Method and apparatus for calibrating an x-ray system

A non-transitory digital storage medium having stored thereon a computer program for performing a method for an X-ray-based calibration and adjustment of axis systems by means of an X-ray system comprising a radiation source and a radiation detector, comprising:

• establishing a kinematic model of the X-ray system with all the kinematic relations for a first position on the movement trajectory and describing the same using a first set of kinematic parameters and using parameters to be calibrated, wherein the first set of kinematic parameters and the parameters to be calibrated define a first equation of a system of equations;
• setting the starting values for the parameters to be calibrated;
• and
• calibrating comprising:
• establishing an X-ray projection of a calibration body for the first position on the movement trajectory in order to acquire a first measuring result for at least one feature of the calibration body;
• and
• comparing the first measuring result to a respective reference in order to determine an error measure;
• and
• solving the system of equations in order to determine the parameters to be calibrated;
• wherein the X-ray system comprises at least one robot or multi-element robot;
• wherein the robot or multi-element robot moves the radiation source, an object or the detector such that the radiation source, the object and/or the radiation detector are movable in dependence on machine parameters for driving the robot;
• and
• wherein the kinematic parameters of the set of kinematic parameters describe the kinematic model of the entire system comprising at least the robot or multi-element robot, wherein the kinematic parameters comprise non-variable kinematic parameters comprising a leg length of a component of the robot or multi-element robot, and variable kinematic parameters comprising the machine parameters which describe the movement or position of the respective joint of the robot or multi-element robot,
• when said computer program is run by a computer.

An apparatus for an X-ray-based calibration and adjustment of axis systems by means of an X-ray system comprising a radiation source and a radiation detector, comprising:

• a calculation unit for establishing a kinematic model of the X-ray system with all the kinematic relations for a first position on the movement trajectory and describing the same using a first set of kinematic parameters and using parameters to be calibrated, wherein the first set of kinematic parameters and the parameters to be calibrated define a first equation of a system of equations,
• a calibrator configured, based on fixed starting values for the parameters to be calibrated, to:
• establish an X-ray projection of a calibration body for the first position on the movement trajectory in order to acquire a first measuring result for at least one feature of the calibration body;
• and
• comparing the first measuring result to a respective reference in order to determine an error measure;
• wherein the calibrator is configured to solve the system of equations in order to acquire the parameters to be calibrated;
• wherein the X-ray system comprises at least one robot or multi-element robot;
• wherein the robot or multi-element robot moves the radiation source, an object or the detector such that the radiation source, the object and/or the radiation detector are movable in dependence on machine parameters for driving the robot;
• and
• wherein the kinematic parameters of the set of kinematic parameters describe the kinematic model of the entire system comprising at least the robot or multi-element robot, wherein the kinematic parameters comprise non-variable kinematic parameters comprising a leg length of a component of the robot or multi-element robot, and variable kinematic parameters comprising the machine parameters which describe the movement or position of the respective joint of the robot or multi-element robot.

A method for an X-ray-based calibration and adjustment of axis systems by means of an X-ray system comprising a radiation source and a radiation detector, wherein the X-ray system comprises two multi-element robots;

• wherein a first one of the two robots moves the radiation source and the second one of the two robots moves the radiation detector so that the radiation source and/or the radiation detector is/are movable in dependence on machine parameters for driving the robots, comprising:
• establishing a kinematic model of the X-ray system with all the kinematic relations for a first position on the movement trajectory and describing the same using a first set of kinematic parameters and using parameters to be calibrated, wherein the first set of kinematic parameters and the parameters to be calibrated define a first equation of a system of equations;
• setting the starting values for the parameters to be calibrated;
• and
• calibrating comprising:
• establishing an X-ray projection of a calibration body for the first position on the movement trajectory in order to acquire a first measuring result for at least one feature of the calibration body;
• and
• comparing the first measuring result to a respective reference in order to determine an error measure;
• and
• solving the system of equations in order to determine the parameters to be calibrated;
• wherein the parameters to be calibrated describe an offset of the radiation source relative to the robot, described in the kinematic model, which moves the radiation source;
• and/or
• wherein the parameters to be calibrated describe an offset between the X-ray detector and the kinematic model of the robot which moves the radiation detector.

An apparatus for an X-ray-based calibration and adjustment of axis systems by means of an X-ray system comprising a radiation source and a radiation detector, wherein the X-ray system comprises two multi-element robots;

• wherein a first one of the two robots moves the radiation source and the second one of the two robots moves the radiation detector so that the radiation source and/or the radiation detector is/are movable in dependence on machine parameters for driving the robots, comprising:
• a calculating unit for establishing a kinematic model of the X-ray system with all the kinematic relations for a first position on the movement trajectory and describing the same using a first set of kinematic parameters and using parameters to be calibrated, wherein the first set of kinematic parameters and the parameters to be calibrated define a first equation of a system of equations;
• a calibrator configured, based on fixed starting values for the parameters to be calibrated, to:
• establish an X-ray projection of a calibration body for the first position on the movement trajectory in order to acquire a first measuring result for at least one feature of the calibration body;
• and
• compare the first measuring result to a respective reference in order to determine an error measure;
• wherein the calibrator is configured to solve the system of equations in order to acquire the parameters to be calibrated;
• wherein the parameters to be calibrated describe an offset of the radiation source relative to the robot, described in the kinematic model, which moves the radiation source;
• and/or
• wherein the parameters to be calibrated describe an offset between the X-ray detector and the kinematic model of the robot which moves the radiation detector.

A non-transitory digital storage medium having stored thereon a computer program for performing a method for an X-ray-based calibration and adjustment of axis systems by means of an X-ray system comprising a radiation source and a radiation detector, wherein the X-ray system comprises two multi-element robots;

• wherein a first one of the two robots moves the radiation source and the second one of the two robots moves the radiation detector so that the radiation source and/or the radiation detector is/are movable in dependence on machine parameters for driving the robots, comprising:
• establishing a kinematic model of the X-ray system with all the kinematic relations for a first position on the movement trajectory and describing the same using a first set of kinematic parameters and using parameters to be calibrated, wherein the first set of kinematic parameters and the parameters to be calibrated define a first equation of a system of equations;
• setting the starting values for the parameters to be calibrated;
• and
• calibrating comprising:
• establishing an X-ray projection of a calibration body for the first position on the movement trajectory in order to acquire a first measuring result for at least one feature of the calibration body;
• and
• comparing the first measuring result to a respective reference in order to determine an error measure;
• and
• solving the system of equations in order to determine the parameters to be calibrated;
• wherein the parameters to be calibrated describe an offset of the radiation source relative to the robot, described in the kinematic model, which moves the radiation source;
• and/or
• wherein the parameters to be calibrated describe an offset between the X-ray detector and the kinematic model of the robot which moves the radiation detector,
• when said computer program is run by a computer.