Automatic detection of manipulated metal objects in X-ray images
The disclosure relates to a method for detecting a tampered metal item (FC), in which a non-metallic substance is concealed and which has been tampered with in such a way that the tampered metal item (FC) produces a two-dimensional X-ray image comparable to a corresponding non-tampered metal item, in two-dimensional X-ray data of an inspection object (O 1 , O 2 , O 3 ) containing the metal item (FC), the method including (S 10 ) determining a region containing a metal item (FC), (S 20 ) providing an attenuation curve (D(r)) for or intensity curve (I(r)) of detected X-ray radiation along a line (L) through said metal item (FC), (S 30 ) evaluating whether the attenuation curve (D(r)) or the intensity curve (I(r)) shows a characteristic anomaly (P 1 , P 2 ) in a predetermined area, and when the attenuation curve (D(r)) or the intensity curve (I(r)) in the predetermined range shows the characteristic anomaly (P 1 , P 2 ), (S 40 ) triggering an alarm function.
1. A method for detecting a tampered metal item in which a non-metallic substance is concealed and which has been tampered with such that the tampered metal item produces a two-dimensional X-ray image comparable to a corresponding non-tampered metal item, in two-dimensional X-ray data of an inspection object containing the metal item, the method comprising:
determining an area containing a metal item in the X-ray data; providing an attenuation curve for or intensity curve of detected X-ray radiation along a line through the metal item from the X-ray data;
evaluating whether the attenuation curve or the intensity curve shows a characteristic anomaly in a predetermined area, and if the attenuation curve or the intensity curve shows the characteristic anomaly in the predetermined area, triggering an alarm function.
2. The method according to claim 1 , wherein determining the area containing the metal item in the X-ray data comprises:
determining that an area in the X-ray data comprises metal based on whether the area causes a minimum attenuation of X-ray radiation and/or on what atomic number or effective atomic number is assigned to a material in the X-ray data.
3. The method according to claim 1 , wherein providing the attenuation curve or intensity curve along the line through the metal item from the X-ray data comprises:
determining a longitudinal direction of the metal item; and
establishing the attenuation curve or intensity curve for a location variable along the line through the metal item.
4. The method according to claim 3 , wherein the line is set up such that the line runs orthogonal to the determined longitudinal direction.
5. The method according to claim 1 , wherein evaluating whether the attenuation curve or correspondingly for the intensity curve in the predetermined area shows a characteristic anomaly, comprises at least one of: determining whether the value of the attenuation increases along the attenuation curve from the edge of the metal item towards the center of the metal item; determining whether the attenuation curve has a step at the edges or in the edge areas of the metal item; determining whether the attenuation curve in the edge areas of the metal item has a attenuation maximum and, based thereon, decreases towards the center of the metal item and/or runs at a lower level compared to the edge areas; and determining a first derivative of the attenuation curve according to the location and determining whether the derivative shows a peak in each of the edge areas of the metal item.
6. The method according to claim 1 , wherein triggering an alarm function comprises at least one of:
overlaying the attenuation curve or the intensity curve as well as the line along which the attenuation curve or the intensity curve is present into an X-ray image of the inspection object;
triggering a manual inspection of the inspection object; and
triggering of an optical and/or acoustic alarm on an inspection system on which the method is applied.
7. The method according to claim 1 , wherein the tampered metal item is an item with a metal sleeve or metal cover.
8. The method according to claim 1 , wherein the tampered metal item is a tampered accumulator cell or battery cell.
9. The method according to claim 8 , wherein the tampered metal item is a tampered lithium accumulator cell.
10. A processing device for evaluating transmission images, wherein the processing device is adapted to perform a method according to claim 1 .
11. A processing device according to claim 10 , wherein the processing device is further connected to an output unit, and wherein the output unit is adapted to perform an alarm function.
12. A processing device according to claim 10 ,
wherein the processing device has a communication interface by which the processing can be networked with one or more inspection apparatuses for non-destructive inspection of inspection objects for data communication to receive from the one or more inspection devices transmission images for visual evaluation by the data communication.
13. An inspection device set up for transporting inspection objects through an inspection device, for carrying out an imaging inspection method for non-destructive inspection of the inspection objects and for providing transmission images of the inspection objects to a processing device according to claim 10 , the inspection device connected to the processing device for data communication.
14. An inspection system including the processing device, which is spatially separated from and connected to the inspection device according to claim 13 for data communication, wherein transmission images of inspection objects inspected at the inspection device are transmitted to the processing device for visual evaluation.