Claims
- 1. Apparatus for determining liquid level in a container, wherein the container can be subjected to attitude variations, comprising: a plurality of transducers for emitting acoustic energy into the liquid in a plurality of different predetermined directions relative to a reference towards the liquid surface from a position below the liquid surface and for receiving echoes; and control electronics means for determining liquid level height based on echo amplitude and time delay between said emissions and detection of said echoes.
- 2. The apparatus according to claim 1 wherein each said transducer is disposed at an angular offset with respect the other transducers such that each transducer emits acoustic energy towards the liquid surface at a respective angle relative to a reference.
- 3. The apparatus of claim 2 wherein said transducers are disposed along an arc that extends from a bottom wall of the container.
- 4. The apparatus of claim 2 wherein each transducer detects a maximum echo energy reflected from the liquid surface when the surface is normal to the respective direction of acoustic energy transmitted from the transducer.
- 5. The apparatus of claim 2 wherein each transducer detects a maximum echo energy reflected by the liquid surface based on the attitude of the container with respect to said reference.
- 6. The apparatus of claim 5 wherein said control electronics means detects attitude of the container based on which of said transducers detects a maximum echo amplitude.
- 7. The apparatus of claim 1 wherein said plurality of transducers are arranged in a transducer array; said apparatus further comprising means for energizing said transducers so as to produce a steered beam of acoustic energy directed towards the liquid surface at different angles with respect to a reference.
- 8. The apparatus of claim 7 wherein maximum echo energy corresponds to said steered beam impinging the liquid surface substantially normal thereto.
- 9. The apparatus of claim 1 wherein said control electronics means activates each said transducer to transmit acoustic energy in short duration pulses at a repetition rate that is high relative to liquid surface disturbances.
- 10. A method for determining liquid level in a container without the use of a stillwell, wherein the container can be subjected to attitude variations, comprising the steps of:emitting acoustic energy into the liquid in a plurality of different predetermined directions relative to a reference towards the liquid surface using a plurality of transducers; receiving acoustic echoes using said transducers; and determining liquid level height based on echo amplitude and time delay between said emissions and detection of said echoes.
- 11. The method of claim 10 wherein said transducers are disposed at different angles relative to a reference such that each transducer emits acoustic energy towards the liquid surface at a discrete predetermined angle.
- 12. The method of claim 10 wherein said transducers are energized so as to produce a steered acoustic transmission beam to compensate for attitude of the container.
- 13. Liquid gauging apparatus for an aircraft fuel tank, comprising: transducer means for emitting acoustic energy into a liquid in the tank in a plurality of predetermined directions towards the liquid surface from a position below the liquid surface and for receiving echoes; and signal conditioning means for determining liquid level height based on echo amplitude and time delay between said emissions and detection of said echoes.
- 14. The apparatus of claim 13 wherein said transducer means produces a steered acoustic energy beam directed towards the liquid surface.
- 15. The apparatus of claim 13 wherein said transducer means produces a number of discrete acoustic energy beams each directed towards the liquid surface at a respective angle relative to a reference.
- 16. The apparatus of claim 15 wherein said transducer means comprises an angled transducer array such that each transducer directs ultrasonic acoustic energy towards the liquid surface at a predetermined angle relative to the reference.
Parent Case Info
This is a continuation of copending application Ser. No. 08/223,688 filed on Apr. 6, 1994.
US Referenced Citations (13)
Foreign Referenced Citations (4)
Number |
Date |
Country |
2433133 |
Feb 1975 |
DE |
4014990 |
Nov 1991 |
DE |
4025326 |
Nov 1991 |
DE |
5569024 |
May 1980 |
JP |
Continuations (1)
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Number |
Date |
Country |
Parent |
08/223886 |
Apr 1994 |
US |
Child |
08/720268 |
|
US |