Method and apparatus for calculating corrected vehicle fuel economy

• US 4,845,630 A
• Filed: 03/23/1987
• Issued: 07/04/1989
• Est. Priority Date: 03/23/1987
• Status: Expired due to Fees

• Current Assignee: PACCAR Incorporated
• Original Assignee: PACCAR Incorporated
• Inventors: Stephens, Donald L.
• Primary Examiner(s): Chin, Gary
• Application Number:
  US07/029,271
• Time in Patent Office: 834 Days
• Field of Search: 73/112, 73/113, 73/114, 73/117.3, 364/442, 364/565, 364/424, 340/52 R
• US Class Current: 701/123
• CPC Class Codes: G01F 9/001 with electric, electro-mechanic or electronic means G01F9/008 and G01F9/02 take precedence
• CPC Class Codes: G01F 9/023 with electric, electro-mechanic or electronic means

Abstract

A method and apparatus for calculating a corrected fuel economy rate. A fuel-consuming engine that propels a ground vehicle has at least one fuel rate sensor for measuring the fuel consumption rate of the engine. The apparatus further comprises a sensor for measuring the distance travelled by the ground vehicle. Digital counters accumulate pulse counts from the sensors and the pulse counts are processed by a microprocessor to calculate the distance travelled by the ground vehicle, the fuel consumed by the engine, and the change of the kinetic energy of the vehicle. The microprocessor then corrects the fuel consumed by subtracting the weighted change of the kinetic energy of the vehicle over the sampling period. The microprocessor then calculates the ratio of the distance travelled to the corrected fuel consumed to produce a corrected fuel economy rate, or its reciprocal. The ratio can be displayed on a digital display.

Claims

1. A vehicle fuel economy meter for adjusting the value of a distance traveled by the vehicle per unit of fuel consumed by the vehicle, including means for measuring the speed of the vehicle during a measurement period, means for measuring the change of kinetic energy of the vehicle from measured speeds of the vehicle, and electronic circuitry for adjusting the value in which the value is increased by the change of kinetic energy of the vehicle during the measurement period when the vehicle speed is increasing from a lower value to a higher value, and correspondingly decreased during the measurement period when the vehicle speed is decreasing from a higher value to a lower value.

2. A vehicle fuel economy meter for adjusting the value of a distance traveled by the vehicle per unit of fuel consumed by the vehicle, including means for measuring the speed of the vehicle during a measurement period, means for measuring the change of kinetic energy of the vehicle from measured speeds of the vehicle, and electronic circuitry for adjusting the value in which the consumed fuel equivalent of the change of vehicle kinetic energy in the distance traveled is a fuel decreasing factor in the calculation of the distance traveled per unit of fuel consumed for an increasing vehicle speed from a lower value to a higher value and in which the consumed fuel equivalent of the change of vehicle kinetic energy in the distence traveled is fuel increasing factor in the calculation of distance traveled per unit of fuel consumed for a decreasing vehicle speed from a higher value to a lower value.

3. A fuel economy measurement apparatus for use in a ground vehicle propelled by an engine that consumes a fuel, comprising:

means for producing signals that measure a predetermined interval of time, the interval having a beginning and an end;

means for producing signals that measure a distance traveled by the vehicle in the interval of time;

means for producing signals that measure the fuel consimed by the engine in the interval of time; and

means for receiving the time interval, distance traveled and fuel consumption signals and calculating a corrected fuel consumption of the engine in the interval of time by subtracting a weighted difference of the kinetic energies of the ground vehicle at the end and at the beginning of the interval of time from the measured fuel consumed in the interval of time, and for calculating a value of a ratio of the distance traveled by the ground vehicle in the interval of time and the corrected fuel consumption.

4. The fuel economy measurement apparatus of claim 3 wherein the means for calculating is a microprocessor.

5. The apparatus of claim 4, further comprising read-only memory (ROM) for storing a program for the microprocessor and random-access memory (RAM) for storing one or more values of data generated by the program, wherein the ROM and RAM are connected to the microprocessor.

6. The fuel economy measurement apparatus of claim 5 wherein the microprocessor calculates the difference of the kinetic energies of the ground vehicle at the end and the beginning of the interval of time, based on stored values of the measured fuel consumption rate over the interval of time.

7. A fuel economy measurement apparatus for use in a ground vehicle, propelled by an engine that consumes a fuel, comprising:

means for producing signals that measure a predetermined interval of time, the interval having a beginning and an end;

means for producing signals that measure a distance traveled by the ground vehicle in the interval of time;

means for producing signals that measure the fuel consumed by the engine in the interval of time;

a microprocessor for receiving the time interval, distance travelled, and fuel consumption signals and calculating a corrected fuel consumption of the engine in the interval of time by subtracting a weighted difference of the kinetic energies of the ground vehicle at the end and the beginning of the interval of time from the measured fuel consumed in the interval of time, and for calculating a value of a ratio of the distance traveled by the ground behicle in the interval of time and the corrected fuel consumption; and

means for displaying the value of the ratio.

8. The fuel economy measurement apparatus of claim 7 wherein the display means is a digital display.

9. A method of measuring a corrected fuel economy rate of a fuel-consuming engine in a ground vehicle, the method comprising the steps of:

(A) producing signals that measure a predetermined interval of time, the interval having a beginning and an end;

(B) producing signals that measure a distance traveled by the ground vehicle in the interval of time;

(C) producing signals that measure the fuel consumed by the engine in the interval of time;

(D) receiving the time interval, distance traveled, and fuel consumption signals and calculating the kinetic energy of the ground vehicle at the end and at the beginning of the time interval;

(E) calculating a corrected fuel consumption of the engine in the interval of time by subtracting a weighted difference of the kinetic energies. of the ground vehicle at the end and at the beginning of the interval of time from the measured fuel consumption in the interval of time; and

(F) calculating a value of a ratio of the corrected fuel consumption and the distance traveled by the ground vehicle in the interval of time.

10. The method of claim 9, further comprising the step of displaying the calculated ratio.

11. A fuel economy measurement apparatus for use in a ground vehicle propelled by an engine that consumes a fuel, comprising:

means for producing signals that measure a predetermined interval of distance traveled by the ground vehicle, the interval having a beginning and an end;

means for producing signals that measure the fuel consumed by the engine in the interval of distance; and

means for receiving signals that measure the predetermined interval of distance traveled by the ground vehicle and the signals that measure the fuel consumed by the engine in the interval of distance and calculating a corrected fuel consumption of the engine in the interval of distance by subtracting a weighted difference of the kinetic energies of the ground vehicle at the end and at the beginning of the interval of distance from the measured fuel consumed in the interval of distance, and for calculating a value of a ratio of the interval of the distance traveled by the ground vehicle and the corrected fuel consumption.

12. The fuel economy measurement apparatus of claim 11 wherein the signal-receiving and calculating means is a microprocessor.

13. The apparatus oflaim 12, further comprising read-only memory (ROM) for storing a program for the microprocessor and random-access memory (RAM) for storing one or more values of data generated by the program, the ROM and RAM being connected to the microprocessor.

14. The fuel economy measurement apparatus of claim 13 wherein the RAM stored values of the measured fuel consumed in the interval of distance and said microprocessor calculates the difference of the kinetic energies of the ground vehicle at the end and at the beginning of the interval of distance, based on the values stored in the RAM.

15. A fuel economy measurement apparatus for use in a ground vehicle propelled by an engine that consumes a fuel, comprising:

means for producing signals that measure an interval of distance traveled by the ground vehicle in a predetermined interval of time, the interval of distance having a beginning and an end;

means for producing signals that measure the fuel consumed by the engine in the predetermined interval of time;

a microprocessor for receiving signals that measure the predetermined interval of distance traveled by the ground vehicle and the signals that measure the fuel consumed by the engine in the interval of distance and calculating a corrected fuel consumption of the engine in the predetermined interval of time by subtracting a weighted difference of the kinetic energies of the ground vehicle at the end and at the beginning of the interval of distance from the measured fuel consumed in the interval of distance, and for calculating a value of a ratio of the interval of distance and the corrected fuel cinsumption; and

means for displaying the ratio.

16. The fuel economy measurement apparatus of claim 15 wherein the display means is a digital display.

17. A method of measuring a corrected fuel economy rate of a fuel-consuming engine in a ground vehicle, the method comprising the steps of:

(A) producing signals that measure an interval of distance traveled by the ground vehicle in a predetermined interval of time, the interval of time having a beginning and an end;

(B) producing signals that measure the kinetic energy of the vehicle at the beginning and at the end of the interval of time;

(C) measuring the fuel consumed by the engine in the interval of time to produce a measured fuel consumption rate;

(D) calculating a corrected fuel consumption rate of the engine in the interval of distance by substracting a weighted difference of the kinetic energies of the ground vehicle at the end and at the beginning of the interval of time from the measured fuel consumption rate over the interval of time; and

(E) calculating a value of a ratio of the corrected fuel consumption rate and the interval of distance.

18. The method of claim 17, further comprising the step of displaying the ratio.

19. A vehicle fuel economy meter for adjusting the value of the fuel consumed by the vehicle per unit of distance traveled by the vehicle, including means for measuring the speed of the vehicle during a measurement period, means for measuring the change of kinetic energy of the vehicle from measured speeds of the vehicle, and electronic circuitry for adjusting the value in which the value is decreased by the change of kinetic energy of the vehicle during the measurement period when the vehicle speed is increasing from a lower value to a high value, and correspondingly increased during the measurement period when the vehicle speed is decreasing from a higher value to a lower value.

20. A vehicle fuel economy meter for adjusting the value of the consumed by the vehicle per unit of distance traveled by the vehicle, including means for measuring the speed of the vehicle during a measurement period, means for measuring the change of kinetic energy of the vehicle from measured speeds of the vehicle, and electronic circuitry for adjusting the value in which the consumed fuel equivalent of the change of vehicle kinetic energy in the distance traveled is a fuel decreasing factor in the calculation of the fuel consumed per unit of distance traveled for an increasing vehicle speed from a lower value to a higher value, and in which the consumed fuel equivalent of the change of vehicle kinetic energy in the distance traveled is a fuel increasing factor in the calculation of distance traveled per unit of fuel consumed for a decreasing vehicle speed from a higher value to a lower value.

21. A method for measuring fuel economy in a ground vehicle propelled by an engine that consumes a fuel, comprising the steps of:

(A) measuring a distance interval traveled by the vehicle;

(B) measuring the fuel consumed by the vehicle in the distance interval;

(C) generating a value corresponding to a change in kinetic energy of the vehicle in the distance interval; and

(D) calculating a fuel economy value based on the fuel consumed by the vehicle and said value corresponding to the change in kinetic energy of the vehicle.

22. The method of claim 21, further comprising the step of displaying the fuel economy value.

23. A method for measuring fuel economy in a ground vehicle propelled by an engine that consumes a fuel, comprising the steps of:

(A) measuring the fuel consumed by the vehicle in a time interval;

(B) generating a value corresponding to a change in kinetic energy of the vehicle in the time interval; and

(C) calculating a fuel economy value based on the fuel consumed by the vehicle and said value corresponding to the change in kinetic energy of the vehicle.

24. The method of claim 23, further comprising the step of displaying the fuel economy value.

25. A fuel economy measurement apparatus for use in a ground vehicle propelled by an engine that consumes a fuel, comprising:

means for measuring a distance interval traveled by the vehicle;

means for measuring the fuel consumed by the vehicle in the distance interval;

means for generating a value corresponding to a change in kinetic energy of the vehicle in the distance interval; and

means for calculating a fuel economy value based on the fuel consumed by the vehicle and said value corresponding to the change in kinetic energy of the vehicle.

26. The fuel economy measurement apparatus of claim 25, further comprising means for displaying the fuel economy value.

27. A fuel economy measurement apparatus for use in a ground vehicle propelled by an engine that consumes a fuel, comprising:

means for measuring the fuel consumed by the vehicle in a time interval;

means for generating a value corresponding to a change in kinetic energy of the vehicle in the time interval; and

means for calculating a fuel economy value based on the fuel consumed by the vehicle and said value corresponding to the change in kinetic energy of the vehicle.

28. The fuel economy measurement apparatus of claim 27, further comprising means for displaying the fuel economy value.

29. A fuel economy display and measuring apparatus for a vehicel, comprising:

a fuel sensor for measuring the amount of fuel consumed by said vehicle in a predetermined time period;

a distance sensor for measuring a distance traveled by said vehicle in said predetermined time period;

an electronic circuit for determining a measured fuel economy value based on said fuel consumed and said distance traveled;

means for determining changes in said vehicle'"'"'s kinetic energy in said predetermined time period;

an electronic circuit foe generating a modified fuel economy value based on said changes in said vehicle'"'"'s kinetic energy and said measured fuel economy value; and

a visual display for displaying said modified fuel economy value.

30. The apparatus according to claim 29 wherein said means for determining changes in said vehicle'"'"'s kinetic energy includes means for inputting said vehicle'"'"'s mass.

31. The apparatus according to claim 29 wherein said electronic circuit for generating said modified value includes means for modifying said measured fuel consumed.

32. The apparatus according to claim 29 wherein said electronic circuit for generating said modified value includes means for modifying siad measured distance traveled.