DE3725347A1 - COMPUTER-INTEGRATED MEASURING SYSTEM - Google Patents

Abstract

A system is provided which operates to compare three- dimensional models of inspection gages constructed from computer aided design (CAD) data for a manufactured part and standard geometric dimension and tolerance call-outs to three-dimensional models constructed from inspection data measured from the manufactured part, 17. The comparison is made both graphically, to assist an operator, and mathematically to determine part condition. Parts are found to be either in tolerance or out of tolerance. If out of tolerance they are found to be either reworkable or scrap. Additionally, the system is capable of determining syntax correctness for tolerance standards, defining the sequence of steps for a specific job prior to job execution, performing individual part tolerance conformance analyses and statistical part tolerance analyses for a population of parts, tolerance analyses for mating parts, and generation of tolerance call-outs for fixed and floating fastener features on parts. <IMAGE>

Description

The invention relates to a test tool for mechanical Components and in particular such a tool, which is based on component design data a test gauge and from test data a model of the tested component for comparison with the Teaching created.

The invention provides a method for testing a component with known dimensions and tolerance specifications under Use a calculator attached to a multi-dimensional movable Position measuring device is connected to the Determine positions of component features. After this The process becomes a multi-dimensional model of a test gauge using the dimensional and tolerance specifications of the Partly created. A test path relative to the component is defined on which the position measuring device for checking the Component is moved. The position measuring device is then moves along the test path and collects position data; it is made using the predetermined positions of the Component features a multi-dimensional model of the component created. The test gauge model is made with the component model compared to determine if the component is within its Tolerances remains.

The device according to the invention serves a three-dimensional  Model of a test gauge with a three-dimensional Model of a manufactured component using CAD data to compare for the component. A computer takes that Design data of the component, and a viewing device connected to the computer and presents the models of the Construction part, the test gauge and the finished part visible. Furthermore there is a keyboard on the computer connected to specific dimensions and tolerance specifications to choose on the model of the construction part shown, from which the model of the test gauge is generated. A movable element is attached to a device that it can move in three dimensions. The movement device is connected to the computer, so that Drive the element around the production part on a test path can. A position sensor is on the moving one Element attached and also connected to the research, around the positions of the features of the component to be tested to determine and from them a model of the production part to create. The models of the test gauge and the manufacturing part be visual on the vision unit and mathematically compared by the computer to the tolerance tolerance of the production part to determine.

The invention further provides a method for testing a component with known dimensions and tolerance specifications using a calculator connected to a Position measuring device movable in several dimensions is connected to the positions of the physical in operation Characteristics of the component determined. According to this procedure are the tolerance specifications (tolerance frame) for the component checked for correct syntax and, if correct is, using the dimension and tolerance specifications created a multi-dimensional model of a test gauge. It a test path is created relative to the component, which is the movement the position measuring device for checking the part defined, and then guided along the test path, while recording the location data; from the so determined  Positions of component features becomes a multi-dimensional Model of the component created. The test gauge model is compared with the component model and determined whether the component is within tolerance.

According to a further aspect of the invention, this creates Procedure for predetermining an order or job sequence, which is to be carried out on a component by a system which a to a multidimensionally movable position measuring device connected computer, one connected to the computer Memory that contains a CAD model of the component, on which the job sequence is to be carried out, as well as a machine which carries out the operations on the component and can be coupled to and controlled by the system is. After this procedure, the system becomes the identity communicated to the machine, the machine connected to the system and a point on the CAD model for orientation the position measuring device and the machine. Then those of the machine and the positioning device specified sequences of steps to be carried out and the Data analyzed by the position measuring device operations in question were obtained. Eventually the machine disconnected.

According to a further aspect of the invention, this creates Method for analyzing physical data or physical component that occurs during operation of a system that results in a multidimensional movable position measuring device connected computer, a multi-dimensionally movable machine controlled by the system as well as a memory that relatively CAD data on the part to be analyzed and on the inclusion of Data related to the physical configuration of the part contains or records. According to this procedure, a Test data representing certain characteristics of the Partly built using CAD data related to such Features incorporates the corresponding physical features  of the part measures the data regarding physical Features of the part stores and the match between the teaching and the measured part data.

Another aspect of the invention relates to a system for Checking a component using CAD data for the component is coupled and means for reading the dimensions and tolerances from the CAD data for the part characteristics to be checked, Means using these dimensions and Tolerances a three-dimensional test gauge for the part construct mathematically, means for measuring the test items Part features and how to create them Test data, means for mathematically constructing a three - dimensional model of the tested part characteristics and Has means to the three-dimensional model with the to compare three-dimensional teaching, so that the Compliance with the constructive tolerance data can be determined.

Furthermore, a computer-controlled vision system has to be checked and analysis of predetermined part features on one Component access to CAD and tolerance data for the Component. The system has a visible surface, means for Simultaneously visible representation of a design data model of the component and a test path around the component model for the predetermined sub-features as well Means to optionally choose the test path on the visible surface to change.

In addition, there is a computer-controlled viewing and presentation system for checking and analyzing predetermined sub-characteristics specified on a component that gives access to that Has CAD and tolerance data describing the component a measuring device for the predetermined part features connected. This system has a visible surface and means for the simultaneous visible display of a Model of the measured component characteristics as well as a model a test gauge based on the CAD and tolerance data has been built with respect to the predetermined part characteristics.  

In addition, the invention provides a method for testing the tolerance of the tolerance specifications of paired parts, where design and tolerance data for the paired Parts are saved. Then you read from the Save the design and tolerance data regarding of the paired parts, examines the worst case tolerance cases for dimensional conflicts between the paired parts, and shows the location of a possible conflict of dimensions at.

In another aspect, the invention provides a method for checking tolerance specifications for paired parts, where the design and tolerance data including the reference type ("date") for the paired parts are available. After this procedure you read the construction and tolerance data regarding the paired Parts from the memory, determined if necessary Inconsistencies in the reference location specifications for the tolerance data for the paired parts, and shows the location if necessary existing discrepancies.

In another aspect, the invention provides a method to determine tolerance specifications for the characteristics fixed and floating fastener ("fixed and floating fasteners ") on paired parts, the design data stored for the paired parts. After that if one chooses a fastener, indicates the place on one Component on which the fastener is to be used the reference location specifications for the attachment locations, selects a tool for forming the component characteristics to accommodate the fastener, determines the largest and that Smallest dimension of the component feature considering the Tool and the chosen fastener, and shows the Position tolerance for the part characteristics associated with the fastener at.

The invention is described below using exemplary embodiments explained in more detail with reference to the accompanying drawing. In the Drawing shows

Fig. 1 is a block diagram of the components of the system according to the invention,

Fig. 2 is a flowchart for the computer-integrated test system,

Fig. 3 is a perspective representation of a model of a part manufactured to be tested,

Fig. 4 is a perspective view of a master gauge according to the invention built up,

Fig. 5 diagrammatically creating a Prüfweges,

Fig. 6A is a plan view of the master gauge to Fig. 4,

Fig. 6B is a plan view of the manufacturing Steep according to Fig. 1,

FIG. 7 is a flow chart showing details of the beginning of the flow chart of FIG. 2;

Fig. 8 is a flow chart illustrating details of subsequent parts of the flow chart of Fig. 2,

Fig. 9 is another flow chart with details flußabwärtiger parts of the flowchart of Fig. 2,

Fig. 10 is a data flow diagram of the system,

Fig. 11 is a table of representative standard ANSI symbols for tolerances (tolerance frame),

Fig. 12 is a perspective view of a component made with reference locations,

FIG. 13A-13C tabulated test gauges and reference points for the finished part according to Fig. 12,

Fig. 14 is a plan view illustration of a part with syntactically incorrect feature indication,

Fig. 15 is a plan view of the part of Fig. 14 with a further feature of syntactically wrong indication,

Fig. 16 shows a top view of paired parts, the acceptable data for part features.

A brief description of the system described executed function is CIG (Computer Integrated Gaging = integrated testing).

The system is shown in FIG. 1, in which a computing system 11, for example of the VAX 11/780 type, is connected to a viewing unit 12, for example of the Textronics 4115 type. A keyboard 13 can be used to enter data into the system, which the computer then uses for the system control. The keyboard entries are also displayed on the display device 12 . The mechanics or the robot 14 , which can carry out a three-dimensional movement in a predetermined spatial area, can be the Automatix AID 800 model. A camera 16 is arranged at a known location above the work area and is used to determine the orientation of a part 17 located on the support surface 18 . A sensor 19 is attached to the robot 14 ; it can be a non-contact (NCI) test device, as shown in FIG. 1 as a laser from SELCOM. It is pointed out that the position sensing device 19 can also be a coordinate measuring machine (CMM) or an NC machine tool with a probe.

As the flow chart of FIG. 2 shows, the first step of the method is the creation of a test gauge. For this purpose, CAD design data for a part 17 are given to the computer 11 ( FIG. 1) and then in a perspective representation (see FIG. 3) together with dimensions and tolerance information in accordance with the dimensional and tolerance standards ("geometricdimensioning and tolerancing standards") ; GD) shown (see 20 ). The selected display standard corresponds to the ANSI standard Y 14.5 of the United States government. Three surface references A, B and C are shown. Alternatively, the covers can also be the edge of a part, a point on a part, a hole and the like. As shown in FIG. 3, the dimensional specifications have four holes, each 25.4 mm (1 in.) Plus 3.18 mm (0.125 in.) Minus 0.0 mm, on the model 20 of part 17 . These dimensions and tolerance specifications represent a critical and essential feature of the part shown. The positions of the bores are marked with the symbol used in the tolerance frame as "true position" (see FIG. 11). Other designations are also possible for the tolerance information, for example as a surface profile or an oversize or undersize. The holes in Fig. 3 must be arranged so that their centers on the finished part under MMC conditions ("maximum material conditions", smallest hole) are only shifted within a circle with a diameter of 1.52 mm (0.06 in.) . If the hole is larger than the MMC specification, the diameter of the tolerance circle increases proportionally. The "true position" of each hole is given with respect to the three areas A, B, C indicated.

The operator observes the ideal design or model 20 of part 17 on the display device 12 and can use the keyboard 13 to designate one of the various tolerance indication conventions that appear as a menu on the screen to the system. . In the illustration of Figure 3 is the "true position" is specified, and a running mark (cursor) is moved on the screen so that it refers to the dimension and tolerance zone for the four holes of the member 17; this dimension and tolerance information is taken over by the computer and checked for correct syntax. If the tolerance syntax is correct, the computer generates a model 21 of a test gauge, as shown in FIG. 4; this confirms the consistency of the tolerance symbols. From the previous description of the part on the basis of its design data and the tolerances applied to the described features, the computer now creates a test or functional gauge with the same tolerance references that apply to the part and displays it on the screen; this step is shown at A in FIG . The test gauge data are saved for further use.

The designer has specified specific dimensions and tolerances for the component to be used in an arrangement. Test data have just been created for this component. The system now performs what is referred to as tolerance analysis in FIG. 2. The purpose of the tolerance analysis is to determine whether the component with its tolerance specifications fits under all tolerance conditions with the part belonging to it in the arrangement. Details of this test procedure are shown in FIG. 7. This operator must decide whether to analyze the tolerances assigned to the part by the designer or to define new optimal tolerances for the part. If existing tolerances are to be analyzed, the computer generates a worst-case component in the so-called "virtual state" (ANSI Y 14.5), in which all holes are at the lower tolerance limit and all lugs, flanges, etc. are at the upper tolerance limit. If the bores are still dimensioned with respect to the "true position", their size is further reduced by the specified position tolerance. This procedure simulates a state in which the holes for the representation of the "worst case" lie at the opposite limits of their permissible tolerance range.

After the computer has created the worst case component (virtual state, MMC state and maximum position deviation), the references of the tolerance specifications are aligned with those of the paired part. The computer also generates this paired part in its virtual state. He checks the compatibility of the tolerance-analyzed component with the component paired with it. If they match, the tolerance is saved together with the design data for further use; if they do not match, the process goes back to point G ( FIG. 7) so that the design can be improved in tolerance by making holes and / or inserts with other nominal dimensions (ie to change the model geometry).

As shown in FIG. 7, if the predetermined analyzed tolerances do not match, the component is checked or modified again starting at G. In one case, new tolerances can be entered into the system by the designer; a syntax check is then carried out on these. Alternatively, the tolerances are analyzed to change the model geometry; assuming a correct tolerance syntax, the computer then creates a new test gauge. Analyzing any set of existing tolerances requires repeating the process just described.

The CIGMA system can have any set of tolerances analyze according to DG. At the moment, however, it can only define new tolerances for two specific design cases, d. H. firm and floating fasteners. In these Special cases in which parts are held together under tension FFF analysis ("fixed and floating fastener "). A bolt is an example of a fastener. It can run through or into a part be screwed in. A fastener is generally selected according to the US standard H-28. The designer goes based on a stress analysis. The specified US standard specifies the bolt dimensions for US federal services, including the body diameter, the contact surface and the thread length. The size of the associated hole is then calculated with the upper and lower limit and a tolerance for the "true position" for the hole specified. The references for the position of the hole will be with tolerance data such as flatness, straightness, roundness and Provide cylindricity to ensure that any Position deviations from the references are less than 10% of the specified error regarding the true position. For example, the position tolerance of the hole (true position) 1.52 mm (0.06 in.) may result in errors of flatness deviations as a reference for the hole position serving reference area not more than 0.152 mm (0.006 in.) Contribute to the hole position deviation. To this The interchangeability of parts is guaranteed.

Then the tolerances are analyzed by the program, to ensure that the mounting surface of the fastener by the hole position error with respect to the associated one Part of the component pair for the analyzed component is not is reduced, namely as a result of a lateral shift of the analyzed part in such a way that the contact surface under the head of a threaded bolt, for example partially over the hole surface, not on the hole surrounding workpiece surface. As can be seen  there is an optimal tolerance analysis (definition of new Tolerances) through the CIGMA system for two special DG cases, namely for fixed and floating fasteners, while the CIGMA system one Worst case analysis (analysis of existing tolerances) for carries out all cases of DG.

FIG. 2 now shows the step following the tolerance analysis, namely the generation of a test path for the three-dimensionally movable element, which is part of the robot 14 of FIG. 1. The details of this test path generation are set out in the flow chart of FIG. 7. This process cannot start until it is ensured that a test gauge has been built for the respective part and the analysis of the design tolerances has shown that the component fits perfectly with the associated component. After the test gauge is built and the tolerance analysis is successfully completed, the test path graphic is generated and displayed as shown in FIG. 5. The x marked points represent measuring points on the areas A, B, C. Three test points on each of the areas A, B, C define these. On the screen 12 , a probe 22 is shown with a number of tips 22 a , which optionally touch one of the test points (shown on area C ) of the CAD component model 20 . Item 22 in FIG. 5 is referred to as a probe set. A probe vector extends from the probe set and is provided at its free end with a probe tip 22 a . A number of view representations are available in the system. A probe vector can be guided on the screen to each of the x- marked test points in FIG. 5.

Alternatively, the tip may flash on the screen 22 a of the respective probe used vector. Also available is a representation in which the probe set 22 bypasses the component model 20 and the probe tips are placed one after the other at the test points. The path of the probe tip in the representation used is a logical progression from one point ( x) to the next, taking into account the shortest connection between them and avoiding obstacles. This progress is intended to provide the user with the direction from which the probe is approaching the area under test and to provide information that can be used to avoid collisions between the probe set and the component. Measured values are generated for each special component feature at every point of contact of the probe. It can further be seen that each of the four bores in part 17 are assigned three measuring points which completely define each of the holes. After scanning the test path graphic, the computer generates a path program on command according to the test path shown on the screen. This path program is converted into a program that can be read by robot 14 ; the test route data is saved for later use. This part of the process is shown at B in Fig. 2 and Fig. 7.

If the test route is to be modified, a function is entered via the keyboard 13 and the cursor or the vector on the screen 12 is controlled by the user. A menu of the desired changes in the test path is output, whereby the user can, for example, add a test point on a surface or change the movement of the movable element in order to avoid an obstacle. If another test point is to be specified on a surface for the purpose of testing, the associated function is selected, the tick mark is set on the additional test point and the program is informed of the addition via the keyboard. If part of the test path of the movable element is to be changed in order to avoid an obstacle, the instructed function is selected and a point or a sequence of points is marked on the screen with the tick mark, which the movable element should now touch or pass through to avoid the obstacle. The new points are entered into the test program using the keyboard and the program describing the path of the movable element is changed. After the test path has been generated and / or changed, the test path program can be called up and displayed on the screen, the running mark running through the entire test path to display the sequence of movements of the movable element on the robot 14 .

As shown in FIG. 2, after the generation of the test path and any changes to it that may be desired, the next process section relates to job execution. A "job" is a task that the CIGMA system can perform, including cutting of parts, statistical process control, etc. Jobs can be carried out manually by keyboard input or automatically under computer control. If automatic execution is desired, the job control language is first defined, as described below. Then the job execution is simulated by a visual representation on the screen. All steps to be carried out are simulated on the screen. After determining the usefulness of the simulation, the operator calls an automatic job execution. The usability criterion is that all analysis runs with zero deviation from the perfect state were correct. The operator selects the automatic job execution on a screen menu "Run Job" from which he selects the manual or the automatic execution.

As further shown in FIG. 2, the next step is to measure data on the finished part 17 , but only after the test gauge has been built and the test path created, as described above and shown in FIG. 8. Furthermore, a determination is made as to whether the job should be carried out by the operator manually or by the system, as also described above. If automatic job control is implemented, the stored job control program is called, as shown at E in Fig. 8, and the process continues computer controlled. Otherwise, the following functions are performed one after the other using the keyboard by selecting the various menu items from the operator.

The orientation of the part 17 on the support surface 18 is recorded by the camera 16 , which is arranged at a known location above the defined work space. The part alignment serves to determine the test path as the movable element is to drive through. The movable element is guided on the oriented test path by actuating the robot 14 . The sensor 19 (NCI or CMM), which is attached to the robot, records position data for the physical features of the workpiece that are of interest, which are then brought into a form in which they can be represented as a model 17 a of the workpiece on the viewing unit 12 . The measured model 17 a of the workpiece 17 is then stored for further use. This is shown at C in Figs. 2 and 8.

As shown in FIG. 2 after C , measurement data recorded on the workpiece 17 (which are used to construct the measurement model 17 a ) are statistically analyzed, as explained in detail below with reference to FIG. 9. Either the operator or the job control program (depending on who is in control) determines whether the measurement data is analyzed relative to the test gauge constructed at A or to the measurement values already taken on samples of the same component (or both). If the latter is the case, the measurement is analyzed statistically and the result is used to determine whether the process is in control, as described below. A process out of control is terminated and the cause of the static deviation is determined. If the analysis is carried out relative to the constructed test gauge, the measurement data are compared with the test gauge 21 of FIG. 4. As FIG. 9 shows, the data representing the test gauge 21 , the test path between the test points of FIG. 5 and the measurements on the workpiece 17 must be completed and complete before the comparison or the statistical examination can be carried out. The statistical data from the process are updated taking into account the measured workpiece data. The type of analysis to be performed, ie statistical or relative to the test gauge, is decided by the operator or by the job control language. If an analysis has been selected relative to the teaching, the data of the test gauge 21 and the measured workpiece 17 a are called up and compared graphically on the viewing unit 12 and mathematically in the computer 11 . The test gauge 21 of FIG. 6A is generally shown in green on the screen, the model 17 a of the workpiece 17 in cyan (light blue). The template and the workpiece model are then placed one on top of the other so that the workpiece can be compared with the template in an immediately visible manner. There is also a mathematical analysis. The colored visual representation for comparison by the operator is only for their convenience and for verification. From the point of view, it can be determined immediately whether the jig and the workpiece have intersecting surfaces, since they are represented in different colors. However, it is the results of the mathematical comparison generated by the computer that are used afterwards and are stored at this point in time, as shown at D. The comparison results are also kept available for evaluation in other systems, which can be assigned to the integrated test system disclosed here.

The comparison results are then formulated in the form of an error report, as can be seen in FIG. 9, which is called up on the screen 12 . If there are no errors, a green light is activated to indicate that the workpiece is within tolerance. If the measurements have shown that the tolerance has been exceeded, they are examined to determine whether the workpiece can be saved by reworking. In the illustrated case, this is done by graphically expanding the bore to its maximum size (LMC state, minimum material) and again comparing the reworked bores in the workpiece model with the test gauge 21 . If the gauge fits into the workpiece, a yellow light is excited, indicating that the workpiece can be reworked. If the test gauge does not fit into the reworked workpiece model, a red lamp lights up, indicating that it is no longer reworkable and scrap.

If a statistical analysis has been selected, the statistical history of a measured dimension of a specified workpiece is checked. For this purpose, the measured dimensions are continuously monitored. The last entered workpiece measurement is examined to determine if the process is still under control; it is therefore determined whether the measured value lies within the range below the bell curve of a normal distribution within +3 σ of the mean value of the normal distribution. If this is the case for the last measured value, the program records additional workpiece data. If a measured value falls outside the +3 σ range below the bell curve, the process is stopped and the statistical ranges for the respective measured variable are output. The cause of the error can thus be determined from an analysis of trends in the statistical process history. The process is then repaired, making such outliers less likely to occur.

An abbreviated program listing now follows, which shows a type of program formulation for the operation of the measuring and testing process disclosed here. Copyright FMC Corporation 1987.

With reference to the data flow diagram of FIG. 10, the system parts within which the CIGMA modules are executed will now be shown. The user or operator communicates with the CIGMA system via one or more input / output devices (I / O devices), as shown as user I / O device 30 in FIG. 10. This can be an interactive graphics terminal with which three-dimensional wire mesh images as well as alphanumeric text can be displayed, manipulated and identified. The drivers for the I / O devices and the associated software routines are provided by the CAD database generator shown at 31 . A CIGMA I / O processor (shown at 32 in FIG. 10) represents another link in the interaction between a user and the CIGMA system, as is the case for the CAD database generator 31 of FIG. 10. Examples of this interaction are the selection of various CIGMA modules, the number input via a keyboard or by geometry selection, as is required as input for generating a test gauge, via the I / O processor. The capabilities of the CAD database generator are actually used to generate the gauge graphics; however, the CIGMA I / O processor creates the commands that activate the appropriate CIGMA routines and retrieve data from the database. An interface specification is left to the CAD salesperson, who uses it to write subroutines with which the CAD database generator can be connected directly to the CIGMA system. The routines resulting from these interface specifications represent the means by which the CIGMA system takes over data from the user and returns information to the user.

Within the CIGMA system, information and data are exchanged using one of the following methods, as shown in FIG. 10:

• 1. Communication between the modules takes place via the CIGMA main database 33 .
• 2. Test, analysis and statistical results are read from I / O files 34 or written to them.
• 3. Position data are read (or sent to) by various electromechanical test devices such as coordinate measuring machines, vision systems, NC machine tools and laser distance measuring devices, which are symbolized in FIG. 10 by 35 .

The CAD database generator 31 of FIG. 10 is essential for numerous CIGMA system functions that deliver a 3D CAD geometry as input data. Numerous CIGMA functions also generate 3D CAD geometry for output and visual display. The CIGMA system was designed so that a CAD database generator (ie Anvil-4000, Unigraphics, CADAM) can work directly in it. The CAD database generator allows the user to create 3D basic geometry and the CIGMA system to use the built-in CAD functions to create and display CAD geometry. With the CAD system, CIGMA carries out the basic I / O functions for controlling the view unit, the menu display and the data inputs. Because CIGMA takes advantage of many of the capabilities of the CAD system in business, users working with CIGMA may recognize whether they are using seller software or CIGMA software.

Each of the five CIGMA modules described above will now be described in more detail. The data flow diagram of FIG. 10 shows the five modules as follows: the test gauge module 36 , the test module 37 , the analysis module 38 , the job control module 39 and the tolerance module 40 . For each module, the following should be explained (1) the module input, (2) its mode of operation and task as well as the algorithms used, and (3) the module output.

A description of the gauge module 36 of FIG. 10 begins with the input quantities. These are the symbols for technical drawings shown in FIG. 11 (the table is taken from the "American Standard for Dimensioning and Tolerancing" ANSI Y14.5M), which are used together with an oversize-undersize indication. The oversize undersize tolerance specification applies to all dimensions outside the system of the ANSI standard Y14.5M. The 3D geometry comes from the CAD database generator 31 integrated in the CIGMA system.

In addition to the 3D geometry information from the CAD database generator 31 , the test gauge module 36 also requests drawing information from the database in order to define tolerances. The CIGMA software queries this information in a fixed order, which is shown in a menu offered to the user. The menu first prompts the user to specify the reference locations on the 3D geometry display of the workpiece to be dimensioned. For this purpose, a symbol is assigned to the reference location (level, hole, etc.) and the reference feature is then designated to the program, ie the edges and the location of a reference level are communicated. CIGMA understands the drawing symbolism according to ANSI X14.5M. The reference locations are therefore further defined by the four shape properties (straightness, flatness, circularity or roundness and cylindricity), as indicated in FIG. 11. The tolerances of the shape properties assigned to the reference locations must never be greater than approximately 10% of the permissible dimensional deviation of the other workpiece features that refer to these reference locations. For example, if the location tolerance for another workpiece feature is 0.152 mm (0.006 in.), The flatness deviation of a selected reference plane must not be more than 0.0152 mm (0.0006 in.).

The CIGMA system understands the entire drawing text of FIG. 11, which can be assigned to the different part features. Syntax checks are carried out simultaneously with the input of the drawing text into the CIGMA system, examples of which are given below.

Profile, alignment, location and exit tolerances are all specified relative to a reference location ( Fig. 11). When specifying these tolerances, one or more reference locations must be specified in the characteristic control symbol. As an example of a paint control symbol as it appears on a drawing representing a workpiece, it is as follows:

0 0 0.060 M A B C

This information is used by the user towards the CIGMA system as

TP CZ 0.060 M, A, B, C

communicated. In this example, the position tolerance of 0.060 with respect to the three references A, B, C must be considered. The reference locations indicated with these characteristic control symbols serve to define the functional requirements for the controlled characteristic; this means that the degrees of freedom of the controlled feature are defined. Examples of the application of reference points to a workpiece with certain controlled features can be seen on the workpiece 41 in FIG. 12. A number of references are shown in FIG. 12 on the workpiece 41 with A through E , as are some workpiece features. The workpiece 41 has a solid rectangular lower part with similar length and width dimensions and a smaller height dimension. The top 42 of the lower part is designated as reference point A. The workpiece 41 also has four identical lugs 43 , which protrude upward from the reference plane A , and a fifth lug 44 , which is referred to as reference E. As shown, a vertical side surface of the lower part is identified as a reference surface C , another side surface as a reference surface B. A hole 46 arranged centrally in the lower part 42 is identified as reference D.

FIGS . 13A, B and C show test gauges which the CIGMA system can construct for checking various features of the component or workpiece 41 of FIG. 12. These Figures 13A-C are each laid out with four columns (a, b, c, d) and four rows (e, f, g, h). As can be seen, a test gauge according to FIG. 13A, a, e for the four lugs 43 of the part 41 , if constructed in the geometrical tolerances only with the reference A , has four holes 47 and the dimension has three remaining degrees of freedom in the X translation direction (XTT) , the Y translation direction (Ytt) and the Z rotation direction (ZTR) . This approach A does not define the approaches in the X or Y translation direction or in the Z rotation direction. The references used for the geometric dimensions of the component 41 are indicated at the other teachings of the Fig. 13A, B, C and have the remaining degrees of freedom as a result of this geometric dimensioning of. The reference information sometimes also contains modifying symbols such as M (MMC state, maximum remaining material) and S (regardless of the feature size), which affect the remaining degrees of freedom, as described below.

The CIGMA system automatically determines the functional requirements of a given set of features. It then displays this functionality on the screen by creating a three-dimensional model of the worst-case mating part (also referred to as "functional theory"), a number of which are shown in FIGS. 13A, B, C. The CIGMA system determines the functionality underlying a set of references and modifying symbols given in a particular order by applying the following rules.

FIG. 13A shows test gauges for testing different features of the component 41 of FIG. 12, the reference for the dimensional tolerances being a plane. If this is the primary reference, the CIGMAL system forces three points of contact between this reference and the mating part; if it is the secondary reference, the CIGMA system forces two points of contact between the reference and the mating part. If it is the tertiary reference, the CIGMA system forces a point of contact between this reference and the mating part. The primary, secondary, and tertiary references are the first, second, and third symbols in the feature control block, respectively, and appear at the right end thereof, as shown in FIGS. 13A-C.

If the reference specified in the control block is a feature such as a hole or an extension, the test gauges of FIGS . 13B, C apply . If the material state is MMC or M (maximum material), as can be seen in FIG. 13B, it is enforced the CIGMA system, if the reference is the primary reference, the axis of the mating part in the parallelism of the axis of the reference in three dimensions. If it is the secondary reference, the CIGMA system places the feature of the mating part in this reference if it is a hole, or around it if it is an approach. Accordingly, if the reference is a tertiary reference, the CIGMA system places the feature of the mating part in the reference if it is a hole or completely around it if it is the approach.

If RFS or S ( Fig. 13C; "regardless of the feature size") is specified for the material status, the CIGMA system, if it is the primary reference, places the axis of the pair part parallel to Axis of this reference in three dimensions and prevents translation of the mating feature within this reference. In other words, the mating feature is simulated by a tapered pin on an axially extending compression spring that forces the mating feature to take up space between itself and the cover. This is shown in FIG. 13C, where a tapered pin 48 is shown on the teaching illustrations in the event that the control block indicates the reference D (central hole 46 ) of part 41 of FIG. 12. For comparison, approach 49 of the teachings of FIG. 13B, for which the MMC symbol M is indicated.

In FIG. 13C RFS or S is specified. If the cover to which the material condition applies is the secondary cover, the CIGMA system places the feature of the mating part in the cover if it is a hole, or completely around the cover if it is a shoulder. As explained in the previous case for the primary reference, the pairing feature on the test gauge ( FIG. 13C) is prevented in this way from a translation in relation - here D on the component 41 of FIG. 12. If it is the tertiary reference, the CIGMA system analogously places the mating feature in the reference if it is a hole, or completely around the reference if it is an attachment. As with the primary and secondary reference, such a material state assigned to a tertiary reference prevents the mating feature on the gauge (the tapered pin 48 on the gauge of FIG. 13C) from within the reference (in this case D on part 41 of FIG. 12) is moved.

If references are specified in a feature control block, the rules just described can be used to determine the exact functionality of the mating part with regard to the features being checked. If the primary reference is a plane and the feature control block appears as "true position, diameter, 0.060 M A" (with A as a plane), then this plane A physically determines the alignment of the mating part. In other words: the mating part must touch the three high points of the plane A given as the primary reference; the mating surface can then perform a translation and rotation, but remains complanar with the reference surface A. An example of such a dimensioning result can be seen in FIG. 13A, g, a, which represents a pairing part (in this case: a test gauge) for the part 41 , which shift in the XT and YT directions and by ZTX can turn. Furthermore, it can be seen that for the indication "true position, diameter, 0.060, reference A" (with A as a plane) the mating part or the teaching of FIGS. 13, e, a applies, which is a translation of the mating part relative to the part 41 of FIG. 12 in the XT - and the YT - and the YT direction and a rotation around the ZT axis. Mathematically, reference A reduces a completely uncontrolled movement (translation in three axes in two directions and rotation around three axes in two directions) to three degrees of freedom, ie translation in XT and YT and rotation around ZT .

If the primary reference is a hole or an extension, the symbols M or S are used as described above. If MMCV or M is specified as the material status for the primary reference , the characteristic control block can look as follows:

0 0 0.060 M D

In the previous example, hole 46 (indicated as reference D in FIG. 12) controls the orientation of the mating part associated with part 41 . The axis of the mating part is placed parallel to that of the reference hole D , corresponding to the pin 49 of the test gauge of FIG. 13B, e, a parallel to the axis of the reference hole D. If the cover and the mating part (or the teaching) are correctly oriented, the mating features are allowed to move and rotate within the covers (if there are holes) or around the covers (if there are approaches). Geometrically speaking, the mating part can be moved along the XT and YT axes and rotated around the ZT axis, as can be seen, for example, in FIG. 13B, f, a. The pairing part is always kept within these when there are reference holes (D) or always around them when there are be approaches (E) . Mathematically speaking, the reference D reduces the six degrees of freedom of the completely uncontrolled movements to three. Furthermore, a reference hole or approach limits the XT and YT translation by the deviation between the reference feature and the mating feature.

If the material condition on the primary reference is specified as RFS or S , the feature control block appears as "0 0 0.060 S D" , where D is a hole or an approach. In the examples given here, the reference D is a hole, as shown in FIG. 12. The hole 46 physically controls the orientation of the mating part by forcing the parallelism of its axis to that of the reference hole (or approach). If the cover and the mating part are correctly oriented, the mating feature can only rotate about the axis determined by the cover. In contrast to the MMC or M modifier described above, no rotation is allowed. This is shown in Fig. 13C, e, a, where rotation about the ZT axis is now indicated as allowed. In this case, the specification RFS mathematically reduces the six degrees of freedom of the uncontrolled movement to the only degree of freedom with the state ZTR .

The CIGMA system checks the syntax of the dimensional specifications according to the ANSI standard, as mentioned above. Fig. 14 shows a workpiece 54 having seven bores 56. As FIG. 14 shows, the cover B is a lip or a shoulder on the part 54 . In the box, the reference B is neither modified by the MMC specification M nor by the RFS specification S. This is a mistake, because without such a specification the approach is not fully specified and the reference is therefore not usable. The same would apply if B were a reference hole. The box must therefore be as

"0 00 M D B S F"

appear. The system recognizes the error and reports it on the Screen and prompts the user to set the tolerance to bring it into the correct form mentioned above.

FIG. 15 shows the ANSI standard specification for two threaded holes 57 in part 54 , the tolerance of the hole diameter for the MMC state being indicated. This information is not completely wrong from the point of view of the tolerance information standard. However, the holes are internally threaded and the default M would require measurement of the tip and root diameters, which is certainly impractical in terms of the measurement itself and the application. The created test gauge does not recognize the MMC specification. All that is required is proper positioning of the fixed fastener that is screwed into the thread. The system therefore issues a warning that the test gauge will be RFS-tolerant and prompts the user to specify S (instead of M) for the hole diameter tolerance.

The test gauges of FIGS . 13A-C are shown on the screen together with an XYZ coordinate system and only show the controlled features on the component which they have been mathematically created for testing. Therefore, the relatively simple specification with only reference A for part 41 of FIG. 12 causes the CIGMA system to construct the relatively simple test gauge shown in FIG. 13, e, a; it consists of only four holes 47 in the reference plane A. As can be seen, the stricter specification of FIGS. 13A, h, d uses plane A , hole D and extension E of component 41 of FIG. 12 as references; the holes 47 thus appear together with the tapered pin 48 (since the reference D is modified with the RFS symbol) and a tapered hole 51 (because the reference approach E is also modified with the RFS symbol). The test gauge for specifications for the primary, secondary and tertiary planes A, B and C is shown in FIGS. 13A, f, b, with flanges 52, 53 being arranged on the test gauge in order to make contact with the references B and C, respectively to force. For the teachings of FIGS. 13A-C, a coordinate system with the three axes is also shown, along which and around which the translation or rotation can take place in accordance with the degrees of freedom (DF) remaining under the tolerance specifications.

The functions of the test module 37 of FIG. 10 will now be described. The test gauges of FIGS . 13A-C are stored in the computer together with the description of the test gauge module 36 , likewise a three-dimensional CAD representation of the part to be tested. The computer knows the shape of the part so that it can create a useful test path. The sensor arrangement (sensor set) depends on this shape. Set 22 of FIG. 5 uses standard system components from Renishaw Corporation. Such a probe 22 a is a shaft with a ruby tip. The sensor is sensitive to pressure and is guided on the robot arm from point to point around the part to be tested.

The CIGMA system now begins to create the test route. There are two options for this. In the first option, the previously defined critical and essential features on the component to be tested are used, as represented by the saved test gauge. As described above, the test gauge uses the dimensional and tolerance specifications of the part drawing as they are in the CAD representation of the part on the computer. The system now chooses an appropriate tip of set 22 ( FIG. 5) and creates a three-dimensional test path that is logical for testing the required features. The required characteristics are those that are considered critical and essential in the test gauge. From this point of view, the test gauge models are used to determine the test path.

Alternatively, the user or the operator selects the feature of the component to be checked. The system knows the configuration of the probe set, designates a suitable tip 22 a of the probe set 22 for testing the respective feature and generates the test path relative to the CAD model contained in the computer. At this point, the user can select five physical features of the component in the "Definition of the test path by the user" operating mode, ie thread features, bores, lugs, flat surfaces and edges.

The test route can be modified in different ways. The user can tell the system a path section to be modified on the screen and enter new coordinates for each waypoint using the keyboard. Alternatively, a new point or a new coordinate can be added to the test path by placing the tick on the screen on the new point and entering it using a key selection. Test waypoints can also be deleted by marking them with the tick on the screen and deleting them from the keyboard. The test path can also be modified with regard to the "approximate distance". Any contact between a probe 22 a and a component requires a suitable positioning of the probe at a nominal distance from the test point, which is known as the "proximity distance". After the test, the probe 22 a is withdrawn by the "withdrawal distance". Both distances and thus the test route can be changed by selecting the keyboard.

The test route has now been created. The CIGMA system is now entering its orientation process. The location of the component lies within certain limits, which are referred to as machine envelope. A certain approximation of the position of the part within the machine envelope, as shown on the screen, must already be known. The probe set is brought up to the component until certain easily accessible, known features are touched on the component, while the component adopts this orientation. Examples of such combinations of features that allow the orientation to be determined are three levels, one level and two holes, one level and a cylinder with a known axis position, etc. After the orientation for the test path, the probe set is calibrated. It can be seen that the probe set itself is manufactured with certain tolerances with regard to the actual location of the probes 22 a with respect to the set body 22 . For this purpose, a calibration artefact is arranged on the test machine bed, the dimensions of which are precisely known. The machine brings the probe set over this artifact and each probe is attached to it. Since the dimensions of the calibration artefact are known, errors can be identified from the measured values supplied by the probe set and compensation values can be saved with which the results of the tests carried out can be modified later.

The job control module 30 of FIG. 10 will now be described. The job control section of the CIGMA system determines the sequence of steps for a particular job before it is executed. First of all, the system is informed of the identity of a certain type of machine that will be connected to the system - for example an NC milling machine from Cincinnati.

The ATTACH command stands for a job control language used in the system. It is used to connect the CIGMAL system with the specified CMM or DNC machine. If the ATTACK command occurs in the JOB file first the specified machine is "connected" to the CIGMA system.  

The device name used in the computer assignment must be defined by the logical name CIG MACHINE; this takes place externally to the job. For example, the file LOGIN.L COM include the following command: ASSIGN TXC3: CIG-MACHINE. The operator will be in the execution of ATTACH issued certain instructions that depend on the machine. When the requested operations are completed, the Job execution continued. The following is the job control language explained that use with the ATTACH command finds.

FORMAT: ATTACH (machine type) PARAMETERS: (machine type)

With the machine type specified in the ATTACH command, it can are one of the following.

○ CINCINNATI for Milicron 5VC machines from Company Cincinnati, ○ DEA for the DEA-CMM machine, ○ AUTOMATIX for the laser robot CMM from the company Automatix, ○ SIMULATE for testing and debugging jobs. The simulated The machine requests data that is stored on a Simulate machine readings. These Option is useful for software quality control. ○ ECHO for checking JOB. The ECHO machine delivers a perfect measurement. This option is useful for Verify that a job runs correctly if a Part is manufactured correctly. ○ WALDRICH for the Waldrich-Coburg machines.  

QUALIFICATORS / TOOL-NUMBER = nnnn

/ TOOL-NUMBER gives the tool number to be selected during ATTACH at. If available, the requested tool when connecting the machine to the SPINDLE for the first time used. This process can be useful if the NC data file does not contain a tool change or the toolpath of the CAD model to the postprocessor no tool instructs. The option is only for DNC / CMM or CND machines applicable and is ignored on all other machines.

RELATED OPERATIONS

An ATTACH command must be executed before a DNC or CMM command can be used. If it doesn't run a system error is output. The command DISCONNECT can be used to use the device release in another process.

EXAMPLE ATTACH / TOOL = 9999 SIMULATE

This information regarding the type of machine connected to the system serves as a "wake-up call" for the system, which then carries out the calibration process described with reference to the test module 37 .

CALIBRATE also explains the job control language of the system. CALIBRATE is used to measure the actual geometry of a probe set 22 before use. The system requires that all probe tips 22 a are calibrated before use when measuring components. If the probe geometry is known exactly and the design of the probe set in the system is exact and is to be checked, a probe can be calibrated to the design values contained in the CAD system. If an earlier calibration is to be used, the calibration results can be read from a data file. The calibration table is defined as the vector from the reference point of the probe set to the center of the ball tip on each probe. The job control language used with the CALIBRATE command is as follows:

FORMAT: CALIBRATE process number
CALIBRATE / DESIGN
CALIBRATE / FILE = (FILENAME)
CALIBRATE process number.

PARAMETER

In this form the CALIBRATE command will the process number to be used is specified as a parameter. This form is used when an actual calibration of a probe set is to be carried out. The Use of FILE, DESIGN and other qualifiers is not allowed (so there are three different forms of the CALIBRATE command).

QUALIFICATORS (OUTPUT-FILE = (file name)

The results of the calibration are given in the File saved. This file can later be downloaded from the CIGMA system be read in to calibrate a probe instead to have to spend machine time for this.

/ MAXTIPERR = (real value)

The MAXTIPERR value is used to control how far the calibrated Probe can deviate from the design value. The The location of each tip relative to the target location is then checked, whether it lies within this MAXTIPERR to the target location. If the error is greater, the CIGMA system ends the Process with an error message. MAXTIPERR will not or specified at 0.0, there is no check.  

/ MAXRADERR = (real value)

This value is used to check how far the radius of the Ball point can be from the setpoint. If not specified, there is no check.

/ MAX VARIATION

Serves to check how large the maximum deviation of the calculated probe tips may be. The calibration process creates five points on a ball 10 ( Fig. 1) to calibrate each tip; for each ball tip, five calculated diameters are obtained, from which an average is formed. If the deviation from the mean value for any probe tip exceeds MAX-VARIATION, CIGMA aborts the process with an error message.

/ TOOL = (tool number)

If / TOOL is specified, the specified tool is used before the Execution of the calibration process loaded into the spindle.

CALIBRATE / DESIGN

With this form of the CALIBRATE command no other Parameters or qualifiers used. He states that the design values of the probe set for its calibration should be used.

CALIBRATE / FILE = (file name)

With this form of the CALIBRATE command no other Parameters or qualifications used. He states that the calibration can be read from a calibration file should. NOTE: The name of the probe set is in this File and must match the probe set that is in the Operation of the machine during the following test operations should be used.  

RELATED OPERATIONS

The ORIENT and INSPECT commands require calibration of the probe set. Becomes an INSPECT or ORIENT command Tried with a non-calibrated probe, the system breaks the process and issues an error message. Used an INSPECT or ORIENT operation other than that previously calibrated probe set, the system also breaks and outputs an error message.

Example:

CALIBRATE / DESIGN
CALIBRATE / FILE = STAR-CLUSTER.CAL
CALIBRATE / OUTPUT = START- - - - -CLUSTER.CAL/MAXTIP
ERR = .0001 901

After executing the CALIBRATE command in the job control becomes a point on the stored in the computer CAD model found by using the tick mark as a cross manually placed on the desired point on the CAD model becomes. A corner is a useful point for that Labeled by hand as it is easier to mark the ticker to align exactly with it. The CAD representation of the component, for which the job control sequence is generated shown on the screen. Then the runs in Connection with the orientation process described in the test module from. The orientation process can also be for others Purposes. The job can be the Manufacturing new features on or around the workpiece Acting Checked Features Act: Both Functions can be carried out using the initially defined references. Furthermore, it may be desirable in certain cases be to machine a workpiece and the machined Check features immediately using the references mentioned. In this way, a workpiece can be practically gradual with reference to the references and contained in the CAD model using the test gauges described above.  

After the test process has been carried out step by step with individual test after each machining process, for the entire workpiece in one pass or according to a desired sequence of steps, the job control for analyzing the test results is carried out. For the simulation, the analysis runs in the manner described below with the aid of the analysis module 38 . After the analysis step in the job control definition, the instruction is given to disconnect the machine and the system is switched off.

The creation of the job control sequence contains further functions, that may be required for certain jobs. Like for example the output of certain visual representations during a job run for special purposes or for Notices applicable to the respective job to the operator. This is all - including that for one specific job other or special functions - is taken into account, the job control is simulated by the Step sequence is carried out in such a way that the operator, that she just generated, follow the process can. If the operator is satisfied with the process, can then call the job control as desired.

During the actual execution of the job control in the machine hall, the identification of the connected machine provides the CIGMA system with information regarding the available tools and / or the test facilities. The operator then commands run the job and the system enters the calibration process for the probe set as described above. The designated 13442 00070 552 001000280000000200012000285911333100040 0002003725347 00004 13323ete orientation point on the component (after its approximate alignment using the screen display) flashes and the operator guides the probe to this point by hand. The orientation process then begins and the CIGMA system takes control of the operator. The predetermined component features are then produced and / or checked on the component according to the designation by the job controller (if included in the job controller). The test results are added to the computer data and analyzed by the analysis module 38 in FIG. 10. At the end of the job control sequence, the machine is disconnected and the process is exited.

The analysis module 38 of FIG. 10 mentioned above will now be explained. The analysis module performs two tasks, gauge analysis and statistical process control (SPC). The system can perform these two analyzes simultaneously or separately. The gage analysis wants to ask the question "Is this component OK?" answer. The applicable control gauges are identified by the job control routine. They are placed on the component as they were constructed from the test results; the system tries to fit them to the workpiece within the degrees of freedom allowed for the gauges. If the teaching fits, the exam is finished. If not, the possibility of reworking is examined. If, as described above, it is found that reworking is possible, the operator is informed of how to proceed. If the teaching still does not fit, reworking is not possible; the machine is disconnected and the process is switched off.

The statistical process control answers the question: "Does the machine tool produce the parts as they did in the past when they were perfect?" For this purpose, the measured values are recorded in the system file with regard to all checked features on each workpiece. These records result in a distribution that is included in the defined part tolerances for the tested popularity. The popularity serves as a reference value for the features tested later on the corresponding parts. In this way, a normal distribution is determined within the defined part tolerances, in which values within the +3 σ limit (99.7% of the population) are acceptable. If a checked characteristic falls outside of this range (3 out of 1000), a check mark is set for the associated process, even if the part still contains tolerances, and the process is examined. Outliers outside the 3+ σ range can be caused by numerous influences - for example a new operator, a loose clamping device, a bad or wrong material, a worn tool and the like. At some point in the machining process, corrective intervention then takes place, and about five workpieces are produced using the same process; if they are all perfect, the process will start again. If all workpieces are not perfect, the investigation is continued.

If a process is out of control, the operator can get a visual representation of past data. It can call up a flow chart that shows how a specified processed feature appears as a result of the test procedure, or a column chart X , ie a visual representation of the mean value of the sample values of the test. Alternatively, they can call up an R diagram that shows the area of the inspection points for the respective characteristic in the relevant production run. With this information, the operator is in a better position to identify one of the potential causes of the fault condition mentioned above. An intelligent means has thus been created to be able to carry out the aforementioned intervention in the process before the five samples mentioned are produced in order to determine whether the process is again under control.

The tolerance module 40 of FIG. 10 will now be explained. The tolerance module in the CIGMA system is intended for use by the designer rather than the quality assurance or manufacturing engineer. It performs two separate functions, the first of which is the less complex. It has long been known that it is difficult for the designer to create two paired parts with tolerance specifications for both in such a way that the parts can be assembled with certainty without any dimensional conflict for any conditions within the tolerance ranges. Often, one of the paired components is designed by one designer, the associated mating part by another. The CIGMA system takes both paired parts describing data together with the tolerance specifications according to the ANSI standard and examines them in their composition if the worst case dimensions for the assembled state are available for each part. The CIGMA system also checks whether each of the paired parts is described with correct dimensions and tolerances regarding the other part. In this way, paired parts can be identified with regard to (1) potential dimensional conflicts and (2) incompatibilities between the reference specifications between the parts. The first function of the tolerance module therefore checks tolerance values that the designer (s) have already specified and shows the user potential dimensional conflicts or contradictory reference specifications with which an otherwise correctly tolerated pairing part is tolerant but does not match.

The second function of the tolerance module 40 in FIG. 10 is to carry out an analysis of fixed and floating fastener analysis. Workshop drawings contain numerous tolerances only for the location of features used to hold parts together - for example fasteners. A fixed fastener can be represented by a threaded bolt that runs with play through a hole in one part and is screwed into a second; A floating fastener can be represented by a bolt that runs through holes in both parts with play, the two parts being clamped together, for example, with a nut screwed onto the fastener. The second tolerance module is used to generate the tolerance values that the designer must indicate on the workshop drawings for both of the paired parts.

The analysis to be done by the user for one in Fasteners not fixed to him to be clamped ("floating fastener") in the second function of the tolerance module first requires the choice of the fastener to be used. Fasteners are made according to standard shaft diameters and head sizes (e.g. on threaded bolts), which have certain contact areas under the head. These descriptions can be found in construction tables Find. Then the user designates the locations on one Workpiece on which the chosen fasteners are inserted should be. This is done by looking at a screen of the workpiece on the attachment points sets and with the keyboard the information enters how this previously worked for the other functions of the CIGMA system is described. The user now designates that when positioning the features on the workpiece covers, for example holes, in the fasteners are used and enters them into the system. The The CIGMA system calculates the optimal hole size for each fastener and the true position of the holes on the paired Component while it stores the saved CAD models of the workpiece and its mating part examined. The bores are made for both workpieces their upper and lower diameter limits calculated so that the entire contact area of a head on the surface of the penetrated workpiece. It can be seen that it may be disadvantageous for the construction of the arrangement can if there are holes in the fastener receiving part are so large that they are outside the dimensions of the holding Lay part of the fastener (head).

The CIGMA system also takes the properties into account of the tool with which the workpiece feature in question should be generated. For example, a drill with increasing  Drill increasingly large holes; the construction tables provide guidelines for estimating the extent the expansion. For example, a drill with a 15.06 mm (0.593 in.) In diameter never has a hole of more than 15.88 mm (0.625 in.) diameter, even if it has become completely blunt. The CIGMA system knows this and takes advantage of it to find suitable tolerances for the paired To fix workpieces.

As an example of the fixing of a hole tolerance for a fastener bracing two workpieces by the CIGMA system, reference is made to FIG. 16, in which a component 57 with four holes 58 is shown. In this case, the designer chooses a stud with a shank diameter of 12.7 mm (0.500 in.) And a head size of 19.05 mm (0.750 in.) To screw the part 57 to a part 59 , which also has four holes 61 contains. If the holes 58 are a maximum of 15.88 mm (0.625 in.), The bearing surface of the bolt head covers the holes 58 . A 15.06 mm (0.593 in.) Drill bit, which can never drill a hole larger than 15.88 mm (0.625 in.), As previously mentioned, is chosen and the four holes are 15.06 mm + 0.81 mm (0.593 in. Plus 0.032 in.) Diameter, which allows a maximum hole size of 15.88 mm (0.625 in.). The minimum hole size is the difference between 15.06 mm (0.593 in.) And the bolt shank diameter, the dimension of the hole max. 12.7 mm (0.500 in.). The dimensions and tolerances according to the ANSI standard thus appear in the order of true position, diameter, zero tolerance under MMC conditions relative to reference A (top of part 57 ), as shown in FIG. 16.

If the CIGMA system is informed that a fixed (ie fixed in one of the components to be clamped) fastener is to be provided with tolerance information regarding the paired parts, the user enters the values exactly as stated above for the "floating" fastener. In addition, the CIGMA system asks for the thickness of the part containing the holes to be drilled with play and that of the part with the corresponding threaded holes, as explained above. In this case, the through holes are to be drilled with oversize as in the analysis of a floating fastener, but the dimension of the through holes is smaller because the fastener screwed into the threaded holes can no longer move; the through holes in the "floating" part must therefore be tolerated more closely. The CIGMA system recognizes this need in the analysis and - for comparison - the tolerances for the holes 61 in part 59 of FIG. 16, which are assumed here as threaded holes for receiving the fastener, with 1.57 mm (0.062 in.) in the MMC state, where the thickness of part 57 is taken into account. The ANSI standard specifications for the four threaded bores 61 in FIG. 16 would therefore appear as follows:

½ 13 UNC-2B
0 0 0.062 M A
0.510 p

An abbreviated program listing follows, which shows a way of formulating a program for operating the disclosed system when carrying out the analyzes explained, the job control and tolerance module processes.
Copyright FMC Corporation 1987.

Claims (73)

1. A method for testing a workpiece with known dimensional features and tolerance specifications using a computer to which a multi-dimensionally movable position measuring device is connected to determine the locations of structural features of the workpiece, characterized in that
creates a multi-dimensional model of a test gauge using the dimensional and tolerance specifications for the workpiece,
defines a test path relative to the workpiece, which defines the movement of the position measuring device,
the position measuring device leads along the test path,
creates a multi-dimensional model of the workpiece using the positions determined on the component features, and
compares the model of the gauge with the model of the workpiece to determine whether the workpiece is tolerant. 2. The method according to claim 1, characterized in that that if the workpiece proves to be out of tolerance, appears whether it is reworkable or scrap is. 3. The method according to claim 1, characterized in that three-dimensional models of the test gauge and the Workpiece created. 4. The method according to claim 1, characterized in that a display device is connected to the computer and one for creating a multidimensional test gauge
Accepts data with regard to the known dimensional characteristics and tolerance specifications of the workpiece,
shows a model of the workpiece derived from the transferred data,
on the model shown, selects the dimension and tolerance standard that is applicable to the workpiece characteristics to be tested, and
uses the visual representation to select the design features that apply to the standard, so that data relating to the test gauge are obtained. 5. The method according to claim 1, characterized in that the test gauge data received are saved. 6. The method according to claim 1, characterized in that a viewing unit is connected to the computer and one for generating a test path
displays the test route on the screen,
forms a test path program corresponding to the test path shown, and
converts the test path program for the movable position measuring device into understandable instructions. 7. The method according to claim 6, characterized in that that the instructions are saved. 8. The method according to claim 1, characterized in that for moving the position measuring device
the orientation of the workpiece is determined,
the orientation of the test path is brought into line with that of the workpiece and
the measuring device is guided along the oriented test path. 9. The method according to claim 1, characterized in that a viewing unit is connected to the computer and to create a multidimensional model of the Workpiece during the movement of the measuring device along of the relative test path records dimensional data on the workpiece and visualize it. 10. The method according to claim 9, characterized in that the dimension data is saved. 11. The method according to claim 1, characterized in that a viewing unit is connected to the computer and one
shows the models of the test gauge and the workpiece visibly,
aligns the models of the test gauge and the workpiece with each other by means of suitable translation and rotation and
the fitting of the test gauge to the workpiece is determined. 12. The method according to claim 11, characterized in that the determination is done by sight and mathematically. 13. The method according to claim 2, characterized in that to indicate whether the workpiece can be reworked,  the workpiece model within the known tolerance specifications changes, the changed workpiece model again with the gauge model, and indicates that the Workpiece can be reworked or scrap if the test gauge fits or does not fit. 14. The method according to claim 1, characterized in that that the tolerance information is checked for syntactical correctness will.  15. The method according to claim 1, characterized in that the position measuring device is calibrated. 16. A method for testing a workpiece with known critical and essential dimension features and tolerance specifications in accordance with a known dimension and tolerance specification standard and using a computer to which a viewing unit is connected, and a three-dimensionally movable element which carries a position measuring device in order to operate the Determine locations of the dimensional features on the workpiece, characterized in that one
takes over the critical and essential dimensions and tolerances of the workpiece,
shows a model of the workpiece including its critical and essential dimensions and tolerances,
selects the known tolerance specification standard and the workpiece dimensions to which this standard applies on the visual display,
Data generated according to a three-dimensional test gauge, which correspond to the selected tolerance specification standard and the workpiece dimensions,
generates a test path for testing the selected workpiece dimensions,
Issues instructions such that the three-dimensionally movable element follows the test path,
measures the positions of the workpiece features that correspond to the selected workpiece dimensions,
Data generated according to a three-dimensional model of the measured workpiece characteristics and
determines whether the test gauge fits the workpiece model. 17. The method according to claim 16, characterized in that one
reworks the workpiece model within the tolerance limits if the test gauge does not fit, and
indicates that the workpiece can be reworked if the test gauge fits the reworked workpiece model, or that it is scrap if it does not fit. 18. The method according to claim 16, characterized in that that the three-dimensional workpiece and gauge model data get saved. 19. The method according to claim 16, characterized in that that before creating the three-dimensional test gauge known critical and essential tolerance information syntactical correctness are checked. 20. The method according to claim 19, characterized in that the tolerance information will be changed if it turns out to be turn out to be syntactically incorrect. 21. The method according to claim 16, characterized in that that the position measuring device is calibrated. 22. Device for comparing a three-dimensional model of a test gauge with a three-dimensional model of a workpiece using CAD data for the workpiece, characterized by
a computer device into which the design data relating to the workpiece can be entered,
a viewing unit connected to the computer for the visual representation of models of the construction part, the test gauge and the workpiece,
a keyboard connected to the computer for selecting specific dimensions and tolerances on the model of the structural part shown, from which data describing the model of the test gauge are derived,
a device for moving an element in three dimensions, which is connected to the computer so that a test path around the workpiece can be described, and
a position sensor which is attached to the movable element and connected to the computer in order to determine the locations of the tested workpiece features and thus the data describing the workpiece model,
the models of the test gauge and the workpiece are compared visually on the viewing unit and mathematically by the computer to determine the tolerance tolerance of the workpiece. 23. The device according to claim 22, characterized in that that the position sensor comprises a coordinate measuring machine. 24. The device according to claim 22, characterized in that that the position sensor works without contact Test system includes. 25. The device according to claim 22, characterized in that the position sensor is an NC machine tool with a Includes contact sensor. 26. The apparatus according to claim 22, characterized by a device for indicating that the workpiece can be reworked or scrap if it turns out to be non-tolerant has proven.   27. The apparatus according to claim 22, characterized by a device for calibrating the position sensor. 28. Device for testing a component with known dimensions and tolerance specifications, characterized by
a facility that creates a multi-dimensional model of a test gauge using the component dimension and tolerance specifications,
a multi-dimensionally movable position measuring device for determining the locations of structural features on the component,
a device for generating a test path relative to the component, which determines the movement of the position measuring device,
a device which can guide the position measuring device along the test path,
a device for creating a multidimensional model of the component using the determined positions of the structural features thereof, and
a device that compares the model of the test gauge with the model of the component in order to determine the tolerance tolerance of the component. 29. The device according to claim 28, characterized by a device for indicating whether the component can be reworked or if it turned out to be out of tolerance has, is scrap. 30. A method for testing a component with known dimensional features and tolerance specifications using a computer to which a multi-dimensionally movable position measuring device is connected, which can determine the locations of structural features on the component, characterized in that
checks the tolerance specifications for syntactical correctness,
the tolerance specifications, if they prove to be incorrect, are syntactically corrected,
creates a multi-dimensional model of a test gauge using the dimensional and tolerance specifications of the component,
creates a test path relative to the component, which defines the movement of the position measuring device,
the position measuring device leads along the test path,
creates a multi-dimensional model of the component using the determined locations of the features, and
compares the model of the test gauge with the model of the component in order to determine the tolerance tolerance of the component. 31. The method according to claim 30, wherein a viewing unit is connected to the computer, characterized in that for creating a multidimensional test gauge
Adopts data regarding the known dimensional characteristics and syntactically correct tolerance specifications,
shows a model of the transferred data visibly,
selects the dimensional and tolerance standard applicable to the data from the visual representation and
selects from the visual representation the design features to which the standard applies so that data relating to the test gauge are obtained. 32. The method according to claim 30, wherein a viewing unit is connected to the computer, characterized in that one for creating a test path
represents the test route on the viewing unit,
determines the orientation of the component,
draws up a test path program corresponding to the test path shown and
align the test path so that it corresponds to the detected orientation of the component. 33. The method according to claim 30, characterized in that the position measuring device is calibrated. 34. Method for testing a component with known critical and essential dimensions and tolerance information standard, wherein a computer is connected to a viewing device and a three-dimensional movable element carries a position measuring device that determines the location of structural features on the component in operation, characterized , that he
takes over the critical and essential dimensions and tolerances of the component,
shows a model of the component including the critical and essential dimensions and tolerances,
selects the known tolerance specification standard and the component dimensions to which this applies from the visual representation,
the syntactical correctness of the known tolerance specifications is determined,
creates a three-dimensional test gauge that corresponds to the selected tolerance specification standard and the component dimensions,
defines a test route for testing the selected component dimensions,
the three-dimensionally movable element leads along the test path,
measures the position of the component features embodied by the selected dimensions,
creates a three-dimensional model of the measured component characteristics,
aligns the three-dimensional model with the three-dimensional test gauge and
determines whether the test gauge fits the component model. 35. The method according to claim 34, characterized in that one
rework the component model within the tolerances if the test gauge does not fit, and
indicates that the component can be reworked if the test gauge matches the reworked component model or is otherwise scrap. 36. The method according to claim 34, characterized in that the position measuring device is calibrated. 37. Method for predetermining a job sequence that is to be carried out on a component by a system that has a computer connected to a multi-dimensionally movable position measuring device, a memory connected to the computer that contains a CAD model of the component on which the job sequence is executed are to be included, as well as a machine that can perform operations on the component and that can be connected to and controlled by the system, characterized in that
communicates the identity of the machine to the system,
the machine connects to the system,
specifies a point on the CAD model for orientation of the position measuring device and the machine,
indicates the sequence of operations to be carried out by the machine and the position measuring device,
analyzes the data obtained in the operations relating to the position measuring device, and
the machine disconnects. 38. The method according to claim 37, characterized in that that the position measuring device is calibrated becomes. 39. The method according to claim 38, characterized in that the steps of communicating, connecting, Calibrating, specifying, labeling, analyzing and separating be simulated for observation. 40. Method for the analysis of data relating to a component, which occur in the operation of a system with a computer connected to a multi-dimensionally movable element and a machine controlled by the system, with a memory connected to the computer CAD data relating to a component to be analyzed and Contains data regarding the configuration of the component, characterized in that
creates a test gauge for design data representing characteristics of the component by reading CAD data assigned to these characteristics,
measures the corresponding physical characteristics of the component and stores the relevant data, and
the matching of the test gauge and the measured component data determined. 41. The method according to claim 40, characterized in that
the data measured and stored on the physical characteristics changes within the specified tolerance range and
determines whether the changed data result in a component with tolerance. 42. The method according to claim 41, characterized in that it is indicated that the component is scrap is when the modified component proves to be non-tolerance turns out.   43. The method according to claim 40, characterized in that that a lot of data about physical Component characteristics for a variety of components measured corresponding characteristics are stored and it is determined whether the machine produces the characteristics in the same way as in the past. 44. The method according to claim 43, characterized in that that an out of control condition is indicated if it turns out that the component characteristics are not the same as made in the past, and that the Cause of this condition is determined. 45. The method according to claim 44, characterized in that the cause of the out of control state corrected, a limited number of components were manufactured and it is determined whether the machine has the component characteristics manufactured exactly as in the past. 46. The method according to claim 43, characterized in that that the stored for certain physical characteristics Data is continuously updated. 47. System for testing a component, which has access to CAD design data for the component, characterized by
a device for reading the dimensions and tolerances from the CAD data for the component features to be tested,
a device that mathematically creates a three-dimensional test gauge for the component using the dimensions and tolerances,
a device for measuring the component features to be tested, which delivers these test data representing
a device that mathematically creates a three-dimensional model of the tested component features, and
a device for comparing the three-dimensional component model with the three-dimensional test gauge, so that the tolerance can be determined. 48. System according to claim 47, characterized in that that the comparison device is a device for visible simultaneous representation of the three-dimensional Model and the three-dimensional test gauge in one has a distinguishable shape, whereby the Tolerance can be determined visually. 49. System according to claim 47, characterized in that the comparison device means for visual representation which has tolerance tolerance in tabular form. 50. System according to claim 47, characterized in that the measuring device is a device to a measuring element around the component and has a device, which creates a test path for the measuring element that this is between the component features to be tested emotional. 51. System according to claim 50, characterized by a device for creating a three-dimensional Model of the component using the CAD data and by a facility that determines the test route and the test items Component features the three-dimensional component model superimposed visible. 52. System according to claim 47, characterized by a device for determining the syntax of the tolerance specifications using the dimensions and tolerances. 53. System according to claim 47, characterized by a device for the permanent storage of component features measured data for a population of Components and a device that each measurement for  statistically analyzed a component feature to determine whether the manufacturing process for the respective component still has acceptable control. 54. System according to claim 47, characterized by a device for determining the tolerances for certain Component characteristics that match the description of the component should be added. 55. System according to claim 47, characterized in that CAD design data for a paired with the component Part present, a facility that tolerances for the paired part in worst case condition and for the component is analyzed for dimensional conflict, and a Facility are provided, which are the results of the Analysis is visible. 56. System according to claim 47, characterized in that that the system connects to any of a variety of machines can be connected to a job (work order) can run a device that the machine identified to whom the system will execute the Jobs is connected, a facility that the operator when defining the job to be executed prompts for input, a facility to specify the Orientation of the component to be exposed to the job process, a facility for entering the definition of job and Test operations in the system and a facility for Analysis of the measured values recorded on component characteristics on the effectiveness of job control are provided. 57. System according to claim 56, characterized in that the analysis device is a device for statistical Examination of those recorded on component characteristics Readings from a population of components included to determine whether the parts are manufactured as they were in the past will.   58. System according to claim 56, characterized in that the analysis device has a device which, if the comparison device lacks tolerance tolerance specifies whether the component can be reworked. 59. System according to claim 56, characterized by means for simulating the execution of a defined jobs. 60. Computer-controlled visual display system for checking and analyzing predetermined features on a component with access to CAD construction and tolerance data for the component, characterized by
a visible area
a device which can simultaneously display a construction data model of the component and a test path around the component model for the specific component characteristics, and
a device by means of which the test path on the visible surface can be changed optionally. 61. Computer-controlled visual display system for testing and analyzing predetermined features on a component, which has access to CAD design and tolerance data describing the component and to a measuring device for the predetermined component features, characterized by
a visible surface and
a device that can visually display a model of the measured component features and at the same time a model of a test gauge that has been created from the CAD design and tolerance data relating to the predetermined component features. 62. Computer-controlled visual display system according to Claim 61, characterized in that the device has a device for simultaneous display,  to display test results at the same time. 63. Computer-controlled visual display system according to Claim 62, characterized in that the test results are available in tabular form. 64. Computer-controlled visual display system according to Claim 62, characterized by a device for Representation of a statistical analysis of the test results. 65. Computer-controlled visual display system according to Claim 62, characterized by a device which based on the test results instructions regarding a Reworkability delivers. 66. Computer-controlled visual display system according to Claim 61, characterized in that the device is a device for simultaneous display, which represents the models in different colors. 67. A method for examining the tolerance of tolerance specifications for paired parts, for which construction and tolerance data for the paired parts are available stored, characterized in that one
which retrieves design and tolerance data relating to the paired parts from the memory,
determines the worst case tolerance state for a dimensional conflict between the paired parts, and
indicates whether or where there is a conflict of dimensions. 68. The method according to claim 67, characterized in that the tolerance data reference locations on each of the paired parts included and it is determined whether the reference specifications in the tolerance data for the paired parts are compatible with each other and it is displayed whether or where appropriate where such an intolerance is present.   69. Procedure for testing the tolerability of Tolerance specifications for paired parts, for the construction and tolerance data including reference locations for the paired parts are available stored, characterized, that you have the design and tolerance data retrieves the paired parts from memory, determines whether the tolerance data in the reference project for the paired parts are compatible with each other, and indicates whether or, if so, where an intolerance is present. 70. The method according to claim 69, characterized in that that one has the worst case tolerance state for a dimensional conflict examined between the paired parts and indicates whether or where there is a conflict of dimensions. 71. A method for determining the tolerance specifications of the component characteristics for fixed and floating fasteners in paired components, for which design data for the paired parts are available stored, characterized in that one
chooses a fastener,
indicates the location on a component where the fastener is to be used,
denotes the references on the component, relative to which the fastener positions should apply,
selects a tool for forming the component features to accommodate the fasteners,
taking into account the tool and the fastener chosen, the maximum and minimum dimensions of the component feature are determined, and
clearly shows the tolerances applicable to the true position of the component features affecting the fastener. 72. The method according to claim 71, characterized in that the fastener is a floating fastener and in the representation one related to the true position Tolerance range from zero shown under MMC conditions becomes. 73. The method according to claim 71, characterized in that that the fastener is a fixed fastener and the features in a floating component with a hole Play and that determines the thickness of the floating part and the tolerance of the bore with play of this thickness be reduced accordingly.