Measurement device and method for operating the measurement device
The measuring device addresses the challenge of accurately measuring flat test subjects by using a movable and tiltable surveying device with a second measuring device to maintain alignment with a reference test, ensuring precise surface recording.
Patent Information
- Application Number
- PCT/EP2024/076982
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-09-29
- Filing Date
- 2024-09-25
- Publication Date
- 2025-04-03
AI Technical Summary
Existing measuring devices, such as Fizeau interferometers, face challenges in accurately measuring flat test subjects like mirrors without shifting or tilting the reference test subject, which can lead to inaccuracies in surface alignment and measurement.
A measuring device comprising a test subject device with two holders for the test subject and a reference test, and a surveying device that can be moved and tilted relative to the test subject device. The device includes a first measuring device for recording the test subject's surface and a second measuring device for determining the alignment of the surveying device relative to the reference test, allowing for precise measurement without shifting the reference test.
The solution enables precise and accurate measurement of flat test subjects by maintaining the alignment of the surveying device relative to the reference test, ensuring that the surface of the test subject is recorded correctly, even when the surveying device is moved or tilted.
Smart Images
Figure EP2024076982_03042025_PF_FP_ABST
Abstract
Description
[0001] DESCRIPTION
[0002] Measuring device, method for operating the measuring device
[0003] The invention relates to a measuring device for measuring a test object and a method for operating the measuring device.
[0004] The invention further relates to a computer program which has instructions which, when the computer program is executed by a control device, cause the control device to carry out the above-mentioned method.
[0005] Furthermore, the invention relates to a control device for executing the computer program.
[0006] A method for measuring a mirror using a Fizeau interferometer is known from the scientific article "A stitching figure profiler of large X-ray mirrors using RADSI for subaperture data acquisition" by T. Kimura et al. in Nucl. Instrum. Methods Phys. Res. A from 2010 (https: / / doi.org / 10.1016 / j.nima.2009.l l.014). In order to capture the entire surface of a test specimen, however, the Fizeau interferometer, or at least a portion of it, must be moved relative to the test specimen, in particular parallel to the surface of the test specimen. This disadvantageously requires a reference specimen to be tilted relative to the test specimen in order to perform the measurement.
[0007] The invention is based on the object of creating an improved measuring device for measuring a test object, a method for measuring a test object and a method for calibrating the measuring device, wherein the above-mentioned disadvantages are at least partially remedied, preferably avoided.
[0008] The object underlying the invention is achieved by a measuring device with the features of claim 1 for measuring a flat test specimen. The measuring device has a test specimen holding device and a measuring device, wherein the measuring device is displaceable, in particular sliding and / or tiltable, relative to the test specimen holding device. The test specimen holding device has a first test specimen holder, on which the test specimen can be arranged, and a second test specimen holder, which is fixedly connected to the first test specimen holder and on which at least one reference test specimen can be arranged. The measuring device has at least one first measuring device and a second measuring device, which is fixedly connected to the first measuring device. The at least one first measuring device is designed and arranged to detect a surface to be measured of the test specimen arranged on the first test specimen holder.The second measuring device is designed and arranged to detect an orientation of the measuring device relative to the reference test piece. Advantageously, the measuring device is thus configured to detect the surface to be measured and, in parallel thereto, the orientation of the measuring device relative to the reference test piece. In addition, the orientation of the measuring device relative to the reference test piece is advantageously obtained directly by means of the measuring device, and the surface to be measured is detected as a function of the orientation of the measuring device. In addition, the reference test piece is not displaced and / or tilted relative to the test piece during the method. In particular, the flat test piece is a mirror or an EUV mirror. Preferably, the measuring device is displaceable relative to the test piece holding device.In a particularly preferred embodiment, the at least one reference test specimen is arranged on the second test specimen holder. In particular, exactly one reference test specimen is arranged on the second test specimen holder. In particular, the first test specimen holder and the second test specimen holder are configured to hold the test specimen and the reference test specimen firmly in the measuring device. Particularly preferably, the first measuring device is a Fizeau interferometer. "Planar" in this case means slightly curved, in particular aspherical or free-form.
[0009] According to a preferred development of the invention, the second measuring device comprises at least one sensor selected from a group consisting of a distance sensor, an angle sensor, an autocollimator, and a differential interferometer. Advantageously, the orientation of the measuring device relative to the reference test object is easily detected by means of the at least one distance sensor. In particular, the second measuring device comprises at least two angle sensors configured to perform tilt displacement measuring interferometry. Alternatively, the second measuring device preferably comprises three distance sensors. The three distance sensors are preferably arranged in a triangular arrangement.Particularly preferably, the second measuring device is configured to perform displacement-measuring interferometry—in particular called "displacement measuring interferometry"—, difference-measuring interferometry—in particular called "difference-measuring interferometry"—or absolute range-resolved interferometry. Based on the triangular arrangement of the three distance sensors, a two-dimensional plane is advantageously determined as an interpolation to the surface of the reference test piece, thus detecting the orientation of the measuring device relative to the reference test piece.
[0010] Preferably, the measuring device is mounted displaceably parallel to a longitudinal extension of the first test specimen holder. This ensures that the test specimen arranged in the first test specimen holder can be measured preferably completely along its longitudinal extension, and its surface can be detected. In particular, the measuring device is mounted displaceably parallel to a longitudinal extension of the test specimen. Alternatively or additionally, the measuring device is mounted tiltably perpendicular to the longitudinal extension of the first test specimen holder.
[0011] According to a preferred embodiment of the invention, the second test specimen holder, in particular the reference test specimen, extends along the entire displacement path of the measuring device. Advantageously, this allows the orientation of the measuring device relative to the reference test specimen to be detected at any position along the displacement path.
[0012] According to a further development of the invention, it is preferably provided that the measuring device has a control device that is configured to combine measured values from the first measuring device and measured values from the second measuring device. This advantageously ensures that the surface of the test object can be precisely measured regardless of any tilting of the measuring device. In particular, the control device is configured to manipulate and / or correct the measured values from the first measuring device depending on the measured values from the second measuring device. Particularly preferably, the measuring device has a control device, in particular with the features of claim 15, that is specifically designed to carry out the inventive method described below when used as intended.Alternatively or additionally, the control device is preferably configured to carry out a method for measuring a test specimen having the features of claims 6 to 13. The control device is preferably configured to correct measured values of the surface to be measured as a function of the orientation of the measuring device relative to the reference test specimen. The inventive method for operating the measuring device according to the invention or a measuring device according to one or more of the previously explained preferred embodiments having the features of claim 6 is characterized in that a test specimen to be measured is arranged in the first test specimen holder and the reference test specimen is or will be arranged in the second test specimen holder.In a step VI), in a first measuring position of the test specimen holding device and the measuring device, a surface of the test specimen to be measured is detected by means of the first measuring device, whereby a first test specimen measured value is obtained. In a step V2), in the first measuring position of the test specimen holding device and the measuring device, an orientation of the measuring device relative to the reference test specimen is detected by means of the second measuring device, whereby a first reference measured value is obtained. Subsequently, in a step V3), the first test specimen measured value and the first reference measured value are combined with one another, whereby a first corrected test specimen measured value is obtained. In connection with the method for measuring a test specimen, the advantages that have already been explained in connection with the measuring device arise in particular.Advantageously, the orientation of the measuring device relative to the reference test piece is directly detected and used to obtain the first corrected test piece measurement value. Particularly preferably, the reference test piece, in particular a surface of the reference test piece, is known with a predetermined uncertainty that is less than an uncertainty threshold. In a particularly preferred embodiment, the first test piece measurement value is manipulated and / or corrected depending on the first reference measurement value, thereby obtaining the first corrected test piece measurement value.
[0013] According to a preferred development of the invention, a roll angle of the measuring device in the first measuring position is determined based on the first reference measured value. In step V3), the first test object measured value is manipulated and / or corrected based on the roll angle. Alternatively or additionally, a pitch angle of the measuring device in the first measuring position is determined based on the first reference measured value. In step V3), the first test object measured value is manipulated and / or corrected based on the pitch angle. If the measuring device is displaced relative to the test object holding device, it is possible that the measuring device and the test object holding device tilt relative to one another, thus changing a roll angle and / or pitch angle. Advantageously, the test object measured value is therefore easily manipulated and / or corrected using the roll angle and / or pitch angle.Preferably, the roll angle and / or pitch angle of the measuring device in the first measuring position is determined based on the first reference measured value as a function of a first actual reference measured value.
[0014] Preferably, in a step V4), the test specimen holding device 5 and the measuring device 7 are displaced relative to one another into a second measuring position. Subsequently, step V11) is performed again, whereby a second test specimen measurement value is obtained. Furthermore, step V2) is performed again, whereby a second reference measurement value is obtained. Subsequently, step V3) is performed again, whereby a second corrected test specimen measurement value is obtained. In the repeated execution of step V3), the second test specimen measurement value and the second reference measurement value are combined, whereby the second corrected test specimen measurement value is obtained. Advantageously, the entire surface of the test specimen is thus measured iteratively. Particularly preferably, the second test specimen measurement value is manipulated and / or corrected depending on the second reference measurement value, whereby the second corrected test specimen measurement value is obtained.
[0015] Particularly preferably, in a step V5), the first corrected test object measurement value and the second corrected test object measurement value are combined to form a total test object measurement value. Advantageously, the test object is thus characterized based on one measurement value, in particular the total test object measurement value, and can be analyzed based on the one measurement value. In particular, the first corrected test object measurement value and the second corrected test object measurement value are combined to form the total test object measurement value using a stitching method.
[0016] A particularly preferred development of the invention is characterized in that the measuring device is calibrated. In this case, a calibration test specimen is arranged in the first test specimen holder and a reference test specimen is or will be arranged in the second test specimen holder. In a step K1), in the first measuring position of the test specimen holding device and the measuring device, an alignment of the measuring device relative to the calibration test specimen is detected by means of the first measuring device, whereby a first calibration measured value is obtained. In a step K2), in the first measuring position of the test specimen holding device and the measuring device, the reference test specimen is detected by means of the second measuring device, whereby a first uncorrected reference measured value is obtained.In a step K3), the first calibration measured value and the first uncorrected reference measured value are combined, whereby the first actual reference measured value is obtained. Advantageously, due to the calibration of the measuring device, a predetermined measurement uncertainty is not exceeded when measuring a test object, even if the reference test object has an imperfect surface. In addition, the surface of the reference test object, in particular a curvature of the surface of the reference test object, and an associated uncertainty value of the reference measured values are advantageously determined by means of the calibration. Preferably, a planar test object, in particular a planar mirror, is used as the calibration test object, wherein a surface of the calibration test object is known.Particularly preferably, the first uncorrected reference measurement value is manipulated and / or corrected depending on the first calibration measurement value, thereby obtaining the first actual reference measurement value. In particular, the calibration steps are performed prior to the measurement of the test object. Alternatively, the calibration steps are performed as a method for calibrating the measuring device independently of whether a test object is actually being measured by the measuring device, in particular whether it is being measured according to the method according to the invention.
[0017] Particularly preferably, it is provided that the roll angle of the measuring device in the first measuring position is determined based on the first calibration measured value. In the third step K3), the first uncorrected reference measured value is manipulated and / or corrected based on the roll angle. Alternatively or additionally, the pitch angle of the measuring device in the first measuring position is determined based on the first calibration measured value. In the third step K3), the first uncorrected reference measured value is manipulated and / or corrected based on the pitch angle. As already mentioned above, it is possible that, when the measuring device is displaced relative to the test specimen holding device, the measuring device and the test specimen holding device tilt relative to one another and thus a roll angle and / or pitch angle changes.Advantageously, the uncorrected reference measurement value is easily manipulated and / or corrected by means of the roll angle and / or pitch angle, thus obtaining the actual reference measurement value.
[0018] According to a preferred development of the invention, it is provided that in a step K4) the test specimen holding device and the measuring device are displaced relative to one another into the second measuring position. Subsequently, step K1) is carried out again, whereby a second calibration measured value is obtained. In addition, step K2) is carried out again, whereby a second uncorrected reference measured value is obtained. Subsequently, step K3) is carried out again, whereby a second actual reference measured value is obtained. When step K3) is carried out again, the second calibration measured value and the second uncorrected reference measured value are combined with one another, whereby the second actual reference measured value is obtained. Advantageously, the measuring device is thus iteratively calibrated along the entire extent of the reference test specimen.Particularly preferably, the second uncorrected reference measured value is manipulated and / or corrected as a function of the second calibration measured value, whereby the second actual reference measured value is obtained.
[0019] According to a further development of the invention, a stitching method and / or a shearing method based on a Fourier transform is used to obtain the actual reference measurement value. Advantageously, by means of a time-shift property of the Fourier transform, the surface of the reference test object, in particular the curvature of the surface of the reference test object, is determined in a simple manner based on the uncorrected reference measurement values and the calibration measurement values, and the actual reference measurement values are thereby obtained. In particular, a stitching method and / or a shearing method based on a Fourier transform is used to obtain the first actual reference measurement value and / or the second actual reference measurement value. A discrete Fourier transform is particularly preferably used.
[0020] The computer program according to the invention with the features of claim 14 is characterized in that it comprises instructions which, when the computer program is executed by a control device, cause the control device to execute the method according to the invention for operating the measuring device or a method for operating the measuring device according to one or more of the previously explained preferred embodiments. In connection with the computer program, the advantages already explained in connection with the measuring device and the method for operating the measuring device arise in particular.
[0021] The control device according to the invention with the features of claim 15 is specifically designed to execute the method according to the invention for operating the measuring device or the computer program according to the invention when used as intended. In connection with the control device, the advantages already explained in connection with the measuring device and the method for operating the measuring device arise in particular. In a particularly preferred embodiment, the measuring device comprises the control device according to the invention. Further preferred features and combinations of features emerge in particular from the above description and from the claims. The invention is explained in more detail below with reference to the drawing. In the drawings:
[0022] Figure 1 is a schematic representation of an embodiment of a measuring device,
[0023] Figure 2 shows a flow chart of an embodiment for measuring a test specimen using the measuring device, and
[0024] Figure 3 is a flow chart of an embodiment for calibrating the measuring device.
[0025] Figure 1 shows a schematic representation of an exemplary embodiment of a measuring device 1 for measuring a flat test piece 3, in particular a mirror or an EUV mirror. In particular, the flat test piece 3 is an elongated, aspherical mirror extending in the x-direction. Figure 1 a) shows a yz-plane of the measuring device 1—a side view—and Figure 1 b) shows an xy-plane of the measuring device 1—a top view.
[0026] The measuring device 1 has a test specimen holding device 5 and a measuring device 7, wherein the measuring device 7 is displaceable, in particular sliding and / or tiltable, relative to the test specimen holding device 5. In particular, the measuring device 7 is mounted and / or displaceable relative to the test specimen holding device 5 in the x-direction. Additionally or alternatively, it is tiltable about the y-direction. When the measuring device 7 is displaced relative to the test specimen holding device 5, it is possible for the measuring device 7 and the test specimen holding device 5 to tilt relative to one another, wherein the measuring device 7 rotates about the y-axis and / or the x-axis. Particularly preferably, the measuring device 1 additionally has a control device 15.
[0027] The test specimen holding device 5 comprises a first test specimen holder 9.1, on which the test specimen 3 and / or a calibration test specimen 21 can be arranged, and a second test specimen holder 9.2, which is firmly connected to the first test specimen holder 9.1 and on which at least one reference test specimen 11 can be arranged. In particular, the first test specimen holder 9.1 and the second test specimen holder 9.2 are configured to firmly hold the test specimen 3, the reference test specimen 11, and / or the calibration test specimen 21 in the measuring device 1. In particular, the second test specimen holder 9.2, in particular the reference test specimen 11, extends along the entire displacement path of the measuring device 7.
[0028] The measuring device 7 comprises a first measuring device 13.1 and a second measuring device 13.2 which is permanently connected to the first measuring device 13.1. The first measuring device
[0029] 13.1 is designed and arranged to detect a surface to be measured of the test specimen 3 arranged on the first test specimen holder 9.1. In particular, the first measuring device 13.1 is a Fizeau interferometer. In particular, the first measuring device 13.1 is additionally designed and arranged to detect the calibration test specimen 21 arranged on the first test specimen holder 9.1. An observation area 17 of the first measuring device 13.1, in particular of the Fizeau interferometer, is shown in Figure 1b). The observation area 17 is smaller than a length of the test specimen 3 and / or the calibration test specimen 21 in the x-direction, so that the measuring device must be displaced relative to the test specimen holding device in order to measure the entire test specimen 3 and / or the calibration test specimen 21. The second measuring device 13.2 is designed and arranged to detect an orientation of the measuring device 7 relative to the reference test specimen 11.Particularly preferably, the second measuring device 13.2 comprises at least one sensor 19 selected from a group consisting of a distance sensor, an angle sensor, an autocollimator, and a differential interferometer. In particular, the second measuring device 13.2 comprises two angle sensors or three distance sensors. The second measuring device is preferably
[0030] 13.2 is set up to carry out displacement measuring interferometry - in particular called displacement measuring interferometry - a difference measuring interferometry - in particular called difference measuring interferometry - or an interferometry with absolute range resolution - in particular called absolute range resolved interferometry.
[0031] The control device 15 is connected in a manner not explicitly shown to the first measuring device
[0032] 13.1 and the second measuring device 13.2 and configured to control them respectively. Furthermore, the control device 15 is configured in particular to control an actuator for displacing the measuring device 7 relative to the test specimen holding device 5. The control device 15 is further configured to combine measured values 23, 33 - a so-called sub-aperture - of the first measuring device 13.1 and measured values 25, 35 of the second measuring device 13.2, in particular to combine the measured values 23, 33 of the first measuring device 13.1 as a function of the measured values 25, 35 of the second measuring device
[0033] 13.2. Furthermore, the control device 15 is specifically designed to execute a method for operating the measuring device 1 when used as intended. A preferred embodiment of the method for operating the measuring device 1 is explained in more detail in Figures 2 and 3.
[0034] Figure 2 shows a flow chart of an embodiment for operating the measuring device 1.
[0035] In step a), the test specimen 3 to be measured is placed in the first test specimen holder 9.1.
[0036] In a step b), the reference test specimen 11 is arranged in the second test specimen holder 9.2.
[0037] In a step c), the test specimen holding device 5 and the measuring device 7 are arranged in a first measuring position.
[0038] In a step VI), in the first measuring position of the test specimen holding device 5 and the measuring device 7, a surface of the test specimen 3 to be measured is detected by means of the first measuring device 13.1, whereby a first test specimen measurement value 23.1 is obtained.
[0039] In a step V2), in the first measuring position of the test specimen holding device 5 and the measuring device 7, an orientation of the measuring device 7 relative to the reference test specimen 11 is detected by means of the second measuring device 13.2, whereby a first reference measured value 25.1 is obtained. Preferably, a roll angle of the measuring device 7 in the respective measuring position is determined based on the reference measured value 25, in particular as a function of an associated actual reference measured value 31. Alternatively or additionally, a pitch angle of the measuring device 7 in the first measuring position is determined based on the reference measured value 25, in particular as a function of the associated actual reference measured value 31.
[0040] In particular, steps VI) and V2) are performed simultaneously. Alternatively, steps VI) and V2) are performed sequentially, with VI) or V2) being performed first.
[0041] In a step V3), the first test object measurement value 23.1 and the first reference measurement value 25.1 are combined, thereby obtaining a first corrected test object measurement value 27.1. Particularly preferably, the first test object measurement value 23.1 is manipulated and / or corrected as a function of the first reference measurement value 25.1, thereby obtaining the first corrected test object measurement value 27.1. Preferably, the respective test object measurement value 23 is manipulated and / or corrected based on the roll angle and / or the pitch angle, thereby obtaining the respective corrected test object measurement value 27.
[0042] Optionally, in a step V4), the test specimen holding device 5 and the measuring device 7 are moved relative to each other into a second measuring position. Subsequently, step V11) is performed again, obtaining a second test specimen measurement value 23.2. Furthermore, step V2) is performed again, obtaining a second reference measurement value 25.2. Subsequently, step V3) is performed again, obtaining a second corrected test specimen measurement value 27.2.
[0043] Optionally, step V4) and the subsequent steps VI), V2) and V3) are carried out several times, in particular until the entire test specimen 3 has been measured.
[0044] Optionally, in a step V5), the first corrected test object measurement value 27.1 and the second corrected test object measurement value 27.2, in particular the plurality of corrected test object measurement values 27, are combined to form an overall test object measurement value 29. In particular, the plurality of corrected test object measurement values 27 are combined to form the overall test object measurement value 29 using a stitching method.
[0045] Optionally, the measuring device 1 is calibrated in a calibration procedure K). An exemplary embodiment of the calibration procedure K) is shown in Figure 3.
[0046] Figure 3 shows a flow chart of an embodiment for calibrating the measuring device 1.
[0047] In step a), the calibration test piece 21 is placed in the first test piece holder 9.1.
[0048] In step b), the reference test specimen 11 is arranged in the second test specimen holder 9.2.
[0049] In step c), the test specimen holding device 5 and the measuring device 7 are arranged in the first measuring position.
[0050] In a step K1), in the first measuring position of the test piece holding device 5 and the measuring device 7, an orientation of the measuring device 7 relative to the calibration test piece 21 is detected by means of the first measuring device 13.1, whereby a first calibration measurement value 33.1 is obtained. Preferably, the roll angle of the measuring device 7 in the respective measuring position is determined based on the calibration measurement value 33. Alternatively or additionally, the pitch angle of the measuring device 7 in the respective measuring position is determined based on the calibration measurement value 33.
[0051] In a step K2), the reference test specimen 11 is detected in the first measuring position of the test specimen holding device 5 and the measuring device 7 by means of the second measuring device 13.2, whereby a first uncorrected reference measured value 35.1 is obtained.
[0052] In particular, steps K1) and K2) are performed simultaneously. Alternatively, steps K1) and K2) are executed sequentially, with K1) or K2) being executed first.
[0053] In a step K3), the first calibration measurement value 33.1 and the first uncorrected reference measurement value 35.1 are combined, thereby obtaining the first actual reference measurement value 31.1. Particularly preferably, the first uncorrected reference measurement value 35.1 is manipulated and / or corrected as a function of the first calibration measurement value 33.1, thereby obtaining the first actual reference measurement value 31.1. Preferably, the respective uncorrected reference measurement value 35 is manipulated and / or corrected based on the roll angle and / or the pitch angle, thereby obtaining the respective actual reference measurement value 31.
[0054] Optionally, in a step K4), the test specimen holding device 5 and the measuring device 7 are moved relative to each other into the second measuring position. Subsequently, step K1) is performed again, obtaining a second calibration measurement value 33.2. Furthermore, step K2) is performed again, obtaining a second uncorrected reference measurement value 35.2. Subsequently, step K3) is performed again, obtaining a second actual reference measurement value 31.2.
[0055] Optionally, step K4) and the subsequent steps K1), K2) and K3) are carried out several times, in particular until the entire calibration test piece 21 has been measured.
[0056] Particularly preferably, a stitching method and / or a shearing method based on a Fourier transform, in particular a shearing method based on a discrete Fourier transform, is used to obtain the actual reference measured value 31, in particular the first actual reference measured value 31.1 and / or the second actual reference measured value 31.2. In particular, a shearing method is applied which utilizes the time shift property of the discrete Fourier transform. A calibration measurement series is reconstructed from the calibration measured values 33 known at the plurality of measurement positions by shifting and shearing the plurality of calibration measured values 33, thereby obtaining a plurality of shear calibration measured values, and by forming a difference between the plurality of calibration measured values 33 and the plurality of shear calibration measured values.This advantageously utilizes the fact that the discrete Fourier transform of the plurality of calibration measurement values 33 and the difference between the plurality of calibration measurement values 33 and the plurality of shear calibration measurement values are linked by the time-shift property of the discrete Fourier transform, so that the calibration measurement series can be reconstructed. Furthermore, it is possible to obtain the difference based on two calibration measurement values 33, with a second measurement system providing an invariant contribution to each of the two calibration measurement values 33. The difference retains all.
[0057] Coefficients of the discrete Fourier transform of the majority of calibration measurements 33, ( ■271 \ e'^ qs — 1 j becomes zero. This means that to identify all coefficients, at least a second shift must be performed so that both shifts do not contain zero values for the same coefficients
Claims
CLAIMS 1. Measuring device (1) for measuring a flat test piece (3), in particular a mirror or an EUV mirror, with a test piece holding device (5) and with a measuring device (7), wherein - the test specimen holding device (5) has a first test specimen holder (9.1) on which the test specimen (3) can be arranged, wherein - the measuring device (7) has at least one first measuring device (13.1), in particular a Fizeau interferometer, which is designed and arranged to detect a surface to be measured of the test piece (3) arranged on the first test piece holder (9.1), and wherein - the measuring device (7) is displaceable, in particular displaceable and / or tiltable, relative to the test specimen holding device (5), characterized in that - the test specimen holding device (5) has a second test specimen holder (9.2) which is firmly connected to the first test specimen holder (9.1) and on which a reference test specimen (11) can be arranged, and that - the measuring device (7) has a second measuring device (13.2) which is fixedly connected to the first measuring device (13.1), wherein - the second measuring device (13.2) is designed and arranged to detect an orientation of the measuring device (7) relative to the reference test object (11).
2. Measuring device (1) according to claim 1, characterized in that the second measuring device (13.2) has at least one sensor (19), preferably two or three sensors (19), selected from a group consisting of a distance sensor, an angle sensor, an autocollimator, and a differential interferometer.
3. Measuring device (1) according to one of the preceding claims, characterized in that the measuring device (7) is mounted so as to be displaceable parallel to a longitudinal extent of the first test specimen holder (9.1), in particular of the test specimen (3), and / or so as to be tiltable perpendicular to the longitudinal extent of the first test specimen holder (9.1), in particular of the test specimen (3).
4. Measuring device (1) according to one of the preceding claims, characterized in that the second test specimen holder (9.2), in particular the reference test specimen (11), extends along the entire displacement path of the measuring device (7).
5. Measuring device (1) according to one of the preceding claims, characterized in that the measuring device (1) has a control device (15) which is designed to combine measured values (23, 33) of the first measuring device (13.1) and measured values (25, 35) of the second measuring device (13.2), in particular to manipulate and / or correct the measured values (23, 33) of the first measuring device (13.1) depending on the measured values (25, 35) of the second measuring device (13.2).
6. A method for operating a measuring device (1) according to one of claims 1 to 5, wherein - a test specimen (3) to be measured is placed in the first test specimen holder (9.1), whereby - a reference test specimen (11) is or will be arranged in the second test specimen holder (9.2), wherein - VI) in a first measuring position of the test piece holding device (5) and the measuring device (7), a surface of the test piece (3) to be measured is detected by means of the first measuring device (13.1), whereby a first test piece measured value (23.1) is obtained, characterized in that V2) in the first measuring position of the test specimen holding device (5) and the measuring device (7) by means of the second measuring device (13.2) a Alignment of the measuring device (7) relative to the reference test piece (11) is detected, whereby a first reference measurement value (25.1) is obtained, and that - V3) the first test object measurement value (23.1) and the first reference measurement value (25.1) are combined with each other, in particular the first test object measurement value (23.1) is manipulated and / or corrected depending on the first reference measured value (25.1), whereby a first corrected test object measured value (27.1) is obtained.
7. Method according to claim 6, characterized in that - a roll angle and / or a pitch angle of the measuring device (7) in the first measuring position is determined on the basis of the first reference measured value (25.1), in particular as a function of a first actual reference measured value (31.1), wherein - in V3) the first test object measurement value (23.1) is manipulated and / or corrected based on the roll angle and / or the pitch angle.
8. Method according to claim 6 or 7, characterized in that - V4) the test specimen holding device (5) and the measuring device (7) are displaced relative to each other into a second measuring position, wherein - VI ) is carried out again, whereby a second test sample measurement value (23.2) is obtained, wherein - V2) is carried out again, whereby a second reference measurement value (25.2) is obtained, where - V3) is carried out again, resulting in a second corrected test sample measurement value (27.2) is obtained.
9. Method according to one of claims 6 to 8, characterized in that in V5) the first corrected test object measurement value (27.1) and the second corrected test object measurement value (27.2) are combined to form an overall test object measurement value (29).
10. Method according to one of the preceding claims, characterized in that for the calibration of the measuring device (1) - a calibration test specimen (21) is arranged in the first test specimen holder (9.1), wherein - a reference test specimen (11) is or will be arranged in the second test specimen holder (9.2), wherein - Kl) in the first measuring position of the test piece holding device (5) and the measuring device (7) by means of the first measuring device (13.1) an alignment of the measuring device (7) relative to the calibration test piece (21) is detected, whereby a first calibration measurement value (33.1) is obtained, wherein - K2) in the first measuring position of the test specimen holding device (5) and the measuring device (7) by means of the second measuring device (13.2) the reference test specimen (11) is detected, whereby a first uncorrected reference measured value (35.1) is obtained, wherein - K3) the first calibration measured value (33.1) and the first uncorrected reference measured value (35.1) are combined with one another, in particular the first uncorrected reference measured value (35.1) is manipulated / corrected as a function of the first calibration measured value (33.1), whereby the first actual reference measured value (31.1) is obtained.
11. Method according to claim 10, characterized in that - the roll angle and / or the pitch angle of the measuring device (7) in the first measuring position is determined based on the first calibration measured value (33.1), whereby - in K3) the first uncorrected reference measured value (35.1) is manipulated and / or corrected based on the roll angle and / or the pitch angle.
12. Method according to claim 10 or 11, characterized in that - K4) the test specimen holding device (5) and the measuring device (7) are displaced relative to each other into the second measuring position, wherein - K1) is carried out again, whereby a second calibration measurement value (33.2) is obtained, whereby - K2) is carried out again, whereby a second uncorrected reference measurement value (35.2) is obtained, where - K3) is carried out again, whereby a second actual reference measured value (31.2) is obtained.
13. Method according to one of claims 10 to 12, characterized in that a stitching method and / or a shearing method based on a Fourier transformation is used to obtain the actual reference measured value (31).
14. A computer program, characterized in that the computer program comprises instructions which, when the computer program is executed by a control device (15), cause the control device (15) to carry out a method according to one of claims 6 to 13.
15. Control device (15) which is specially adapted to carry out a method according to one of claims 5 to 13 and / or a computer program according to claim 14 when used as intended.
Citation Information
Patent Citations
Method and apparatus for interferometric measurement of components with large aspect ratios
US20060033934A1