METHOD AND DEVICE FOR DETERMINING MEASURING POINTS OF AN ADAPTED MEASURING RAILWAY FOR SURVEYING A MEASURING OBJECT BY A COORDINATE MEASURING DEVICE AND PROGRAM

Description

[0001] The invention relates to a method and a device for determining measuring points of an adapted measuring path for measuring a measuring object by a coordinate measuring device and a program.

[0002] Coordinate measuring machines are well-known in the state of the art. They are used, for example, for quality control, to inspect workpieces or to determine their geometry. A wide variety of other applications are also conceivable.

[0003] To measure a measurement object, a sensor on a coordinate measuring machine is moved along a measuring path, with measured values ​​being generated at points on the measuring path, which then represent the coordinates of a point or section of the measurement object. The measuring path is often determined using ideal geometric data of the measurement object. However, if the geometry of the actual measurement object deviates from this ideal geometry, e.g. due to a deformation such as bending of the measurement object, it may happen that the measurement object or the section of the measurement object to be measured is no longer within the detection range of the sensor or moves out of it when the sensor is moved along the measuring path. For example, a tactile sensor may no longer have contact with the measurement object or may lose contact. With an optical sensor, the measurement object may not be within the detection range of the sensor or may move out of it.This risk is particularly high when measuring an edge of a target object, for example. In such a case, the target object can no longer be measured reliably.

[0004] Therefore, approaches exist to determine an adjusted or corrected measuring path.

[0005] DE10 2016 120 557 A1 discloses a system for dimensional measurement of an object, comprising an optical 3D sensor with areal scanning for capturing initial three-dimensional data of the object, and a coordinate measuring machine with an optical and / or tactile sensor for three-dimensional scanning of the object. The system comprises: an optical 3D sensor with areal probing for acquiring first three-dimensional data of the object; a coordinate measuring machine with an optical and / or tactile sensor for three-dimensional scanning of the object; a memory unit for storing a target measuring path determined on the basis of a target contour of the object, along which the optical and / or tactile sensor of the coordinate measuring machine is to be moved to scan the object; and an evaluation and control unit which is configured to determine a corrected measuring path based on the first three-dimensional data acquired by the optical 3D sensor with area probing and the target measuring path stored in the memory unit, and to move the optical and / or tactile sensor of the coordinate measuring machine along the corrected measuring path to acquire second three-dimensional data of the object.The system described in DE 10 2016 120 557 A1 requires an optical 3D sensor with area scanning to determine the corrected measuring path. This increases the system's manufacturing costs and installation space requirements.

[0006] US 2016 / 341533 A1 discloses a method for controlling a shape measuring device. US 2019 / 316893 A1 discloses coordinate measuring machines and, in particular, the operation of coordinate measuring machines.

[0007] WO 2018 / 060693 A1 discloses a method and a device for measuring an object, in particular a technique for measuring an object's offset using a scanning sensor carried by a machine tool. The technical problem is to create a method and a device for determining measurement points of an adjusted measuring path for measuring a measurement object using a coordinate measuring device, as well as a program, that avoid the disadvantages explained above, in particular to create the determination of a corrected measuring path with a reduced number of required components and thus also with reduced manufacturing costs and reduced installation space requirements.

[0008] The solution to the technical problem is achieved by the subject matter having the features of the independent claims. Further advantageous embodiments of the invention are set forth in the subclaims.

[0009] A method is proposed for determining measurement points along an adapted measuring path. The measuring path is used to measure a measuring object using a coordinate measuring device. A measuring point refers to a point on the measuring object, in particular a surface point.

[0010] Depending on the measurement point, a measurement-point-specific sensor pose can be determined. The measurement-point-specific sensor pose refers to a position and / or orientation of a sensor of the coordinate measuring device. A coordinate measurement of the measurement point is performed when the sensor is located at the position and / or has the orientation. Thus, a sensor path or trajectory can be determined depending on the measurement path.

[0011] The position and orientation can be referenced to a reference coordinate system, for example, a coordinate system of the coordinate measuring device. The measurement of the measuring object by the coordinate measuring device is performed by moving the sensor along measurement-point-specific sensor poses, and then performing a coordinate measurement to capture the measurement points, i.e., to capture coordinate information. The coordinate measuring device, in particular moving parts of the coordinate measuring device, can be controlled in such a way that the sensor is moved along the corresponding sensor path.

[0012] The coordinate measuring machine can, for example, be a coordinate measuring machine in a column or gantry design.

[0013] Various types of sensors can be used in coordinate measuring machines to record the coordinates of the object to be measured. The sensor of the coordinate measuring machine can, for example, be a tactile measuring sensor, as marketed by the applicant under the product name "VAST XT" or "VAST XXT." In this case, the surface of the object to be measured is scanned with a stylus, the coordinates of which are constantly known in the measuring space. Such a stylus can also be moved along the surface of an object, so that in such a measuring process, a large number of coordinates of the measuring object can be recorded at specified time intervals within the framework of a so-called "scanning process." Optical sensors can also be used, which enable contactless recording of an object's coordinates.An example of such an optical sensor is the optical sensor marketed by the applicant under the product name "LineScan." Like tactile sensors, optical sensors are primarily point or line sensors that detect a point or line while stationary. Camera sensors, such as the optical sensor "ViScan" marketed by the applicant, capture an image while stationary. For a comprehensive determination of the object's geometry, these sensors are moved across the object's surface along the measuring path using a coordinate measuring machine.

[0014] The proposed method comprises determining measurement points of an ideal measuring path, particularly as the first step of the method. These ideal measuring points are measuring points that the sensor of the coordinate measuring machine can reliably detect in a corresponding measuring point-specific sensor pose when the measuring object has its ideal shape, i.e., the target shape. In particular, the detectability of an ideal measuring point can be assumed under the assumption of the ideal shape of the measuring object by the sensor in a measuring point-specific sensor pose, for example, contact of the measuring object by a tactile sensor or a state in which the measuring object is within the detection range of an optical sensor. In such a detectable state, the sensor can therefore reliably detect the measuring point or the coordinates of the measuring point.

[0015] In the following, a detectable state refers to a state in which a sensor of the coordinate measuring device can reliably detect the measurement object, in particular measuring points of the measurement object, and thus generate a reliable measured value, e.g. a tactile sensor touches the measurement object, in particular a desired section of the measurement object, or the measurement object, in particular a desired section of the measurement object, is located in a detection range of an optical sensor. A non-detectable state refers to a state in which a sensor of the coordinate measuring device cannot or can no longer reliably detect the measurement object, in particular measuring points of the measurement object, and thus cannot generate a reliable measured value, e.g. a tactile sensor does not touch the measurement object or the measurement object, in particular a desired section of the measurement object, is not located in a detection range of an optical sensor.

[0016] The measurement points of the ideal measuring path can be determined, in particular, based on previously known geometric data of the measuring object, particularly CAD data. For example, a user or an automated process can define a measuring path based on the previously known geometric data.

[0017] This measuring path can be determined in a coordinate system of the geometric data, which then requires a transformation into the coordinate system of the coordinate measuring device. To determine such a transformation, a calibration process known to those skilled in the art can be performed, which determines the position of the measuring object in the measuring space of the coordinate measuring device. Once this position is known, a transformation can be determined from the coordinate system of the geometric data to the coordinate system of the coordinate measuring device, and this transformation can then be used to determine the measuring points of the measuring path in this coordinate system.

[0018] It is also possible to determine measurement points of the ideal measuring path by measuring the measurement object, in particular by the coordinate measuring device or another coordinate measuring device different from the coordinate measuring device for measuring with the adapted measuring path, wherein geometric data of the measurement object are determined by the measurement and the measurement points are then determined depending on / based on this geometric data. For the measurement to determine the geometric data for determining the measurement points of the ideal measuring path, a tactile, preferably an optical sensor, particularly preferably an optical 3D sensor with area probing, can be used, wherein the optical 3D sensor can generate a three-dimensional point cloud representing the surface of the measurement object. Such a sensor can be a fringe projection sensor, which is described in DE 10 2016 120 557 A1, explained above.In this case, the sensor used for the measurement to determine the geometric data for determining the measuring points of the ideal measuring path may be different from the sensor by which the measurement is carried out with the adapted measuring path to be determined as proposed.

[0019] Furthermore, the target measurement points of at least one guideway that differs from the ideal measurement path are determined, particularly in a second step of the proposed method. The target measurement points of the guideway can be determined—as previously with reference to the measurement points of the ideal measurement path—depending on previously known geometric data of the measurement object or depending on geometric data of the measurement object determined by a measurement using the coordinate measuring device or another coordinate measuring device.

[0020] In particular, the target measurement points of the guideway can be determined in such a way that the sensor of the coordinate measuring device performs coordinate measurements in or along a section of the measuring object that differs from the section to be measured by the ideal measuring path. The section of the measuring object to be measured by the target measurement points can, in particular, be selected in such a way that the risk of an undetectable condition occurring is reduced compared to a measurement along the ideal measuring path.

[0021] In particular, the target measurement points of the guideway can be selected such that a maximum value of the set of minimum distances between the target measurement points of the guideway and the ideal measurement path is smaller than a predetermined value. This value can be selected depending on the application and can, for example, be in a range from 0.1 mm to 10.0 mm.

[0022] The number of nominal measurement points on the guideway can be equal to the number of measurement points on the ideal measurement path. However, a ratio between the number of nominal measurement points on the guideway and the number of measurement points on the ideal measurement path can also be selected depending on the application and can, in particular, be between 0.1 (inclusive) and 1.0 (inclusive) or even higher.

[0023] Furthermore, actual measurement points along the at least one guideway are recorded by the coordinate measuring device or by another coordinate measuring device, in particular in a third step of the proposed method. In particular, for this purpose, the sensor is moved along the measurement-point-specific sensor poses, which were determined depending on the measurement points of the guideway. Furthermore, an actual measurement point is recorded in each of all or selected sensor poses of this sensor path, in particular the coordinates of such an actual measurement point.

[0024] Furthermore, the deviations between the target measurement points and the actual measurement points of the at least one guideway are determined, in particular in a fourth step of the proposed method. The deviation can be determined, in particular, in the form of a distance between the target measurement point and the actual measurement point detected in the target measurement point-specific sensor pose, and further, in particular, as the difference between the coordinate values ​​of these measurement points.

[0025] Furthermore, the measurement points of the adjusted measuring path, which can also be referred to as adjusted measuring points, are determined by changing the measuring points of the ideal measuring path depending on the deviations, in particular in a fifth step of the proposed method. In particular, for each or selected ideal measuring point(s), an adjusted measuring point can be determined in such a way that the distance to the corresponding ideal measuring point, in particular the difference between the coordinate values ​​of the measuring points, corresponds to the distance between a target measuring point of the guideway assigned to the ideal measuring point, and the actual measuring point detected in the target measuring point-specific sensor pose, in particular the difference between the coordinate values ​​of these measuring points.

[0026] For this purpose, a target measuring point of the guideway can be assigned to each measuring point of the ideal measuring path. For example, the target measuring point of the guideway that is the shortest distance of all measuring points on the guideway to the measuring point of the ideal measuring path can be the measuring point assigned to this. To determine such a point on the guideway, an interpolation can also be carried out depending on the target measuring points of the guideway, for example a spline interpolation. This can be done in particular if the number of target measuring points of the guideway differs from the number of points on the ideal measuring path. Furthermore, an adapted sensor pose and thus also an adapted sensor trajectory can be determined for each or selected adapted measuring points. This adapted sensor trajectory can then be used to measure the measurement object.In particular, the coordinate measuring device can be controlled in such a way that the sensor is moved along the adapted sensor path and detects measuring points along this path.

[0027] This advantageously results in a method for determining measuring points of an adapted measuring path, which reliably reduces the risk of the occurrence of an undetectable state of the measuring object, in particular of a desired section of the measuring object, while at the same time reducing the number of components required for this purpose and thus also manufacturing costs and the installation space required for a device suitable for carrying out the method.

[0028] According to the invention, the measuring path runs along an edge of the measurement object. The ideal measuring path runs along the edge of the measurement object. Edges pose a particularly high risk of an undetectable state, especially if the actual geometry of the measurement object deviates from the ideal geometry, e.g., due to bending or deformation. This advantageously results in a method for determining a measuring path for detecting the position of an edge of the measurement object, which reduces the increased risk of an undetectable state of the edge occurring.

[0029] In a further embodiment, the at least one guideway runs parallel to the ideal measuring path. This advantageously results in a simple determination of the target measuring points of the guideway, which are assigned to the measuring points of the ideal measuring path. In particular, the measuring point assigned to a selected measuring point of the ideal measuring path can be determined as the intersection point of a connecting line between the guideway and the ideal measuring path, wherein the connecting line intersects the selected measuring point on the ideal measuring path and is oriented perpendicular to the ideal measuring path.Furthermore, the reliability of avoiding undetectable states is advantageously increased, especially when measuring an edge, since it can be assumed for a large number of measuring objects that deviations between the target position and the actual position of measuring points do not change significantly for parallel measuring paths that are not more than a predetermined distance apart from each other.

[0030] According to the invention, the guide track runs along a surface of the measuring object. A surface can be an area of ​​the measuring object in which no discontinuous change in the orientation of the normal vector of the surface of the measuring object occurs. In particular, the surface can be a non-curved surface. However, this is not mandatory. It is also conceivable for the surface to be curved. However, the surface does not include an edge or corner. This advantageously increases the reliability of the recording of actual measuring points, since the risk of undetectable states is lower with measuring paths along surfaces than, for example, with measuring paths along edges. This also advantageously increases the reliability of determining the measuring points of the adapted measuring path.

[0031] Furthermore, according to the invention, the ideal measuring path runs along an edge of the measuring object, wherein the surface is a surface delimited by the edge. In other words, the surface is a surface adjacent to the edge or a surface that terminates at the edge. It can be assumed that if the measuring object is deformed, the effects on the edge profile are similar to or equal to the effects on the surface profile. This increases the reliability of avoiding undetectable states when measuring an edge, since it can be assumed that deviations between the target position and actual position of measuring points along the guideway are equal to the deviation between the target position and actual position of measuring points along the ideal measuring path.

[0032] In a further embodiment, a maximum value of the distances between a desired measurement point of the guideway and the nearest measurement point of the ideal measurement path is smaller than a predetermined distance. This was explained previously. The spatial proximity between the guideway and the ideal measurement path advantageously increases the probability that the effect of deformations of the measurement object on the course of the ideal measurement path is similar to or equal to the effect on the course of the desired guideway, along which these effects are then quantified by determining the deviations between the desired position and the actual position of the measurement points.If this effect is then transferred to the course of the ideal measuring path, as explained above, in order to determine the actual course of the ideal measuring path, this advantageously results in a high degree of reliability in avoiding undetectable conditions when measuring along the adapted measuring path.

[0033] In a further embodiment, an orientation of the sensor for detecting at least one actual measuring point of the guide path is different from an orientation of the sensor for detecting at least one measuring point of the ideal measuring path.

[0034] For this purpose, after determining the measuring points of the ideal measuring path as explained above, the measuring point-specific orientation of the sensor with which the corresponding measuring point is / should be recorded can also be determined. Furthermore, after determining the target measuring points of the guideway as explained above, the measuring point-specific orientation of the sensor with which the corresponding measuring point is / should be recorded can also be determined, whereby this orientation differs from the previously determined orientation of the sensor for recording the measuring points of the ideal measuring path. It is also possible that the orientation of the sensor for recording at least one measuring point of the adapted measuring path differs from the orientation of the sensor for recording at least one target measuring point of the guideway.For this purpose, after determining the measuring points of the adjusted measuring path, a measuring-point-specific sensor orientation can be determined for each of these measuring points. This orientation differs from the sensor orientation for detecting the respective assigned target measuring points of the guideway. The sensor orientation for detecting at least one measuring point of the adjusted measuring path can also be the same as the sensor orientation for detecting at least one measuring point of the ideal measuring path.

[0035] It is possible that the same sensor orientation is determined for the detection of all measuring points on the guideway. It is also possible to determine the same sensor orientation for the detection of all measuring points on the ideal measuring path, as well as the same sensor orientation for the detection of all measuring points on the adapted measuring path. However, it is also possible to determine different sensor orientations for different measuring points on the guideway and / or different sensor orientations for different measuring points on the ideal measuring path and / or different sensor orientations for different measuring points on the adapted measuring path. In this case, the sensor orientations for the detection of mutually assigned measuring points on the ideal measuring path and the guideway can be determined as different orientations, whereby a measuring point on the ideal measuring path, for example,The intersection point of a connecting line with the guideway is assigned as the associated measuring point of the guideway, whereby the connecting line intersects the ideal measuring path at the measuring point and is oriented perpendicular to the measuring path. The same applies to the assignment of measuring points of the ideal measuring path to measuring points of the adjusted measuring path.

[0036] Setting different orientations advantageously enables particularly reliable detection of measurement points along the guideway. In particular, the orientation of the sensor for detecting the measurement points of the guideway can be selected parallel to the orientation of a surface normal vector of the measurement object at the measurement point. This is particularly advantageous for determining measurement points along an edge, since in this case the orientation of the sensor for determining the actual measurement points along the guideway can be adapted to the orientation of a surface normal of an area bounded by the edge.

[0037] Setting different orientations also allows a sensor to be aligned in such a way that its accuracy in determining deviations is maximized. For example, if the target measurement points of the guideway lie in a plane and deviations parallel to a normal to this plane are to be determined, the orientation of a tactile sensor with a stylus can be set such that a longitudinal axis of the stylus is also parallel to the normal in a non-deflected state, since such a tactile sensor can generally detect such deflections along the longitudinal axis very accurately.However, if the sensor is an optical sensor, the orientation of the optical sensor can be adjusted, for example, so that the optical axis of the sensor is oriented perpendicular to the normal, since such an optical sensor usually has a high resolution and thus accuracy in determining deviations in directions perpendicular to the optical axis.

[0038] This adjustment can also reduce the undesirable effect of probe deflection on a measurement result.

[0039] In a further embodiment, the orientations differ by 90°. This advantageously results in a particularly good adaptation to a tactile sensor comprising various styli with stylus balls arranged thereon for contacting a surface of the measurement object, wherein the orientations of the longitudinal axes of the styli differ from one another by 90°.

[0040] In addition to the aforementioned advantages, a further advantage is that an edge profile can be reliably measured, whereby the edge is formed by two surfaces oriented at right angles or substantially at right angles to each other. For example, the edge profile of an edge formed by an inner surface or an outer surface of a (hollow) cylindrical test element and a front surface of this test element oriented perpendicularly to it can be measured.

[0041] In a further embodiment, the measurement points of the ideal measuring path and the target measurement points of the guideway are determined based on a model, in particular a CAD model. This has already been explained above. This advantageously results in a particularly simple and timely determination of the measurement points of the ideal measuring path and thus also a rapid determination of the measurement points of the adjusted measuring path.

[0042] In a further embodiment, at least the following steps are carried out again for each object to be measured: Recording actual measuring points along the at least one guideway by the coordinate measuring device or another coordinate measuring device, determining the deviations between the target measuring points and the actual measuring points of the at least one guideway, determining the measuring points of the adapted measuring path by changing the measuring points of the ideal measuring path depending on the deviations.

[0043] Of course, it is also possible to determine the measuring points of an ideal measuring path and the target measuring points of at least one guideway that differs from the ideal measuring path again for each new measuring object. For this purpose, a previously determined adjusted measuring path can be reset before determining the adjusted measuring path for a new measuring object, in particular to the ideal measuring path or another ideal measuring path. This advantageously results in the risk of an undetectable state of the measuring object, in particular of a desired section of the measuring object, being reliably reduced for each measuring object.

[0044] Further proposed is a program which, when executed on or by a computer or an evaluation device, causes the computer or evaluation device to perform one, several, or all steps of the method described in this disclosure for determining measurement points of an adapted measuring path. In particular, the program can perform the corresponding determination and ascertainment steps. The program can also control a coordinate measuring device to acquire the actual measurement points of the guideway.

[0045] Alternatively or cumulatively, a program storage medium or computer program product is described on or in which the program is stored, in particular in a non-temporary, e.g., permanent, form. Alternatively or cumulatively, a computer is described which comprises this program storage medium. Further alternatively or cumulatively, a signal is described, for example, a digital signal, which encodes information representing the program and which comprises code means adapted to carry out one, several, or all steps of the method presented in this disclosure for determining measuring points of an adapted measuring path for measuring a measurement object using a coordinate measuring device. The signal can be a physical signal, e.g., an electrical signal, which is generated in particular technically or mechanically.The program can also cause the computer to generate measurement points along the adjusted measurement path.

[0046] Furthermore, the method for determining measuring points of an adapted measuring path can be a computer-implemented method. For example, one, several, or all steps of the method can be carried out by a computer. One embodiment of the computer-implemented method is the use of the computer to carry out a data processing method. The computer can, for example, comprise at least one computing device, in particular a processor, and, for example, at least one storage device, in order to process the data, in particular technically, e.g. electronically and / or optically. A computer can be any type of data processing device. A processor can be a semiconductor-based processor. Furthermore, the program can also cause the computer to carry out the acquisition of actual measuring points along the at least one guideway using the coordinate measuring device or another coordinate measuring device.In this case, the program can be used to control the coordinate measuring device or another coordinate measuring device.

[0047] This advantageously results in a program for implementing the proposed method with the corresponding technical advantages already explained.

[0048] Further proposed is a device for determining measuring points of an adapted measuring path for measuring a measurement object using a coordinate measuring device. The device comprises the coordinate measuring device or another coordinate measuring device and at least one control and evaluation device. The control and evaluation device can, in particular, be a computing device. This has already been explained above. Such a computing device can, in particular, be designed as a microcontroller or integrated circuit, or can comprise one or more of these.

[0049] The device is configured to perform a method according to one of the embodiments described in this disclosure with the corresponding technical advantages. In particular, the device is configured to perform a method comprising the following steps: Determining measuring points of an ideal measuring path, determining target measuring points of at least one guideway that is different from the ideal measuring path, detecting actual measuring points along the at least one guideway by the coordinate measuring device or another coordinate measuring device, determining the deviations between the target measuring points and the actual measuring points of the at least one guideway, determining the measuring points of the adapted measuring path by changing the measuring points of the ideal measuring path depending on the deviations.

[0050] Furthermore, the device can comprise an input device for defining the measurement points of the ideal measuring path, e.g., by a user. This can also be used to define the orientation of the sensor for detecting measurement points of the ideal measuring path and / or for detecting target measurement points of the guideway.

[0051] The input device can also be used to define the target measurement points of the guideway. Furthermore, the input device can be used to specify parameters necessary for the process, such as a maximum permissible distance between the measurement points of the ideal measurement path and the measurement points of the guideway.

[0052] Furthermore, the device can comprise a display device for displaying the measuring object, the ideal measuring path, the measuring points of the ideal measuring path, the orientation of a sensor for detecting the measuring points of the ideal measuring path, the guide path, the desired measuring points of the guide path and the orientation of the sensor for detecting the desired measuring points.

[0053] Further described is a method for measuring a measurement object, wherein measuring points of an adapted measuring path for measuring the measurement object are determined by a coordinate measuring device according to one of the embodiments described in this disclosure, wherein the coordinate measuring device is then controlled to detect the adapted measuring points and corresponding measured values ​​are generated, e.g. by a sensor.

[0054] Further described is a coordinate measuring device for measuring a measurement object, wherein the coordinate measuring device comprises a device for determining measurement points of an adapted measurement path for measuring the measurement object by the coordinate measuring device according to one of the embodiments described in this disclosure. The coordinate measuring device can then be controlled to detect the adapted measurement points and corresponding measurement values ​​can be generated, e.g., by a sensor. The control can be carried out, e.g., by a control device of the coordinate measuring device.

[0055] The invention is explained in more detail using exemplary embodiments. The figures show: Fig. 1 is a schematic block diagram of a device according to the invention, Fig. 2 is a schematic flow diagram of a method according to the invention, Fig. 3a is a schematic representation of an ideal measurement object with an exemplary measuring point of an ideal measuring path, Fig. 3b is Fig. 3a shown ideal measuring object with a shifted measuring point, Fig. 3cdas in Figur 3a shown ideal measuring object with a target measuring point of a guideway, Fig. 4a a schematic representation of a real measuring object with an actual measuring point along the guideway and Fig. 4b a schematic representation of the real measuring object with an adjusted measuring point.

[0056] In the following, the same reference symbols designate elements with the same or similar technical features.

[0057] Fig. 1 shows a schematic block diagram of a device 1 according to the invention for determining measuring points MPa (see Fig. 4b ) of an adapted measuring path for measuring a measuring object 2 by a coordinate measuring device 3. This device 1 comprises the coordinate measuring device 3 and a control and evaluation device 4. Furthermore, the device 1 comprises an input device 5 for a user input and a display device 6 for displaying a virtual representation of the measuring object 2 and for displaying a virtual representation of measuring points MPi of the ideal measuring path, target measuring points MPs of a guide path and orientations of a tactile sensor 7, which is set to record measuring points MPs, MPf, MPa along the various paths.

[0058] These orientations for recording measuring points MPi, MPs, MPa of the ideal measuring path, the guide path and the adapted measuring path can be entered by a user using the input device 5.

[0059] The illustrated device 1 is configured to Fig. 2 to carry out the procedures described.

[0060] Fig. 2 shows a schematic flow diagram of a method according to the invention for determining measuring points MPa of an adapted measuring path for measuring a measuring object 2 (see Fig. 1 The method comprises a first determination step BS1 for determining measurement points MPi of an ideal measurement path. These can be determined, for example, in a virtual environment, for example, by a user or a (partially) automated process.

[0061] In a second determination step BS2, the target measurement points MPs of a guideway that differs from the ideal measurement path are determined. These target measurement points MPs can also be defined by a user or a (partially) automated process. Furthermore, the measurement points can be assigned a position and / or orientation of a sensor, e.g., the Fig. 1 The tactile sensor 7 shown can be assigned to a coordinate measuring device 3. For this purpose, a desired orientation can be set, for example, by a user or (partially) automatically. The position of the sensor for detecting the specified measuring point MPi, MPs with the orientation specified by the user can then be determined automatically.

[0062] In a detection step ES, actual measurement points MPf are detected along the guideway defined in the second determination step BS2 by the coordinate measuring device 3 or another coordinate measuring device (not shown). In a third determination step BS3, the deviation A between the target measurement points MPs and the actual measurement points MPf of the guideway is determined (see Fig. 4a ).

[0063] In a fourth determination step BS4, adapted measuring points MPa are then determined by changing the measuring points MPi of the ideal measuring path depending on the deviations A. An example of such a change in the measuring points MPi of the ideal measuring path has already been explained previously.

[0064] Fig. 3a shows a schematic representation of an ideal measurement object 2, in particular an edge of this ideal measurement object 2. Also shown is an ideal measurement point MPi of an ideal measurement path and an orientation of a sensor for detecting this measurement point MPi, wherein the orientation is represented by an arrow Oi. It can be seen that the measurement point MPi is a point along / at an edge of the measurement object 2. In particular, the ideal measurement path can therefore run along this edge of the measurement object 2, wherein, in addition to the illustrated measurement point MPi, further measurement points of this ideal measurement path are also arranged along the edge.

[0065] Fig. 3b shows a schematic representation of the ideal measuring object 2 with a measuring point MPs shifted by the distance D, which forms a target measuring point MPs of a guideway that is different from the ideal measuring path and runs parallel to it. In the illustrated embodiment, it is shown that the measuring paths are oriented parallel to a direction that is perpendicular to the plane of the drawing. It is further shown that the distance D between the measuring point MPi of the ideal measuring path and the target measuring point MPs of the guideway is measured along a straight line that runs perpendicular to the ideal measuring path and along a surface F of the ideal measuring object 2, wherein the surface F is a surface delimited by the edge.In this case, the distance D can be selected such that a maximum value of the distances D between a desired measuring point MPs of the guideway and the nearest measuring point MPi of the ideal measuring path is smaller than a predetermined maximum permissible distance.

[0066] Fig. 3c shows a schematic representation of the Fig. 3b shown measuring object 2, wherein an orientation Os of the sensor for detecting the measuring point MPs of the guideway is additionally shown. It can be seen that the orientation of the sensor for detecting the measuring point MPi of the ideal measuring path is different from the orientation of the sensor for detecting the measuring point MPs of the guideway, wherein the angular difference between the orientations is 90°. The orientation of the sensor for detecting a measuring point MPs of the guideway can in particular be set such that it is parallel to a normal vector of the surface of the ideal measuring object at the measuring point MPs. If the measuring point MPs lies on a non-curved surface that is bounded by the edge, the orientation of the sensor for detecting the measuring point MPs can in particular be set such that it is parallel to a normal vector of this non-curved surface.

[0067] Fig. 4a shows a schematic representation of a real measuring object 2` in conjunction with the Fig. 3C shown ideal measuring object 2. Here, the target measuring point MPs of the guideway and the corresponding orientation Os of the sensor for detecting this measuring point are shown. Also shown is the actual measuring point MPf, which is detected when the sensor is controlled by the coordinate measuring device 3 to detect the target measuring point MPs. It can be seen that a distance A exists between the actual measuring point MPf and the target measuring point MPs. This results from the deviation of the shape of the real measuring object 2 from the shape of the ideal measuring object 2. In Fig. 4a It is shown that this distance A is detected due to the set orientation of the sensor along a distance detection direction that is oriented perpendicular to the surface F.

[0068] Fig. 4b shows a further schematic representation of the ideal measurement object 2 and the real measurement object 2`. It is shown that the Fig. 3a shown measuring point MPi of the ideal measuring path has been shifted by the distance A along the distance detection direction, whereby a position of an adapted measuring point MPa is defined, in particular in a coordinate system of the measuring object 2. It is further shown that the orientation Oa of the sensor for detecting this adapted measuring point MPa is set equal to the orientation Oi for detecting the measuring point MPi of the ideal measuring path. If the edge along which the measuring point MPi of the ideal measuring path is arranged is formed as an intersection or contact line of two surfaces and the guide path lies in one of these surfaces, then, for example, the orientation of the sensor for detecting the measuring points of the adapted measuring path can be set parallel to a normal vector of the remaining surface in the adapted measuring point.

[0069] If a sensor of a coordinate measuring device, e.g. the one in Fig. 1 If the coordinate measuring device 3 shown is positioned such that the adjusted measuring point MPa of the adjusted measuring path is detected by the sensor, the explained adjustment advantageously increases the reliability of the sensor's generation of a measured value that represents a spatial position of a surface point of the real measuring object 2'. The probability that the correspondingly generated measured value actually represents a position of a desired spatial point of the measuring object 2, in this embodiment an edge point, can also be increased.

[0070] In particular, the probability that the correspondingly positioned sensor has no contact with the real measurement object 2' can be reduced. If the correspondingly positioned sensor has no contact with the real measurement object 2', the adaptation can advantageously ensure that the distance between the correspondingly positioned sensor and a surface point of the real measurement object 2' is smaller than without adaptation. This in turn facilitates and accelerates corresponding, e.g. automated, contact detection by a sensor if the sensor is positioned accordingly. Setting different orientations can also contribute to reducing the probability that the correspondingly positioned sensor has no contact with the real measurement object 2'.reduce the explained distance in such a scenario, whereby the probability can also be increased that the correspondingly generated measured value actually represents a position of a desired spatial point of the measurement object 2, in this embodiment an edge point.

[0071] In the Fig. 4b In the illustrated embodiment, a sensor will then approach the real measurement object 2' from the right, contact it in the area of ​​the edge, and generate a measured value. It is evident that the measured value generated in this way represents a more precise position of the edge than a measured value generated when the sensor is controlled to detect the measuring point MPi of the ideal measuring path. List of reference symbols

[0072] 1Device 2Measurement object, ideal measurement object 2`Real measurement object 3Coordinate measuring device 4Control and evaluation device 5Input device 6Display device 7Sensor FFarea BS1First determination step BS2Second determination step ESDetection step BS3Third determination step BS4Fourth determination step MPiMeasurement points of the ideal measuring path MPsTarget measuring points of the guideway MPfActual measuring point of the guideway MPaMeasurement point of the adapted measuring path OiOrientation of the sensor for detecting the measuring point of the ideal measuring path OsOrientation of the sensor for detecting target measuring points of the guideway OaOrientation of the sensor for detecting measuring points of the adapted measuring path DAdistance Adistance

Claims

1. Method for determining measurement points (MPa) of an adapted measurement path for measuring a measurement object (2, 2') using a coordinate measuring machine (3), comprising the steps of - determining measurement points (MPi) of an ideal measurement path, - determining target measurement points (MPs) of at least one guide path, which differs from the ideal measurement path, - capturing actual measurement points (MPf) along the at least one guide path using the coordinate measuring machine (3) or a further coordinate measuring machine, - determining the deviations (A) between the target measurement points (MPs) and the actual measurement points (MPf) of the at least one guide path, - determining the measurement points (MPa) of the adapted measurement path by changing the measurement points (MPi) of the ideal measurement path in dependence on the deviations (A), characterized in that the guide path runs along a surface (F) of the measurement object (2), wherein the ideal measurement path runs along an edge of the measurement object (2), wherein the surface (F) is a surface bounded by the edge.

2. Method according to Claim 1, characterized in that the guide path runs parallel to the ideal measurement path.

3. Method according to one of the preceding claims, characterized in that a maximum value of the distances between a target measurement point (MPs) of the guide path and the respectively closest measurement point (MPi) of the ideal measurement path is smaller than a predetermined distance.

4. Method according to one of the preceding claims, characterized in that an orientation (Os) of the sensor for capturing the actual measurement points (MPf) of the guide path differs from an orientation (Oi) of the sensor for capturing the measurement points (MPi) of the ideal measurement path.

5. Method according to Claim 4, characterized in that the orientations (Oi, Os) differ by 90°.

6. Method according to one of the preceding claims, characterized in that the measurement points (MPi) of the ideal measurement path and the target measurement points (MPs) of the guide path are determined based on models.

7. Method according to one of the preceding claims, characterized in that the adapted measurement path is reset to the ideal measurement path or to a further ideal measurement path before the adapted measurement path for a new measurement object (2) is determined.

8. Program which, when executed on or by a computer or an evaluation device, causes an apparatus according to Claim 9 to carry out all of the steps of a method for determining measurement points (MPa) of an adapted measurement path according to one of Claims 1 to 7.

9. Apparatus for determining measurement points (MPa) of an adapted measurement path for measuring a measurement object (2, 2') using a coordinate measuring machine (3), wherein the apparatus (1) comprises the coordinate measuring machine (3) or a further coordinate measuring machine, and at least one control and evaluation device (4), wherein the apparatus (1) is configured to carry out a method comprising the following steps: - determining measurement points (MPi) of an ideal measurement path, - determining target measurement points (MPs) of at least one guide path, which differs from the ideal measurement path, - capturing actual measurement points (MPf) along the at least one guide path using the coordinate measuring machine (3) or a further coordinate measuring machine, - determining the deviations (A) between the target measurement points (MPs) and the actual measurement points (MPf) of the at least one guide path, - determining the measurement points (MPa) of the adapted measurement path by changing the measurement points (MPi) of the ideal measurement path in dependence on the deviations (A), characterized in that - the guide path runs along a surface (F) of the measurement object (2), wherein the ideal measurement path runs along an edge of the measurement object (2), wherein the surface (F) is a surface bounded by the edge.