Calculating a calibration parameter for a robot tool

1. A method for calculating a calibration parameter for a robot tool, which comprises the following method steps of:

receiving an image dataset from medical imaging of an image volume via a first interface, the image volume comprising a part of the robot tool, and the robot tool being attached to a robot;

receiving a robot dataset via a second interface, the robot dataset comprising a position of at least one movable axis of the robot during a recording of the image dataset;

determining at least one of a position and an orientation of a marking in the image dataset via a computing unit;

calculating at least one of an image-based position and an image-based orientation of a tool center point of the robot tool by transforming at least one of the position and the orientation of the marking via the computing unit; and

calculating the calibration parameter based on the robot dataset and on at least one of the image-based position and the image-based orientation of the tool center point via the computing unit.

2. The method according to claim 1 , wherein the image dataset contains a two-dimensional X-ray projection of the image volume.

3. The method according to claim 1 , wherein the image dataset contains a three-dimensional volume image reconstructed from a plurality of two-dimensional X-ray projections of the image volume.

4. The method according to claim 3 , wherein a reconstructed three-dimensional volume image is reconstructed from two-dimensional radiographic X-ray projections of the image volume.

5. The method according to claim 1 , wherein a structure of the robot tool is depicted in the image dataset and the marking is embodied as the structure of the robot tool.

6. The method according to claim 5 , wherein the step of calculating at least one of the image-based position and the image-based orientation of the tool center point is performed by registering the image dataset with a three-dimensional model of the robot tool.

7. The method according to claim 1 , wherein the marking contains a plurality of marking elements, and the marking elements are disposed at least on one of an outside of the robot tool and inside the robot tool.

8. The method according to claim 1 , wherein the step of calculating the calibration parameter is based on the robot dataset such that at least one of a predicted position and orientation of the tool center point is calculated from the robot dataset, and that the calibration parameter contains deviations of at least one of the predicted position and orientation from at least one of the image-based position and the image-based orientation.

9. The method according to claim 1 , wherein the robot dataset furthermore contains an influencing variable of an environment of the robot, the influencing variable influences a measurement of at least one of the robot dataset and the position of the tool center point.

10. The method according to claim 9 , wherein the influencing variable contains at least one of the following variables:

an ambient temperature;

a force acting on the robot tool; and

loading of the robot tool.

11. A calibration unit for calculating a calibration parameter for a robot tool, the calibration unit comprising:

a first interface embodied for a first reception of an image dataset from medical imaging of an image volume, the image volume comprising a part of the robot tool and the robot tool is attached to a robot;

a second interface embodied for a second reception of a robot dataset, the robot dataset comprising a position of at least one movable axis of the robot during a recording of the image dataset; and

a computing unit embodied for determining at least one of a position and an orientation of a marking in the image dataset, said computing unit embodied for:

calculating at least one of an image-based position and image-based orientation of a tool center point of the robot tool by transforming at least one of the position and the orientation of the marking; and

calculating the calibration parameter based on the robot dataset and on at least one of the image-based position and the image-based orientation of the tool center point.

12. The calibration unit according to claim 11 , wherein the image dataset contains a two-dimensional X-ray projection of the image volume.

13. The calibration unit according to claim 11 , wherein the image dataset contains a three-dimensional volume image reconstructed from a plurality of two-dimensional X-ray projections of the image volume.

14. The calibration unit according to claim 13 , wherein a reconstructed three-dimensional volume image is reconstructed from two-dimensional radiographic X-ray projections of the image volume.

15. The calibration unit according to claim 11 , wherein a structure of the robot tool is depicted in the image dataset and the marking is embodied as the structure of the robot tool.

16. The calibration unit according to claim 15 , wherein the step of calculating at least one of the image-based position and the image-based orientation of the tool center point is performed by registering the image dataset with a three-dimensional model of the robot tool.

17. The calibration unit according to claim 11 , wherein the marking contains a plurality of marking elements, and the marking elements are disposed at least on one of an outside of the robot tool and inside the robot tool.

18. The calibration unit according to claim 11 , wherein the step of calculating the calibration parameter is based on the robot dataset such that at least one of a predicted position and an orientation of the tool center point is calculated from the robot dataset, and that the calibration parameter contains deviations of at least one of the predicted position and the orientation from at least one of the image-based position and the image-based orientation.

19. The calibration unit according to claim 11 , wherein the robot dataset furthermore contains an influencing variable of an environment of the robot, the influencing variable influences a measurement of at least one of the robot dataset and the position of the tool center point.

20. The calibration unit according to claim 19 , wherein the influencing variable contains at least one of the following variables:

an ambient temperature;

a force acting on the robot tool; and

loading of the robot tool.

21. A computer program product with computer executable non-transitory instructions, which when loaded directly into a memory of a calibration unit, carrying out the steps of a method according to claim 1 .

22. A non-transitory computer-readable storage medium comprising computer executable instructions to be read and executed by a calibration unit for carrying out all steps of method claim 1 when the computer executable instructions are executed by the calibration unit.

23. A robot, comprising:

a calibration unit for calculating a calibration parameter for a robot tool, said calibration unit comprising:

a first interface embodied for a first reception of an image dataset from medical imaging of an image volume, the image volume comprising a part of the robot tool and the robot tool is attached to a robot;

a second interface embodied for a second reception of a robot dataset, the robot dataset comprising a position of at least one movable axis of the robot during a recording of the image dataset; and

a computing unit embodied for determining at least one of a position and an orientation of a marking in the image dataset, said computing unit embodied for:

calculating at least one of an image-based position and an image-based orientation of a tool center point of the robot tool by transforming at least one of the position and the orientation of the marking; and

calculating a calibration parameter based on the robot dataset and on at least one of the image-based position and the image-based orientation of the tool center point.