Apparatus and method for dynamic peak detection, identification, and tracking in level gauging applications

• US 8,224,594 B2
• Filed: 08/03/2009
• Issued: 07/17/2012
• Est. Priority Date: 09/18/2008
• Status: Active Grant

• Current Assignee: Enraf B. V.
• Original Assignee: Enraf B. V.
• Inventors: Sai, Bin
• Primary Examiner(s): Huynh, Phuong
• Application Number:
  US12/534,679
• Publication Number:
  US 20100070208A1
• Time in Patent Office: 1,079 Days
• Field of Search: 702 55- 78, 702/103, 702/104, 702182-190
• US Class Current: 702/55
• CPC Class Codes: G01F 23/284 Electromagnetic waves

Abstract

A method includes receiving data identifying wireless signals including wireless signals reflected off a surface of material in a tank and detecting a plurality of reflection peaks associated with the wireless signals. The method also includes classifying at least some of the detected reflection peaks and tracking at least some of the classified reflection peaks. The method further includes identifying a level of the material using at least one of the tracked reflection peaks. The classified peaks could include main-mode and/or high-mode reflection peaks, where the material level is identified using the main-mode peak or using an estimated location of the main-mode peak based on the high-mode peak. The classified peaks could also include level, bottom, and obstruction peaks, where the material level is identified by using a known permittivity, the bottom peak, and a tank height to estimate a location of the level peak when the level peak is lost or obscured.

Claims

1. A method comprising:

identifying a level of material in a tank using at least one processing device, wherein identifying the level of the material in the tank comprises;

receiving data identifying wireless signals including wireless signals reflected off a surface of the material in the tank;

detecting a plurality of reflection peaks associated with the wireless signals;

classifying at least one of the detected reflection peaks including a bottom peak associated with a bottom of the tank;

tracking at least one of the classified reflection peaks; and

identifying the level of the material in the tank using a known permittivity based on a previously-tracked level reflection peak, the bottom peak, and a known height of the tank to estimate a location of a level peak associated with the material when the level peak is lost or obscured by interference.

2. The method of claim 1, further comprising:

performing dynamic screening of the detected reflection peaks to reduce a number of reflection peaks that are classified during the classification.

3. The method of claim 2, wherein performing the dynamic screening comprises:

filtering all peaks associated with a distance greater than a specified maximum distance.

5. The method of claim 1, wherein classifying at least one of the detected reflection peaks comprises:

comparing positions of at least two of the reflection peaks to a specified position; and

comparing amplitudes of at least two of the reflection peaks.

6. The method of claim 5, wherein the at least two reflection peaks are initially selected to perform bottom detection in the tank.

7. The method of claim 1, further comprising:

constructing a profile of obstructions in the tank using at least one of the classified reflection peaks; and

identifying one of the tracked reflection peaks as the reflection peak associated with the wireless signals reflected off the surface of the material using the profile.

8. The method of claim 1, wherein detecting the plurality of reflection peaks associated with the wireless signals comprises detecting all reflection peaks associated with the wireless signals.

9. The method of claim 1, wherein:

classifying at least one of the detected reflection peaks comprises classifying the level peak associated with the material in the tank, the bottom peak associated with the bottom of the tank, and an obstruction peak associated with an obstruction in the tank; and

tracking at least one of the classified reflection peaks comprises tracking the level peak, the bottom peak, and the obstruction peak and associating a confidence level with each peak.

4. A method comprising:

identifying a level of material in a tank using at least one processing device, wherein identifying the level of the material in the tank comprises;

receiving data identifying wireless signals including wireless signals reflected off a surface of the material in the tank;

detecting a plurality of reflection peaks associated with the wireless signals;

classifying at least one of the detected reflection peaks;

tracking at least one of the classified reflection peaks; and

identifying the level of the material in the tank using at least one of the tracked reflection peaks;

wherein classifying at least one of the detected reflection peaks comprises detecting at least one of;

(i) a main-mode reflection peak associated with the wireless signals reflected off the surface of the material and (ii) a high-mode reflection peak associated with wireless transmission through a stillpipe in the tank;

wherein, if the main-mode reflection peak is classified, the level of the material in the tank is identified using the main-mode reflection peak; and

wherein, if the main-mode reflection peak is not classified, the high-mode reflection peak is used to estimate a location of the main-mode reflection peak, the level of the material in the tank is identified using the estimated location of the main-mode reflection peak, and a confidence level is associated with the identified level.

10. An apparatus comprising:

a data acquisition unit configured to generate data associated with received wireless signals including wireless signals reflected off a surface of material in a tank; and

at least one processing device configured to;

detect a plurality of reflection peaks associated with the wireless signals;

classify at least one of the detected reflection peaks;

track at least one of the classified reflection peaks; and

identify a level of the material in the tank using at least one of the tracked reflection peaks;

wherein the at least one processing device is configured to classify at least one of the detected reflection peaks by detecting at least one of;

(i) a main-mode reflection peak associated with the wireless signals reflected off the surface of the material and (ii) a high-mode reflection peak associated with wireless transmission through a stillpipe in the tank;

wherein the at least one processing device is configured to identify the level of the material in the tank using the main-mode reflection peak if the main-mode reflection peak is classified; and

wherein the at least one processing device is configured to estimate a location of the main-mode reflection peak using the high-mode reflection peak, identify the level of the material in the tank using the estimated location of the main-mode reflection peak, and associate a confidence level with the identified level if the main-mode reflection peak is not classified.

11. The apparatus of claim 10, wherein the at least one processing device is further configured to perform dynamic screening of the detected reflection peaks to reduce a number of reflection peaks that are classified during the classification.

12. The apparatus of claim 10, wherein:

the at least one processing device is configured to classify a level peak associated with the material in the tank, a bottom peak associated with a bottom of the tank, and an obstruction peak associated with an obstruction in the tank;

the at least one processing device is configured to track the level peak, the bottom peak, and the obstruction peak and to associate a confidence level with each peak; and

the at least one processing device is configured to identify the level of the material in the tank using a known permittivity based on a previously-tracked level reflection peak, the bottom peak, and a known height of the tank to estimate a location of the level peak when the level peak is lost or obscured by interference.

13. The apparatus of claim 10, wherein the at least one processing device is configured to classify at least one of the detected reflection peaks by:

comparing positions of at least two of the reflection peaks to a specified position; and

comparing amplitudes of at least two of the reflection peaks.

14. The apparatus of claim 10, wherein the at least one processing device is further configured to:

construct a profile of obstructions in the tank using at least one of the classified reflection peaks; and

identify one of the tracked reflection peaks as the reflection peak associated with the wireless signals reflected off the surface of the material using the profile.

16. The apparatus of claim 10, wherein the at least one processing device comprises a digital signal processor.

17. The apparatus of claim 10, further comprising:

a controller configured to control operation of the apparatus.

15. An apparatus comprising:

a data acquisition unit configured to generate data associated with received wireless signals including wireless signals reflected off a surface of material in a tank; and

at least one processing device configured to;

detect a plurality of reflection peaks associated with the wireless signals;

classify at least some of the detected reflection peaks;

track at least some of the classified reflection peaks; and

identify a level of the material in the tank using at least some of the tracked reflection peaks;

wherein the at least one processing device is configured to classify a level peak associated with the material in the tank, a bottom peak associated with a bottom of the tank, and an obstruction peak associated with an obstruction in the tank;

wherein the at least one processing device is configured to track at least the level peak, the bottom peak, and the obstruction peak and to associate a confidence level with each peak; and

wherein the at least one processing device is configured to identify the level of the material in the tank using a known permittivity based on a previously-tracked level reflection peak, the bottom peak, and a known height of the tank to estimate a location of the level peak when the level peak is lost or obscured by interference.

18. A non-transitory computer readable medium embodying a computer program executable by at least one processing device, the computer program comprising:

computer readable program code for receiving data identifying wireless signals including wireless signals reflected off a surface of material in a tank;

computer readable program code for detecting a plurality of reflection peaks associated with the wireless signals;

computer readable program code for classifying at least one of the detected reflection peaks including a bottom peak associated with a bottom of the tank;

computer readable program code for tracking at least one of the classified reflection peaks; and

computer readable program code for identifying a level of the material in the tank using a known permittivity based on a previously-tracked level reflection peak, the bottom peak, and a known height of the tank to estimate a location of a level peak associated with the material when the level peak is lost or obscured by interference.

20. The non-transitory computer readable medium of claim 18, wherein the computer readable program code for classifying at least one of the detected reflection peaks comprises:

computer readable program code for comparing positions of at least two of the reflection peaks to a specified position; and

computer readable program code for comparing amplitudes of at least two of the reflection peaks.

19. A non-transitory computer readable medium embodying a computer program executable by at least one processing device, the computer program comprising:

computer readable program code for receiving data identifying wireless signals including wireless signals reflected off a surface of material in a tank;

computer readable program code for detecting a plurality of reflection peaks associated with the wireless signals;

computer readable program code for classifying at least one of the detected reflection peaks;

computer readable program code for tracking at least one of the classified reflection peaks; and

computer readable program code for identifying a level of the material in the tank using at least one of the tracked reflection peaks;

wherein the computer readable program code for classifying at least one of the detected reflection peaks comprises computer readable program code for detecting at least one of;

(i) a main-mode reflection peak associated with the wireless signals reflected off the surface of the material and (ii) a high-mode reflection peak associated with wireless transmission through a stillpipe in the tank; and

wherein the computer readable program code for identifying the level of the material comprises;

computer readable program code for identifying the level of the material in the tank using the main-mode reflection peak if the main-mode reflection peak is classified; and

computer readable program code for using the high-mode reflection peak to estimate a location of the main-mode reflection peak, computer readable program code for using the estimated location of the main-mode reflection peak to identify the level of the material, and computer readable program code for associating a confidence level with the identified level if the main-mode reflection peak is not classified.