Fluid level detection apparatus, fluid level detection method, and computer-readable medium containing fluid level detection program

Patent metadata

Field	Value
Publication number	US-11385094-B2
Application number	US-202016752765-A
Country	US
Kind code	B2
Filing date	Jan 27, 2020
Priority date	Mar 14, 2019
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A fluid level detection apparatus includes a vibrator, a vibration sensor, and a controller. The vibrator is configured to apply a vibration to a container that contains a fluid. The vibration sensor is configured to detect a vibration wave that is generated by the vibrator and propagates through the container. The controller is configured to control an operation of the vibrator and perform arithmetic processing on a detection signal obtained from the vibration sensor. The vibrator and the vibration sensor are provided on an outer wall surface of the container at respective positions that interpose, from above and below, a fluid level of the fluid provided in the container. The controller is configured to calculate a height of the fluid level, on the basis of the vibration wave detected by the vibration sensor.

First claim

The invention claimed is:

1. A fluid level detection apparatus comprising:
a vibrator configured to apply a vibration to a container that contains a fluid;
a vibration sensor configured to detect a vibration wave that is generated by the vibrator and propagates through the container; and
a controller configured to control an operation of the vibrator and perform arithmetic processing on a detection signal obtained from the vibration sensor, wherein,
the vibrator and the vibration sensor being provided on an outer wall surface of the container at respective positions that interpose, from above and below, a fluid level of the fluid provided in the container,
the controller being configured to calculate a height of the fluid level, on a basis of the vibration wave detected by the vibration sensor,
the controller is configured to cause the vibrator to generate, as the vibration, an ultrasonic vibration that covers a predetermined frequency range, and
the controller is configured to calculate, as the height of the fluid level, a nominal value of the height of the fluid level on a basis of a high frequency component in the vibration wave detected by the vibration sensor, and correct the nominal value on a basis of a low frequency component in the vibration wave detected by the vibration sensor, the high frequency component being higher than a first predetermined frequency, the low frequency component being lower than a second predetermined frequency.

2. The fluid level detection apparatus according to claim 1 , further comprising a temperature sensor configured to measure a temperature of the fluid provided in the container, wherein
the controller is configured to correct the height of the calculated fluid level on a basis of the temperature measured by the temperature sensor.

3. The fluid level detection apparatus according to claim 2 , wherein
the controller is configured to cause the vibrator to generate, as the vibration, an ultrasonic vibration that covers a predetermined frequency range, and
the controller is configured to calculate, as the height of the fluid level, a nominal value of the height of the fluid level on a basis of a high frequency component in the vibration wave detected by the vibration sensor, and correct the nominal value on a basis of a low frequency component in the vibration wave detected by the vibration sensor, the high frequency component being higher than a first predetermined frequency, the low frequency component being lower than a second predetermined frequency.

4. The fluid level detection apparatus according to claim 3 , wherein
the vibrator comprises at least three vibrators provided at respective positions that are different from each other within a horizontal plane of the container that is in an ordinary state, the ordinary state being a state in which the container is not tilted, and
the vibration sensor comprises at least three vibration sensors provided at respective positions that correspond to the at least three vibrators and that are different from each other within the horizontal plane of the container that is in the ordinary state.

5. The fluid level detection apparatus according to claim 4 , wherein the controller is configured to cause the at least three vibrators to apply, to the container, the vibrations at frequencies that are different from each other.

6. The fluid level detection apparatus according to claim 2 , wherein
the vibrator comprises at least three vibrators provided at respective positions that are different from each other within a horizontal plane of the container that is in an ordinary state, the ordinary state being a state in which the container is not tilted, and
the vibration sensor comprises at least three vibration sensors provided at respective positions that correspond to the at least three vibrators and that are different from each other within the horizontal plane of the container that is in the ordinary state.

7. The fluid level detection apparatus according to claim 6 , wherein the controller is configured to cause the at least three vibrators to apply, to the container, the vibrations at frequencies that are different from each other.

8. The fluid level detection apparatus according to claim 1 , wherein
the vibrator comprises at least three vibrators provided at respective positions that are different from each other within a horizontal plane of the container that is in an ordinary state, the ordinary state being a state in which the container is not tilted, and
the vibration sensor comprises at least three vibration sensors provided at respective positions that correspond to the at least three vibrators and that are different from each other within the horizontal plane of the container that is in the ordinary state.

9. The fluid level detection apparatus according to claim 8 , wherein the controller is configured to cause the at least three vibrators to apply, to the container, the vibrations at frequencies that are different from each other.

10. The fluid level detection apparatus according to claim 2 , wherein the fluid level detection apparatus is mounted on an aircraft and configured to detect the fluid level of a lubricant serving as the fluid and provided in a lubricant sump of the aircraft, or detect the fluid level of a fuel serving as the fluid and provided in a fuel tank of the aircraft.

11. The fluid level detection apparatus according to claim 3 , wherein the fluid level detection apparatus is mounted on an aircraft and configured to detect the fluid level of a lubricant serving as the fluid and provided in a lubricant sump of the aircraft, or detect the fluid level of a fuel serving as the fluid and provided in a fuel tank of the aircraft.

12. The fluid level detection apparatus according to claim 1 , wherein
the vibrator comprises at least three vibrators provided at respective positions that are different from each other within a horizontal plane of the container that is in an ordinary state, the ordinary state being a state in which the container is not tilted, and
the vibration sensor comprises at least three vibration sensors provided at respective positions that correspond to the at least three vibrators and that are different from each other within the horizontal plane of the container that is in the ordinary state.

13. The fluid level detection apparatus according to claim 12 , wherein the controller is configured to cause the at least three vibrators to apply, to the container, the vibrations at frequencies that are different from each other.

14. The fluid level detection apparatus according to claim 1 , wherein the fluid level detection apparatus is mounted on an aircraft and configured to detect the fluid level of a lubricant serving as the fluid and provided in a lubricant sump of the aircraft, or detect the fluid level of a fuel serving as the fluid and provided in a fuel tank of the aircraft.

15. The fluid level detection apparatus according to claim 1 , wherein the fluid level detection apparatus is mounted on an aircraft and configured to detect the fluid level of a lubricant serving as the fluid and provided in a lubricant sump of the aircraft, or detect the fluid level of a fuel serving as the fluid and provided in a fuel tank of the aircraft.

16. A fluid level detection method comprising:
providing a vibrator and a vibration sensor on an outer wall surface of a container at respective positions that interpose, from above and below, a fluid level of a fluid provided in the container, the vibrator being configured to apply a vibration to the container that contains the fluid, the

Assignees

• Subaru Corp

Inventors

• Tomizawa Tsutomu
• Murata Iwao
• Takahashi Kohei
• Hori Keiji

Classifications

• G01F23/808

  containing circuits handling parameters other than liquid level · CPC title

• G01K1/22

  by means of fluid contained in a hollow body having parts which are deformable or displaceable under the pressure developed by the fluid · CPC title

• G01F23/2961 Primary

  for discrete levels (G01F23/2962 - G01F23/2968 take precedence) · CPC title

• G01F23/296

  Acoustic waves · CPC title

• G01D3/0365

  the undesired influence being measured using a separate sensor, which produces an influence related signal · CPC title