Image measuring apparatus and program

Abstract

To provide an image measuring apparatus that can reduce the work conventionally required in image measurement.SOLUTION: An image measuring apparatus comprises: a CAD data storage section that stores CAD data of an article and CAD data information including design dimensions extracted from the CAD data, measurement points corresponding to the design dimensions, and edge detection tool conditions used to detect edges of the measurement points in advance for each different CAD data; a CAD data retrieval section that retrieves, from the CAD data storage section, the CAD data in which the shape of the article is similar to that of a measurement object represented in a captured image; a CAD data setting section that causes the CAD data identified on the basis of the retrieval to fit best to the image of the measurement object as the CAD data of the measurement object and sets the coordinate system of the CAD data which has been fitted best as a measurement coordinate system; and a measurement performing section that performs edge detection and dimensional measurement for each measurement point using the CAD data information corresponding to the CAD data of the measurement object for the image of the measurement object.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image measuring instrument and a program. [Background technology]

[0002] An image measuring instrument is a device that takes an image of a measurement object and measures the dimensions of a measurement point on the measurement object by analyzing the image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-169584 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventionally, when performing image measurement, it was necessary to prepare in advance a part program for each object to be measured, in which the measurement content and procedures were recorded, set a measurement coordinate system according to the position and orientation of the object to be measured placed on the mounting table, and manually set an edge detection tool that specifies the range of the edge detection processing for each measurement location.

[0005] An object of the present invention is to provide an image measuring device and a program that can reduce the work that has conventionally been required during image measurement. [Means for solving the problem]

[0006] The image measuring instrument of the present invention is an image measuring instrument that captures an image of a measurement object and measures the dimensions of a measurement location of the measurement object by analyzing the image, and is equipped with a CAD data storage unit that pre-stores, for each different CAD data, CAD data of the object, design dimensions extracted from the CAD data, measurement locations corresponding to the design dimensions, and CAD data information including conditions of an edge detection tool used to detect the edges of the measurement locations; a CAD data search unit that searches the CAD data storage unit for CAD data having a shape similar to the measurement object represented in the captured image; a CAD data setting unit that best-fits the CAD data identified based on the search to the image of the measurement object as CAD data of the measurement object and sets the coordinate system of the best-fit CAD data as the measurement coordinate system; and a measurement execution unit that detects edges and measures dimensions for each measurement location of the image of the measurement object using CAD data information corresponding to the CAD data of the measurement object.

[0007] The device may further include a display unit, wherein the CAD data setting unit causes the display unit to superimpose the best-fit CAD data of the measurement object onto an image of the measurement object, and the measurement execution unit causes the measurement results to be displayed at the display position of the design dimensions for each measurement point in the CAD data of the measurement object.

[0008] The CAD data information may include information on the tolerance of the design dimensions, and the measurement execution unit may cause the display unit to display, in a visibly identifiable manner, that the measurement results for each measurement location are outside the range of the tolerance of the design dimensions.

[0009] The functions of the image measuring machine of the present invention may be realized by writing the functions of the image measuring machine of the present invention in a program and having a computer execute the program. Effect of the Invention

[0010] According to the image measuring machine and program of the present invention, it is possible to eliminate tasks that have conventionally been required in image measurement, such as creating a part program, setting a measurement coordinate system, and setting an edge detection tool, thereby reducing the workload of image measurement. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing an example of the appearance of an image measuring machine 1 that executes an image measuring method of the present invention. [Diagram 2] 1 is a schematic diagram showing the internal structure of an image measuring instrument 1. FIG. [Diagram 3] FIG. 2 is a functional block diagram of the image measuring instrument 1. [Figure 4] FIG. 1 is a diagram showing an example of CAD data of an article. [Diagram 5] FIG. 4 is a diagram showing an example of a captured image of a measurement object. [Figure 6] FIG. 13 is a diagram showing an example of best fitting CAD data to a captured image. [Figure 7] FIG. 13 is a diagram showing an example of a display form of the measurement results. [Figure 8] FIG. 13 is a diagram showing an image of manipulating the display of measurement results. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description and drawings, the same functional units are denoted by the same reference numerals, and the description of functional units that have already been described will be omitted or will be described only to the extent necessary.

[0013] Fig. 1 is a schematic diagram showing an example of the appearance of an image measuring instrument 1 of the present invention. Fig. 2 is a schematic diagram showing an example of the internal structure of the image measuring instrument 1. Fig. 3 is a functional block diagram of the image measuring instrument 1. Note that in this embodiment, a case where a coaxial epi-illumination method is adopted as the illumination method will be described as an example, but the illumination method is not important as long as it is possible to capture an image of a measurement target.

[0014] The image measuring instrument 1 includes a mounting table 2, an imaging unit 3, a control and calculation unit 4, a storage unit 5, a display unit 6, a telecentric optical system 7, an illumination unit 8, and an operation unit 10.

[0015] The mounting table 2 is a table on which a measurement object (not shown) is placed.

[0016] The imaging unit 3 is provided opposite the mounting table 2 and captures an image by receiving light from the direction of the mounting table 2. The imaging unit 3 includes an image sensor and converts the brightness of the image formed on the light receiving surface into an electrical signal to generate image data. The image sensor may be a semiconductor solid-state imaging element such as a Charge-Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS).

[0017] The display unit 6 is any display means, and displays images captured by the imaging unit 3 and the like.

[0018] The telecentric optical system 7 includes an objective lens 71 that collects light from the direction of the mounting table 2, and an imaging lens 72 that forms an image of the light that has reached the objective lens 71 on the light receiving surface of the imaging unit 3. The objective lens 71 and the imaging lens 72 may each be provided on multiple surfaces.

[0019] The illumination unit 8 is a coaxial epi-illumination means including a light source 81 that emits illumination light, and a beam splitter 82 that causes the illumination light from the light source 81 to be split into the telecentric optical system 7 and irradiated toward the mounting table 2 as coaxial epi-illumination light whose optical axis coincides with the optical axis of the imaging unit 3. The illumination unit 8 may include transmitted illumination and side illumination in addition to the coaxial epi-illumination for the purpose of clarifying an image, etc.

[0020] The operation unit 10 is an input means for inputting information necessary for measurement. In Fig. 1 and Fig. 2, an example is shown in which a touch panel display is adopted and configured integrally with the display unit 6, but this is not limited thereto, and the operation unit 10 may be configured as an independent input means.

[0021] The storage unit 5 is any storage means capable of storing digital data. In the present invention, the storage unit 5 includes a CAD data storage unit 51.

[0022] The CAD data storage unit 51 stores in advance, for each different CAD data, CAD data of an article, design dimensions extracted from the CAD data, measurement points corresponding to the design dimensions, and CAD data information including conditions of an edge detection tool used to detect edges of the measurement points. If necessary, the tolerances may be stored together with the design dimensions.

[0023] FIG. 4 shows an example of CAD data of an article. The CAD data includes information such as the outline, hidden line, and center line that indicate the shape of the article, as well as information such as the design dimensions, dimensional tolerances, dimension lines, extension lines, and leader lines. Therefore, for example, starting from the description of the design dimensions, the location and shape of the outline line corresponding to the design dimensions can be specified by tracing the dimension lines corresponding to the design dimensions and the extension lines corresponding to the dimension lines, and further, the conditions of the edge detection tool to be applied to the location can also be specified. Note that when designing with CAD, it is generally necessary to specify which geometric element is used to illustrate the dimensions (length, diameter, radius, etc.), so that link information between the dimension values ​​and the geometric elements can be included in the CAD data. Therefore, this link information may be used to improve the efficiency of the process of specifying the location and shape of the outline line.

[0024] CAD data information can be generated by such processing, but the efficiency of the generation process may also be improved by providing application software that automatically performs the generation process in response to input CAD data and outputs CAD data information.

[0025] The control and calculation unit 4 controls each unit within the image measuring instrument 1 and performs necessary calculation processing in order to realize image capture and image measurement by the image measuring instrument 1.

[0026] In the present invention, the control operation unit 4 includes a CAD data search unit 41 , a CAD data setting unit 42 and a measurement execution unit 43 .

[0027] The CAD data search unit 41 searches the CAD data storage unit 51 for CAD data similar in shape to the measurement object depicted in the image captured by the imaging unit 3. Any method may be used to determine the degree of similarity. The similar CAD data may be identified as the one with the highest degree of similarity, or a top several data may be provisionally identified. When a top several data are provisionally identified, for example, the top several data may be displayed on the display unit 6, and input of information identifying one of the data may be received, allowing the user to identify one of the data.

[0028] The CAD data setting unit 42 best fits the CAD data identified based on the search in the CAD data search unit 41 to the image of the object to be measured as the CAD data of the object to be measured, and sets the coordinate system of the best-fitted CAD data as the measurement coordinate system. Any method such as pattern matching or parametric matching may be used as a method of best fitting the CAD data to the image of the object to be measured.

[0029] For example, when the CAD data shown in Fig. 4 is identified by a search as CAD data similar in shape to the measurement object shown in the captured image shown in Fig. 5, the CAD data shown in Fig. 4 is best-fitted to the captured image shown in Fig. 5, as shown in Fig. 6. By performing the best-fitting, the position range of the measurement object in the coordinate system of the CAD data can be made to correspond to the position range of the measurement object in the measurement coordinate system grasped from the captured image, so that the coordinate system of the CAD data can be set as the measurement coordinate system.

[0030] The measurement execution unit 43 executes edge detection and dimension measurement for each measurement point on the image of the measurement object, using CAD data information corresponding to the CAD data of the measurement object stored in the CAD data storage unit 51.

[0031] Note that, for each CAD data, the illumination conditions of the illumination unit 8 may be automatically or manually set so that the contrast of the measurement point is maximized prior to the first measurement. Furthermore, the illumination conditions set for each measurement point may be stored in the CAD data storage unit 51 by adding them to the CAD data information, and the illumination conditions may be automatically set when the second or subsequent measurement is performed.

[0032] The CAD data setting unit 42 may superimpose the best-fitted CAD data of the measurement object on the image of the measurement object and display it on the display unit 6, and the measurement execution unit 43 may display the measurement results at the display position of the design dimensions for each measurement point in the CAD data of the measurement object. An example of the display form of the measurement results is shown in Fig. 7. Fig. 7 shows an example in which the measurement results are displayed superimposed on the display of the design dimensions in the CAD data, but the measurement results may be displayed slightly shifted without superimposition, or the display of the design dimensions may be replaced with the measurement results.

[0033] Information on the tolerance of the design dimension of the measurement point may be added to the CAD data information stored in the CAD data storage unit 51, and when the measurement result for each measurement point is outside the tolerance of the design dimension, the measurement execution unit 43 may display on the display unit 6 in an identifiable manner that the result is out of range. Any method for making the result identifiable may be used, and for example, the color or font of the display of the measurement result may be changed, or a message indicating that the result is out of range may be displayed in any position.

[0034] In the present invention, the control calculation unit 4 may be configured with a CPU, and each function may be realized by having the CPU execute a program describing the functions of the CAD data search unit 41, the CAD data setting unit 42, and the measurement execution unit 43, as well as functions for controlling the imaging unit 3, the illumination unit 8, etc. The program may be read out from the memory unit 5, or may be read out from another storage means. The control calculation unit 4 and the memory unit 5 may be provided in the main body of the image measuring instrument 1, or may be provided in a device such as a personal computer connected to the main body of the image measuring instrument 1 so as to be able to communicate with it.

[0035] According to the image measuring machine and program of the present invention described above, it is possible to eliminate tasks that have conventionally been required in image measurement, such as creating a part program, setting a measurement coordinate system, setting an edge detection tool, and adjusting the display position of the measurement results, thereby reducing the workload of image measurement.

[0036] In addition, since the CAD data is fitted to the image of the object to be measured, the display of the measurement results can be enlarged, reduced, rotated and scrolled on the screen, as shown in Fig. 8. When fitting the CAD data by the CAD data setting unit 42, information on the position and orientation of the object to be measured can be obtained, and this information can be used to automatically enlarge, reduce, rotate and move the measurement results so that they can be displayed in an easy-to-read manner for the user.

[0037] The present invention is not limited to the above-mentioned embodiment and modified examples. The above-mentioned embodiment and modified examples are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. In other words, appropriate modifications are possible within the scope of the technical idea expressed in the present invention, and forms with such modifications and improvements are also included in the technical scope of the present invention. [Explanation of symbols]

[0038] 1...Image measuring device 2…Placement table 3. Imaging unit 4...Control and calculation section 5...Storage section 6...Display section 7...Telecentric optical system 8…Lighting section 10...Operation unit 41…CAD data search section 42…CAD data setting section 43…Measurement execution unit 51…CAD data storage section

Claims

1. An image measuring device that captures an image of a measurement object and measures dimensions of a measurement point of the measurement object by analyzing the image, a CAD data storage unit that prestores, for each different CAD data, CAD data of an article, CAD data information including design dimensions extracted from the CAD data, measurement points corresponding to the design dimensions, and conditions of an edge detection tool used to detect edges of the measurement points; a CAD data search unit that searches the CAD data storage unit for CAD data having a shape similar to that of the measurement object represented in the captured image; a CAD data setting unit that best fits the CAD data identified based on the search to an image of the object to be measured as CAD data of the object to be measured, and sets a coordinate system of the best-fitted CAD data as a measurement coordinate system; a measurement execution unit that executes edge detection and dimension measurement for each measurement point on the image of the measurement object by using the CAD data information corresponding to the CAD data of the measurement object; An image measuring machine comprising:

2. Further comprising a display unit, the CAD data setting unit causes the display unit to display the best-fit CAD data of the measurement object superimposed on the image of the measurement object; The measurement execution unit displays the measurement results at display positions of design dimensions for each measurement point in the CAD data of the measurement object.

2. The image measuring device according to claim 1,

3. The CAD data information includes information on tolerances of design dimensions, When the measurement result for each measurement point is outside the tolerance range of the design dimension, the measurement execution unit causes the display unit to identifiably display that the measurement result is outside the tolerance range.

3. The image measuring device according to claim 2,

4. A program for causing a computer to function as the image measuring instrument according to any one of claims 1 to 3.

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