Mobile and free-form x-ray imaging systems and methods

• US 10,539,708 B2
• Filed: 05/04/2017
• Issued: 01/21/2020
• Est. Priority Date: 02/01/2016
• Status: Active Grant

• Current Assignee: University of North Carolina At Chapel Hill (University of North Carolina System)
• Original Assignee: University of North Carolina At Chapel Hill (University of North Carolina System)
• Inventors: Zhou, Otto Z., Lu, Jianping, Chtcheprov, Pavel
• Primary Examiner(s): Midkiff, Anastasia
• Application Number:
  US15/587,052
• Publication Number:
  US 20170329037A1
• Time in Patent Office: 992 Days
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: B64U 20/87 Mounting of imaging devices, e.g. mounting of gimbals
• CPC Class Codes: B64U 2101/30 for imaging, photography or videography
• CPC Class Codes: G01N 2223/301 portable apparatus
• CPC Class Codes: G01N 2223/303 calibrating, standardising
• CPC Class Codes: G01N 2223/3037 standards (constitution)
• CPC Class Codes: G01N 2223/3303 object fixed; source and detector move
• CPC Class Codes: G01N 2223/401 image processing
• CPC Class Codes: G01N 2223/419 computed tomograph
• CPC Class Codes: G01N 23/046 using tomography, e.g. computed tomography [CT]
• CPC Class Codes: G01V 5/222 measuring scattered radiation
• CPC Class Codes: G01V 5/224 Multiple energy techniques using one type of radiation, e.g. X-rays of different energies
• CPC Class Codes: G01V 5/226 using tomography
• CPC Class Codes: G01V 5/232 having relative motion between the source, detector and object other than by conveyor G01V5/226 takes precedence
• CPC Class Codes: G01V 5/271 using a network, e.g. a remote expert, accessing remote data or the like
• CPC Class Codes: G06T 2207/10032 Satellite or aerial image; Remote sensing
• CPC Class Codes: G06T 2207/10116 X-ray image
• CPC Class Codes: H01J 2237/1501 Beam alignment means or procedures
• CPC Class Codes: H01J 2237/24578 Spatial variables, e.g. position, distance
• CPC Class Codes: H01J 2237/2482 Optical means
• CPC Class Codes: H01J 37/244 : Detectors; Associated components or circuits therefor

Abstract

A three-dimensional (3D) x-ray tomographic imaging system includes an x-ray source fixedly attached to a first unmanned vehicle, which can be aerial or otherwise configured for locomotion, and an x-ray detector. A vehicle controller is configured to be operated by an operator, and an optical camera is mounted to the first unmanned vehicle at a fixed position relative to the x-ray source, and an optical pattern is fixed at a position relative to the x-ray detector. The x-ray source and x-ray detector are configured to be positioned on substantially opposite sides of the object, while the x-ray source is rotated radially around the object to one or more imaging positions.

Claims

1. A three-dimensional x-ray tomography imaging system, comprising:

an x-ray source fixedly attached to a first unmanned aerial vehicle (UAV);

an x-ray detector;

a vehicle controller configured to be operated by an operator;

an optical camera mounted to the first UAV at a fixed position relative to the x-ray source;

an optical pattern fixed at a position relative to the x-ray detector; and

an electronic controller configured for controlling the imaging system;

wherein the vehicle controller is configured to transmit a sign to identify an object to be imaged,

wherein the x-ray source and x-ray detector are configured to be positioned on substantially opposite sides of the object,

wherein the x-ray source is configured to be rotated radially around the object to one or more imaging positions, and

wherein the x-ray source and the x-ray detector are configured to be activated when the x-ray source is at each of the one or more imaging positions, so that x-ray projection images of the object are captured by the x-ray detector.

2. The system of claim 1, wherein the imaging system is configured for the x-ray projection images to be reconstructed to create a three-dimensional (3D) image of the object.

3. The system of claim 1, wherein the first UAV comprises a distance sensor configured to detect a distance from the first UAV to the object and/or the x-ray detector so that the first UAV can maintain a substantially consistent distance from the x-ray detector and/or the object.

4. The system of claim 1, wherein the x-ray source is configured to generate x-ray radiation at two different energy levels at each of the one or more imaging positions, so that the system can automatically classify and identify internal contents of the object.

5. The system of claim 1, wherein the x-ray detector and the optical pattern are fixedly mounted on a second UAV.

6. The system of claim 5, wherein the first and second UAVs are configured to automatically move to substantially opposite sides of the object to be imaged.

7. The system of claim 6, wherein the first and second UAVs are configured to rotate radially around the object to a plurality of imaging positions that are on substantially opposite sides of the object.

8. The system of claim 7, wherein the x-ray source and x-ray detector are activated at a same time at each of the plurality of imaging positions to generate one of a plurality of x-ray projection images at each of the plurality of imaging positions.

9. The system of claim 1, wherein the optical camera is configured to capture an optical image containing the optical pattern at a same position of the first UAV at which the x-ray source and the x-ray detector are activated.

10. The system of claim 1, wherein the x-ray detector and the optical pattern are mounted on a wheeled trolley configured to rotatably move the x-ray detector and the optical pattern around the object to be on a substantially diametrically opposite side of the object from the first UAV as the first UAV moves between the one or more positions.

11. The system of claim 1, wherein the x-ray detector and the optical pattern are fixedly mounted on a first side of a bracket attached to the first UAV, and wherein the x-ray source and the optical camera are fixedly mounted on a second side of the bracket attached to the first UAV.

12. The system of claim 11, wherein the bracket is configured to rotate about a central axis so that the x-ray source and the optical camera are configured to rotate radially around the object on substantially opposite sides of the object from the x-ray detector and the optical pattern while the bracket is rotating about the central axis.

13. A method of generating at least one three-dimensional (3D) image of an object from a plurality of x-ray images of the object, the method comprising:

mounting an x-ray source to a first unmanned aerial vehicle (UAV);

attaching an optical camera to the first UAV at a fixed position relative to the x-ray source;

identifying a location of the object;

positioning an x-ray detector and an optical pattern associated with the x-ray detector on a first side of the object;

moving the first UAV to a second side of the object, wherein the second side of the object is at least substantially diametrically opposite the first side of the object;

pointing the optical camera so the optical pattern is in a field of vision of the optical camera;

capturing an optical image and an x-ray projection image when first UAV is stationary;

rotating the first UAV around the object to a plurality of imaging positions around the object;

capturing further optical images and x-ray projection images at the plurality of imaging positions around the object, so that a plurality of optical images and a plurality of x-ray projection images are generated;

applying geometric image correction to the x-ray projection images by using the optical images; and

reconstructing the x-ray projection images to create a 3D image of the object.

14. The method of claim 13, comprising, when the optical pattern is no longer visible in the field of vision of the optical camera, moving the x-ray detector and the optical pattern to a further position around the object and generating further optical images and x-ray projection images by rotating the first UAV around the object to further imaging positions around the object.

15. The method of claim 13, comprising automatically classifying and identifying internal contents of the object by generating x-ray radiation at two different energy levels at each of the plurality of imaging positions.

16. The method of claim 13, wherein the first UAV uses a distance sensor to maintain a substantially consistent distance from the object at each of the plurality of imaging positions.

17. The method of claim 13, comprising:

attaching the x-ray detector and the optical pattern to a second UAV;

rotating the first and second UAVs radially around the object to a plurality of imaging positions, so the first and second UAVs are at substantially opposite sides of the object;

activating the x-ray detector and x-ray source to generate x-ray projection images of the object at each of the plurality of imaging positions; and

capturing optical images from the optical camera at each of the plurality of imaging positions,

wherein the optical pattern is within a field of vision of the optical camera at each of the plurality of imaging positions.

18. The method of claim 13, comprising:

mounting the x-ray detector and the optical pattern on a wheeled trolley; and

moving the x-ray detector and the optical pattern rotatably around the object to be on a substantially diametrically opposite side of the object from the first UAV as the first UAV moves between the one or more positions.

19. The method of claim 13, comprising:

mounting a bracket to the first UAV;

fixedly mounting the x-ray detector and the optical pattern on a first side of the bracket; and

fixedly mounting the x-ray source and the optical camera on a second side of the bracket.

20. The method of claim 19, comprising rotating the bracket about a central axis so that the x-ray source and the optical camera rotate radially around the object on substantially opposite sides of the object from the x-ray detector and the optical pattern.

21. A three-dimensional x-ray tomography imaging system, comprising:

an x-ray source fixedly attached to a first unmanned vehicle (UV);

an x-ray detector;

a vehicle controller configured to be operated by an operator;

an optical camera mounted to the first UV at a fixed position relative to the x-ray source;

an optical pattern fixed at a position relative to the x-ray detector; and

an electronic controller configured for controlling the imaging system;

wherein the vehicle controller is configured to transmit a sign to identify an object to be imaged,

wherein the x-ray source and x-ray detector are configured to be positioned on substantially opposite sides of the object,

wherein the x-ray source is configured to be rotated radially around the object to one or more imaging positions, and

wherein the x-ray source and the x-ray detector are configured to be activated when the x-ray source is at each of the one or more imaging positions, so that x-ray projection images of the object are captured by the x-ray detector.

22. A method of generating at least one three-dimensional (3D) image of an object from a plurality of x-ray images of the object, the method comprising:

mounting an x-ray source to a first unmanned vehicle (UV);

attaching an optical camera to the first UV at a fixed position relative to the x-ray source;

identifying a location of the object;

positioning an x-ray detector and an optical pattern associated with the x-ray detector on a first side of the object;

moving the first UV to a second side of the object, wherein the second side of the object is at least substantially diametrically opposite the first side of the object;

pointing the optical camera so the optical pattern is in a field of vision of the optical camera;

capturing an optical image and an x-ray projection image when first UV is stationary;

rotating the first UV around the object to a plurality of imaging positions around the object;

capturing further optical images and x-ray projection images at the plurality of imaging positions around the object, so that a plurality of optical images and a plurality of x-ray projection images are generated;

applying geometric image correction to the x-ray projection images by using the optical images; and

reconstructing the x-ray projection images to create a 3D image of the object.