Coordinate measuring apparatus and method for measuring an object
AssigneeWerth Messtechnik GmbH
InventorsRalf Christoph, Wolfgang Rauh
Life of this patent
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Abstract
The invention relates to a coordinate measuring apparatus for measuring an object, having an x-ray sensory mechanism as a first sensory mechanism that is provided with an x-ray source and at least one x-ray sensor which detects the x-rays, and a second sensory mechanism such as a tactile and/or an optical sensory mechanism that can be placed in the x, y, and/or z direction of the coordinate measuring apparatus in relation to the object. In order to be able to easily measure also large-size test objects, the x-ray sensory mechanism can be positioned in the coordinate measuring apparatus according to the second sensory mechanism.
Claims12
A method for measuring an object, said method comprising:
- providing a coordinate measuring device having an x-ray detector, an x-ray sensor system with an x-ray source, and a rotatable table, having a rotation axis, arranged between the x-ray source and the x-ray detector;
- arranging the object and a calibration body on the table;
- rotating the table about the rotation axis;
- imaging, by tomography, the object and the calibration body during the rotating step;
- using the calibration body to determine a position of the rotation axis relative to at least one of the x-ray source and the x-ray detector during the imaging;
- mathematically correcting the determined position;
- and
- factoring into a reconstruction algorithm, a position of the rotation axis that deviates from a nominal position.
A method for measuring an object, said method comprising:
- providing a coordinate measuring device having an x-ray detector, an x-ray sensor system with an x-ray source, and a rotatable table, having a rotation axis, arranged between the x-ray source and the x-ray detector;
- arranging the object on the table;
- determining a spatial location of the rotation axis relative to the x-ray source and the x-ray detector using at least one of the x-ray sensor system, a tactile sensor system, and an optical sensor system;
- mathematically correcting a position of the rotation axis that deviates from a nominal position, using the determined spatial location;
- and
- factoring into a reconstruction algorithm, the position of the rotation axis that deviates from the nominal position.
A method for measuring an object, said method comprising:
- providing a coordinate measuring device having an x-ray sensor system with an x-ray detector and an x-ray source,
- adjusting a rotation axis of a rotatable rotation table, on which the object is arranged, using at least one of a calibration procedure and correcting a drift of the rotation axis,
- wherein determining a position of the rotation axis in the coordinate measuring device comprises:
- providing a standard comprising four spheres arranged at corners of a rectangle, wherein spacing of the spheres relative to one another is known or is calibrated;
- positioning the standard on the rotation axis;
- rotating the standard so that a defined plane is parallel to the x-ray detector;
- measuring a position of the four spheres in a measuring field of the x-ray detector by capturing an x-ray image;
- calculating an average magnification M1 from the four measured sphere distances, nominal sphere distances, and a nominal pixel size of the x-ray detector;
- rotating the rotation axis by 180°;
- measuring positions of the four spheres in an image;
- and
- calculating an average magnification M2 from the four measured sphere distances, the nominal sphere distances, and the nominal pixel size.
Dependencies are inferred from the claim text.