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A coordinate measurement machine with a first frame element, a second frame element, a linear drive unit with a motor for moving the second frame element relative to the first frame element and a position measurement instrument, for determining a drive position of the second frame element relative t

A coordinate measurement machine with a first frame element, a second frame element, a linear drive unit with a motor for moving the second frame element relative to the first frame element and a position measurement instrument, for determining a drive position of the second frame element relative to the first frame element. The drive unit has limited stiffness and dynamic deflections on movement. The machine comprises a mechanical coupler from the drive unit to the second frame element, which coupler comprises a first part fixed to the drive unit and a second part fixed to the second frame element, which parts are movable relative to each other by an active compensation actuator. The active compensation actuator is built in such a way to shift the second frame element against the drive unit to introduce a counter-displacement in such a way that the dynamic deflections are at least partially compensated.

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1. A coordinate measurement machine for determination of at least one space coordinate of a measurement point on a measured object, comprising: a first frame element;a second frame element;a linear drive unit with a motor for moving the second frame element relative to the first frame element in a d

1. A coordinate measurement machine for determination of at least one space coordinate of a measurement point on a measured object, comprising: a first frame element;a second frame element;a linear drive unit with a motor for moving the second frame element relative to the first frame element in a direction of movement; anda position measurement instrument, for determining a drive position of the second frame element relative to the first frame element,wherein the drive unit has limited stiffness and dynamic deflections on movement, wherein a mechanical coupler from the drive unit to the second frame element, which coupler comprises a first part fixed to the drive unit and a second part fixed to the second frame element, which parts are movable relative to each other by an active compensation actuator, wherein the coupler and the active compensation actuator are built in such a way to shift the second frame element against the drive unit to introduce a counter-displacement for at least partially compensating the dynamic deflections. 2. The coordinate measuring machine according to claim 1, wherein dynamic deflections comprise: a dynamic deformation in the drive unit at acceleration/deceleration of the frame element and/ora transient oscillation in the drive unit, stimulated by the movement of the frame element. 3. The coordinate measuring machine according to claim 1, wherein the parts are movable relative to each other in the direction of movement by the active compensation actuator. 4. The coordinate measuring machine according to claim 1, wherein the coupler comprises a flexible element between the first and the second part of the coupler and the counter-displacement is introducible by a deformation of the flexible element by the active compensation actuator. 5. The coordinate measuring machine according to claim 1, wherein the coupler comprises a displacement sensor which is built and arranged in such a way to determine the dynamic deflections. 6. The coordinate measuring machine according to claim 1, wherein the dynamic deflections are determined by the sensor: according to a measured change of geometry of a part of the drive unit; oraccording to a measured force or acceleration. 7. The coordinate measuring machine according to claim 6, wherein the active compensation actuator is built in such a way to function as the displacement sensor for determining the dynamic deflections. 8. The coordinate measuring machine according to claim 1, wherein the active compensation actuator is driven by a control loop according to the dynamic deflections determined by the displacement sensor in such a way that the dynamic deflections are at least partially compensated by the counter displacement. 9. The coordinate measuring machine according to claim 1, wherein the active compensation actuator is driven by a control loop according to the dynamic deflections determined by the displacement sensor in such a way that the dynamic deflections are at least partially compensated by the counter displacement with the control loop having a bandwidth higher than the bandwidth of a controller for the drive unit. 10. The coordinate measuring machine according to claim 1, wherein the active compensation actuator comprises a magnetic actuator. 11. The coordinate measuring machine according to claim 10, wherein the active a magnetic actuator is a voice coil. 12. The coordinate measuring machine according to claim 1, wherein the active compensation actuator comprises a drive based on a piezo active material. 13. The coordinate measuring machine according to claim 1, wherein the dynamic deflections are determined by a calculation unit dependent on the difference of a desired trajectory of the movement and the determined drive position from the position measurement instrument. 14. The coordinate measuring machine according to claim 1, wherein the drive unit comprises a belt drive with a belt for the transmission of forces of movement. 15. The coordinate measuring machine according to claim 14, wherein the belt is a tooth belt. 16. The coordinate measuring machine according to claim 14, wherein the coupler conjoins the second frame element with the belt and compensates the dynamic deflections resulting from a strain of the belt due to the forces of movement. 17. The coordinate measuring machine according to claim 1, wherein the dynamic defections comprise a micro-vibration, introduced by the drive unit. 18. The coordinate measuring machine according to claim 17, wherein the micro-vibration results from a tooth system within the drive unit and/or torque ripples from the motor. 19. A method for actively compensating dynamic deflections in a coordinate measuring machine° comprising: at least two frame elements being movable relative to each other;a linear drive unit with a motor for moving the frame elements relative to each other;a coupler, providing a mechanical link for conjoining one of the frame elements with the linear drive unit,wherein moving of the frame elements is causing a dynamic deflection in the drive unit, and wherein the method comprises: moving the at least two frame elements relative to each other; andactively introducing a counter-displacement in the coupler for at least partially compensating the dynamic deflection by applying a counter-force by an active compensation actuator in the coupler and thereby counter-displacing the drive unit against one of the frame elements. 20. The method according to claim 19, wherein the dynamic deflection comprise dynamic deformations, transient oscillations and/or micro-vibrations on dynamic drive movement. 21. The method according to claim 19, wherein the counter-displacement is corresponding but contrarily in direction to the dynamic deflection and the dynamic deflection is determined by measuring a displacement or displacing force. 22. The method according to claim 19, wherein a controlling of the active compensation actuator according to a desired trajectory of the drive mechanism by a main control loop which is also controlling the drive unit. 23. The method according to claim 19, wherein a controlling of the active compensation actuator in a dedicated control loop according to the determined dynamic deflections. 24. The method according to claim 23, wherein the controlling is independent of a main control loop for controlling the drive unit and having a higher bandwidth than the main control loop. 25. A computer program product with program code being stored on a machine readable medium, the program code being configured to automatically execute and operate the method of actively reducing dynamic deflections according to claim 19.