Dimension measurement management system and dimension measurement management method

Abstract

To provide a dimension measurement management system and a dimension measurement management method that can improve the economic efficiency of dimension measurement.SOLUTION: A dimension measurement management system of the present invention includes: an information extraction unit that extracts shape information including dimensions to be measured based on design information of a target member: a measurement coordinate calculation unit that calculates measurement coordinates from the extracted shape information; a simulated measurement data generation unit that creates simulated measurement data based on the measurement coordinates calculated by the measurement coordinate calculation unit and performance information of a dimension measurement device; a measurement error calculation unit that processes the simulated measurement data generated by the simulated measurement data generation unit to calculate a measurement error; and a measurement determination unit that compares the measurement error with a tolerance of the measurement coordinates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dimension measurement management system and a dimension measurement management method. [Background technology]

[0002] Geometric tolerance management has become commonplace in manufacturing. The measurement accuracy of geometric shapes is determined not by the accuracy of the measuring instrument, but by the results of processing the acquired data, so the number of points to measure is important. Furthermore, while the widespread use of measuring instruments has made it easier to acquire large amounts of data, acquiring more data than necessary tends to increase measurement time, data processing time, and data storage capacity.

[0003] This ultimately leads to increased measurement costs, so it is important to measure rationally using methods and points that match the required accuracy.

[0004] Patent Document 1 discloses a technology for a workpiece measurement device that includes a display unit that displays an image of the workpiece, a measurement target acquisition unit that accepts the specification of a measurement target for the workpiece image and detects a measurement target structure corresponding to the specified measurement target, a measurement item setting unit that accepts the specification of measurement items for the workpiece image, and a measurement program generation unit that generates a measurement program in which measurement points and approach points corresponding to the measurement items specified by the measurement item setting unit and a measurement path including the measurement points and approach points are set for the measurement target structure.

[0005] Patent Document 2 discloses a technology for a simulation device that includes a camera that captures an image of an object for shape measurement, a first extraction unit that extracts feature points of the object for shape measurement from the image acquired by the camera, a generation unit that generates, on a computer, a virtual object corresponding to the object for shape measurement and a virtual camera corresponding to the camera, a second extraction unit that extracts feature points of the virtual object from the virtual image acquired by the virtual camera, and a correction unit that corrects mathematical parameters used by the generation unit to generate the virtual object based on differences between the first feature points extracted by the first extraction unit and the second feature points extracted by the second extraction unit. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-017111 [Patent Document 2] Japanese Patent Application Publication No. 2018-077168 Summary of the Invention [Problem to be solved by the invention]

[0007] However, Patent Document 1 is a technology in which a measurement target is extracted from a displayed image, measurement items are presented, and necessary items are selected from the presented items, and no consideration is given to whether measurement is possible or not.

[0008] Patent Document 2 describes a technology in which the shape of the object to be measured (virtual shape) is prepared in advance, feature points of the object are extracted from the displayed image, the imaging direction of the camera is inferred, the prepared virtual shape is corrected, and the corrected virtual shape is compared with the measurement results to perform measurement; however, no consideration is given to whether measurement is possible or not.

[0009] It is desirable to determine whether dimensions can be measured at the upstream design stage of manufacturing, and if there are any parts that are difficult to measure, to reconsider and take measures at the design stage, thereby avoiding rework and additional consideration at the downstream manufacturing and quality assurance stages, and preventing process delays and increased measurement costs.

[0010] An object of the present invention is to provide a dimension measurement management system and a dimension measurement management method that can improve the economic efficiency of dimension measurement. [Means for solving the problem]

[0011] The dimension measurement management system of the present invention is characterized by having an information extraction unit that extracts shape information of the object to be measured from design information of a target component, a measurement coordinate calculation unit that calculates measurement coordinates from the shape information extracted by the information extraction unit, a simulated measurement data generation unit that creates simulated measurement data based on the measurement coordinates calculated by the measurement coordinate calculation unit and performance information of a dimension measurement device, a measurement error calculation unit that processes the simulated measurement data generated by the simulated measurement data generation unit to calculate a measurement error, and a measurement judgment unit that compares the measurement error calculated by the measurement error calculation unit with the tolerance of the measurement coordinates calculated by the measurement coordinate calculation unit.

[0012] Alternatively, the dimension measurement management method of the present invention is characterized in that it extracts shape information to be measured from design information of a target part, calculates measurement coordinates from the extracted shape information, creates simulated measurement data based on the calculated measurement coordinates and performance information of a dimension measurement device, processes the created simulated measurement data to calculate a measurement error, and compares the measurement error with a tolerance of the measurement coordinates. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a dimension measurement management system and a dimension measurement management method that can improve the economic efficiency of dimension measurement. [Brief explanation of the drawings]

[0014] [Figure 1] 1 shows a configuration of a dimension measurement determination unit according to the first embodiment. [Figure 2] FIG. 1 is a diagram showing a contact-type three-dimensional measuring machine. [Figure 3] FIG. 2 is an enlarged view of the tip portion of the contact-type coordinate measuring machine. [Figure 4]FIG. 2 is a diagram showing a cylinder as an example of a measurement target in the present embodiment 1. [Figure 5] 1 is a diagram showing a hollow cylinder as an example of a measurement target in this Example 1. FIG. [Figure 6] FIG. 2 is a diagram showing measurement points of a hollow cylinder in the present Example 1. [Figure 7] FIG. 1 is a diagram showing simulated measurement data of a hollow cylinder according to the first embodiment. [Figure 8] FIG. 10 is a diagram showing the relationship between the number of measurement points and measurement error in the present embodiment 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] In an embodiment of the present invention, the target component has a complex shape, and its contour and surface are grasped at the design stage, and simulated measurements are performed taking into consideration the performance of the dimension measuring equipment. The results of the simulated measurements can also determine whether dimension measurement is possible, as well as the appropriate measurement locations and number of measurement points. Note that the examples are merely illustrative examples for explaining the present invention, and have been omitted or simplified as appropriate for clarity of explanation. The present invention can also be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0016] Furthermore, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings. Specific examples will be described below. [Example]

[0017] A first embodiment of the present invention will be described with reference to Fig. 1 to Fig. 8. Fig. 1 shows the components of a dimension measurement determination system in this first embodiment. Note that this embodiment will be described using a contact-type three-dimensional measuring device as an example of the measuring device, but the present invention is not limited to contact-type three-dimensional measuring devices as the measuring device.

[0018] As shown in FIG. 1, the dimension measurement management system of this embodiment includes an information extraction unit 3 that extracts shape information of the object to be measured from design information 2 of the target component, a measurement coordinate calculation unit 4 that calculates measurement coordinates from the extracted shape information, a simulated measurement data generation unit 6 that creates simulated measurement data based on the measurement coordinates calculated by the measurement coordinate calculation unit 4 and performance information of the dimension measurement device, a measurement error calculation unit 7 that processes the simulated measurement data generated by the simulated measurement data generation unit 6 to calculate a measurement error, and a measurement determination unit 8 that compares the measurement error with the tolerance of the measurement coordinates.

[0019] A designer 1 designs a target component and creates design information 2. A specific example of the design information 2 is data such as a CAD drawing. This design information 2 is sent to an information extraction unit 3.

[0020] Next, the information extraction unit 3 extracts shape information about the contour and surface of the measurement target of the target component from the design information 2. Specific examples of contour and surface shape information include, for example, if the measurement target of the target component has a cylindrical shape as shown in FIG. 4, the contour and surface shape information would be the contour 10 of the bottom surface of the cylinder, the cylinder bottom surface 11, and the side surface 12 of the cylinder. If the measurement target of the target component is the inner surface of a hollow cylinder as shown in FIG. 5, the contour and surface shape information would be the side surface 12, the edge 13 of the hollow portion, and the inner surface 14. The information extracted by the information extraction unit 3 is sent to the measurement coordinate calculation unit 4. In this way, the contour or surface, which is the external shape of the target component, can be determined by the information extraction unit 3 based on the design information 2.

[0021] Next, the measurement coordinate calculation unit 4 calculates the measurement coordinates of the measurement target from the extracted information. For convenience, this embodiment will be described in two dimensions. For example, when measuring the diameter of the inner surface of a hollow cylinder, as shown in FIG. 6, the ball at the tip of the contact probe 106 is brought into contact with the inner surface of the hollow cylinder to perform the measurement. This contact position becomes the measurement coordinates, but this information is not recorded in the CAD, which is the design information 2. Therefore, measurement coordinates (target position of the contact probe 106) such as those shown at 201a to 201h in FIG. 6 are obtained. These measurement coordinates are used in the simulated measurement described later, and the coordinates may be calculated using a CAD function. Alternatively, a new coordinate system may be used, for example, with the center of the circumference of the circle 13 shown in FIG. 6 as the origin.

[0022] In the example shown in Fig. 6, eight measurement points are evenly arranged around the entire circumference. However, for example, the measurement range may be limited to a range of 180 degrees, or the measurement points may be unevenly arranged. The information on the measurement coordinates in this measurement coordinate calculation unit 4 is sent to the simulated measurement data generation unit 6. In this way, the measurement coordinate calculation unit 4 can calculate the measurement coordinates of the measurement object from the information extracted by the information extraction unit 3.

[0023] Next, the simulated measurement data generation unit 6 receives information on the measurement coordinates from the measurement coordinate calculation unit 4 and information on the required measurement performance of the measuring instrument. The measurement performance of the measuring instrument and the measurement instrument database 5 will be described later. From the measurement instrument database 5, the simulated measurement data generation unit 6 receives information on the measurement uncertainty and measurement instrument error of the measuring instrument, which is performance information stored therein. Based on this information on the measurement uncertainty and measurement instrument error of the measuring instrument and the measurement coordinates 201a to 201h obtained by the measurement coordinate calculation unit 4, simulated measurement data 202a to 202h are generated. Specifically, simulated measurement data is generated by adding random numbers to the coordinates 201a to 201h, with the measurement uncertainty and measurement error as the full range (maximum value, minimum value). In other words, simulated measurement data is generated by adding random numbers within a predetermined range (range from maximum value to minimum value) based on the measurement uncertainty and measurement error. Note that although random numbers are used in this embodiment, any numerical value with some variation will suffice. The generated simulated measurement data is transmitted to the measurement error calculation unit 7. In this way, the simulated measurement data generating unit 6 can generate simulated measurement data based on the information on the measurement coordinates obtained by the measurement coordinate calculating unit 4 and the performance information of the measuring device.

[0024] Next, the measurement error calculation unit 7 uses the simulated measurement data 202a to 202h to calculate the diameter of the circle 13. Specifically, a fitting process such as the least squares method is performed. A simulated measurement is performed using the simulated measurement data to determine the dimensions of the measurement object, and the measurement error is calculated by comparing the dimensions with the nominal value (design value). Note that accuracy is improved by repeating the simulated measurement multiple times. It is also possible to determine the minimum number of measurement points where the measurement error is less than the tolerance. In this way, the measurement error calculation unit 7 can perform a simulated measurement using the simulated measurement data, and can calculate the measurement error by comparing the measurements with the nominal value (design value). The measurement error obtained by the measurement error calculation unit 7 is then sent to the measurement determination unit 8.

[0025] Next, the measurement judgment unit 8 judges the measurement situation. That is, it compares the calculated measurement error with the tolerance of the measurement object to determine whether measurement is possible. Specifically, it compares the diameter of the circle obtained by the fitting process with the diameter of the circle on the drawing in the design information, and if the difference is within the tolerance, it is judged that measurement is possible. If the difference is greater than the tolerance, it can be judged that measurement is difficult. In other words, by applying this embodiment at the design stage, it is possible to confirm in advance whether measurement is difficult in measuring the dimensions of the target component, and if necessary, this can be reflected in design changes or consideration of special measurement methods, and reworking can be avoided, leading to improved measurement economy.

[0026] Here, we will explain the appropriate number of measurement points. As shown in Figure 8, in addition to measuring at eight points, we also show the results of measurements at six, four, and two points (all evenly spaced around 360 degrees). The design diameter is 45.5 mm, the tolerance is 0.2 mm, and the random numbers above were generated in increments of 0.01 mm between -0.2 mm and +0.2 mm. These results show that when measurements are taken with a small error relative to the tolerance, four measurement points is sufficient. In other words, it is possible to confirm the minimum number of measurement points where the measurement error is less than the tolerance.

[0027] The number of measurement points affects the measurement time and therefore the measurement cost. This information is useful when considering ways to reduce the measurement cost during actual measurement, leading to improved measurement economy.

[0028] In this way, the measurement determination unit 8 can determine whether measurement is possible for a target component using a specific measuring device, the number of measurement points taking into consideration measurement costs, etc. The obtained information can be sent from the measurement determination unit 8 to the output unit 9.

[0029] Next, the output unit 9 can output and present to the designer 1 information such as whether measurement is possible or not from the measurement decision unit 8 and the number of measurement points taking into consideration the measurement cost.

[0030] As described above, according to this embodiment, it is possible to grasp, at the design stage, whether or not the shape and dimensions of a target component can be measured using a specified measuring instrument, and the number of measurement points taking into consideration the measurement cost. Furthermore, the designer 1 can obtain information that allows him or her to consider not only whether or not measurement is possible, but also the measurement cost, and can make design changes or consider measurement means as necessary. In other words, it is possible to improve economic efficiency.

[0031] Next, the performance information of the measuring instruments will be explained. Here, the performance information includes information on measurement uncertainty and measuring instrument error. It is desirable that the performance information of a given measuring instrument is stored in the measuring instrument database 5. This information can be sent to the simulated measurement data generator 6.

[0032] As an example of measuring equipment, a contact-type coordinate measuring machine will be described. Figure 2 shows an example of the configuration of a contact-type coordinate measuring machine. This contact-type coordinate measuring machine is equipped with a surface plate 100, and measures the dimensions of a measurement target placed on the surface plate 100. It is equipped with an X-axis linear motion mechanism 101 that moves linearly in the X direction, a Y-axis linear motion mechanism 102 that moves linearly in the Y direction, and a Z-axis linear motion mechanism 103 that moves linearly in the Z direction.

[0033] An enlarged view of the tip 104 is shown in Figure 3. The tip is equipped with a rotation mechanism 105 that rotates around the Z axis, and a swing mechanism 108 that rotates around the Y axis in the state of Figure 3, changing the orientation of the contact probe 106 mounted on the tip in direction 107. This allows the contact probe 106 to approach the measurement object, and the coordinates of the measurement object are obtained by bringing the tip of the contact probe 106 into contact with the measurement object, and the dimensions are calculated from the results.

[0034] When measuring the dimensions of target components with complex structures, simulated measurements can be performed by grasping measurement uncertainty information or measurement error information in advance as performance information for such contact-type coordinate measuring machines, and storing and utilizing this information in the measuring equipment database 5. Note that information on multiple measuring instruments may be stored and stored in the measuring equipment database 5, and sorted according to the target component. In other words, the outline specifications for dimensional inspection can be considered at the design stage.

[0035] As described above, according to this embodiment, by determining whether a given measuring device can be measured at the design stage of upstream manufacturing processes, if there are any parts that are difficult to measure, it becomes possible to reconsider and take measures at the design stage. This also makes it possible to avoid rework and additional consideration at the manufacturing and quality assurance stages of downstream processes, thereby preventing process delays and measurement cost overruns. In other words, this leads to improved economy throughout the entire process. Furthermore, if measurement is possible, the appropriate number of measurement points can be calculated, which improves efficiency at the quality assurance stage of downstream processes and improves economy. [Explanation of symbols]

[0036] 1…Designer 2…Design information 3…Information extraction part 4...Measurement coordinate calculation section 5. Measuring equipment database 6...Simulated measurement data generation unit 7...Measurement error calculation section 8...Measurement and Judgment Section 9...Output section 10...Contour of the bottom of the cylinder 11...Cylindrical bottom 12...Side 13 yen 14...Inner surface of hollow cylinder 100...Surface plate 101...X-axis linear motion mechanism 102...Y-axis linear motion mechanism 103...Z-axis linear motion mechanism 104...Tip of contact type three-dimensional measuring instrument 105...Z-axis rotation mechanism 106...3D measuring instrument probe (stylus) 107... Swing direction of the probe of the three-dimensional measuring instrument 108...Swing mechanism

Claims

1. an information extraction unit that extracts shape information of a target component from design information of the target component, the shape information being the target of dimension measurement; a measurement coordinate calculation unit that calculates measurement coordinates from the shape information extracted by the information extraction unit; a simulated measurement data generation unit that generates simulated measurement data based on the measurement coordinates calculated by the measurement coordinate calculation unit and performance information of the dimension measurement device; a measurement error calculation unit that processes the simulated measurement data generated by the simulated measurement data generation unit to calculate a measurement error, and a measurement determination unit that compares the measurement error calculated by the measurement error calculation unit with a tolerance of the measurement coordinate calculated by the measurement coordinate calculation unit.

2. 2. The dimension measurement management system according to claim 1, A dimension measurement management system comprising a measuring instrument database that stores performance information of the dimension measurement instruments and that can transmit the performance information of the dimension measurement instruments to the simulated measurement data generating unit.

3. 2. The dimension measurement management system according to claim 1, Dimension measurement management system, characterized in that the performance information of the dimension measurement device includes measurement uncertainty information or measurement error information.

4. 2. The dimension measurement management system according to claim 1, The dimension measurement management system is characterized in that the shape information is the contour or surface to be measured of the target component.

5. 2. The dimension measurement management system according to claim 1, The dimension measurement management system is characterized in that the measurement determination unit compares the measurement error with the tolerance of the measurement coordinates and determines whether measurement is possible or the number of measurement points.

6. 2. The dimension measurement management system according to claim 1, Dimension measurement management system, characterized in that the simulated measurement data generating unit generates simulated measurement data a plurality of times.

7. 2. The dimension measurement management system according to claim 1, The measurement error calculation unit calculates the measurement uncertainty of the measuring instrument or the measurement error within a predetermined range. A dimension measurement management system characterized by adding random numbers within the range to generate simulated measurement data.

8. Extract shape information to be measured from the design information of the target component, Calculating measurement coordinates from the extracted shape information; creating simulated measurement data based on the calculated measurement coordinates and performance information of the dimension measuring device; A dimension measurement management method comprising the steps of: processing the generated simulated measurement data to calculate a measurement error; and comparing the measurement error with a tolerance of the measurement coordinates.

9. 9. The dimension measurement management method according to claim 8, A dimension measurement management method characterized by comparing the measurement error with the tolerance of the measurement coordinates to determine whether measurement is possible or the number of measurement points.

10. 9. The dimension measurement management method according to claim 8, A dimension measurement management method characterized in that the simulated measurement data is generated multiple times.

11. 9. The dimension measurement management method according to claim 8, A dimension measurement management method characterized in that, when processing the simulated measurement data, the measurement uncertainty of the measuring instrument or the measurement error is set to a predetermined range, a random number is added within that range, the measurement error is calculated, and the simulated measurement data is generated.

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