System of drones provided with recognition beacons

1. A system ( 1 ) of remotely controlled drones ( 10 , 12 ) fitted with respective cameras ( 14 ) enabling a virtual shot from an assailant drone ( 12 ) at a target drone ( 10 ) to be validated by recognizing the target drone ( 10 ) in a video image ( 17 ) supplied by the camera ( 14 ) of the assailant drone ( 12 ) while firing a virtual shot,

the system being characterized in that the recognition means comprise a beacon ( 15 , 16 ) arranged on the target drone ( 10 ) and covered in two first strips ( 18 ) of a first color reflecting light at a first wavelength, situated on either side of at least one second strip ( 19 , 20 ) of a second color reflecting light at a second wavelength, different from the first;

in that the emission spectrum of the first color of the two first strips ( 18 ) lies in the range 590 nm to 745 nm, while the emission spectrum of at least one second strip ( 19 , 20 ) lies in the range 445 nm to 565 nm, and

the assailant drone comprising means for analyzing the image taken while firing a virtual shot that comprises the following means:

means for detecting a first pixel of the first color in the image;

means for detecting a first group of pixels of said first color including the previously-detected pixel;

means for detecting a group of pixels of the second color in the vicinity of the first group of pixels of the first color;

means for recognizing a second group of pixels of the first color; and

means for verifying recognition and consistency conditions amongst the detected groups of pixels.

2. A system according to claim 1 , characterized in that the beacon ( 15 , 16 ) is cylindrical in shape.

3. A system according to claim 2 , characterized in that the axis ( 3 ) of the cylindrical beacon ( 15 , 16 ) is perpendicular to a main plane ( 5 ) of the target drone.

4. A system according to claim 3 , characterized in that the first strips ( 18 ) and at least one of the second strips ( 19 , 20 ) extend circumferentially over the surface of the beacon ( 15 , 16 ) in mutually coplanar planes that are perpendicular to the axis ( 3 ) of the cylinder.

5. A system according to claim 1 , characterized in that the first color of the two first strips ( 18 ) is fluorescent.

6. A system according to claim 1 , characterized in that the beacon ( 16 ) presents at least two second strips ( 19 , 20 ).

7. A system according to claim 1 , characterized in that the means for verifying the recognition and consistency conditions of the groups of pixels include at least:

means for verifying horizontal connectivity of the groups of pixels; and

means for verifying vertical semi-connectivity of the groups of pixels, such that a row of pixels belonging to no group is acceptable between the different groups.

8. A system according to claim 1 , characterized in that the means for verifying the recognition and consistency conditions of the groups of pixels include at least:

means for analyzing luminance variation for each group of pixels;

means for analyzing the chrominance difference between the two first strips of the first color and the at least one second strip of the second color in a V image coding channel (red);

means for analyzing the chrominance difference between the two first strips of the first color in a U image coding channel (blue); and

means for analyzing the minimum chrominance of the two first strips and of the second strip(s).

9. A drone ( 10 , 12 ) provided with a camera ( 14 ) enabling a virtual shot at a target drone ( 10 ) to be validated by recognizing the target drone ( 10 ) in a video image ( 17 ) supplied by its camera ( 14 ) while firing the virtual shot, the drone being characterized in that it includes recognition means enabling it to be used ( 12 ) in a system as a target drone ( 10 ) and as an assailant drone ( 12 ),

the system being characterized in that the recognition means comprise a beacon ( 15 , 16 ) arranged on the target drone ( 10 ) and covered in two first strips ( 18 ) of a first color reflecting light at a first wavelength, situated on either side of at least one second strip ( 19 , 20 ) of a second color reflecting light at a second wavelength, different from the first;

in that the emission spectrum of the first color of the two first strips ( 18 ) lies in the range 590 nm to 745 nm, while the emission spectrum of at least one second strip ( 19 , 20 ) lies in the range 445 nm to 565 nm, and

the assailant drone comprising means for analyzing the image taken while firing a virtual shot that comprises the following means:

means for detecting a first pixel of the first color in the image;

means for detecting a first group of pixels of said first color including the previously-detected pixel;

means for detecting a group of pixels of the second color in the vicinity of the first group of pixels of the first color;

means for recognizing a second group of pixels of the first color; and

means for verifying recognition and consistency conditions amongst the detected groups of pixels.

10. A system according to claim 7 , characterized in that the means for verifying the recognition and consistency conditions of the groups of pixels include at least:

means for analyzing luminance variation for each group of pixels;

means for analyzing the chrominance difference between the two first strips of the first color and the at least one second strip of the second color in a V image coding channel (red);

means for analyzing the chrominance difference between the two first strips of the first color in a U image coding channel (blue); and

means for analyzing the minimum chrominance of the two first strips and of the second strip(s).

11. A system according to claim 4 , characterized in that the first color of the two first strips ( 18 ) is fluorescent.

12. A system according to claim 4 , characterized in that the beacon ( 16 ) presents at least two second strips ( 19 , 20 ).

13. A system according to claim 5 , characterized in that the beacon ( 16 ) presents at least two second strips ( 19 , 20 ).