Dual robot control systems for non-destructive evaluation

{
  "publication_number": "US11619597B2",
  "country": "US",
  "kind": "B2",
  "title": "Dual robot control systems for non-destructive evaluation",
  "abstract": "A system for non-destructive evaluation of an object uses a spherical coordinate system to control two robotic arms. In some examples, the system includes a radiation source coupled to one robotic arm, a radiation detector coupled to the other robotic arm; and a control unit configured to determine, based on input, a first position located on a first surface of a first sphere within the spherical coordinate system; determine, based on the input, a second position located on a second surface of a second sphere within the spherical coordinate system, wherein the second position is located opposite a midpoint of the spherical coordinate system from the first position; and control a motion of the source robotic arm and the detector robotic arm such that the radiation source and the radiation detector move to different ones of the first position and the second position.",
  "claims": [
    "1. A system for non-destructive evaluation of an object comprising: a first robotic arm; a radiation source coupled to the first robotic arm, the radiation source configured to emit radiation; a second robotic arm; a radiation detector coupled to the second robotic arm, the radiation detector configured to measure the radiation emitted by the radiation source; a stage configured to support the object for non-destructive evaluation; and a control unit configured to: receive input identifying an imaging angle for evaluation of the object; determine, based on the imaging angle, a first position located on a first surface of a first sphere within a spherical coordinate system; determine, based on the imaging angle, a second position located on a second surface of a second sphere within the spherical coordinate system, wherein the second position is located opposite a center of the spherical coordinate system from the first position; and control a motion of the first robotic arm and the second robotic arm such that the radiation source and the radiation detector move to different ones of the first position and the second position.",
    "2. The system of claim 1, the control unit further configured to: control a source orientation of the radiation source such that the radiation is aimed at the detector from the first position or the second position; and control a detector orientation of the detector such that the detector is aimed at the radiation source from the first position or the second position.",
    "3. The system of claim 1, wherein: the first position is a position of the radiation source, the second position is a position of the radiation detector, the control unit further configured to: receive the input, wherein the input indicates a magnification for evaluation of the object; as part of determining the first position, determine, based on the magnification, a source radius, wherein the source radius is a radius component of spherical coordinates of the first position; and as part of determining the second position, determine, based on the magnification, a detector radius, wherein: the detector radius is a radius component of spherical coordinates of the second position, and the sum of the detector radius and the source radius divided by the source radius equals the magnification, and wherein the source position and the detector position are different ones of the first position and the second position.",
    "4. The system of claim 1, wherein the control unit is further configured to cause the radiation source to irradiate the object in response to controlling the motions of the first robotic arm and the second robotic arm.",
    "5. The system of claim 1, wherein the radiation detector comprises a protective plate having at least one pressure sensor configured to disable the motion of the second robotic arm in response to the pressure sensor detecting contact with an item.",
    "6. The system of claim 1, wherein the control unit is further configured to: acquire a series of radiographs at different detector positions along a plane located tangentially to the second surface of the second sphere within the spherical coordinate system, the different detector positions separated by a distance finer than a pixel size of the radiation detector; and assemble the radiographs to form a composite radiograph with finer resolution than the acquired radiographs.",
    "7. The system of claim 1, wherein the control unit is further configured to: acquire a series of radiographs at different detector positions along a plane located tangentially to the second surface of the second sphere within the spherical coordinate system, the different detector positions separated by a distance greater than a pixel size of the radiation detector but less than a physical size of the detector; and assemble the radiographs to form a composite radiograph having a larger area than the physical size of the detector.",
    "8. A computer-readable storage medium including program instructions that, when executed by a system for non-destructive evaluation of an object placed on a stage, cause the system to: receive input identifying an imaging angle for evaluation of the object; determine, based on the imaging angle, a first position located on a first surface of a first sphere within a spherical coordinate system; determine, based on the imaging angle, a second position located on a second surface of a second sphere within the spherical coordinate system, wherein the second position is located opposite a center of the spherical coordinate system from the first position; and control a motion of a first robotic arm and a motion of a second robotic arm such that a radiation source and a radiation detector move to different ones of the first position and the second position.",
    "9. The computer-readable storage medium of claim 8, wherein the execution of the program instructions further causes the system to: control a source orientation of the radiation source such that the radiation is aimed at the detector from a source position; and control a detector orientation of the detector such that the detector is aimed at the radiation source from a detector position, wherein the source position and the detector position comprise different ones of the first position and the second position.",
    "10. The computer-readable storage medium of claim 8, the first position is a position of the radiation source, the second position is a position of the radiation detector, wherein the execution of the program instructions further causes the system to: receive the input, wherein the input indicates a magnification for evaluation of the object; as part of determining the first position, determine, based on the magnification, a source radius, wherein the source radius is a radius component of spherical coordinates of the first position; and as part of determining the second position, determine, based on the magnification, a detector radius, wherein: the detector radius is a radius component of spherical coordinates of the second position, and the sum of the detector radius and the source radius divided by the source radius equals the magnification, and wherein the source position and the detector position are different ones of the first position and the second position.",
    "11. The computer-readable storage medium of claim 8, wherein the execution of the program instructions further causes the radiation source to irradiate the object in response to controlling the motions of the source robotic arm and the detector robotic arm.",
    "12. The computer-readable storage medium of claim 8, wherein the execution of the program instructions further causes the system to: acquire a series of radiographs at different detector positions along a plane located tangentially to the second surface of the second sphere within the spherical coordinate system, the different detector positions separated by a distance finer than a pixel size of the detector, and assemble the radiographs to form a composite radiograph with finer resolution than the acquired radiographs.",
    "13. A method comprising: receive input identifying an imaging angle for non-destructive evaluation of an object placed on a stage; determining, based on the imaging angle, a first position located on a first surface of a first sphere within a spherical coordinate system; determining, based on the imaging angle, a second position located on a second surface of a second sphere within the spherical coordinate system, wherein the second position is located opposite a center of the spherical coordinate system from the first position; and controlling a motion of a first robotic arm and a motion of a second robotic arm such that a radiation source and a radiation detector move to different ones of the first position and the second position.",
    "14. The method of claim 13, further comprising: controlling a source orientation of the radiation source such that the radiation is aimed at the detector from a source position; and controlling a detector orientation of the detector such that the detector is aimed at the radiation source from a detector position, wherein the source position and the detector position comprise different ones of the first position and the second position.",
    "15. The method of claim 13, wherein the first position is a position of the radiation source, the second position is a position of the radiation detector, the method further comprising: receiving the input, wherein the input indicates a magnification for evaluation of the object; as part of determining the first position, determining, based on the magnification, a source radius, wherein the source radius is a radius component of spherical coordinates of the first position; and as part of determining the second position, determining, based on the magnification, a detector radius, wherein: the detector radius is a radius component of spherical coordinates of the second position, and the sum of the detector radius and the source radius divided by the source radius equals the magnification, and wherein the source position and the detector position are different ones of the first position and the second position.",
    "16. The method of claim 13, further comprising causing the radiation source to irradiate the object in response to controlling the motions of the first robotic arm and the second robotic arm.",
    "17. The method of claim 13, further comprising: acquiring a series of radiographs at different detector positions along a plane located tangentially to the second surface of the second sphere within the spherical coordinate system, the different detector positions separated by a distance finer than a pixel size of the detector, and assembling the radiographs to form a composite radiograph with finer resolution than the acquired radiographs.",
    "18. The system of claim 1, wherein the control unit is further configured to: translate the spherical coordinates of the first position and the spherical coordinates of the second position to linear coordinates."
  ],
  "description_excerpt": "This disclosure relates to non-destructive evaluation of objects.\n\nX-ray digital radiography (DR) is a commonly used non-invasive and non-destructive imaging technique using digital x-ray detectors, such as flat-panel detectors, charge-coupled device (CCD) cameras, or complementary metal-oxide-semiconductor (CMOS) cameras, or linear diode arrays (LDAs). X-ray computed tomography (CT) is a procedure that uses computer-processed x-rays radiographs acquired at different view angles to produce 3D images of an object. A tomographic image of an object is an image of a conceptually two-dimensional “slice” of the object. A computing device may use the tomographic images of the object to generate a 3-dimensional image of the object. X-ray CT may be used for industrial purposes to conduct non-destructive evaluation of objects.\n\nIn general, this disclosure relates to non-destructive evaluation (NDE), such as industrial x-ray radiography, computed tomography (CT) and metrology. This disclosure describes an apparatus and method that may enable non-destructive evaluation of an object from many different perspectives while also simplifying for a user the alignment of a radiation source and a detector. The techniques of this disclosure provide an instrumentation design, user control mechanism, and software algorithm for the apparatus. The apparatus may be used for NDE of naturally occurring objects, such as rock core samples, as well as manufactured components and systems, such as metal casts, engine components, and complete engine units.",
  "cpc": [
    "G01N 23/083",
    "A61B 6/4452",
    "A61B 6/4458",
    "A61B 6/5241",
    "A61B 6/588",
    "B25J 13/081",
    "B25J 15/0019",
    "B25J 19/02",
    "B25J 9/045",
    "B25J 9/1669",
    "G01N 2223/306",
    "G01N 2223/308",
    "G01N 23/046",
    "G01N 23/18",
    "G06T 2207/10116",
    "G06T 2207/20221",
    "G06T 5/50",
    "G06T 7/70"
  ],
  "ipc": [
    "B25J 13/08",
    "B25J 15/00",
    "B25J 19/02",
    "B25J 9/04",
    "B25J 9/16",
    "G01N 23/00",
    "G01N 23/046",
    "G01N 23/083",
    "G01N 23/18",
    "G06T 5/50",
    "G06T 7/70"
  ],
  "assignees": [
    "Illinois Tool Works Inc"
  ],
  "inventors": [
    "Joseph Schlecht",
    "Caleb N. Hay",
    "Jackson Turner",
    "Sean Lin",
    "Sean M. Anderson",
    "Kirk Guillaume",
    "Matthew James Johnson"
  ],
  "filing_date": "2020-05-27",
  "publication_date": "2023-04-04",
  "grant_date": "2023-04-04",
  "priority_date": "2020-05-27",
  "application_number": "US-202016885115-A",
  "family_id": "75801650",
  "cited_by_count": 2,
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}