DE10108688A1 - measuring device - Google Patents

Abstract

The invention relates to a device for creating a measuring sequence for a co-ordinate measuring unit (1), said device comprising the following: at least one computer (3, 7) for generating CAD data (12) of a workpiece (4) to be measured and for generating a CNC programme (10, 17) from the CAD data (12); a co-ordinate measuring unit (1) for executing the CNC programme (17). The aim of the invention is to simplify the modification process for the CAD data (12). To achieve this, the computer (3, 7) generates the CNC programme (10, 17) by additionally taking into consideration a modification file (23, 16) with stored modification instructions, which define modifications to a measuring sequence, said sequence having been created on the basis of the CAD data during the generation of the CNC programme.

Description

The invention is based on a device for generating a measurement sequence for Coordinate measuring device comprising at least one computer for generating CAD data workpiece to be measured and to generate a CNC program from the CAD data and a coordinate measuring machine on which the generated CNC program is executed.

Such a device is already from the book coordinate measuring technology by Hans Joachim Neumann, published in 1993 by Expert Verlag, ISBN no. 3-8169-0965-5 known. Here is on Pages 1 to 17 described that CNC programs that control the automated Coordinate measuring device are necessary, are generated automatically from the CAD data can. This is usually done from the data of the CAD model via a first compiler creates a test plan, from which the CNC Program is generated, which is executed on a corresponding coordinate measuring machine can be.

Publication WO 99/58931 also shows a similar process to a Generate measurement sequence for a coordinate measuring machine. This will focus in particular on the Object-oriented creation of a test plan from specified CAD data. to First, the individual test items are drawn up one after the other Inspection characteristics derived from the CAD data. After that, everyone will be examined Test feature assigned the geometric elements of the workpiece to be checked. Which to Geometric elements that are to be checked will then again be the ones to be checked Assigned measuring elements to be scanned to geometric elements, as well as the suitable styli are needed for scanning. The test plan created in this way then becomes a final one Step derived the travels of the coordinate measuring machine. Although not here has been expressly described, it is of course, as with computer-controlled Machine tools common to a CNC program in which a number of CNC Program commands are generated which are used to control the measuring sequence one after the other be processed.  

During the creation of the actual CNC program there are often changes to the CAD data necessary because, for example, the position of individual on the workpiece existing geometric elements is changed, or because, for example, dimensions or tolerances be changed. In such a case, the CAD compiler Data again generated a measurement plan and this measurement plan via said second compiler another CNC program generated. However, this has the consequence that all so far by the Operator of the coordinate measuring machine changes made to the CNC program lost are. Thus, the operator of the coordinate measuring machine must all be on the CNC program Enter the changes made again.

Proceeding from this, our invention is based on the object of a device Type mentioned, as well as propose an associated procedure, with the simplified a final measurement sequence can be generated.

The object is according to the characterizing part of independent claim 1 and solved the features of independent claims 7, 13 and 19, in which the computer the CNC Program also created taking into account a change file in which Change instructions are stored, which define changes to a measurement sequence, which at Generation of the CNC program based solely on the CAD data.

Through this procedure according to the invention when generating a new CNC program The CAD data now has the considerable advantage that changes to one already exist CNC program once created also when a new CNC program is created from the changed CAD data can be transferred back to the new CNC program.

The creation of the CAD data, the creation of the test plan, the creation of the CNC Program and the execution of the CNC program could in principle on the computer of the Coordinate measuring device are carried out. Usually, however, one gets out for technical reasons, the creation of the CAD data, the generation of the test plan and the generation of the CNC program on a first CAD computer provided for this purpose carry out. The execution of the CNC program and the creation of the change file  will, however, preferably be carried out on the computer of the coordinate measuring machine, since this computer is directly connected to the coordinate measuring machine. It will therefore in the following for the sake of simplicity between the computer of the coordinate measuring machine and the CAD calculator, even if in principle only one calculator would be necessary.

The incorporation of changes from the change file can basically be done by two different places happen. Firstly, those contained in the change file Changes directly in the computer of the coordinate measuring machine by the operating program the coordinate measuring machine can be made in the finished CNC program, so that the CNC program commands contained in the finished CNC program accordingly changes to the change file. Alternatively, the changes to the Change file also immediately when the CNC program is created by the second Compiler in the CAD computer are taken into account.

In a preferred embodiment, the operating program of Coordinate measuring device and / or from said compiler for generating the CNC program automatically checks for the presence of a change file and, if available, into the Generation of the CNC program included.

The change file can be generated particularly advantageously from a measurement plan document in all the data of the measuring sequence necessary for the operator of the coordinate measuring machine are shown. The said measurement plan document is usually a Word processing document, such as a Winword document, where the changing CNC program commands at a defined point, such as one previously entered table. The changed program command could, for example according to the following nomenclature: $$ program command $$.

The creation of a change file can now be done very easily by using the Word processing document simply as a plain text file, for example in ASCII or as ANSI Character set is saved. The resulting change file therefore only exists still from text characters, all formatting of the word processing document completely disappear. When reading the change file into the operating program of the  Coordinate measuring device and / or in the compiler for generating the CNC program can the CNC program commands to be changed can be found very easily in the after the command delimiter "$$" is searched.

Further advantages and developments of the invention can be found in the advantageous exemplary embodiment described in connection with FIGS. 1 to 5. Show here:

Fig. 1 shows an inventive device for the automated generation of a CNC program for a coordinate measuring machine

Fig. 2 is a schematic representation of the files and programs of an embodiment of an apparatus according to the invention

Fig. 3 is a schematic representation of a table in a measurement plan document in which measurement technology changes are entered

Fig. 4 is a schematic representation of a change file

Fig. 5 is a schematic representation of a table in a measurement plan document in which changes in the characteristics to be scanned on the workpiece are recorded

Fig. 1 is a purely schematic illustration showing an apparatus according to the invention for the automated production of a CNC program for a coordinate measuring machine (1) from the CAD data of a workpiece to be measured (4). As can be seen in FIG. 1, the device comprises a computer ( 3 ) on which the CAD data for a workpiece ( 4 ) to be measured can be entered. From the CAD data of the workpiece ( 4 ), a test plan is now generated semi-automatically via a compiler, in which the individual test features to be tested are derived one after the other from the CAD data. The geometric elements of the workpiece to be tested are also assigned to each test feature to be tested. In addition, the measuring points to be scanned on the geometric elements to be scanned are defined, as well as the suitable styli that are required for scanning. A detailed explanation of how to create the test plan can be found in our patent application WO 99/58931. From the test plan created in this way, which defines the measurement sequence, a CNC program can now be generated on the one hand via a further compiler, which can be executed on the coordinate measuring machine ( 1 ), as well as a test plan document in the form of a commercially available word processing file in which all the technological data of interest for the measuring sequence are described for the operator of the coordinate measuring machine. This shows, for example, a perspective view of the workpiece ( 4 ) to be measured, a description of the styli to be used, and instructions for aligning and clamping the workpiece ( 4 ) on the measuring table ( 6 ) of the coordinate measuring machine ( 1 ). In the exemplary embodiment shown in FIG. 1, the CAD data, the test plan, the CNC program and the measurement plan document are stored on a data memory, such as the hard disk of the computer ( 3 ). The CNC program and the measurement plan document are then additionally copied to a central server ( 2 ), to which the computer ( 7 ) of the coordinate measuring machine ( 1 ) also has access.

The computer ( 7 ) of the coordinate measuring machine ( 1 ) can download the CNC program and the measurement plan document ( 11 ) from the server ( 2 ) onto a data carrier of the computer ( 7 ) of the coordinate measuring machine ( 1 ). The operator of the coordinate measuring machine can then clamp a workpiece ( 4 ) to be measured on the measuring table ( 6 ) of the coordinate measuring machine ( 1 ) under the guidance of the measuring plan document, and can provide the styli prescribed in the measuring plan document in the magazine ( 5 ) of the coordinate measuring machine ( 1 ). In a next step, the CNC program can be started by the operator. During the measurement sequence that is now running, errors are usually visible that were not recognized during the largely automated creation of the CNC program and the measurement plan document.

How the change in the CNC program works in detail is now to be illustrated with reference to FIG. 2.

FIG. 2 shows a schematic representation of the stored files and programs according to FIG. 1. The reference symbol ( 3 ) designates the computer ( 3 ), as in FIG . As already explained above, the CAD data of a workpiece ( 4 ) to be measured are stored in a file ( 12 ) of the computer ( 3 ). The creation of the CAD data ( 12 ), as well as all the processes described below in connection with the computer ( 3 ), such as, for example, compiling files, copying files and also changing files, is carried out under the control of the operating program ( 22 ). instead of. This is an application program that runs on a commercially available operating system such as Windows, Unix, Linux etc.

From the designated file ( 12 ), "CAD data", a file ( 13 ) "test plan" is now generated semi-automatically via a corresponding compiler ( 20 ). As already explained above, all the data relevant for the measurement process, such as the test features to be determined, the geometric elements to be measured, the points to be scanned on the geometric elements, the buttons to be used, etc., are stored here. As already explained above, a detailed explanation of how to create a test plan is contained in our patent application WO 99/58931. In a next step, a further CNC program is generated from said test plan ( 13 ) by means of a further compiler ( 19 ), which is stored in a corresponding file ( 10 ) on the computer ( 3 ). The abbreviation CNC stands for "Computer Numerical Control" and, as is common with computer-controlled machine tools, contains all travel commands and instructions via which the coordinate measuring machine is controlled. The CNC program commands, for example, control the mechanics for moving the probe in the three coordinate directions. Furthermore, a measurement plan document in the form of a word processing document, such as a Winword document, is generated from the file ( 13 ) "test plan" via the said compiler ( 19 ) and stored in the file ( 11 ) on the computer ( 3 ). All the technological data of interest to the operator of the coordinate measuring machine are described therein. For example, it contains a perspective view of the workpiece ( 4 ) to be measured, a description of the styli to be used, and instructions for aligning and clamping the workpiece ( 4 ) on the measuring table ( 6 ) of the coordinate measuring machine ( 1 ). The files ( 10 ) "CNC program" and ( 11 ) "Measurement plan document" are now copied to the server ( 2 ). The files ( 10 ) "CNC program" and ( 11 ) "measurement plan document" therefore have the same reference numerals ( 10 ) and ( 11 ), since the files in question are identical copies of the files in question on the computer ( 3 ).

Said files ( 10 ) "CNC program" and ( 11 ) "measurement plan document" are now from the operating program ( 14 ) of the computer ( 7 ) of the coordinate measuring machine ( 1 ) from the server ( 2 ) into corresponding files ( 17 ) "CNC program "and ( 15 )" Measurement plan document "saved. The operating program ( 14 ) of the computer ( 7 ) is also an application program that runs on a commercially available operating system, such as Windows, Unix, Linux, etc., which is also analogous to the operating program ( 22 ) of the computer ( 3 ) all operations described in connection with the computer ( 7 ), such as, for example, compiling files, copying files and also changing files.

On the basis of the copied file ( 17 ) "CNC program", the operating program ( 14 ) then issues the corresponding movement commands to the mechanics of the coordinate measuring machine ( 1 ) on the basis of which the workpiece ( 4 ) clamped on the measuring table ( 6 ) is then measured.

If the operator of the coordinate measuring machine ( 1 ) detects an error in the measurement process, he enters the CNC commands to be changed in a corresponding table in the measurement plan document which is stored in the file ( 15 ). The relevant CNC commands are started with "$$" and ended with "$$". The modified measurement plan document is saved back to the file ( 15 ). Furthermore, a new file ( 16 ) "change file" is generated from the file ( 15 ), in which the entire measurement plan document of the file ( 15 ) is stored as a pure text file, only the pure text data, for example, as ASCII text or as ANSI -Text can be saved. When the CNC program from the file ( 17 ) is executed again, a compiler ( 18 ) of the operating program ( 14 ) changes the CNC program ( 17 ) according to the data in the change file ( 16 ). For this purpose, the operating program ( 14 ) opens the change file ( 16 ), then looks for the CNC program commands between the control characters "$$" and "$$" and changes the CNC program ( 17 ) in accordance with those in the change file ( 16 ) CNC program commands found. The measurement sequence for measuring the workpiece ( 4 ) is then carried out again with the correspondingly modified file ( 17 ) “CNC program”.

Now that the measurement sequence has functioned correctly after possibly a series of changes, the correspondingly adapted file ( 15 ) "measurement plan document" is copied by the operating program ( 14 ) into a file ( 21 ) "measurement plan document changed" of the server ( 2 ). If the CAD designer now creates a file ( 13 ) "test plan" on the computer ( 3 ), for example because of a change in the file ( 12 ) "CAD data", the CNC program can now be used to generate the file ( 10 ) "and the file ( 11 )" measurement plan document "the changes in the file ( 21 )" measurement plan document changed "are taken into account. For this purpose, the file ( 21 ) "Measurement plan document changed" is saved as a pure text document in a file ( 23 ) "change file" as on the computer ( 7 ). When a new file ( 10 ) "CNC program" and a new file ( 11 ) "measurement plan document" are created from the changed file ( 13 ) "test plan" by the compiler ( 19 ), then automatically a file ( 23 ) " Change file "searched. If this file ( 23 ) "change file" is present, as in the present case, it is opened by the compiler ( 19 ), as described above in connection with the computer ( 7 ), and the changed program commands between the control characters "$$ "and" $$ "selected. The corresponding CNC program commands corresponding to the changes in the change file ( 21 ) are then automatically adopted in the file ( 10 ) “CNC program” generated by the compiler ( 19 ).

Fig. 3 shows, purely by way of example a table contained in Meßplandokument (15), (1) Amendments have been input to the measurement technology in the operator of the coordinate. The first line shows the column headings of the table. As can be seen from this, a brief description of the change is made in the first column. The modified CNC program commands are then entered in the second column between the control characters "$$" and "$$", which are intended to replace and / or supplement the relevant CNC program commands of the CNC program. The operator who made the changes is then entered in the third column and the current date of the change in the fourth column. The table shown in FIG. 3 is a table created by default in a word processing document, such as Word 97 from Microsoft.

In order to be able to incorporate the changes into the CNC program ( 17 ), the measurement plan document ( 15 ), which contains the table shown in FIG. 3, is stored as a pure text document which contains only text and no formatting. This file is now the change file ( 16 ). The table shown in Fig. 3 appears in the change file ( 16 ) as shown in Fig. 4. As can be seen from FIG. 4, all the entries in the table are displayed one below the other in rows. The operating program ( 14 ), which includes a compiler that carries out the changes to the change file ( 16 ) in the CNC program ( 17 ), can find the changed CNC program commands very easily by searching for text components according to the following nomenclature: $ $ CNC program command $$. The compiler ( 18 ) of the operating program ( 14 ) can then simply change the corresponding CNC program commands of the CNC program ( 17 ) according to the CNC program commands read from the change file ( 16 ), that is to say add or replace existing CNC program commands.

In Fig. 5, a further table of the Meßplandokumentes (15) is shown (1) changes on the on the workpiece (4) to be scanned in the characteristics from the operator of the coordinate. The table according to FIG. 5 is constructed exactly like the table according to FIG. 3 and is stored in the change file ( 16 ) and incorporated into the CNC program ( 17 ) in exactly the same way as in connection with FIG. 4 for the table according to FIG. 3 has been explained.

Finally, it should also be noted that the exemplary embodiment described in connection with FIGS. 1 to 5 is only a possible example.

Of course, numerous modifications are possible. For example, all files that were generated on the computer ( 3 ) of the CAD work station could just as well be created on the computer ( 7 ) of the coordinate measuring machine ( 1 ), so that the server ( 2 ) and the computer ( 3 ) are then dispensed with could be. The design of the coordinate measuring machine ( 1 ) shown purely schematically is of course only exemplary. Instead of the portal measuring device shown here, for example, a bridge measuring device, a column measuring device or a robot arm with several swivel joints could be used. Of course, the derivation of the change file ( 16 ) from a measurement plan document ( 15 ) is only exemplary. Alternatively, the change file ( 16 ) might as well be a database file, for example.

Claims (24)

1. Device for generating a measurement sequence for a coordinate measuring machine ( 1 ) comprising;
at least one computer ( 3 , 7 ) for generating CAD data ( 12 ) of a workpiece ( 4 ) to be measured and for generating a CNC program ( 10 , 17 ) from the CAD data ( 12 )
a coordinate measuring machine ( 1 ) for executing the generated CNC program ( 17 )
characterized in that
the computer ( 3 , 7 ) also generates the CNC program ( 10 , 17 ) taking into account a change file ( 23 , 16 ), in which change instructions are stored, which define the changes to a measurement sequence which occurs when the CNC program is generated Based on the CAD data would be created. 2. Device according to claim 1, characterized in that the computer ( 3 , 7 ) in the generation of the CNC program ( 10 , 17 ) automatically queries the presence of an associated change file ( 23 , 16 ) and this change file ( 23 , 16 ) then included in the creation of the CNC program if available. 3. Device according to one of claims 1 or 2, characterized in that the change file ( 23 , 16 ) from a measurement plan document ( 15 ) is created in which essential data of the measurement sequence are summarized for the operator of the coordinate measuring machine ( 1 ). 4. The device according to claim 3, characterized in that the measurement plan document ( 15 ) is a word processing document. 5. The device according to claim 4, characterized in that the change file ( 16 ) is generated by storing the measurement plan document ( 15 ) as a pure text file. 6. The device according to claim 4 or 5, characterized in that the changes of Measurement sequence in a predefined column of one or more tables of the Measurement plan document can be entered.   7. Coordinate measuring device ( 1 ) with which it is possible to execute a CNC program ( 17 ) generated beforehand on the basis of CAD data for measuring a workpiece, characterized in that the CNC program ( 17 ) is automated, taking into account a change file ( 16 ) can be changed by the computer of the coordinate measuring machine ( 1 ), change instructions being stored in the change file, which define the changes to a measuring sequence that would be created solely on the basis of the CAD data when the CNC program was generated. 8. Coordinate measuring device according to claim 7, characterized in that the computer ( 7 ) in the generation of the CNC program ( 17 ) automatically queries the presence of an associated change file ( 16 ) and this change file ( 16 ) then exists in the generation of the CNC Program 9. Coordinate measuring device according to one of claims 7 or 8, characterized in that the change file ( 16 ) from a measurement plan document ( 15 ) is created in which for the operator of the coordinate measuring machine ( 1 ) essential data of the measurement sequence are summarized. 10. Coordinate measuring device according to claim 9, characterized in that the measurement plan document ( 15 ) is a word processing document. 11. Coordinate measuring device according to claim 10, characterized in that the change file ( 16 ) is generated by storing the measurement plan document ( 15 ) as a pure text file. 12. Coordinate measuring machine according to claim 10 or 11, characterized in that the Changes to the measurement process in a predefined column of one or more tables of the Measurement plan file can be entered. 13. Computer ( 3 ) with which a CNC program ( 10 ) for a coordinate measuring machine ( 1 ) for measuring a workpiece can be generated on the basis of CAD data, characterized in that the CNC program ( 10 ) is automated taking into account a Change file ( 23 ) can be generated by the computer, with change instructions being stored in the change file, which define changes to a measurement sequence that would be created solely on the basis of the CAD data when the CNC program was generated. 14. Computer ( 3 ) according to claim 13, characterized in that the computer ( 3 ) in the generation of the CNC program ( 10 ) automatically queries the presence of an associated change file ( 23 ) and this change file ( 23 ) then in the presence Includes generation of the CNC program 15. Computer ( 3 ) according to one of claims 13 or 14, characterized in that the change file ( 23 ) from a measurement plan document ( 15 ) is created in which for the operator of the coordinate measuring machine ( 1 ) essential data of the measurement sequence are summarized. 16. Computer ( 3 ) according to claim 15, characterized in that the measurement plan document ( 15 ) is a word processing document. 17. Computer ( 3 ) according to claim 16, characterized in that the change file ( 16 ) is generated by storing the measurement plan document ( 15 ) as a pure text file. 18. Computer ( 3 ) according to claim 16 or 17, characterized in that the changes in the measurement sequence can be entered in a predefined column of one or more tables of the measurement plan file. 19. A method for generating a measuring sequence for a coordinate measuring machine ( 1 ) comprising the following method steps:
Generation of CAD data ( 12 ) of a workpiece to be measured ( 4 )
Generation of a CNC program ( 10 , 17 ) from the CAD data ( 12 )
Execution of the generated CNC program ( 17 ) on the coordinate measuring machine ( 1 )
characterized in that
the CNC program ( 10 , 17 ) can also be generated taking into account a change file ( 16 , 23 ) in which change instructions are stored which define changes to a measurement sequence which, when the CNC program is generated, is based solely on the CAD data ( 12 ) would be created. 20. The method according to claim 19, characterized in that when the CNC program is generated, the presence of an associated change file ( 23 , 16 ) is queried automatically and this change file ( 23 , 16 ) is then present in the generation of the CNC program ( 10 , 17 ) is included. 21. The method according to any one of claims 19 or 20, characterized in that the change file ( 23 , 16 ) from a measurement plan document ( 15 ) is created in which for the operator of the coordinate measuring machine ( 1 ) measurement technology data of the measurement sequence are summarized. 22. The method according to claim 21, characterized in that the measurement plan document ( 15 ) is a word processing document. 23. The method according to claim 22, characterized in that the change file ( 16 ) is generated by storing the measurement plan document ( 15 ) as a pure text file. 24. The method according to claim 22 or 23, characterized in that the changes in the measurement sequence in a predefined column of one or more tables of the measurement plan document ( 15 ) can be entered.