Method of locating a source of transient signals in a dispersive environment

Patent metadata

Field	Value
Publication number	US-10191103-B2
Application number	US-201515111702-A
Country	US
Kind code	B2
Filing date	Jan 6, 2015
Priority date	Jan 16, 2014
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

The invention relates to a method of locating in a dispersive medium ( 5 ) a source ( 7 ) of pulses (s 1 , s 2 ) by at least one pair of sensors ( 1, 2 ), the method comprising the following steps: at the level of each sensor ( 1, 2 ), detecting a pulse (s 1 , s 2 ) originating from the source ( 7 ); for each of said pulses, constructing a phase diagram on the basis of N vectors of which the co-ordinates correspond to the amplitude of the pulse (s 1 , s 2 ) at successive sampling instants t i ; and for each pair of sensors, calculating the ratio between the distances L 1 and L 2 of each sensor from the source through the formula (I) where (II) and (III) are the norms of the vectors (IV) and (V) of the phase diagrams corresponding to the pulses detected by the sensors ( 1, 2 ).

L
1

L
2

=

∑

i
=
1

N

⁢

⁢



r
1

⁡

(

t
i

)

→



/

∑

i
=
1

N

⁢

⁢



r
2

⁡

(

t
i

)

→



(
I
)



r
1

⁡

(

t
i

)

→



(
II
)



r
2

⁡

(

t
i

)

→



(
III
)

r
1

⁡

(

t
i

)

→

(
IV
)

r
2

⁡

(

t
i

)

→

(
V
)

First claim

The invention claimed is:

1. A method of locating in a dispersive environment a source of pulses with at least a pair of sensors, the method comprising the steps of:
positioning a pair of sensors in the dispersive environment, the pair of sensors being located at a predetermined distance L to each other;
detecting a pulse at the level of each sensor originating from the source;
constructing a phase diagram for each of said pulses from N vectors having their coordinates corresponding to the amplitude of the pulse at a sampling time t i and at next successive sampling times; and
calculating the ratio for each pair of sensors between distances L 1 and L 2 from each sensor to the source with formula:

L
1

/

L
2

=

∑

i
=
1

N

⁢



r
1

⁡

(

t
i

)

→



/

∑

i
=
1

N

⁢



r
2

⁡

(

t
i

)

→



where



r
1

⁡

(

t
i

)

→



⁢

⁢
and
⁢

⁢



r
2

⁡

(

t
i

)

→



are the norms of vectors

r
1

⁡

(

t
i

)

→

⁢

⁢
and
⁢

⁢

r
2

⁡

(

t
i

)

→

of the phase diagrams corresponding to the pulses detected by the sensors so that the source is located by the phase diagrams without synchronization of the sensors;
wherein the calculated location of the source is communicated to specify the location of a maintenance operation.

2. The method of claim 1 , wherein the dispersive environment is a guided environment.

3. The method of claim 2 , wherein the dispersive environment is an electric cable.

4. The method of claim 3 , wherein the coordinates of the vectors of the phase diagrams correspond to three successive sampling times.

5. The method of claim 3 , wherein the detection of a pulse at the level of each sensor comprises the steps of:
dividing a signal received by the sensor into portions of same duration;
filtering each portion with a plurality M of bandpass filters having different central frequencies f j ;
calculating an average energy level associated with each frequency f j of a portion;
calculating a spectral distance DW/W+1 between a first and a second successive portions; and
comparing spectral distance DW/W+1 with a threshold.

6. The method of claim 5 , wherein the value of the threshold is set during a previous sampling state.

7. The method of claim 2 , wherein the coordinates of the vectors of the phase diagrams correspond to three successive sampling times.

8. The method of claim 2 , wherein the detection of a pulse at the level of each sensor comprises the steps of:
dividing a signal received by the sensor into portions of same duration;
filtering each portion with a plurality M of bandpass filters having different central frequencies f j ;
calculating an average energy level associated with each frequency f j of a portion;
calculating a spectral distance DW/W+1 between a first and a second successive portions; and
comparing spectral distance DW/W+1 with a threshold.

9. The method of claim 1 , wherein the coordinates of the vectors of the phase diagrams correspond to three successive sampling times.

10. The method of claim 1 , wherein the coordinates of the vectors of the phase diagrams correspond to three successive sampling times.

11. The method of claim 10 , wherein the detection of a pulse at the level of each sensor comprises the steps of:
dividing a signal received by the sensor into portions of same duration;
filtering each portion with a plurality M of bandpass filters having different central frequencies f j ;
calculating an average energy level associated with each frequency f j of a portion;
calculating a special distance

Assignees

• Inst Polytechnique Grenoble
• Inst Polytechique De Grenoble

Inventors

• Ioana Cornel

Classifications

• G01R31/088

  Aspects of digital computing · CPC title

• G01R31/08

  Locating faults in cables, transmission lines, or networks · CPC title

• G01R31/083 Primary

  in cables, e.g. underground · CPC title