Combined chemical and velocity sensors for fluid contamination analysis

Patent metadata

Field	Value
Publication number	US-10935692-B2
Application number	US-201916599700-A
Country	US
Kind code	B2
Filing date	Oct 11, 2019
Priority date	May 17, 2017
Publication date	Mar 2, 2021
Grant date	Mar 2, 2021

Abstract

Methods and systems for locating a chemical source include cross-correlating chemical concentration data from pairs of positions using a processor to determine an average velocity vector for a group of positions that averages away turbulence contributions. A convergence region is determined based on multiple average velocity vectors to determine a chemical source location.

First claim

What is claimed is:

1. A computer-implemented method for locating a chemical source, comprising:
cross-correlating measured chemical concentration data from pairs of sensor positions using a processor to determine an average velocity vector for a group of sensor positions that averages away turbulence contributions; and
determining a convergence region based on a plurality of average velocity vectors to determine a chemical source location.

2. The method of claim 1 , wherein determining the convergence region comprises reversing a direction of each of average velocity vector.

3. The method of claim 1 , wherein cross-correlating chemical concentration data comprises integrating over a product of concentration values measured at a pair of sensor positions at times separated by a time lag to produce a cross-correlation product C.

4. The method of claim 3 , wherein cross-correlating chemical concentration data further comprises determining a time lag that produces a maximum cross-correlation product.

5. The method of claim 4 , wherein the cross-correlation product is calculated as:
C t a ,t b (τ)=∫ t a t b S 1 ( t ) S 2 ( t −τ) dt

where t a and t b are time limits, S 1 (t) and S 2 (t) are measurements from a first sensor and a second sensor at a time t, and τ is a time lag.

6. The method of claim 4 , further comprising determining the average velocity vector based on a normalized sum of distances between each pair of sensor positions divided by a respective determined time lag for each pair of sensor positions.

7. The method of claim 1 , wherein each group of sensor positions comprises at least four chemical concentration sensors at respective positions.

8. The method of claim 7 , wherein cross-correlating chemical concentration data from pairs of sensor positions comprises determining respective average velocity vectors for a plurality of groups of sensor positions.

9. A combined chemical and velocity sensor system, comprising:
a sensor control module comprising a processor configured to cross-correlate measured chemical concentration data from pairs of chemical concentration sensor positions and to determine an average velocity vector for a group of sensor positions that averages away turbulence contributions to determine a chemical source location.

10. The system of claim 9 , wherein the sensor control module is further configured to integrate over a product of concentration values measured at a pair of sensor positions at times separated by a time lag to produce a cross-correlation product C.

11. The system of claim 10 , wherein the sensor control module is further configured to determine a time lag that produces a maximum cross-correlation product.

12. The system of claim 11 , wherein the cross-correlation product is calculated as:
C t a ,t b (τ)=∫ t a t b S 1 ( t ) S 2 ( t −τ) dt

where t a and t b are time limits, S 1 (t) and S 2 (t) are measurements from a first sensor and a second sensor at a time t, and τ is a time lag.

13. The system of claim 11 , wherein the sensor control module is further configured to determine the average velocity vector based on a normalized sum of distances between each pair of sensor positions divided by a respective determined time lag for each pair of sensor positions.

14. The system of claim 9 , wherein the chemical concentration sensors comprise at least four chemical concentration sensors.

15. The system of claim 14 , wherein the chemical concentration sensors are non-coplanar.

16. A chemical source location system, comprising:
a plurality of chemical and velocity sensor (CCVS) systems, each CCVS system comprising:
a sensor control module comprising a processor configured to cross-correlate measured chemical concentration data from pairs of chemical concentration sensor positions and to determine an average velocity vector for a group of sensor positions that averages away turbulence contributions; and
an analysis module comprising a processor configured to determine a convergence region based on the plurality of average velocity vectors to determine a chemical source location.

17. The system of claim 16 , wherein the analysis module is further configured to reverse the direction of each average velocity vector to determine the convergence region.

18. The system of claim 16 , wherein each CCVS system further comprises at least four chemical concentration sensors.

19. The system of claim 18 , wherein the at least four chemical concentration sensors of each CCVS system are non-coplanar.

20. The system of claim 16 , comprising at least four non-coplanar CCVS systems.

Assignees

• IBM

Inventors

• Elmegreen Bruce G

Classifications

• G01V9/007 Primary

  by detecting gases or particles representative of underground layers at or near the surface (analysing earth materials G01N33/24; analysing gases per se G01N) · CPC title

• G01P5/001

  Full-field flow measurement, e.g. determining flow velocity and direction in a whole region at the same time, flow visualisation · CPC title

• G01V9/00 Primary

  Prospecting or detecting by methods not provided for in groups G01V1/00 - G01V8/00 · CPC title

• G06F7/64

  Digital differential analysers, i.e. computing devices for differentiation, integration or solving differential or integral equations, using pulses representing increments; Other incremental computing devices for solving difference equations (G06F7/70 takes precedence; differential analysers using hybrid computing techniques G06J1/02 {; DDA application in numerical control G05B19/18}) · CPC title