed at predetermined periods of time during the time interval and for generating corresponding velocity signals; means for determining a change in kinetic energy of the vehicle during the time interval based solely on the velocity signals and the mass of the vehicle; means for determining a change in potential energy of the vehicle; means for determining the effective fuel economy based on the amount of chemical energy, the change in kinetic energy and the change in potential energy; means for generating an electrical signal corresponding to the effective fuel economy; and a display for displaying the effective fuel economy upon receipt of the electrical signal.
Claim 13
Dependent Claim
31 words
The system as recited in claim 10 wherein the means for determining the change in potential energy includes means for determining a pitch of the vehicle with respect to a horizontal.
Claim 14
Dependent Claim
20 words
The system as recited in claim 11 wherein the means for determining the pitch of the vehicle is an inclinometer.
Claim 15
Dependent Claim
27 words
The system as recited in claim 10 wherein the means for determining the change in the kinetic energy includes means for determining a mass of the vehicle.
Claim 16
Dependent Claim
21 words
The system as recited in claim 13 wherein the means for determining the mass of the vehicle is a pressure transducer.
Claim 17
Dependent Claim
19 words
The system as recited in claim 10 wherein the enthalpy of reaction of the fuel is a preselected value.
Claim 18
Dependent Claim
51 words
The system as recited in claim 10 wherein the means for determining the enthalpy of reaction of the fuel comprises: means for determining a mass fraction of alcohol contained in the fuel; means for determining an enthalpy of reaction of alcohol; and means for determining an enthalpy of reaction of gasoline.
Claim 19
Dependent Claim
28 words
The system as recited in claim 10 wherein the means for determining the amount of chemical energy includes means for determining a mass flow rate of the fuel.
Claim 20
Dependent Claim
36 words
The system as recited in claim 10 wherein the means for determining the change in potential energy includes means for determining a change in height of the vehicle above a datum plane during the time interval.
Claim 21
Dependent Claim
22 words
The system as recited in claim 18 wherein the means for determining the change in height of the vehicle is an altimeter.
Claim 22
Dependent Claim
23 words
The system as recited in claim 18 wherein the means for determining the change in height of the vehicle is a navigation device.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-26 | 2000-05-27 | 2000-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-26 | 2004-05-27 | 2004-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-26 | 2008-05-27 | 2008-11-26 | $7700.00 | Window Closed / Lapsed |