SYSTEM AND METHOD FOR THE DETECTION OF OBJECTS CONCEALED BENEATH THE CLOTHING OF A PERSON

Abstract

A system and method for the detection of objects concealed beneath the clothing of a person that includes at least one acoustic wave emitter directed toward the person, where the waves are non-stationary low frequency near-field acoustic waves. At least one acoustic wave detector is oriented towards the person in order to receive any acoustic waves reemitted by the person in response to interaction with the non-stationary low frequency near-field acoustic waves, in such a wat that analysis of the reemitted acoustic waves detected by at least one detector enables the determination of whether the person is carrying any object concealed beneath their clothing.

Claims

1. A system for the detection of objects concealed beneath clothing worn by a person, the system comprising: a first emitter configured to emit towards the person in a first direction low frequency acoustic waves in near field and non-stationary regime; a first detector of acoustic waves directed towards the person in a second direction, the first detector configured to receive first acoustic waves reemitted by the person in response to the interaction with the low frequency acoustic waves in near field and non-stationary regime; and a processor configured to communicate with the first detector and configured to analyze the reemitted first acoustic waves detected by the first detector to determine if the person carries objects concealed beneath the clothing worn by the person.

2. The system according to claim 1, where the low frequency acoustic waves in near field and non-stationary regime have a frequency between 2 Hz and 200 Hz.

3. The system according to claim 1, where the first emitter is at a distance between 50 millimeters and 700 millimeters away from the person.

4. The system according to claim 2, where the first emitter is at a distance between 50 millimeters and 700 millimeters away from the person.

5. The system according to claim 1, where the first detector is at a distance between 0.1 meters and 2 meters from the person.

6. The system according to claim 3, where the first detector is at a distance between 0.1 meters and 2 meters from the person.

7. The system according to claim 4, where the first detector is placed at a distance between 0.1 meters and 2 meters from the person.

8. The system according to claim 1, further comprising a second emitter that is configured to emit low frequency acoustic waves in near field and non-stationary regime towards the person in a third direction different than the first direction.

9. The system according to claim 1, further comprising a second detector directed towards the person in a third direction different than the second direction, the second detector configured to receive second acoustic waves reemitted by the person in response to the interaction with the low frequency acoustic waves in near field and non-stationary regime emitted by the first detector, the second acoustic waves remitted being different than the first acoustic waves remitted.

10. The system according to claim 9, wherein the processor is configured to communicate with the first detector and the second detector and to analyze the reemitted first acoustic waves detected by the first detector and the remitted second acoustic waves detected by the second detector to determine if the person carries objects concealed beneath the clothing worn by the person.

11. A method for the detection of objects concealed beneath clothing of a person, the method comprising: emitting from a first emitter low frequency acoustic waves in near field and non-stationary regime towards the person in a first direction; receiving in a first detector first acoustic waves reemitted by the person in response to the interaction with the low frequency acoustic waves in near field and non-stationary regime, the first detector directed towards the person in a second direction: and analyzing the reemitted first acoustic waves detected by the first detector to determine if the person carries objects concealed beneath the clothing worn by the person.

12. The method according to claim 11, where the low frequency acoustic waves in near filed and non-stationary regime comprise a frequency between 2 Hz and 200 Hz.

13. The method according to claim 11, wherein prior to emitting from the first emitter low frequency acoustic waves in near field and non-stationary regime towards the person, the first emitter emits a first tone of fixed frequency for synchronization with the first detector.

14. The method according to claim 13, where the first tone persists at least two cycles of the fixed frequency.

15. The method according to claim 11, wherein analyzing the reemitted first acoustic waves detected by the first detector to determine if the person carries objects concealed beneath the clothing worn by the person comprises comparing the reemitted first acoustic waves with a reference signal corresponding to acoustic waves reemitted by the person without any hidden object and/or a reference signal in absence of the person.

16. The method according to claim 11, where the first emitter is placed at a distance between 50 millimeters and 700 millimeters away from the person.

17. The method according to claim 12, where the first emitter is placed at a distance between 50 millimeters and 700 millimeters away from the person.

18. The method according to claim 11, where the first detector is placed at a distance between 0.1 meters and 2 meters from the person.

19. The method according to claim 16, where the first detector is placed at a distance between 0.1 meters and 2 meters from the person.

20. The method according to claim 17, where the first detector is placed at a distance between 0.1 meters and 2 meters from the person.

21. The method according to claim 11, further comprising emitting from a second emitter low frequency acoustic waves in near field and non-stationary regime towards the person in a third direction different than the first direction.

22. The method according to claim 11, further comprising a second detector directed towards the person in a third direction different than the second direction the second detector configured to receive second acoustic waves reemitted by the person in response to the interaction with the low frequency acoustic waves in near field and non-stationary regime emitted by the first detector, the second acoustic waves remitted being different than the first acoustic waves remitted.

23. The system according to claim 22, further comprising analyzing the reemitted second acoustic waves detected by the second detector to determine if the person carries objects concealed beneath the clothing worn by the person.

Description

BRIEF DESCRIPTION OF FIGURES

[0047] FIG. 1 shows a schematic view of a system for the inspection of a person.

[0048] FIG. 2 shows three response signals corresponding respectively, to the absence of person, person without attached object and person with attached object.

DETAILED DESCRIPTION OF EXAMPLES

[0049] FIG. 1 shows an example of configuration of a system according to the present invention where the parts that conform it are shown. The system of this example comprises an emitter 1, in this case a PreSonus Temblor T10, and a detector 3, in this case, a Beyerdynamic MM1. The emitter 1 is pointed towards the person 5 and placed at approximately 1 meter from the person. On the opposite side of the person according to the direction of the emitter 1 it is the detector 3. The detector 3 is also oriented towards the person 5 and placed at 1 meter from the person. The emitter 1 and the detector 3 are both connected to a means for processing 4, in this case a PC with a sound interface 2 model Focusrite Scarlett 2i2.

[0050] Now, it is briefly described the use procedure of the described system. First, a first measurement is done in the absence of a person that will be used as reference (absent). Then, a second measurement is done with a person not carrying any object 6 attached (negative). Lastly, a third measurement is done with a person 5 that in this case carries an object 6 attached to the body (positive).

[0051] Each measurement includes the emission from the emitter 1 of low frequency acoustic waves in non-stationary and near field regime according to a sweep of frequencies that varies between 2 to 200 Hz. At the beginning, a fixed frequency tone is maintained for a few cycles to allow an appropriate synchronization. Then, the detector 3 receives the acoustic waves reemitted by the person 5, with or without attached object 6, and from the room wherein it is. These received acoustic waves are transmitted to the means of processing 4 to be analyzed.

[0052] FIG. 2 shows the obtained results. It can be seen how in the case of a negative, the received signal presents, in a particular interval, a higher amplitude than of a positive or an absence, as well as a different profile. This enables the distinction of some signals from others manually, by a well-trained technician or automatically by an artificial intelligence, also well-trained. Thus, the system can be trained for automatic detection by using artificial intelligence algorithms that could be for instance the ones included in the package Classification Learner for MATLAB.

[0053] The research works associated with this disclosure was funded by H2020 program of the European Union under contract number 700399.