US 12,078,770 B2
Autonomous detection of concealed weapons at a distance by sensor fusion
Jun Amano, Hillsborough, CA (US)
Assigned to Konica Minolta Business Solutions U.S.A., Inc., San Mateo, CA (US)
Filed by Konica Minolta Business Solutions U.S.A., Inc., San Mateo, CA (US)
Filed on May 23, 2022, as Appl. No. 17/750,838.
Prior Publication US 2023/0375736 A1, Nov. 23, 2023
Int. Cl. G01V 3/08 (2006.01); G01R 33/09 (2006.01); G06V 10/764 (2022.01); G06V 10/774 (2022.01); G06V 10/82 (2022.01)
CPC G01V 3/081 (2013.01) [G01R 33/096 (2013.01); G06V 10/764 (2022.01); G06V 10/774 (2022.01); G06V 10/82 (2022.01); G06V 2201/05 (2022.01)] 16 Claims
OG exemplary drawing
 
1. An apparatus for distant detection of ferrous metallic objects, the apparatus comprising:
a plurality of magnetic field sensors that each measure an ambient magnetic field; and
a fingerprint processing system, wherein the fingerprint processing system:
receives, from the plurality of magnetic field sensors, magnetic field data corresponding to the ambient magnetic field,
generates, from the magnetic field data, a magnetic fingerprint image of one or more perturbations of the ambient magnetic field, and
classifies, using a pretrained magnetic fingerprint image classifier, the magnetic fingerprint image into one of a set of classes that each correspond to a different type of ferrous metallic object, wherein
the plurality of magnetic field sensors is separated from the ferrous metallic objects being detected by a detection distance that is greater than or equal to 0.5 meters, and
the magnetic fingerprint image classifier is trained using labeled training data that includes a set of standard labeled fingerprint images selected from a group consisting of:
a set of artificially-generated magnetic fingerprint images based on simulations of magnetic field perturbations that correspond to ferrous metallic objects,
a set of empirically-generated magnetic fingerprint images, of known ferrous metallic objects, that are physically measured using the plurality of magnetic field sensors, and
combinations of the set of artificially-generated magnetic fingerprint images and the set of empirically-generated magnetic fingerprint images.