Method for measuring workpiece to be measured using coordinate measuring machine

Abstract

A method for measuring a workpiece to be measured using a coordinate measuring machine and a device for carrying out said method, the device comprising:-access means,-evaluation means configured to determine workpiece coordinates of the workpiece to be measured by evaluating measurement data of the workpiece to be measured (31) and / or planning data of the workpiece to be measured (31), -a determination device configured to determine, using the workpiece coordinates, whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one of the plurality of data records, and to create a corresponding determination result, and-a test planning device configured to plan a test on the workpiece to be measured, the test planning device being configured to determine whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one of the plurality of data records. And a determination unit configured to incorporate the at least one assigned test feature or at least one of the assigned test features into a test plan for measuring a workpiece to be measured or for measuring a workpiece of the same type or to confirm it as part of the test plan, depending on a determination result relating to the respective data record.

Description

Technical Field

[0001] The invention relates to a method for measuring a workpiece to be measured using a coordinate measuring machine. A workpiece is also understood in particular to mean an arrangement of interconnected parts. In particular, the invention relates to the automatic creation of a measurement sequence for measuring a workpiece. The automatic creation does not exclude the possibility that parts of the measurement sequence can be optionally checked and / or modified by a person. Background Art

[0002] When measuring a workpiece, at least one coordinate measuring machine is used to determine the coordinates of the workpiece. Therefore, a specific configuration of the method according to the invention comprises a process of measuring a workpiece and determining the coordinates of the workpiece to be measured or of the same type of workpiece from the measurement data.

[0003] The term "coordinate measuring machine" includes any type of machine that can be used to determine the coordinates of a workpiece. In one type of coordinate measuring machine, the coordinates are surface coordinates, i.e., the coordinates of points on the surface of the workpiece are determined. Another type of coordinate measuring machine is alternatively or additionally capable of determining the coordinates inside the workpiece. This type includes coordinate measuring machines that utilize invasive radiation that penetrates into the material of the workpiece and in particular measures the intensity of the radiation transmitted through the workpiece. Typically, the radiation is transmitted through the workpiece from different directions, and a computer-assisted reconstruction is performed on the scanned workpiece based on the results of the radiation transmission. This process is also known as computed tomography (CT). However, the term "coordinate measuring machine" also includes conventional coordinate measuring machines, such as machines with a gantry design or a gantry design, in particular coordinate measuring machines with a movable bridge, articulated arm machines and machines with a hexapod mechanism, on which a quill with a sensor that can be moved relative to the bridge is particularly mounted. Coordinate measuring machines also include machines in which at least one sensor is fixedly positioned relative to at least one degree of freedom of relative movement of sensor and measurement object, and in which case the workpiece to be measured can be moved relative to the at least one sensor, for example in the case of a machine with a movable measuring table. The term "coordinate measuring machine" also covers machines which, although not primarily designed as coordinate measuring machines, are arranged to work like coordinate measuring machines. In particular, these machines have at least one measuring sensor for determining coordinates. For example, robots, such as articulated arm robots, are known, on which sensors for capturing the surface of the workpiece (e.g. structured light sensors) are fastened instead of or in addition to the tool, or machine tools are known, on which measuring sensors (e.g. tactile sensors) are fastened instead of or in addition to the machining tool. For example, hexapods are also known, on which sensors for capturing the surface of the workpiece (e.g. tactile sensors) are fastened instead of or in addition to the machining tool.

[0004] Also known are personnel-guided (e.g., hand-guided) sensors for capturing workpieces, wherein at least one sensor is optionally arranged on a movable mechanism. This case lacks a motor drive for moving the sensor. Instead, the movement is achieved by a person. The measurement object can be captured either by scanning or from a corresponding fixed position with the sensor fixedly aligned. The triangulation principle is often used for personnel-guided sensors: for example, a known pattern is projected onto the measurement object and at least one image of the measurement object is recorded from different viewing angles of the surface. Instead of the projected pattern, laser radiation can also be used in the application of the triangulation principle. In particular, the receiving position of the reflected laser radiation contains information about the surface coordinates of the measurement object. However, machines with personnel-guided sensors are also known, which have at least one motor for supporting the movement and / or positioning of the sensor.

[0005] The invention also does not restrict the type of sensor used by the coordinate measuring machine to determine the coordinates. Tactile sensors have been mentioned as examples, which can be, for example, tactile sensors of the switch type or the measuring type. The tactile sensor can in particular be a passive sensor or an active sensor. The active sensor can be configured to generate a detection force, with which the tactile probe detects the surface of the workpiece to be measured. Optical sensors are often used alternatively or in addition, for example, projection sensors, in particular structured light sensors, laser triangulation sensors, line scan cameras, cameras for capturing two-dimensional images, cameras for capturing three-dimensional images, arrangements with at least two cameras or confocal color sensors. There are also, for example, capacitive sensors and inductive sensors.

[0006] Therefore, the term "coordinate measuring machine" also includes 3D scanners. As mentioned above, but not limited to personnel-guided sensors, systems based on triangulation (such as laser scanners and projection sensors) are particularly advantageous here because they can create many measurement points with 3D coordinates in a short time. Projection sensors project a pattern (such as a stripe pattern) onto the surface area of ​​the measured object and use at least one image capture unit (camera) to capture the image of the measured object and the projected pattern. The 3D coordinates of the surface points of the measured object can be determined by evaluating the image record. In order to completely capture the measured object or the surface of the measured object, only one measuring position is usually not enough, so the relative position of the 3D scanner relative to the measured object is usually changed repeatedly. This positioning can be performed manually (in a handheld manner) or semi-automatically or automatically, for example by using a robot to guide the 3D scanner. The position change can also or additionally be achieved by moving the object relative to the 3D scanner, for example by a rotating table.

[0007] Workpieces of the same type can be measured and tested according to the same test plan. In order to prepare for the measurement and to evaluate the measurement data obtained by measuring the workpiece, it is known to prepare a test plan, in which the test features of the workpiece to be determined based on the measurement data are defined and included in the test plan as part of it. In turn, measurement instructions can be created based on the test features. The measurement instructions specify which measurement points of the workpiece should be measured by the coordinate measuring machine in order to be able to determine a single test feature, multiple test features or all test features to be determined. Therefore, the method also includes the creation of a configuration of measurement instructions for at least one test feature of the workpiece, wherein the measurement instructions specify the measurement points of the workpiece to be measured. As in the case of the measurement plan, the measurement instructions may already contain all the information required to control the measurement sensor of a specific coordinate measuring machine type, or specify measurement points that can be measured with the aid of different types of coordinate measuring machines and / or at least one of different types of measurement sensors.

[0008] In particular, the test plan defines a test procedure by which the quality of the workpiece to be measured can be judged. For example, such a test plan can be defined based on some general standard or manufacturer specification or customer specification.

[0009] The test plan or the measurement plan derived therefrom may contain program instructions and / or algorithms which prompt the coordinate measuring machine and at least one measuring computer to carry out a test process according to the test plan and in particular to determine a test feature relative to the measured workpiece, i.e. typically to determine at least one value of the test feature in each case.

[0010] In general, a test plan and / or a measurement plan can be a file or a computer program that is readable and / or executable by a control device, in particular a control device of a coordinate measuring machine and / or at least a measuring computer, which evaluates the measurement data created by the coordinate measuring machine in order to determine the test features. In particular, however, a test plan can also be just a list of test features or a list of test feature extensions. In the simplest case, the list can contain a single test feature. In any case, however, a test plan is a rule for the measurement of the workpiece to be measured and for the evaluation of the measurement data obtained during the measurement, at least by determining the test features based on the measurement data.

[0011] Generally speaking, a test feature is a quality feature of a process or product. In coordinate measurement technology, a test feature is a direct and indirect measurement result based on a measurement from a workpiece. Typically, the coordinates of the corresponding workpiece are initially determined by measuring the corresponding workpiece using one or more coordinate measuring machines, and then at least one value of the test feature is determined for at least one predefined test feature. Usually, the coordinates of more than one measuring point or at least one area of ​​the workpiece are required to determine the test feature. Examples of test features include straightness, flatness, roundness, cylindricity, line profile, surface profile, position, verticality, inclination, parallelism, symmetry, coaxiality, concentricity, true (radial) runout, true (axial) runout, total true (radial) runout and total true (axial) runout. Those skilled in the art are familiar with many other test features, such as gaps and transition dimensions. Allowable tolerances are usually defined so that the workpiece can be tested at a later stage based on the corresponding test features to see if it meets expectations. Even if the test plan is reused, the amount of tolerance allowed may vary in individual cases. In addition, the method for determining the test feature by evaluating the coordinate measurement data of the workpiece can vary. Optionally, the method can also be defined as additional information of the corresponding test feature. The foregoing also applies in particular to the configuration of the present invention described below.

[0012] The selection and / or definition of the test features of the test plan involves work, in particular if a complete or almost complete list of test features should be drawn up with respect to the verification of a specific workpiece type and its technical specification. In general, and also with respect to the present invention, this technical specification may be available, for example, as a CAD (Computer Aided Design) model with PMI (Product Manufacturing Information). In many cases, however, a complete list of test features cannot be derived from such a technical specification. Instead, additional experience and knowledge are required to complete the list.

[0013] WO 2016 / 150517 A1 has already suggested supporting the operator in this case. A database is provided, which contains a plurality of predefined measurement elements and a plurality of typical test features for these predefined measurement elements. Each typical test feature represents a defined dimensional property of at least one predefined measurement element. In addition, a graphical representation of the measurement object is provided, which shows at least one first geometric element. The operator can select the first geometric element based on the graphical representation. The operator is then displayed suitable test features for the selected first geometric element.

[0014] In this case, a suitable test feature is determined from a plurality of typical test features in a database by assigning the selected first geometrical element to a predefined measurement element of the same type. An operator can select a displayed, suitable test feature. A defined measurement sequence is created from the selected test feature. In a particular configuration, once at least two geometrical elements have been selected in the graphical representation of the measurement object, a suitable linking element is provided to the operator for automatically creating a defined measurement sequence. Preferably, suitable test features and suitable linking elements are displayed simultaneously, so that the operator obtains a complex measurement sequence by selecting test features and linking elements in the representation. Summary of the invention

[0015] It is an object of the present invention to facilitate the determination of at least one test feature for inclusion in a test plan.

[0016] It is proposed that a data record is pre-stored in a database, which data record contains data about at least two geometrical elements of the workpiece and about at least one geometrical relationship of the at least two geometrical elements with respect to one another.

[0017] According to the invention, a geometric relationship is a dimensional relationship, i.e. a relationship defined with respect to one or more dimensions of a size system. Examples of dimensions are lengths (e.g. distances, measurements, diameters), areas (e.g. the area of ​​a surface area), volumes (e.g. partial volumes of a workpiece), angles (e.g. the angle enclosed by two edges or two planes or as a measure of the size of a circular segment), and radius of curvature (e.g. the radius of curvature of an edge). In principle, a value can be assigned to a dimension or to each of the individual dimensions. Thus, in the presence of a real workpiece, or if sufficient planning data of a workpiece or workpiece type (e.g. CAD data used as a basis for production) are available, the value of the corresponding dimension can be determined in particular by using at least one coordinate measuring machine that determines the coordinates of the measuring points of the workpiece or by evaluating the planning data. An example of this is the distance between two geometric elements (e.g. two parallel edges or lines representing these parallel edges). The dimensional relationship of these parallel lines can define that the distance must have a specific value. However, the dimensional relationship need not always be related to the dimensional value that needs to be determined in order to determine the presence of a geometric element in a data record. In other cases, for example, a dimensional relationship may alternatively define a ratio of a dimension of one geometric element to a dimension of another geometric element (e.g. as a quotient or in some other way). A simple example is the ratio of the length of one geometric element to the length of another geometric element. With regard to the example of parallel lines, the ratio of the distance between two lines to the length of at least one of the two lines may also be defined as a dimensional relationship. At this point, however, it should be emphasized that the data record may also contain data about more than two geometric elements (i.e. the geometric elements are defined in such a way that at least these geometric elements are determinable based on measurement data of the workpiece to be measured or based on planning data of the workpiece). Therefore, the data record may also contain one or more dimensional relationships relating to more than two geometric elements.

[0018] In addition, the data record contains at least one test feature assigned to at least two geometric elements, the test feature being testable with respect to the at least two geometric elements of the workpiece. In many cases, the data record contains more than one assigned test feature, even if there are only two geometric elements, the data record contains data about these two geometric elements.

[0019] Such a data record allows determining whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in the data record. If this is determined, the assigned test feature or at least one assigned test feature can be automatically incorporated into a test plan for testing the workpiece.

[0020] Based on geometric dimension criteria, the present invention therefore makes it possible to objectively and automatically determine whether a test feature predefined with respect to the geometry of essentially any desired workpiece is to be included in the test plan for the workpiece to be measured. If the geometry of the workpiece to be measured corresponds to the geometry defined in the corresponding data record, the test feature or at least one assigned test feature (preferably all test features assigned by the data record) is included in the test plan. Thus, the results of a previously created list of test features for similar workpieces can be automatically used for the test plan for the workpiece to be measured. In particular, this also relates to combinations of multiple test features. If such a combination has already been defined for similar workpieces and at least a corresponding data record has been created, such a combination of test features can also be included in the test plan in the case of sufficient correspondence or similarity of the workpieces to be measured.

[0021] Identifying a test feature or a combination of test features according to a data record stored in a database also allows identifying additional information about the implementation of the measurement of the workpiece, provided that this additional information is also stored in the database or a reference to this additional information is stored in the database. In particular, the data record can therefore contain such additional information and / or a reference to it. The reference is configured to allow access to the additional information. In particular, this additional information can therefore be incorporated into a test plan and / or a corresponding measurement plan for measuring the workpiece to be measured or for measuring workpieces of the same type. The recording can be performed depending on the judgment result mentioned below.

[0022] The additional information may also include, in particular, such information relating to the determination of the test feature, for example to the specification of the evaluation method, for example by means of Gaussian elements or with modifiers, for example with projected tolerance zones, and / or to auxiliary constructions indirectly required for the test feature, for example lines of symmetry, points of intersection, etc.

[0023] In particular, the following is proposed: A method for measuring a workpiece to be measured using a coordinate measuring machine, wherein:

[0024] - accessing a database in which a plurality of data records are stored, each data record comprising data relating to:

[0025] a) The workpiece may contain at least two geometric elements,

[0026] b) at least one geometrical relationship of at least two geometrical elements relative to one another, which geometrical relationship is a dimensional relationship and thus allows to determine whether this geometrical relationship exists in the workpiece to be measured by determining and evaluating the coordinates of the at least two geometrical elements,

[0027] c) at least one test feature assigned to the at least two geometrical elements, the at least one test feature being testable with respect to the at least two geometrical elements of the workpiece to be tested,

[0028] - determining the workpiece coordinates of the workpiece to be measured by evaluating measurement data of the workpiece to be measured and / or planning data of the workpiece to be measured,

[0029] - using the workpiece coordinates to determine whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one data record in the plurality of data records, and creating a corresponding determination result, and

[0030] - depending on the decision result relating to the respective data record, at least one assigned test feature or at least one of the assigned test features is incorporated into a test plan for measuring the workpiece to be measured or for measuring workpieces of the same type or is confirmed as part of a test plan.

[0031] The types of geometric relationships have been discussed above. This geometric relationship is a dimensional geometric relationship, and therefore allows to determine whether this geometric relationship exists in the workpiece to be measured by determining and evaluating the coordinates of at least two geometric elements. However, determining whether a geometric relationship exists is not a sufficient condition to make it a dimensional condition. For example, a dimensionless geometric relationship between two parallel lines (each representing an edge of a workpiece) can involve its parallelism. Many types of workpieces meet this condition. Only two parallel edges are required. However, if the geometric relationship additionally defines that the distance between parallel lines must have a defined value (i.e., the value of the dimension length or distance) and / or additionally defines that the length of the distance is in a defined relationship with another dimension of at least one of the geometric elements, then this is a dimensional geometric relationship and allows a more targeted determination of the geometric element group. Therefore, compared to when the dimension of the relationship is not taken into account, test features can be determined in a more targeted manner relative to the workpiece to be measured, which test features correspond to these groups determined in a targeted manner and are useful when testing the workpiece in the past.

[0032] As described above, the data record relates to the workpiece to be measured. In particular, when a plurality of workpieces of the same type are produced, such as batch production, the data record may also relate to the workpiece of the same type. In this case, it can also be said that the data record also relates to the workpiece to be measured. In addition, the workpiece coordinates used to determine whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one of the multiple data records can be obtained from the workpiece of the same type, and it can still be correctly said that the workpiece coordinates are also valid for the workpiece to be measured. In other words, the workpiece to be measured can be a specific instance or any instance of a certain type. Within the scope of this determination, in most cases, it is not important whether there are slight deviations between workpieces of the same type and / or between one of the workpieces of the same type and the planned data. For this reason, it is preferred that when determining whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one of the multiple data records, a tolerance is allowed. This means that, in particular, in the case of not exceeding a specified maximum tolerance, it is also determined that the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in the data record. Then, the tolerance can involve all specifications for size and position, and information for determining geometric elements and geometric relationships. On the contrary, however, the tolerance in individual cases need not apply to all these specifications and information. Rather, it may also be permitted that a tolerance exists only for one of these specifications and / or for one of the information for determining geometrical elements and geometrical relationships. The tolerances take into account various situations, such as the inability to measure workpiece coordinates exactly and the inability to process values ​​(measured values ​​and planning data) by a computer without processing errors (e.g. rounding errors). Similar data records may also be determined by tolerances on geometrical relationships of geometrical elements. Corresponding examples will also be described below based on the accompanying drawings.

[0033] The judgment result can be described as positive, in particular if it means that the workpiece to be measured contains at least two geometric elements and at least one geometric relationship (in general, this can also be described as the workpiece to be measured corresponding to the data record) or may contain these according to a predetermined evaluation method. In the case of a positive judgment result, at least one assigned test feature or at least one of the assigned test features can be incorporated into the test plan for the workpiece to be measured or confirmed as part of the test plan. The procedure of evaluating during the judgment and determining the probability of correspondence between the workpiece to be measured and the data record represents a variant of the above-mentioned deviation tolerance. In particular, the probability can be determined by using statistical methods to determine the deviation of at least two geometric elements defined in the data record for a plurality of measurement points or points of the workpiece to be measured obtained from the plan data, in particular for a defined number of such points, taking into account at least one geometric relationship. For example, in this case, the square root of the sum of the squared deviations of the points can be formed as a measure of probability. Preferably, the measure of probability is normalized. A limit probability can be specified for the normalized measure. If the probability specifically obtained for the workpiece to be measured is higher than the limit probability, the judgment result is positive.

[0034] According to the present invention, each data record defines at least two geometric elements that are in a dimension-defining relationship with each other. When determining whether the geometric elements defined in a particular data record exist in the workpiece to be measured, the geometric elements defined in the data record can be individually checked to determine whether these geometric elements exist in the workpiece to be measured. If it is determined that only one of these geometric elements exists in the workpiece to be measured, or if more than two geometric elements are defined in the data record, not all of these geometric elements exist in the workpiece to be measured, the use of the data record to create / check the test plan is abandoned. In contrast, if all geometric elements defined in the data record exist in the workpiece to be measured, it can be determined whether the dimension-defining geometric relationship defined in the data record also exists in the existing geometric elements.

[0035] More generally, therefore, when determining whether a workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one data record among a plurality of data records, a configuration of the method may include initially determining, with respect to one of the data records, whether the workpiece to be measured contains all geometric elements that define geometric relationships of the geometric elements relative to each other in the data record, and if so, subsequently determining whether a geometric relationship exists among the geometric elements of the workpiece to be measured.

[0036] In particular, a plurality of data records stored in a database can be determined with respect to the same geometric element of the workpiece to be measured, the data records each defining a data record geometric element corresponding to the same plurality of geometric elements of the workpiece to be measured and also each defining a geometric relationship of these data record geometric elements. However, it is often the case that the correspondence between the geometric elements in the data record and the workpiece to be measured is not exact, and / or the geometric relationship defined in the respective data record is not completely present in the geometric element of the workpiece to be measured. It is therefore proposed that for each of the determined data records, a correspondence measure of the geometric element and the geometric relationship is determined. This enables the determined data record to be marked as non-corresponding or having a lower correspondence than at least one other determined data record, and optionally the data record is excluded from the determined set of data records. In particular, the data record with the highest correspondence measure can be selected, and at least one assigned test feature or at least one of the assigned test features in the selected data record can be incorporated into a test plan for measuring the workpiece to be measured or for measuring workpieces of the same type or confirmed as part of a test plan.

[0037] More generally, a plurality of data records stored in a database may be determined, each of which defines a data record geometric element corresponding to the same plurality of geometric elements of a workpiece to be measured and each of which further defines a geometric relationship of the data record geometric elements, wherein a correspondence measure of the geometric element and the geometric relationship is determined for each of the plurality of determined data records, and wherein the correspondence measure is used to determine at least one of the plurality of determined data records as not corresponding or having a lower correspondence than at least one other data record of the plurality of determined data records. For example, the measure may be a measure of the above-mentioned probability of correspondence of the workpiece to be measured and the data record.

[0038] As described above, the corresponding assigned test features can be tested with respect to at least two geometric elements of the workpiece to be tested. When determining the test feature, at least one test feature value is generated if the data pool is sufficient for this purpose. Preferably, the data record contains at least one test feature that depends on at least two geometric elements and / or their relationship to each other. Therefore, such a test feature is not a test feature that can be determined by evaluating the coordinates of only one geometric element. However, it is not excluded and is advantageous in many cases that the data record in any case also contains at least one test feature that can be determined by evaluating the coordinates of one of the geometric elements. For example, in the case of two parallel edges as two geometric elements, each of these geometric elements can be assigned a straightness test feature. In addition, the data record also contains, for example, a test feature for the parallelism of parallel edges as a test feature, the determination of which depends on the relationship of the geometric elements to each other, i.e., on the availability of the coordinates of the two geometric elements.

[0039] As described above, the method can be used not only to adopt at least one test feature from the data record into the test plan in the case of a correspondence between the workpiece to be measured and the data record, but also to confirm the test feature present in the test plan or to confirm whether a test feature considered for inclusion in the test plan is actually included. For example, test features of a test plan that can be used for workpieces of similar types can thus be tested and optionally confirmed in this way. If a test feature is not confirmed, it can be removed from the test plan.

[0040] The invention relates in particular to the automatic determination of workpiece coordinates, the automatic determination of whether a workpiece to be measured contains at least two geometrical elements and at least one geometrical relationship in at least one data record of a plurality of data records, and the automatic incorporation of at least one test feature in at least one data record of a plurality of data records into a test plan and / or the automatic confirmation as a test plan. If the measurement data of the workpiece to be measured are evaluated when determining the workpiece coordinates, the measurement of the workpiece can also be a step in the method. In any case, the evaluation of the measurement data with respect to the determination of the workpiece coordinates consists at least in determining the workpiece coordinates required for the determination to be performed. This can be limited to the selection of measuring points and / or include further evaluation steps, such as determining the selection of measuring points or the coordinates of all measuring points based on the original measurement data of the coordinate measuring machine.

[0041] More generally, therefore, a workpiece to be measured can be measured by means of at least one coordinate measuring machine and measurement data can be created to determine the workpiece coordinates.

[0042] Further, alternatively or in addition to the method as part of the method, the workpiece to be measured or workpieces of the same type can be measured according to the test plan with the aid of at least one coordinate measuring machine and / or the values ​​of test features incorporated into the test plan or confirmed as part of the test plan can be determined.

[0043] As described above, the workpiece coordinates can be used to determine whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one data record of the plurality of data records. Depending on the type of geometric element and / or depending on the program, the presence (or absence) of a geometric element can be determined by evaluating the workpiece coordinates, in particular based on: its geometric position (e.g., position in the coordinate system of the workpiece), alignment (e.g., alignment in the coordinate system of the workpiece), type (e.g., plane, edge, borehole), shape (e.g., straight, curved, angled, circular, elliptical), size (characterized by at least one dimension) and / or relationship to other geometric elements of the workpiece (e.g., edge parallel to another edge, borehole as part of an arrangement with a plurality of boreholes, flat surface area extending at an angle relative to another flat surface area).

[0044] In the case of evaluating the planning data of the workpiece to be measured in workpiece coordinates in order to determine whether the workpiece to be measured contains the corresponding geometric element, the workpiece coordinates can also be point coordinates like in workpiece measurement, that is, they correspond to the measurement points during measurement. However, in the case of planning data, depending on the data format of the planning data, other geometric information can also be evaluated in addition to at least individual coordinates. For example, the format of known planning data is to describe the geometry of the workpiece to be measured using vectors and therefore the direction and / or length of the geometric element. Therefore, depending on the type of geometric element to be determined, such length and / or direction can be evaluated, for example, compared with the corresponding length and / or direction of the geometric element to be determined, optionally considering the position in the coordinate system of the workpiece or another coordinate system. In addition, a known format is to describe the surface of the workpiece in particular by means of a network. For example, a triangular irregular network (TIN) is widely used. Information about the TIN can be stored as a triangular area and / or as nodes at the corners of a triangular area.

[0045] The database can be created only once. Alternatively, the database can be repeatedly supplemented with additional data records, for example formed by existing test plans. This increases the probability that at least one suitable data record is available when creating a test plan for a workpiece.

[0046] The data records in the database may be stored in the same data format as the information about the workpiece to be measured based on the workpiece coordinates or in a different format. In the step of determining whether the workpiece to be measured contains a geometric element defined by the corresponding data record, it may be necessary to at least partially convert one data format into another data format or convert two data formats in a way that comparable data is obtained. However, in principle, it is not necessary to implement exactly the same data format, and the data available in various data formats do not have to be completely converted into a universal data format. Instead, whether and to what extent at least one of the data formats must be changed depends on the type of geometric element and the judgment procedure. For example, a straight line with a known length and a known position in the workpiece coordinate system and corresponding to the edge of the workpiece can be easily compared with a plurality of points defined by the workpiece coordinates to be evaluated. For example, a straight line can be created by curve fitting using a plurality of points, and then the straight line can be tested to see whether it corresponds to the straight line defined in the data record in terms of length and position or the degree of its correspondence. The extent to which these two lines can deviate from each other can be defined in the data record or in another way, so that the judgment is still considered to be positive, that is, there is a geometric element in the measured workpiece. For example, the maximum deviation of the direction of the line and the maximum deviation of the length of the line can be defined relative to the straight line. In order to avoid misunderstandings, it should be observed here that the workpiece coordinates do not necessarily need to be specified in a workpiece coordinate system, even if they can be.

[0047] If a plurality of data records are stored in the database, it is in particular also possible to determine from the workpiece coordinates which geometrical elements in the different data records correspond to geometrical elements of the workpiece to be measured. This can be determined, for example, in each case for the type of geometrical element, for example in each case for an edge or a line, for a surface area or a planar surface, or a circular bore or a circular line, etc. For each geometrical element of the workpiece to be measured (which in principle can be relevant for the testing of the workpiece), a search can be made in the stored data records for the corresponding geometrical element in the process, or vice versa, it can be determined for a geometrical element in a data record whether the workpiece to be measured contains this geometrical element.

[0048] In particular, the method may be an at least partially computer-implemented method. In particular, the above-mentioned automatic steps of determining the workpiece coordinates, implementing the determination and incorporating at least one test feature in at least one of the plurality of data records into the test plan and / or confirming it as a test plan are computer-implemented. In addition, as described in the present specification, the step of measuring the workpiece to be measured or workpieces of the same type may be computer-implemented. However, in any case at least one coordinate measuring machine is used or the corresponding measurement is performed by at least one coordinate measuring machine. This includes automatically operated coordinate measuring machines, but also coordinate measuring machines with handheld sensors.

[0049] Therefore, the scope of the present invention also includes a computer program, which includes commands that, when executed by a computer or by a computer arrangement, prompt the computer or computer arrangement to perform a method in one of the ways or configurations described in this specification. The present invention also includes a computer-readable storage medium, which includes commands that, when executed by a computer or by a computer arrangement, prompt the computer or computer arrangement to perform a method in one of the ways or configurations described in this specification.

[0050] Thus, in particular, the device described below for performing the method may comprise a computer program which, when executed on a computer or a computer arrangement, performs the associated process steps.

[0051] The part of the device that performs the computer-implemented process steps as described above may, for example, consist of or include a single computer or a computer network. With regard to its operating method, the computer or at least one computer may in particular be an analog computer, a digital computer and / or a hybrid computer. In terms of size and design, it may be a smart phone, a personal digital assistant (PDA), a tablet computer, an embedded system (e.g., embedded in a control computer of a coordinate measuring machine), a single-board or multi-board computer, a personal computer (PC), a desktop computer, a workstation computer, a host or server integrated into a computer network, a thin client computer, a netbook, a notebook computer, a laptop computer, a mainframe computer or a supercomputer, wherein a part of the type described may be implemented by means of a single computer (e.g., a multi-board PC). In addition, the computer or at least one computer may have one or more central processing units (CPUs) and / or one or more computing cores per CPU. A graphics card or other dedicated card having a processor as part of a computer may also be a device for performing the method alone or in combination with other computers or processors.

[0052] Furthermore, the scope of the present invention includes a computer program comprising instructions which, when the program is executed by a computer or by a computer arrangement, prompt the computer or the computer arrangement to perform the computer-implemented part of the method, in particular to perform the method in one of the described configurations.

[0053] Furthermore, it should be noted that, although one or more computers are preferably prompted by a computer program to perform the method, the apparatus for performing the method may also comprise at least a hardware-implemented, preferably programmable arrangement (e.g. an arrangement of logic gates), such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device) or an FPGA (Field Programmable Gate Array).

[0054] In addition, the scope of the present invention includes an arrangement having the device, wherein the arrangement further includes at least one coordinate measuring machine, which is configured to measure one or more workpieces and create corresponding measurement data. For example, the measurement data can be original measurement data or existing data about the coordinates of the measurement points. The coordinate measuring machine can also create and output the workpiece coordinates required for the above-mentioned judgment. In addition, the created measurement data can be created by measuring the workpiece to be measured or the same type of workpiece according to the test plan, so as to determine the value of the test feature included in the test plan or confirmed as part of the test plan based on the created measurement data.

[0055] Alternatively or additionally, a database with a plurality of data records may be part of the arrangement.

[0056] As mentioned above, the present invention relates to a device for performing a method in one of the modes and configurations described in this specification, wherein:

[0057] The device comprises in particular:

[0058] - an access device configured to access a database in which a plurality of data records are stored, each data record comprising data relating to:

[0059] a) The workpiece may contain at least two geometric elements,

[0060] b) at least one geometrical relationship of at least two geometrical elements relative to one another, which geometrical relationship is a dimensional relationship and thus allows to determine whether this geometrical relationship exists in the workpiece to be measured by determining and evaluating the coordinates of the at least two geometrical elements,

[0061] c) at least one test feature assigned to the at least two geometrical elements, the at least one test feature being testable with respect to the at least two geometrical elements of the workpiece to be tested,

[0062] an evaluation device configured to determine workpiece coordinates of the workpiece to be measured by evaluating measurement data of the workpiece to be measured and / or planning data of the workpiece to be measured,

[0063] - a determination device configured to determine whether the workpiece to be measured contains at least two geometric elements and at least one geometric relationship in at least one data record of the plurality of data records using the workpiece coordinates, and to create a corresponding determination result, and

[0064] - Test planning means, which is configured to include at least one assigned test feature or at least one of the assigned test features in a test plan for measuring the workpiece to be measured or for measuring workpieces of the same type or to identify it as part of the test plan, depending on a decision result related to the corresponding data record.

[0065] The configuration and development of the device and of an arrangement having the device derive from the configuration and development of the method, and vice versa. For example, as described above, the device can be part of an arrangement comprising at least one coordinate measuring machine, and the coordinate measuring machine or at least one coordinate measuring machine can be configured or used to measure a workpiece to be measured and to create measurement data, so that an evaluation device that evaluates the measurement data determines the workpiece coordinates.

[0066] As already mentioned, tolerances should be taken into account with regard to the measurement and production of workpieces. When defining the corresponding tolerances, a compromise must be found between, on the one hand, the production of workpieces that are as free of tolerance as possible and, on the other hand, feasibility and effort. For this reason, the planning data for the production of the workpieces usually define the permissible tolerances. Thus, the permissible tolerances relative to the assigned test features can already be defined in existing data records stored in the database. However, it is also possible to define the permissible tolerances at a later stage or to determine the permissible tolerances from the planning data for the production of the workpieces. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. In the various figures of the accompanying drawings:

[0068] Figure 1 A coordinate measuring machine is shown, which in this exemplary embodiment is only a conventional coordinate measuring machine of gantry design,

[0069] Figure 2 A computer comprising various means for executing the method according to the invention is schematically shown,

[0070] Figure 3 A wrench is shown having a jaw and a ring, each for contacting the head of a hexagonal screw or a corresponding nut,

[0071] Figure 4 Shows the characterization Figure 3 The geometric elements of the wrench shown in

[0072] Figure 5 A wrench having jaws on each of the opposite ends of the gripping area is shown, with Figure 4 The geometric elements in the embodiment of the present invention are defined, and the geometric relationship corresponding to the wrench is determined for the wrench according to the definition of these geometric elements.

[0073] Figure 6A flow chart schematically illustrates a method for identifying existing data records based on geometric elements and geometric relationships of the geometric elements,

[0074] Figure 7 shows the arrangement of geometric elements defined in an existing data record, and

[0075] Figure 8 The arrangement of geometrical elements of a workpiece to be measured is shown. DETAILED DESCRIPTION

[0076] Figure 1 A coordinate measuring machine 1 of gantry design is schematically shown. A first carriage 3 in the form of a gantry is movably guided along two parallel guides in the region of a measuring table 2, for example a granite slab. A first scale 4 is provided for measuring the position of the gantry according to a first linear movement axis y. The position is read using a suitable reading sensor (not depicted here); this also applies to the further scales described below. Furthermore, a first drive (not depicted here) is provided which can drive the first carriage 3 in a y-direction.

[0077] The second carriage 5 is movably guided along a crossbeam of the gantry-shaped first carriage 3 horizontally across the measuring table 2, wherein a second scale 6 and a corresponding second reading sensor (not shown) are provided for measuring the position of the second carriage relative to the gantry according to a second linear movement axis x. The second carriage 5 can be driven to move in the x direction by a second drive (not shown).

[0078] The third carriage, in particular the quill 7, is in turn movably guided on the second carriage 5, wherein a third scale 8 and a corresponding third reading sensor (not shown) are provided for measuring the position of the quill relative to the second carriage 5 according to a third linear movement axis z. The quill 7 can be driven in the z direction by a third drive. A measuring sensor 10 is arranged below the lower end of the quill 7 and in the present case is implemented in the form of a stylus with a probe ball (i.e. as a tactile sensor), which is fastened to the lower end of the quill 7, for example, by a measuring head and an interchange interface.

[0079] The workpiece 12 is arranged on the measuring table 2 and can be detected by the measuring sensor 10 by moving the three carriages 3, 5, 7, wherein the measured values ​​on the surface of the workpiece 12 to be measured are determined according to the signals of the measuring sensor 10 and / or the measuring head and also according to the scale positions of the scales 4, 6, 8. The controller implemented by a computer program executed on the control computer 14 provides open-loop and / or closed-loop control for the drives of the carriages 3, 5, 7. The measuring computer 17 can be connected to the controller and is used to receive and process the read scale values ​​from the scales 4, 6, 8 and the signals from the measuring sensor 10 and / or the measuring head to create the coordinates of the measuring points on the surface of the workpiece 12 measured by the measuring sensor 10.

[0080] In particular Figure 1 The measuring computer 17 shown in, or another measuring computer or measuring computer arrangement, may include access means for accessing a database, evaluation means for determining workpiece coordinates, determination means for determining whether the workpiece to be measured corresponds to at least one data record of a plurality of data records, and test planning means for incorporating at least one test feature in the data record into a test plan or for confirming at least one test feature as part of a test plan.

[0081] Alternatively, the measuring computer or the measuring computer arrangement can include at least some of these means, in particular the evaluation means for determining the workpiece coordinates. In contrast, the access means, the decision means and the test planning means can in particular be implemented together on at least one other computer or on at least one other computer arrangement.

[0082] Figure 2 A computer is schematically shown, in an exemplary embodiment Figure 1 The computer 17 shown in FIG. The computer includes an access device represented by reference numeral 15, a judgment device represented by reference numeral 16, and a test plan device represented by reference numeral 18. The evaluation device 13 is Figure 2The top of is shown as a device implemented outside the computer. As indicated by the arrow pointing from top to bottom to the access device 15, the access device 15 receives workpiece coordinates from the evaluation device 13 when in operation. In addition, the access device 15 receives data in data records from a database 19 or accesses these data records. Alternatively, the judgment device 16 can receive the workpiece coordinates directly from the evaluation device 13 and also receive the data in the data records from the access device 15 connected to the judgment device 16 in any case. One or more judgment results are transmitted from the judgment device 16 to the test planning device 18 connected thereto. It incorporates at least one assigned test feature or at least one of the assigned test features into a test plan for measuring the workpiece to be measured or for measuring workpieces of the same type or confirms it as part of the test plan, depending on the judgment result related to the corresponding data record. From Figure 2 The arrow pointing to the right of the test plan device 18 at the bottom indicates that corresponding information or corresponding data can be output from the test plan device 18. For example, this can be a test plan. If a plurality of data records from the database 19 are determined to correspond to the workpiece to be measured, a plurality of test features are also incorporated into the test plan and / or are confirmed as part of the test plan.

[0083] Exemplary embodiments of data records and corresponding artifacts are described below. Figure 3 A wrench 21 is shown having a jaw 22 at its left end and a ring 23 at its right end. Both the jaw 22 and the ring 23 are adapted to contact the head of a hexagonal screw having a size corresponding to the inner dimensions of the jaw 22 or the ring 23, so that the screw can be turned in the desired direction of rotation. The long edges of the gripping area of ​​the wrench 21 are parallel to each other, as is conventional.

[0084] Figure 4 The geometric elements corresponding to the long edge of the gripping area, the jaws 22 and the ring 23 are shown. In this case, parallel straight lines 24, 25 of equal length correspond to the long edge of the gripping area, two short parallel straight lines 26, 27 of equal length correspond to the inner edge of the jaws 22, and two concentric circular lines 28, 29 correspond to the ring 23. For the straight lines 24, 25, symmetry lines are shown as dot-dash lines. For the short straight lines 26, 27 of the inner edge of the jaws 22, symmetry lines are also shown as dot-dash lines. The inner circle 28 of the mutually concentric circular lines 28, 29 represents a compensating circular line of the inner surface of the ring 23. For example, the inner circle 28 contacts each segment forming the inner surface of the ring 23, contacting at the point of the segment closest to the common center of the circular lines 28, 29. The outer circle 29 of the mutually concentric circular lines 28, 29 corresponds to the outer edge of the ring 23.

[0085] In particular, the following data record can be formed from these geometric elements (long straight lines 24, 25, short straight lines 26, 27 and concentric circular lines 28, 29), wherein a plurality of data records described below can also optionally be combined in the data record:

[0086] The first data record relates to the jaw 22 and contains data of geometric elements, each of which defines one of the short straight lines 26, 27. The data record also defines that the two straight lines extend parallel to each other. However, this still does not determine the distance between the short straight lines 26, 27, in particular the ratio of their length to their spacing. It is necessary to define the length of the distance or the above ratio to geometrically characterize the jaw 22. Therefore, the following geometric relationship is defined as part of the first data record in the exemplary embodiment specifically described here: The length of the short straight lines 26, 27 is x, where x is the value of the defined dimension. This value of the defined dimension can be specified in the data record or not, for example, after multiplication by a scaling factor, mutually consistent jaws of different wrench sizes should be defined by the data record. In addition, in the exemplary embodiment, a distance equal to the length of the short straight lines 26, 27 multiplied by a factor of 1.3 is defined as a geometric relationship, so that the distance A is equal to the length x multiplied by 1.3, or A=1.3*x. This geometric relationship is a dimensional geometric relationship between two geometric elements (short parallel straight lines 26, 27).

[0087] The second data record relates to the alignment of the jaws 22, which are angled relative to the longitudinal direction of the wrench (e.g., as defined by the direction of the course of the long straight lines 24, 25). Figure 5 In the embodiment, the angled configuration of the jaws 22 can be achieved by Figure 5 The horizontal inclination is identified, and the inclination angle α is 15 degrees. Figure 5 , the extensions of the upper long straight line 24 and the upper short straight line 26 are depicted as dashed lines on the left side of the figure. These extensions include an inclination angle α. Therefore, the second data record contains data of at least one of the long straight lines 24, 25 and one of the short straight lines 26, 27 as data of geometrical elements. In addition, with regard to the geometrical relationship between at least one of the lines 24 or 25 on the one hand and the line 26 or 27 on the other hand in the second data record, it is indicated that they include an angle of 15 degrees with respect to each other. In this case, the dimension of the dimensional relationship is the angle defining the value of 15 degrees.

[0088] The third data record relates to the ring 23. The third data record defines the circular lines 28, 29 as geometric elements. As a geometric relationship, the third data record defines that the circular lines 28, 29 are concentric with each other, and further defines that the diameter (or alternatively the radius) of the outer circular line 28 is 1.4 times the diameter (or radius) of the inner circular line 29. The dimensions are therefore the dimensions of the diameter and therefore the dimensions of the length, wherein only the ratio of the length is defined in the third data record. Alternatively, values ​​can be defined for both the outer circular line 28 and the inner circular line 29.

[0089] In the exemplary embodiment, for example, the first data record is assigned the test features of “parallelism of the short straight lines 26, 27” and “straightness of the short straight lines 26, 27”, the second data record is also assigned such test features of parallelism and straightness (to be precise both relative to the long straight lines 24, 25 and relative to the short straight lines 26, 27) and also the test feature of the “inclination” or angle of the jaws relative to the gripping area, and the third data record is assigned the features of the concentricity of the circular lines 28, 29 and the so-called two-point measurement (in each case relative to a separate circular line 28, 29). The two-point measurement is the deviation of two points on the respective circular line 28, 29, which are opposite to each other in the direction of the line through the center of the circle, from the diameter.

[0090] The three data records mentioned above can in particular be stored in a database, wherein in fact a plurality of further data records are stored in the database. Figure 5 The workpiece shown, specifically the wrench 31 to be measured again, can determine the data record corresponding to the wrench 31 to be measured based on the planning data of the wrench 31 to be measured or based on the measurement result of the wrench 31.

[0091] and Figure 3 Compared with the wrench 21 shown in Figure 5 The wrench 31 shown in FIG. 1 has jaws 32, 34 at each end. Thus, the wrench 31 lacks the Figure 3 The ring 23 at the right end of the wrench 21. Figure 5 In the test of which of the data records stored in the database the wrench corresponds to, no positive determination result is obtained with respect to the third data record, and the third data record is removed as the source of the test feature assigned thereto. In contrast, both the first data record and the second data record can be identified as appropriate with respect to the jaws 32, 34, respectively. More specifically, therefore, in the exemplary embodiment described herein, it is determined that Figure 4The short straight lines 26, 27 of the present as geometric elements in each of the jaws 32, 34, and the spacing of the short straight lines 26, 27 is equal to its length multiplied by 1.3. Therefore, each of the two jaws 30, 34 corresponds to the first data record. Further, relative to each of the jaws 32, 34, both the long straight lines 24, 25 and the short straight lines 26, 27 are present as geometric elements, and for each of the jaws 32, 34, one of the short straight lines 26, 27 forms an angle of 15 degrees with one of the long straight lines 24, 25. Therefore, each of the two jaws 30, 34 also corresponds to the second data record about the gripping area.

[0092] Therefore, in an exemplary embodiment, the above-mentioned test features of "parallelism of short straight lines 26, 27" and "straightness of short straight lines 26, 27" (to be precise relative to each of the two jaws 32, 34) in the first data record, as well as the test features of "parallelism of long straight lines 24, 25", "straightness of long straight lines 24, 25" and "inclination of the jaws relative to the gripping area" in the second data record can be selected, in particular in order to incorporate them into the test plan of the wrench 31 to be measured or to confirm them as test features of the test plan.

[0093] The above exemplary embodiment can be extended, for example, as follows: For example, the data record defined with respect to the wrench can still define additional geometric shapes starting from the first data record (or at least one of these geometric shapes can be defined in another data record), for example, an arc adjacent to two straight lines, the arc corresponding to the course of the closed end of the jaws. The intersection of the straight line and the arc at a predetermined position in the direction of the jaw opening can be defined as a geometric relationship in the data record.

[0094] Finally, the advantages and other aspects of the invention should be pointed out. Previously, the partial test plan for the workpiece to be measured was manually prepared. In doing so, the designers / test technicians were able to draw on their experience. The specification of the test features depended largely on their knowledge.

[0095] In this context, it is not possible to expect a single person to have all the knowledge of previous tests of a workpiece. In the present invention, this expert knowledge can be systematically recorded, centrally stored and automatically used to identify test features.

[0096] Figure 6A method for identifying existing data records based on geometric elements and geometrical relations of geometric elements is schematically depicted. The method can be automatically performed, for example, by a computer program executed on a computer or a computer arrangement. After starting the method in step S1, one of a plurality of stored data records is selected in step S2. Optionally, the selection can be made based on additional information. Alternatively, additional steps can be performed for each of the stored data records. This means that step S2 can be performed repeatedly, in each case followed by steps S3 and S4.

[0097] In the following step S3, the geometric elements defined in the data record are searched in the information about the workpiece and / or the available information. A set of geometric elements that are part of the above-mentioned available information about the workpiece or are determined based on this information can be used as a search space. For example, if the workpiece contains at least one cylindrical borehole in a cuboid block, the "cylinder" and "flat surface" geometric elements are available. In this case, the "cylinder" geometric element corresponds to the cylindrical borehole; the "flat surface" geometric element corresponds in each case to the outer surface of the cuboid block. Therefore, it exists multiple times in this example.

[0098] In a following step S4, the search space is restricted, i.e. the elements of the specified set not corresponding to the data record are removed. In this case, both geometric elements not contained in the data record and geometric elements not satisfying a geometric relationship of at least two geometric elements with respect to each other as defined in the data record may be removed. Alternatively or in addition to removing elements, elements corresponding to the data record (i.e. geometric elements) may be identified, in particular those elements satisfying at least one geometric relationship of at least two geometric elements with respect to each other as defined in the data record.

[0099] In particular, by repeatedly performing step S4, either so many geometric elements are removed from the set that the workpiece no longer corresponds to the data record, or geometric elements are retained and / or identified for which at least one geometric relationship between at least two geometric elements as defined in the data record also applies. In particular, in the set of geometric elements, a plurality of groups of at least two geometric elements can be retained in each case for which at least one geometric relationship applies in each case. If at least one such group remains after reducing the search space by implementing step S4 at least once or by repeatedly implementing step S4, the data record is correspondingly identified according to the workpiece and at least one assigned test feature can be adopted in the test plan or recognized as belonging to the test plan.

[0100] Now based on Figure 7 and Figure 8A specific exemplary embodiment of steps S3 and S4 is described for an existing data record and a workpiece to be measured. Figure 7 As shown), five cylinders exist as geometric elements. Each of the cylinders 40 to 44 can be represented by the radius of the circular cross section depicted and its length (at right angles to Figure 7 The data record is described by the direction of the plane of the drawing, for example defined by the length of the longitudinal axis. According to the existing data record, the cylinders 40 to 44 have the same orientation in space, the same position in space relative to a marking point in its longitudinal direction (for example, the starting point of the longitudinal axis), have equal diameters or radii, and have the same length in its longitudinal direction. In addition, the peripheral cylinders 41 to 44 are at the same distance from the central cylinder 40, and each is at the same distance from the nearest adjacent cylinder in the periphery of the central cylinder 40. For example, the distances between the cylinders 41, 42 and the distances between the cylinders 43, 44 are therefore equal to each other. The data record also assigns test features related to the positions of the cylinders 40 to 44, which are related to the distances between the cylinders. It also includes that the positions of the cylinders 41 to 44 located in the periphery should not deviate from their target positions by more than a specified maximum value of the position tolerance (whose value can be specified in the data record).

[0101] In contrast, the workpiece to be measured has nine cylinders 50 to 58 aligned parallel to one another, such as Figure 8 As shown. These nine cylinders 50 to 58 also have the same orientation in space, the same position in the direction of their longitudinal axis, the same diameter and the same length. In addition, the cylinders 51 to 58 located at the periphery are each at the same distance from the cylinder 50 located in the central area, and also at the same distance from the peripheral cylinder closest to it. In addition, there are two other cylinders 59, 60, whose longitudinal axes extend perpendicularly to the longitudinal axes of the nine cylinders 50 to 58.

[0102] When step S3 is executed, eleven "cylinder" geometrical elements are thus determined for the workpiece to be measured. When step S4 is executed, nine cylinders 50 to 58 are identified as corresponding to existing data records. The tenth cylinder 59 and the eleventh cylinder 60 are excluded from the search space for geometrical elements, because too few of the geometrical relationships defined in the specified data record apply to these cylinders 59, 60. In particular, the central cylinder is missing. In practice, the workpiece to be measured may contain additional geometrical elements, which are identified as corresponding to another specified data record or are removed from their search space for geometrical elements in each case for all specified data records.

[0103] In particular, when step S4 is performed, there may be two parts of the entire search space, either intermittently or until the implementation of step S4 is completed. In an exemplary embodiment, nine cylinders 50 to 58 are located in one part. In an exemplary embodiment, the tenth cylinder 59 and the eleventh cylinder 60 are temporarily located in the other part. However, once it is determined that the indispensable geometric relationship defined in the specified data record does not apply to the cylinders 59, 60, these cylinders are removed from the other part of the search space. As a result, the other part of the search space becomes empty.

[0104] Now a modified definition of the existing data record can be made, in which the above applies, and in addition the absolute values ​​of the distances between the cylinders 41 to 44 located at the periphery are defined, or alternatively the ratio of the distances between the nearest neighboring cylinders 41 to 44 located at the periphery and the distances of these cylinders 41 to 44 located at the periphery from the central cylinder 40 is defined. In this case, the nine cylinders 50 to 58 of the workpiece to be measured will not satisfy all the geometrical relationships between the geometrical elements defined in the data record, in particular the specified additional defined features. However, the selection of the nine cylinders 50 to 58 will also correspond to this existing data record, i.e. satisfy all the defined geometrical relationships. This selection concerns the cylinders 50, 51, 53, 55 and 57. If the search algorithm or recognition algorithm for implementing step S4 is configured accordingly, this selection of cylinders 50, 51, 53, 55 and 57 can therefore also be identified as corresponding to the existing data record. For this purpose, the algorithm may, for example, comprise the following steps: relative to a first cylinder located at the periphery (e.g., cylinder 53), search for an additional cylinder located at the periphery of the central cylinder 50 and at a distance specified by the data record from the first cylinder located at the periphery. With regard to cylinder 53, the same is true for cylinders 51 and 55. For the additional cylinders of the periphery, the procedure will have to be followed accordingly. It should be observed that the modified definition of the existing data record is satisfied not only by the above-mentioned selection of five cylinders, but also by the selection of five cylinders 50, 52, 54, 56, 58. Therefore, in step S4, these two selections or groups of five cylinders are identified in each case.

[0105] Alternatively, in step S4 or in another configuration of the method, if the geometrical elements of the workpiece to be measured do not satisfy all the geometrical relationships defined in the data record, an incomplete correspondence with the existing data record can also be determined. For example, with respect to the previous example with a modified definition of the existing data record, it is also possible to output a test result with respect to the nine cylinders 50 to 58 that there is a broad correspondence with the geometrical relationships defined in the data record, but the absolute values ​​of the spacings of the cylinders 41 to 44 located at the periphery do not correspond to the data record. In this case, it is also possible to advantageously use the above-mentioned assigned test features with distances having a certain position tolerance.

[0106] This is an example of how at least one assigned test feature can be incorporated into the test plan, or can be confirmed to belong to the test plan, even if the workpiece deviates from the definition in the existing data record. Optionally, the geometrical relations can be marked in the existing data record, for example, as non-essential if all other geometrical relations are met, or alternatively as essential. If the basic geometrical relations are not met, it is also judged as not corresponding to the existing data record.

Claims

1. A method for measuring a workpiece (31) to be measured using a coordinate measuring machine (1), wherein: - accessing a database (19) in which a plurality of data records are stored, each data record containing data relating to: a) the workpiece may contain at least two geometric elements (24 to 29), b) at least one geometrical relationship of the at least two geometrical elements (24 to 29) relative to one another, the geometrical relationship being a dimensional relationship, thus allowing to determine whether the geometrical relationship exists in the workpiece to be measured by determining and evaluating the coordinates of the at least two geometrical elements (24 to 29), c) at least one test feature assigned to the at least two geometrical elements (24 to 29), the at least one test feature being testable with respect to the at least two geometrical elements (24 to 29) of the workpiece (31) to be tested, - determining the workpiece coordinates of the workpiece (31) to be measured by evaluating measurement data of the workpiece (31) to be measured and / or planning data of the workpiece (31) to be measured, - using the workpiece coordinates to determine whether the workpiece to be measured contains the at least two geometric elements (24 to 29) and the at least one geometric relationship in at least one data record in the plurality of data records, and creating a corresponding determination result, and - depending on the result of the decision in relation to the corresponding data record, at least one assigned test feature or at least one of the assigned test features is incorporated into a test plan for measuring the workpiece (31) to be measured or for measuring workpieces of the same type or is confirmed as part of the test plan.

2. The method according to claim 1, wherein: At least one of these data records in the database (19) contains, in addition to data about at least one assigned test feature, additional information about how the measurement of the workpiece is implemented or a reference to the additional information, and, depending on the result of the determination, the additional information is incorporated into the test plan and / or a measurement plan corresponding to the test plan for measuring the workpiece (31) to be measured or for measuring workpieces of the same type, and / or is confirmed as part of the test plan.

3. The method according to claim 1 or 2, wherein: When judging whether the workpiece to be measured contains the at least two geometric elements (24 to 29) and the at least one geometric relationship in at least one data record among the multiple data records, with respect to one of the data records, it is initially judged whether the workpiece to be measured contains all geometric elements (24 to 29) that define the geometric relationships of these geometric elements (24 to 29) relative to each other in the data record, and if so, it is then judged whether the geometric relationship exists in the geometric elements (24 to 29) of the workpiece (31) to be measured.

4. A method according to any one of the preceding claims, wherein: A plurality of data records stored in the database (19) are determined, each of which defines a data record geometric element (24 to 29) corresponding to the same plurality of geometric elements (24 to 29) of the workpiece (31) to be measured and each of which also defines a geometric relationship between the data record geometric elements (24 to 29), wherein a correspondence measure between the geometric elements (24 to 29) and the geometric relationship is determined for each of the plurality of determined data records, and wherein the correspondence measure is used to determine at least one of the plurality of determined data records as not corresponding or having a lower correspondence than at least one other data record of the plurality of determined data records.

5. A method according to any one of the preceding claims, wherein: The workpiece (31) to be measured is measured by means of at least one coordinate measuring machine (1), and the measurement data are created to determine the workpiece coordinates.

6. A method according to any one of the preceding claims, wherein: The workpiece (31) to be measured or a workpiece of the same type is measured according to the test plan by means of at least one coordinate measuring machine (1) and / or the values ​​of test features included in the test plan or identified as part of the test plan are determined.

7. A computer program comprising commands which, when the program is executed by a computer or by a computer arrangement, prompt the computer or computer arrangement to carry out the method according to any one of claims 1 to 4.

8. A computer-readable storage medium comprising commands which, when executed by a computer or by a computer arrangement, prompt the computer or computer arrangement to perform the method according to any one of claims 1 to 4.

9. An apparatus for performing the method according to any one of the preceding claims, wherein: The equipment includes: - access means (15) configured to access a database (19) in which a plurality of data records are stored, each data record containing data relating to: a) the workpiece may contain at least two geometric elements (24 to 29), b) at least one geometrical relationship of the at least two geometrical elements (24 to 29) relative to one another, the geometrical relationship being a dimensional relationship, thus allowing to determine whether the geometrical relationship exists in the workpiece to be measured by determining and evaluating the coordinates of the at least two geometrical elements (24 to 29), c) at least one test feature assigned to the at least two geometrical elements (24 to 29), the at least one test feature being testable with respect to the at least two geometrical elements (24 to 29) of the workpiece, an evaluation device (13) configured to determine workpiece coordinates of the workpiece to be measured by evaluating measurement data of the workpiece to be measured (31) and / or planning data of the workpiece to be measured (31), - a determination device (16) configured to use the workpiece coordinates to determine whether the workpiece to be measured contains the at least two geometric elements (24 to 29) and the at least one geometric relationship in at least one data record of the plurality of data records, and to create a corresponding determination result, and - a test planning device (18) which is configured to include at least one assigned test feature or at least one of the assigned test features in a test plan for measuring the workpiece (31) to be measured or for measuring workpieces of the same type or to identify it as part of the test plan, depending on a decision result related to the corresponding data record.

10. An arrangement having a device according to the preceding claim, wherein: The arrangement further comprises: - at least one coordinate measuring machine (1) configured to measure a workpiece and to create corresponding measurement data, and / or - A database (19) having the plurality of data records.

Images