METHOD, COMPUTER PROGRAM AND DEVICE FOR SUPPORTING SOFTWARE-BASED PLANNING OF A DIMENSIONAL MEASUREMENT

Description

[0001] The present invention relates to a method and a device for supporting software-based planning of a dimensional measurement of a measurement object. Furthermore, the present invention relates to a computer program product by means of which the method according to the invention can be executed on a computer.

[0002] The method and device according to the invention are intended to assist the user of a dimensional measuring instrument in planning a measurement on a test object in advance. In practice, such planning is usually carried out using software.

[0003] Dimensional measuring instruments, for which such software-based planning of the measurement process is frequently used, include, for example, coordinate measuring machines or microscopes. Roughness measuring instruments or other measuring instruments for measuring distances and / or surface properties of a test object are also understood as dimensional measuring instruments in this sense.

[0004] Coordinate measuring machines with tactile and / or optical measuring sensors are used in dimensional metrology to determine the shape of a workpiece surface, for example, by scanning. Since dimensional metrology is typically used in industries where very high accuracy is required, for example, for subsequent machining steps or quality assurance, error-free measurement execution is of paramount importance.

[0005] Microscopes (e.g., scanning electron microscopes (SEM) or atomic force microscopes (AFM)) are used, for example, to view or image the surface of a workpiece under high magnification during quality control. The surfaces under observation exhibit structures whose scale is below the resolving power of the human eye, sometimes even at the atomic level. Microscopic measuring instruments are primarily used in the fields of biology, medicine, and materials science.

[0006] Due to the high accuracy requirements of the aforementioned dimensional measuring instruments, it is desirable to ensure a highly automated and consistent measurement process, enabling, for example, the rapid and reproducible measurement of a large number of objects. In such a process, the measuring head of the instrument is preferably moved along a predefined measurement path, which is planned in advance by a software application based on the object being measured. This measurement path, along with various measurement and machine parameters, is stored in a plan typically referred to as a measurement plan or test plan. Creating such an automated measurement process, and thus the measurement plan, requires knowledge of the operating principles of measuring instruments and experience in the optimal methods for measuring different objects.

[0007] For example, Carl Zeiss Industrial Metrology GmbH offers software called CALYPSO for creating such measurement sequences and processing the resulting measurements. The fundamentals of CALYPSO are described, for instance, in a brochure entitled "Measurement Made Easy and What You Should Know About It - A Primer on Metrology" (Carl Zeiss order number: 61212-2400101) or in a promotional brochure from Carl Zeiss Industrial Metrology GmbH entitled "CALYPSO. Simply Programmed" (publication no. 60-11-068).

[0008] The measurement sequence is created using the CALYPSO software based on so-called test characteristics. A test characteristic represents a dimensional property of one or more geometric elements (so-called measuring elements) on a test object.

[0009] Examples of measuring elements include a bore in the object being measured, a cylindrical section on the object being measured, an edge of the object being measured, an outer or inner surface of the object being measured, or a characteristic point on the surface of the object being measured, etc.

[0010] Examples of test characteristics include the diameter of a bore, the roundness of a cylinder section, and a spatial distance between two geometric elements (points, edges or lines or surfaces).

[0011] To quantify a test characteristic of a measuring element, several measuring points on the measuring element of the object being measured usually need to be recorded and approached with the measuring head.

[0012] To create the measurement sequence, the user first defines the measurement elements to be measured on the object. Using a CAD model of the object, the user specifies in the software which geometric elements (measurement elements) of the object are to be measured. The user selects the individual measurement elements using a cursor and confirms their selection, for example, by clicking or double-clicking with the mouse. In addition to the measurement elements, the user must also define the test characteristics of each element; that is, they must define which properties of these selected geometric elements are to be measured. The user must also define the measurement sequence and various other measurement parameters, such as the parameters for the subsequent machine movement.This parameter input must be performed by an experienced user to adapt the measurement process to specific measurement conditions (e.g., a travel speed or tolerance). Parameter input and adjustment are time-consuming, as numerous parameters must be manually entered for each measuring element. Furthermore, manual parameter input requires a high level of expertise, resulting in high costs for developing measurement sequences.

[0013] To simplify this software-based planning of the measurement process for the user, common software applications typically support the user in defining the test characteristics to be measured as follows: As soon as the software receives an input command to select one or more measuring elements (for example, by the user selecting one or more measuring elements with their mouse), the software determines a selection of fundamentally possible, measurable test characteristics that match the selected measuring element. This determination typically depends on the type of selected measuring element(s) and is typically predefined in the software for each type of measuring element. For example, a database contains all possible measurable quantities that are relevant to a bore and could be of interest as measurable test characteristics of the measuring element "bore".Once the user selects a hole on the CAD model of the object being measured as the measuring element, the software determines this selection of measurable test features by accessing the corresponding memory entries and visualizes all test features that are fundamentally measurable for the selected hole on a display. This is typically done by visualizing graphical representations of the individual test features on the display. Each potentially measurable test feature of the selected measuring element is typically displayed with a corresponding graphical representation. Such a graphical representation could, for example, be a dimensioning element comprising a dimension line, a dimension arrow, a dimension symbol, and / or dimension text.The user can then, for example by clicking on a graphical representation of a test feature, select the desired test feature and define and save it in the measurement plan as the test feature to be tested for the respective measuring element (so-called Click&Pick selection).

[0014] The problem here is this: Typically, there are numerous possible test characteristics that can be measured on or for a measuring element. With the approach described above in previously known software applications, this leads to a large number of different graphical representations of possible test characteristics being displayed simultaneously when the user selects a measuring element. When the user selects a test characteristic, they are presented with a large number of corresponding test characteristics at once. Typically, the number of test characteristics suggested by the software, and thus the number of graphical representations of the suggested test characteristics displayed, increases when multiple measuring elements are selected simultaneously.

[0015] In such situations, it is very difficult for a user to select the test characteristics they actually need. The numerous graphical representations displayed on the screen make the available options confusing. This complicates the process of planning the measurement sequence and ultimately costs the user more time.

[0016] While the CALYPSO software mentioned earlier does offer the option for users to make a static preselection of the displayed test characteristics for the sake of clarity, this is not always straightforward. For example, users can predefine that when selecting a specific type of measuring element, only a certain number of their defined test characteristics will be suggested or displayed. However, this measure only partially simplifies the user's experience. Depending on the application and the type of object being measured, it may be necessary to modify the preselection of test characteristic suggestions displayed. To influence this preselection—for example, to suggest a different type of test characteristic when a particular measuring element is selected—manual intervention by the user is required.

[0017] From US 2018 010 910 A1, a computer-aided method for determining dimensional properties of a measured object using a coordinate measuring machine is known.

[0018] It is therefore an object of the present invention to provide a method and a device that overcome the aforementioned disadvantages. In particular, it is an object of the present invention to improve a method and a device for supporting the software-based planning of a dimensional measurement of a measurement object in such a way that the selection of the test features to be included in the measurement plan is simplified for the user of the method and the device.

[0019] This problem is solved according to the invention by a method comprising the following steps: Receiving an input command to select at least one measuring element of the object to be measured; determining a selection of measurable test characteristics of the at least one selected measuring element, wherein each of the test characteristics has a dimensionally measurable measurand of the at least one selected measuring element; determining a reduced subset of the selection of measurable test characteristics depending on a view of the object to be measured currently selected by a user on a display, wherein the reduced subset of test characteristics is determined again as soon as the view of the object to be measured on the display is changed; visualizing the test characteristics contained in the reduced subset by a graphical representation of each of the test characteristics contained in the reduced subset on the display; receiving a second input command to select a test characteristic visualized on the display (46);and storing the selected test feature in a measurement plan, in which the test features to be measured during the dimensional measurement of the object (14) are stored.

[0020] According to a further aspect of the present invention, the above-mentioned problem is solved by a device comprising a display and an evaluation and control unit, wherein the evaluation and control unit is connected to the display via a data connection and is configured to: to receive an input command to select at least one measuring element of the object to be measured; to determine a selection of measurable test characteristics of the at least one selected measuring element, wherein each of the test characteristics has a dimensionally measurable measurement quantity of the at least one selected measuring element; to determine a reduced subset of the selection of measurable test characteristics depending on a view of the object currently selected by a user on a display and to determine the reduced subset of test characteristics again as soon as the view of the object on the display is changed; to visualize the test characteristics contained in the reduced subset by a graphical representation of each of the test characteristics contained in the reduced subset on the display; to receive a second input command to select a test characteristic visualized on the display;and to store the selected test characteristic in a measurement plan, in which the test characteristics to be measured during the dimensional measurement of the object are stored.

[0021] According to another aspect, the present problem is solved according to the invention by a computer program product which has program code which is configured to execute the above-mentioned method when the program code is executed on a computer.

[0022] According to the invention, after selecting at least one measuring element, the user is not presented with all test characteristics that could potentially be measured for that element (selection of measurable test characteristics). Instead, the user is shown a reduced subset of this selection of potentially measurable test characteristics on the display, from which they can then select one or more test characteristics to be included in the measurement plan. This reduced subset of test characteristics is determined based on the view currently selected by the user on the display. Thus, for example, only the graphical representations of the potentially possible test characteristics of a selected measuring element that are clearly visible in the currently selected view are visualized on the display.Inspection characteristics whose graphical representation would be less visible in the currently selected view on the display, for example because they would be obscured by the graphical representations of other inspection characteristics, would be too small in the currently selected view, or would only be partially or not at all visible in the currently selected view, are not assigned to the reduced subset and therefore are not visualized on the display.

[0023] This significantly improves clarity for the user, as only those test characteristics that are clearly visible in the currently selected view are graphically visualized on the display. The user is thus presented with much more intelligent suggestions for test characteristics, which they can then select and incorporate into the measurement plan, for example, by clicking on their graphical representation on the display. This greatly simplifies the user's workflow, enabling them to create a measurement plan for the dimensional measurement of an object much more easily and quickly.

[0024] The present invention is based, among other things, on the idea that the user intuitively selects test characteristics that might be of interest to him or her based on the view he or she chooses on the display. This follows from the assumption that when selecting a measuring element on the display, the user will always choose the view of the object being measured in which the test characteristic he or she is currently looking for, or its graphical representation on the display, is as clearly visible as possible.

[0025] For example, if the user is interested in including the diameter of a bore as a test feature in the measurement plan, they will, before selecting the bore as a measuring element to be measured via an input command, choose a view on the display in which this bore, and especially its diameter, is as clearly visible as possible. In such a case, the user will not, for example, choose a view on the display in which the diameter of the bore is only partially displayed or is otherwise very difficult to see.

[0026] According to the invention, the method comprises the following steps: Receiving a second input command to select a test feature visualized on the display; and saving the selected test feature in a measurement plan in which the test features to be measured during the dimensional measurement of the object being measured are stored.

[0027] The user can therefore preferably select one or more test characteristics from the reduced subset of test features displayed on the screen, or their graphical representations, using a click-and-pick selection process. These selected characteristics are then saved in the measurement plan. The user thus requires only a few steps to select a test feature for the measurement plan. They simply need to select a suitable view on the display in which the part of the object of interest is clearly visible; then, they must select at least one measurement element of the object to be measured using an input command; and finally, with a second input command, they must select a test feature visualized on the display, which is then added to the measurement plan.

[0028] According to the invention, the reduced subset of the test features, whose graphical representations are visualized on the display, is determined again as soon as the view on the display is changed.

[0029] The determination of the reduced subset of test feature suggestions to be visualized on the display is therefore dynamic, depending on the view selected by the user. As soon as the user changes this view on the display, for example by virtually rotating the object being measured or zooming in or out, the test feature suggestions that the user receives from the graphical representations of the test features displayed on the screen are automatically adjusted accordingly. In this way, the user always has a very clear overview in which only a few test features are suggested based on their respective representations, and which might be relevant given the currently selected view.

[0030] According to one embodiment, when determining the reduced subset of test characteristics, it is determined which positions, spatial locations and / or sizes the respective graphical representations of the test characteristics included in the selection would have in the view currently selected on the display, if the graphical representations were displayed on the display, whereby a test characteristic included in the selection is only assigned to the reduced subset if the graphical representation of this test characteristic fulfills at least one predefined criterion regarding the position, spatial location and / or size in the view currently selected on the display.

[0031] When selecting at least one measuring element, a selection of fundamentally measurable test characteristics is first determined, as is standard practice. This selection of measurable test characteristics for the at least one selected measuring element is preferably determined based on the type of the at least one selected measuring element. The selection of fundamentally measurable test characteristics therefore only includes those characteristics that could generally be of interest with regard to the at least one measuring element selected by the user. For example, if the user selects two points on the object being measured, the initially determined selection of fundamentally measurable test characteristics might include, for instance, the distance between the two points or the respective distance of each point from an origin of a coordinate system.The initial selection of fundamentally measurable test characteristics will not include diameter, radius or angle when selecting two points as measuring elements by the user, since such test characteristics would not make sense when selecting two points anyway.

[0032] From this (pre-)selection of generally possible, measurable test characteristics, a reduced subset of test characteristics is then determined. A test characteristic included in the (pre-)selection is only assigned to the reduced subset if its graphical representation in the currently selected view on the display has a certain position, orientation, and / or size. Otherwise, the corresponding test characteristic is not assigned to the reduced subset and therefore not visualized on the display. It is then not available to the user for selection and inclusion in the measurement plan.

[0033] According to a first alternative, this includes at least one predefined criterion, according to which a test characteristic contained in the initially determined selection of generally measurable test characteristics is included in the reduced subset of test characteristics, that the graphical representation of the respective test characteristic, in particular a longitudinal direction of the graphical representation of the respective test characteristic, exceeds a predefined angle in the view currently selected on the display with respect to a normal vector oriented orthogonally to an image plane of the display.

[0034] A test feature is therefore only assigned to the reduced subset if its graphical representation is aligned at a predefined minimum angle to the user's viewing direction, whereby the viewing direction is assumed to be orthogonal (normal direction) to the image plane currently selected on the display. Test features whose graphical representation would, for example, be displayed parallel to the current viewing direction or have only a very small angle with respect to the normal direction of the display's image plane are not assigned to the reduced subset and are therefore not displayed. In the latter case, it is assumed that their graphical representations would be difficult for the user to see anyway in the currently selected view on the display. Test features whose graphical representations lie exactly in the image plane of the display, i.e., perpendicular to it, are not assigned to the reduced subset.However, objects that are orthogonal to the normal direction of the image plane are assigned to the reduced subset and displayed on the screen, as they are very visible in the currently selected view.

[0035] It is understood that the term "image plane" refers to a two-dimensional plane, such as the surface of a flat, two-dimensional display. The aforementioned normal direction is orthogonal to this image plane.

[0036] According to another alternative, this includes at least one predefined criterion, according to which the test characteristics of the reduced subset are assigned, that the graphical representation of the respective test characteristic can be fully displayed in the view currently selected on the display.

[0037] Accordingly, a test characteristic is only assigned to the reduced subset and visualized on the display if its graphical representation can be fully displayed in the currently selected view. If, however, only part of the graphical representation of the test characteristic falls within the area of ​​the currently selected view on the display, the corresponding test characteristic would not be displayed.

[0038] This can occur, for example, if the user selects a magnified view on the display, showing only a detail of a hole, but not the entire hole. In such a case, it is assumed that the user is not interested in the diameter as a test characteristic of the hole, but rather, for example, only in the roundness of the currently visible part of the inner surface of the hole.

[0039] According to another alternative, this includes at least one predefined criterion: the graphical representation of the respective test characteristic in the currently selected view on the display exceeds a predefined size.

[0040] If the graphical representation of a potential inspection feature is displayed too small in the currently selected view because the corresponding detail occupies only a very small portion of the currently selected view on the display, this inspection feature will not be assigned to the reduced subset and therefore will not be displayed at all. Here again, it is assumed that when selecting a measuring element, the user chooses a view on the display in which the currently sought-after inspection feature of that measuring element can be displayed large enough.

[0041] For example, if the user wants to define the diameter of a bore in the object being measured as a test characteristic, they will not select a view of the object in which the corresponding bore is displayed very small. If they click on this bore, despite its small size on the display, this could indicate that they are interested in the distance of the bore's central axis from the origin of the coordinate system as a test characteristic, assuming this origin is located some distance away from the bore. This distance could then be indicated by an arrow, which could be displayed relatively large in the currently selected view.

[0042] It is understood that at least one predefined criterion used for assigning the test characteristics to the reduced subset can include not only one of the above-mentioned alternatives, but also any combination of the above-mentioned alternatives or all of the above-mentioned alternatives as conditions.

[0043] The aforementioned graphical representations of the test characteristics include, for example, dimensioning elements such as a dimension line, a dimension arrow, a dimension symbol, and / or dimension text. In other words, the test characteristics are preferably displayed graphically on the screen in the form of a dimension line, a dimension arrow, a dimension symbol, and / or dimension text. Preferably, each test characteristic has a predefined type of graphical representation. The size of the graphical representation, however, depends on the currently selected view on the display.

[0044] For example, the distance between two points is generally represented graphically by a double arrow between the two points. However, the size and spatial position or orientation of this double arrow naturally vary depending on the view selected on the display.

[0045] Examples of test characteristics include: a spatial distance between two points, a spatial distance between two lines / edges, a spatial distance between two planes, a spatial distance of a point from a line or a plane, a spatial distance of a line from a plane, a spatial distance of a plane, a line or a point from an origin of a coordinate system, a projection of a spatial distance onto a coordinate axis, a spatial angle, a projection of a spatial angle into a coordinate plane, the parallelism of two lines or planes, the perpendicularity of two lines or planes, a shape deviation of a circle, a circular segment, a line, a rectangle, an oblong hole or a plane, a diameter or radius of a circle or a circular segment, a curve length, a curve shape, a roundness of a circle or a circular segment, and a straightness of a line.The flatness of a plane and / or the roughness of a surface.

[0046] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified, but also in other combinations or individually, without leaving the scope of the present invention as defined in the attached claims.

[0047] Furthermore, it is understood that the features mentioned above and those to be explained below refer not only to the method according to the invention, but also, equivalently, to the device according to the invention and to the computer program product according to the invention.

[0048] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description. They show: Fig. 1 a measuring device with an embodiment of the device according to the invention; Fig. 2 a flowchart of an embodiment of the method according to the invention; Fig. 3 a first schematic representation to illustrate principles of the method according to the invention; and Fig. 4 a second schematic representation to illustrate principles of the method according to the invention.

[0049] Fig. 1 Figure 1 shows an exemplary measuring instrument with an embodiment of a device according to the invention, on which the method according to the invention can be carried out. The measuring instrument as a whole is designated by reference numeral 100. The device as a whole is designated by reference numeral 200.

[0050] In this example, measuring instrument 100 is a coordinate measuring machine in a so-called portal design. In other embodiments, measuring instrument 100 could also be a microscope, for example a scanning electron microscope or an atomic force microscope. Likewise, measuring instrument 100 could be other types of coordinate measuring machines or fundamentally different types of measuring instruments for dimensional measurement.

[0051] The in Fig. 1 The coordinate measuring machine 100 shown has a base 10. The base 10 is preferably a stable plate, made, for example, of granite. A workpiece holder 12 is arranged on the base 10, designed to hold or accommodate a measurement object 14. For this purpose, one or more fastening elements 16 (e.g., clamps or screw clamps) are provided on the workpiece holder 12, by means of which the measurement object 14 is preferably detachably attached to the workpiece holder 12. The measurement object 14 can be any object that is to be measured with the coordinate measuring machine 100.

[0052] A portal 18 is arranged on base 10 so as to be slidable in the longitudinal direction. The portal 18 serves as a movable support structure. The portal 18 has two columns projecting upwards from base 10, which are connected to each other by a crossbeam and together form an inverted U-shape.

[0053] The direction of movement of the portal 18 relative to the base 10 is usually referred to as the Y-direction and is effected by a first motorized drive 20 (e.g., an actuator). The first drive 20 is located at the end of one of the projecting columns facing the base 10 and is configured to move the portal 18 along the Y-direction. A carriage 22 is mounted on the upper crossbeam of the portal 18 and can be moved laterally by a second motorized drive 24. This transverse direction is usually referred to as the X-direction. In this case, the second drive 24 is integrated into the carriage 22. The carriage 22 carries a quill 26, which can be moved in the Z-direction, i.e., perpendicular to the base 10, by a third motorized drive 28. The third drive 28 is integrated into the carriage 22. It should be noted that the drives 20, 24, and 28 do not necessarily have to be located in the positions mentioned.For example, the third drive 28 can be installed in the quill 26.

[0054] Reference numerals 30, 32, and 34 denote measuring devices used to determine the X, Y, and Z positions of the portal 18, the carriage 22, and the quill 26. Typically, these measuring devices 30, 32, and 34 are glass scales. These scales, in conjunction with corresponding read heads (not shown here), are designed to determine the current position of the portal 18 relative to the base 10, the position of the carriage 22 relative to the upper crossbeam of the portal 18, and the position of the quill 26 relative to the carriage 22.

[0055] A measuring head 36 is arranged at a lower, free end of the quill 26. The measuring head 36 is configured to detect measurement points on the object 14. The measuring head 36 is part of a measuring sensor, the measuring sensor of which can be arranged separately from the measuring head 36 or integrated into it and connected to it via one or more cables or wirelessly. The measuring head 36 has a tactile probe 38 projecting in the Z-direction towards the base. The probe 38 is configured to scan a surface of the object 14 by means of a probe 40. The probe 40 is, for example, a ruby ​​sphere.

[0056] During scanning of the surface of the object 14, the probe 40 generates an electrical measurement signal in the measuring head 36, based on which the dimensional properties of the object 14 can be determined. To approach the measuring points on the object 14, the measuring head 36 is moved relative to the workpiece holder 12 or to the object 14 by means of the drives 20, 24, 28. For this purpose, the drives 20, 24, 28 receive control commands from an evaluation and control unit 42, based on which the drives 20, 24, 28 are controlled individually or collectively, for example, via a CNC control system.

[0057] The evaluation and control unit 42 is in Fig. 1 The evaluation and control unit 42 is arranged as a separate unit at a distance from the coordinate measuring machine 100 and connected to the base 10 of the coordinate measuring machine via several cables. A wireless connection is also possible. Furthermore, it is possible for the evaluation and control unit 42 to be integrated into the coordinate measuring machine 100 (e.g., in the base 10).

[0058] The evaluation and control unit 42 is also considered part of the device 200. The device 200 not only controls the coordinate measuring machine 100, but also supports software-based planning of the measurement of the object 14 prior to the measurement. Before such a measurement can begin, the measurement sequence is typically defined in a measurement plan using software. This plan specifies, in particular, which geometric elements (measuring elements) of the object 14 are to be measured and which dimensional measurands (inspection characteristics) of these measuring elements are to be quantitatively recorded by the coordinate measuring machine 100. Furthermore, the inspection plan defines various parameters for the measurement strategy, measurement speed, and the control of the coordinate measuring machine 100, and especially the measuring head 36.

[0059] The device 200 is configured here as a computer 44. This computer 44 has, in addition to the evaluation and control unit 42, which is typically configured as the computer's processing unit, a display 46. The evaluation and control unit 42 preferably has a processor and a storage device (e.g., a hard drive). This storage device contains program code for a software application that can be executed using the processor of the evaluation and control unit 42.

[0060] An exemplary software application is the CALYPSO software distributed by the applicant. CALYPSO is software for planning measurement paths and evaluating measurement points, preferably configured to execute the inventive method for supporting the software-based planning of the dimensional measurement of the object 14. Using CALYPSO, a user creates, for example, a measurement plan according to which the measurement of the object 14 is to be carried out.

[0061] To generate this measurement plan, which is also frequently referred to as a test plan, the user first defines at least one measurement element of the object 14 to be measured in the subsequent measurement. For this purpose, the user is provided, for example, with a two-dimensional or three-dimensional virtual view (scene) of a measurement space on the display 46 of the computer 44. In the virtual measurement space scene, the object 14 is preferably displayed to the user in the form of a two-dimensional or three-dimensional model (e.g., a CAD model), from which the user can select one or more geometric elements as measurement elements to be measured (see step S101 in Fig. 2 ).

[0062] To select a measuring element desired by the user, which may be, for example, an edge, a point, a surface or a hole, the user preferably clicks on the corresponding measuring element or its virtual graphic representation on the display 46 using a mouse.

[0063] It is understood that the input command for selecting the measuring element to be measured according to step S101 can also be carried out using a different input device and does not necessarily have to be carried out using a mouse.

[0064] In the next step, S102, the evaluation and control unit 42 determines a selection of measurable test characteristics that are relevant for the measuring element selected by the user. Preferably, in this step, the evaluation and control unit 42 only determines test characteristics that are meaningful for the selected measuring element. If the user selects an edge as the measuring element, a diameter as a test characteristic for this measuring element would be of little relevance and therefore would not be included in the selection of generally measurable test characteristics for the selected measuring element.

[0065] The selection of measurable test characteristics in step S102 is preferably determined based on the type of measuring element selected by the user. Preferably, the evaluation and control unit 42 includes a storage device in which each type of measuring element is assigned a list or selection of potentially measurable test characteristics. Preferably, the evaluation and control unit 42 accesses this assignment list or table in step S102.

[0066] The selection of potentially measurable test characteristics determined in step S102 is reduced in the subsequent step S103 to a selection of fewer test characteristics. This reduced subset of test characteristics determined in step S103 therefore contains fewer test characteristics than the initial selection of test characteristics determined in step S102 that would be potentially measurable with respect to the selected measuring element.

[0067] The reduction of the test characteristics to the aforementioned subset, carried out in step 103, essentially serves the purpose of presenting the user with the smallest possible selection of test characteristics, thus maintaining clarity for them. Preferably, the user should only be presented with those test characteristics for selection that they are most likely to be interested in.

[0068] According to the invention, the reduction to the aforementioned subset is carried out depending on the view currently selected by the user on the display 46. The test characteristics contained in the reduced subset are suggested to the user by means of a graphical visualization of the test characteristics (step S104 in Fig. 2 For this purpose, each test characteristic contained in the reduced subset determined in step S103 is visualized on the display by a corresponding graphic representation of the test characteristic.

[0069] By means of a further input command, the user can select a test characteristic visualized on display 46 in order to transfer this test characteristic to the measurement plan and save it therein. Preferably, this input command is again executed using a click-and-pick command via mouse.

[0070] The software application installed in the evaluation and control unit 42 ensures, as mentioned above, that when selecting a measuring element, not all potentially possible test characteristics are presented to the user on display 46. Instead, only a subset of the test characteristics that are generally possible for the selected measuring element is displayed. The selection of the test characteristics presented to the user on display 46, which they can then transfer to the measurement plan using Click&Pick, depends on the currently selected view on display 46.For this purpose, in step 103, the reduced subset of test characteristics is determined. This involves identifying the positions, spatial orientations, and / or sizes that the respective graphical representations of the test characteristics identified as potentially possible test characteristics in step S102 would have in the currently selected view on the display, if the graphical representations were shown on display 46. The test characteristics included in the selection determined in step S102 are only assigned to the reduced subset in step 103 if the graphical representation of these test characteristics fulfills at least one predefined criterion regarding position, spatial orientation, and / or size in the currently selected view on display 46. This determination of the reduced subset of test characteristics, which is graphically visualized on display 46 in step S104, is preferably performed dynamically.Accordingly, the reduced subset of test characteristics changes as soon as the user changes the view on display 46. In other words, when selecting one and the same measuring elements, the user is presented with different test characteristics through their graphical visualization, depending on the currently selected view on display 46.

[0071] Fig. 3 This shows a first example of such a graphically visualized proposal of test characteristics, from which the user can select one or more test characteristics to include in the measurement plan for subsequent measurement. Two points, 48 ​​and 50, are shown as exemplary measurement elements selected by the user in step S101. Based on the selection of these two points, 48 ​​and 50, the software application determined in step 102 a selection of fundamentally possible test characteristics that would be conceivable if two points were selected. The user is shown in the Fig. 3 In the example situation shown, however, only a subset of these test characteristics are ultimately displayed. Here, for example, a first test characteristic is visualized on the display 46 by means of a graphic representation 52, which includes a dimension arrow 54 and a dimension text 56. This test characteristic is the spatial xyz distance between the two points 48, 50. Further selectable test characteristics are presented to the user in the Fig. 3 In the schematically illustrated example on display 46, a y-distance and a z-distance are graphically displayed. The y-distance is a distance measured parallel to the y-axis between the two points 48 and 50, i.e., a projection of the spatial xyz-distance onto the y-coordinate axis. Similarly, the z-distance is the projection of the spatial xyz-distance onto the z-coordinate axis. Furthermore, the spatial xyz-distance from the origin of a coordinate system 58 to the first point 48, as well as the z-projection of this distance, are displayed for the user to select.

[0072] At the in Fig. 3 In the example situation shown, where the user first selects the two points 48 and 50 as measurement elements (step S101), the software could also display the x-distance, i.e., the projection of the spatial xyz distance of the two points 48 and 50 onto the x-axis. A graphical representation of this test characteristic would be shown in the Fig. 3 However, the selected view is hardly visible, as its graphical representation (dimension arrow and dimension text) is hidden in the Fig. 3 The situation shown would be oriented perpendicular to the image plane 61 (sheet plane).

[0073] For the sake of clarity, the user is only shown those inspection features whose graphical representation in the currently selected view on display 46 exceeds a predefined angle with respect to a normal direction orthogonal to the image plane 61 of display 46. For example, only inspection features whose graphical representation (e.g., their dimension arrows) exceeds an angle > 30° with the normal direction orthogonal to the image plane 61 are displayed. In the Fig. 3 In the schematically shown case, the sheet plane corresponds to the image plane 61 and the x-axis of the coordinate system 58 to the normal direction of this image plane 61.

[0074] For the same reasons, in the Fig. 3 In the schematically shown case, for example, the x-distance between point 48 and the origin of the coordinate system 58 is not displayed to the user as a graphical selection option. The y-distance between point 48 and the origin of the coordinate system 58 is also not displayed. The latter is not shown to the user in this case, for example, because the graphical representation of this y-distance between point 48 and the origin of the coordinate system 58 would not exceed a minimum size in the view currently selected on display 46.

[0075] Fig. 4 This shows another example of possible test characteristics that the software offers the user for selection when choosing a measuring element. In the Fig. 4 In the example shown, the user selects, for instance, a cylinder as the measuring element 60 in step S101. Subsequently, in step S102, the selection of fundamentally measurable test characteristics is determined, which make sense when selecting a cylinder as the measuring element. This selection of fundamentally measurable test characteristics can include, among other things, the diameter of the cylinder and the spatial distance 62 of a point 64 on the cylinder axis from the origin of a coordinate system 58.

[0076] In the Fig. 4 In the schematically represented example case, however, the user is only shown the diameter of the cylinder graphically as a selectable test characteristic for the measurement plan by means of a graphic representation 66, which includes a dimensioning arrow 68 and a dimensioning symbol 70. The spatial distance 62 of point 64 from the origin of the coordinate system 58 is shown in the Fig. 4The situation shown, however, cannot be included in the reduced subset of test characteristics that are graphically displayed on display 46. This is because the graphical representation of this distance cannot be fully displayed in the view currently selected on display 46.

[0077] As a criterion for displaying a test characteristic, the software can therefore specify that a test characteristic is only graphically visualized on display 46 and available for selection by the user if the graphical representation of this test characteristic can be fully displayed in the view currently selected on display 46.

[0078] It is understood that various other criteria can be stored in the software, on the basis of which the reduced subset of test characteristics, which are ultimately graphically visualized on the display 46, can be determined depending on the view currently selected on this display 46.

Claims

1. Method for assisting software-based planning of a dimensional measurement of a measurement object (14), wherein the method comprises the following steps: - receiving (S101) an input command for selecting at least one measurement element (48, 50, 60) of the measurement object (14) that is to be measured during the measurement; - determining (S102) a selection of measurable test features of the at least one selected measurement element (48, 50, 60), wherein each of the test features comprises a dimensionally measurable measurement variable of the at least one selected measurement element (48, 50, 60); - determining (S103) a reduced subset of the selection of measurable test features; - visualizing the test features contained in the reduced subset by means of a graphical representation (52, 66) of each of the test features contained in the reduced subset on a display (46); - receiving a second input command for selecting a test feature visualized on the display (46); and - storing the selected test feature in a measurement plan, in which the test features to be measured during the dimensional measurement of the measurement object (14) are stored; characterized in that the reduced subset of the test features is determined depending on a view of the measurement object (14) currently chosen by a user on the display (46), and in that the reduced subset of the test features is determined again as soon as the view of the measurement object (14) on the display (46) is changed.

2. Method according to Claim 1, wherein determining the reduced subset of test features involves determining what positions, spatial locations and / or sizes the respective graphical representations (52, 62, 66) of the test features contained in the selection would have in the view currently chosen on the display (46) if the graphical representations were to be displayed on the display (46), and a test feature contained in the selection is assigned to the reduced subset only if the graphical representation of the respective test feature, in particular a longitudinal direction of the graphical representation (52, 62, 66) of the respective test feature, in the view currently chosen on the display (46), exceeds a predefined angle in relation to a normal direction oriented orthogonally to an image plane (61) of the display (46).

3. Method according to Claim 1, wherein determining the reduced subset of test features involves determining what positions, spatial locations and / or sizes the respective graphical representations (52, 62, 66) of the test features contained in the selection would have in the view currently chosen on the display (46) if the graphical representations were to be displayed on the display (46), and a test feature contained in the selection is assigned to the reduced subset only if the graphical representation (52, 62, 66) of the respective test feature is completely representable in the view currently chosen on the display (46).

4. Method according to Claim 1, wherein determining the reduced subset of test features involves determining what positions, spatial locations and / or sizes the respective graphical representations (52, 62, 66) of the test features contained in the selection would have in the view currently chosen on the display (46) if the graphical representations were to be displayed on the display (46), and a test feature contained in the selection is assigned to the reduced subset only if the graphical representation (52, 62, 66) of the respective test feature exceeds a predefined size in the view currently chosen on the display (46).

5. Method according to any of the preceding claims, wherein the graphical representation (52, 62, 66) of at least one test feature contained in the reduced subset has a dimensioning element comprising a dimensioning line (62), a dimensioning arrow (54, 66), a dimensioning symbol (70) and / or a dimensioning text (56).

6. Method according to any of the preceding claims, wherein the selection of measurable test features of the at least one selected measurement element is determined depending on a type of the at least one selected measurement element.

7. Method according to any of the preceding claims, wherein the selection of measurable test features comprises a spatial distance between two points; a spatial distance between two straight lines; a spatial distance between two planes; a spatial distance between a point and a straight line; a spatial distance between a point and a plane; a spatial distance between a straight line and a plane; a spatial distance between a plane, a straight line or a point and an origin of a coordinate system; a projection of a spatial distance onto a coordinate axis; a spatial angle; a projection of a spatial angle into a coordinate plane; a parallelism of two straight lines or planes; a perpendicularity of two straight lines or planes; a shape deviation of a circle, of a circle segment, of a straight line, of a rectangle, of an elongated hole or of a plane; a diameter or a radius of a circle or of a circle segment; a curve length; a curve shape; a circularity of a circle or of a circle segment; a straightness of a straight line; a planarity of a plane and / or a roughness of a surface.

8. Computer program product comprising program code configured to carry out a method according to any of Claims 1 to 7 when the program code is executed on a computer with a display.

9. Device (200) for assisting software-based planning of a dimensional measurement of a measurement object (14), wherein the device (200) comprises a display (46) and an evaluation and control unit (42), wherein the evaluation and control unit (42) is connected to the display (46) via a data connection and is configured: - to receive an input command for selecting at least one measurement element (48, 50, 60) of the measurement object (14) that is to be measured during the measurement; - to determine a selection of measurable test features of the at least one selected measurement element (48, 50, 60), wherein each of the test features comprises a dimensionally measurable measurement variable of the at least one selected measurement element (48, 50, 60); - to determine a reduced subset of the selection of measurable test features; - to visualize the test features contained in the reduced subset by means of a graphical representation (52, 66) of each of the test features contained in the reduced subset on the display (46); - to receive a second input command for selecting a test feature visualized on the display (46); and - to store the selected test feature in a measurement plan, in which the test features to be measured during the dimensional measurement of the measurement object (14) are stored; characterized in that the evaluation and control unit (42) is configured to determine the reduced subset of the test features depending on a view of the measurement object (14) currently chosen by a user on the display (46), and to determine the reduced subset of the test features again as soon as the view of the measurement object (14) on the display (46) is changed.