Method and apparatus for measuring the quantity of a liquid in a vehicle container

• US 6,892,572 B2
• Filed: 09/09/2003
• Issued: 05/17/2005
• Est. Priority Date: 05/09/1994
• Status: Expired due to Fees

• Current Assignee: American Vehicular Sciences LLC (Acacia Research Corporation)
• Original Assignee: Automotive Technologies International Incorporated
• Inventors: Breed, David S., Johnson, Wendell C., DuVall, Wilbur E.
• Primary Examiner(s): CYGAN, MICHAEL T
• Application Number:
  US10/658,750
• Publication Number:
  US 20040079150A1
• Time in Patent Office: 616 Days
• Field of Search: 732/90.R, 732/96, 73/17.3, 340/618, 340/613, 702/55
• US Class Current: 73/290.00R
• CPC Class Codes: B60J 10/00 Sealing arrangements
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60R 21/0136 responsive to actual contact with an obstacle , e.g. to vehicle deformation, bumper displacement or bumper velocity relative to the vehicle monitoring crash strength in combination with passenger seat detection B60R21/01558
• CPC Class Codes: G01F 23/20 by measurement of weight, e.g. to determine the level of stored liquefied gas
• CPC Class Codes: G01F 23/263 by measuring variations in capacitance of capacitors
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/36 using electrically actuated indicating means G01F23/38 takes precedence
• CPC Class Codes: G01F 23/804 containing circuits handling parameters other than liquid level

Abstract

Apparatus and method for measuring the volume of a liquid in a fuel tank in a vehicle subject to varying external forces caused by movement or changes in the roll and pitch angles of the vehicle wherein the tank is mounted to the vehicle and subject to forces along the yaw axis of the vehicle. One or more tank load cells provides an output proportionally representing the load thereon. The load cells are placed between a portion of the tank and a portion of a reference surface of the vehicle and are sensitive along an axis that is substantially normal to the mounting surface and generally parallel to the yaw axis of the vehicle. A processor executes a derived relationship between the load cell output and the volume of fuel in the tank so as to convert the output signal from the load cell into output information representative of the volume of the fuel in the tank.

Claims

1. A method for measuring the volume of a liquid in a fuel tank in a vehicle subject to varying external forces caused by movement or changes in the roll and pitch angles of the vehicle, comprising the steps of:

conducting a plurality of measurements, each measurement including the known volume of the tank and the value of at least three parameters concerning the tank, at least one of the parameters being the pitch or roll angle of the vehicle as determined by an inertial measurement unit (IMU),

generating an algorithm from the plurality of measurements for determining the volume of fuel in the tank upon the receipt of current values of the parameters,

inputting the algorithm into a processor arranged in connection with the vehicle,

measuring the same parameters during operation of the vehicle, and

inputting the measured parameters into the algorithm in the processor such that the algorithm provides the volume of fuel in the tank.

2. The method of claim 1, wherein the remaining ones of the parameters is selected from the group consisting of the load of the tank on a load cell arranged at a first location, the load of the tank on a load cell arranged at a second location, the load of the tank at a load cell arranged at a third location, the height of the fuel at a first location in the tank, the height of the fuel at a second location in the tank and the height of the fuel at a third location in the tank.

3. The method of claim 1, wherein the at least three parameters include the pitch angle of the vehicle and the roll angle of the vehicle, the pitch and roll angle being determined by the IMU.

4. The method of claim 1, wherein the IMU contains three accelerometers and three gyroscopes.

5. The method of claim 1, wherein the at least three parameters include the load of the tank on a load cell arranged at a first location, the pitch angle of the vehicle and the roll angle of the vehicle, the pitch and roll angle being determined by the IMU.

6. The method of claim 1, wherein the at least three parameters include the load of the tank on a first load cell at a first location, the load of the tank on a second load cell at a second location, and the load of the tank on a third load cell at a third location.

7. The method of claim 6, further comprising the steps of:

mounting the tank to the vehicle such that it is subjected to forces along the yaw axis of the vehicle, and

arranging the first, second and third load cells between different portions of the tank and the vehicle such that they are sensitive along an axis that is generally parallel to the yaw axis of the vehicle.

8. The method of claim 6, further comprising the step of:

arranging the first, second and third load cells between the different portions of the tank and a portion of a common reference surface of the vehicle, the load cells being sensitive along an axis that is substantially normal to said surface.

9. The method of claim 1, further comprising the step of:

displaying a signal representative of the volume of fuel contained in the tank.

10. The method of claim 1, further comprising the step of:

placing a skirt under the tank to prevent the build up of mud or ice.

11. The method of claim 1, further comprising the steps of:

determining the specific gravity of the fuel in the tank, and

inputting the specific gravity into the algorithm to be considered in a determination of the quantity of fuel in the tank.

15. The method of claim 1, wherein the IMU contains three accelerometers and three gyroscopes.

12. An apparatus for measuring the volume of a liquid in a fuel tank in a vehicle that is subject to varying external forces caused by movement or changes in the roll and pitch angles of the vehicle, comprising:

a fuel tank mounted to the vehicle and subject to forces along a yaw axis of the vehicle;

measuring means for measuring at least three parameters relating to said tank or the vehicle and generating output signals representative of the at least three parameters, said measuring means including an inertial measurement unit (IMU) arranged to determine at least one of a pitch and roll angle of the vehicle; and

computational means coupled to said measuring means for receiving the output signals and processing the output signals to obtain a volume of fuel in said tank, said computational means comprising means for storing an algorithm representative of a derived relationship between the at least three parameters and the volume of fuel in said tank and applying the algorithm using said output signals as input to obtain the volume of fuel in said tank,

said algorithm being obtained by conducting a plurality of measurements, each measurement including the known volume of the tank and said output signals from said measuring means.

13. The apparatus of claim 12, wherein said IMU contains three accelerometers and three gyroscopes.

14. The apparatus of claim 12, wherein each measurement includes the pitch angle and the roll angle of the vehicle as determined by said IMU.

16. A method for measuring the volume of a liquid in a fuel tank in a vehicle that is subject to varying external forces caused by movement or changes in the roll and pitch angles of the vehicle, comprising the steps of:

generating an algorithm for use on the vehicle by placing a known quantity of fuel into the tank, collecting data from a plurality of sensor systems arranged in connection with the vehicle under various conditions from an at rest position to a driving state over a variety of road surfaces, repeatedly changing the quantity of fuel in the tank and collecting additional data from the sensor systems, inputting the data concerning the quantity of fuel in the tank and the data collected from the plurality of sensor systems into a neural network generating program to obtain an algorithm,

installing the algorithm onto a component in the vehicle,

obtaining data from the plurality of sensor systems during operation of the vehicle, and

inputting the data from the plurality of sensor systems into the algorithm to obtain the quantity of fuel in the tank,

wherein at least one of the sensor systems is an inertial measurement unit (IMU) and the data provided by the IMU is the pitch angle and roll angle of the vehicle.

17. The method of claim 16, wherein the IMU contains three accelerometers and three gyroscopes.