JP2014215153A - Image measuring apparatus and program for controlling the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform measurement in a wide measuring range.SOLUTION: An image measuring apparatus includes: a stage on which a measuring object is placed; an imaging device which is provided so as to be relatively movable with respect to the stage and outputs image information by imaging the measuring object on a prescribed imaging range narrower than the measuring range; a position control device which makes the imaging device move to a plurality of measuring positions within the measuring range and scan in a direction vertical to the stage at each measuring position; and an arithmetic processing device which performs measuring processing for calculating displacement in a scanning direction at each measuring position on the basis of the image information of the prescribed imaging range at each measuring position obtained by scanning of the imaging device. The arithmetic processing device divides the measuring range into a plurality of actual measuring visual field ranges and performs the measuring processing only on the actual measuring visual field range selected as a measuring object range among the plurality of actual measuring visual field ranges.

Description

  The present invention relates to an image measurement apparatus that measures a measurement object three-dimensionally by imaging the measurement object and a control program therefor.

  Examples of an image measuring device that three-dimensionally measures a measurement target based on image information acquired by an imaging device include a device that uses white light having a wide spectrum width and a device that uses contrast information. Such an image measuring apparatus measures the three-dimensional shape of the object to be measured from image information obtained at each vertical position by scanning the imaging apparatus in a direction perpendicular to the stage. In such an image measuring apparatus, for example, when the size of the object to be measured does not fit in one field of view of the imaging apparatus, the imaging apparatus is moved with respect to the stage, and the measurement results at each measurement position are acquired and then combined. The so-called stitching method is sometimes used (Patent Document 1).

JP 2012-112705 A

  However, in such an image measurement device, a rectangular measurement range is specified so that the entire measurement target is included, and the entire rectangular measurement range is divided based on the visual field range of the imaging device, Measurements were made for all of the divided ranges. For this reason, depending on the shape of the object to be measured, although the object to be measured may not be included in this divided range, the measurement was performed for the entire divided range, so that it is difficult to perform efficient measurement. There was a problem of being.

  The present invention has been made in view of these points, and an object thereof is to provide an image measurement apparatus capable of efficiently measuring a wide measurement range.

  An image measurement apparatus according to the present invention is provided with a stage on which a measurement object is placed, and a relative movement with respect to the stage. The measurement object is imaged in a predetermined imaging range narrower than the measurement range, and image information is obtained. An imaging device to output, a position control device that moves the imaging device to a plurality of measurement positions within the measurement range, and scans each measurement position in a direction perpendicular to the stage, and each measurement obtained by scanning the imaging device And an arithmetic processing unit that calculates a displacement in the scanning direction at each measurement position based on image information of a predetermined imaging range of the position. Further, the arithmetic processing device divides the measurement range into a plurality of main measurement visual field ranges, and performs the measurement process only on the main measurement visual field range selected as the measurement target range among the plurality of main measurement visual field ranges.

  That is, the image measuring apparatus according to the present invention divides the measurement range into a plurality of main measurement visual field ranges and performs measurement processing only on the main measurement visual field range selected as the measurement target range among the plurality of main measurement visual field ranges. For example, it is possible to efficiently measure a wide measurement range by selecting only the main measurement visual field range including the measurement target as the measurement target range.

  In addition, the arithmetic processing device generates a rectangular map in which a plurality of main measurement visual field ranges are arranged in the measurement range based on the imaging range of the imaging device, and one or more main measurement visual fields from the plurality of main measurement visual field ranges. It is good also as a measuring object range by selecting a range.

  In addition, the image measurement apparatus according to an embodiment of the present invention is configured to be able to image a preliminary measurement range wider than a predetermined imaging range prior to the main measurement for measuring the displacement in the scanning direction at each measurement position. In such an embodiment, the arithmetic processing unit generates the rectangular map from image information obtained by scanning the preliminary measurement range by the imaging device during preliminary measurement. In such an embodiment, for example, by displaying this rectangular map on a display or the like, it becomes possible to intuitively visually recognize the relative position and size between the measurement target and the main measurement visual field range. It is possible to easily select a range to be measured.

  Further, in the image measurement device according to another embodiment of the present invention, the arithmetic processing device inputs predetermined comparison target data, and a rectangular map in which the main measurement visual field range is arranged on an image corresponding to the comparison target data. May be generated. That is, the rectangular map can be generated from design data such as CAD data, and in such a case, it is possible to easily select an appropriate measurement target range. Further, in the present embodiment, it is possible to perform imaging under the same conditions for a plurality of objects to be measured generated based on this design data, and workability can be improved.

  A control program for an image measuring apparatus according to the present invention is provided with a stage on which a measurement object is placed and a relative movement with respect to the stage, and images the measurement object in a predetermined imaging range narrower than the measurement range. Obtained by scanning the imaging device that outputs image information, a position control device that moves the imaging device to a plurality of measurement positions within the measurement range, and scans in the direction perpendicular to the stage at each measurement position. And an arithmetic processing unit that calculates a displacement in the scanning direction at each measurement position based on image information of a predetermined imaging range at each measurement position. Further, the control program for the image measurement apparatus according to the present invention divides the measurement range into a plurality of main measurement field ranges, and measures only the main measurement field range selected as the measurement target range among the plurality of main measurement field ranges. Process.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the image measurement apparatus which can measure a wide measurement range efficiently, and its control program.

1 is an overall view of an image measuring device according to a first embodiment of the present invention. It is a block diagram which shows the structure of the same apparatus. It is a flowchart explaining operation | movement of the apparatus. It is the schematic for demonstrating operation | movement of the apparatus. It is the schematic for demonstrating operation | movement of the apparatus. It is the schematic for demonstrating operation | movement of the apparatus. It is a flowchart explaining operation | movement of the image measuring apparatus which concerns on 2nd Embodiment of this invention.

[First Embodiment]
Next, the configuration of the image measurement apparatus according to the first embodiment of the present invention will be described with reference to the drawings.

[Constitution]
FIG. 1 is an overall view of an image measuring apparatus according to the present embodiment. The image measuring device 10 is an image measuring device 10 in which cameras 17a and 17b are mounted as image pickup devices for picking up the workpiece 12, and the image measuring device 10 is electrically connected to the image measuring device 10 and stored in a program stored therein. And a computer (hereinafter referred to as “PC”) 20 for controlling the driving of the computer.

  The image measuring machine 10 is configured as follows. That is, a stage 13 for mounting a workpiece 12 (measurement object) is mounted on the gantry 11, and this stage 13 is parallel to the upper surface of the stage 13 by a Y-axis drive mechanism 18. Driven by. Support arms 14 and 15 extending upward are fixed to the center of both side edges of the gantry 11, and an X-axis guide 16 is fixed so as to connect both upper ends of the support arms 14 and 15. An imaging unit 17 that images the workpiece 12 is supported by the X-axis guide 16. The imaging unit 17 is configured to be driven along the X-axis guide 16 in the X-axis direction orthogonal to the Y-axis direction on the top surface of the stage 13 by the X-axis drive mechanism 16a. In addition, the imaging unit 17 can capture an image of the first imaging device 17a having a predetermined imaging range used during the main measurement as a measurement visual field and the entire measurement range that is used during the preliminary measurement and wider than the visual measurement range of the main measurement. A second imaging device 17b. These imaging devices 17a and 17b are configured to be switchable between preliminary measurement and actual measurement. These imaging devices 17a and 17b may be configured as one camera depending on the magnification efficiency of the objective lens. The imaging unit 17 is configured to be movable in the Z-axis direction orthogonal to the upper surface of the stage 13 by the Z-axis drive mechanism 17c. As described above, the X-axis drive mechanism 16a, the Y-axis drive mechanism 18, and the Z-axis drive mechanism 17c are positions that drive the imaging unit 17 relative to the stage 13 in the X, Y, and Z axis directions orthogonal to each other. The control device is configured.

  The image measuring machine 10 according to the present embodiment performs imaging while scanning in the Z-axis direction while moving the first imaging device 17a and the second imaging device 17b in the XY direction with respect to the upper surface of the stage 13, The displacement in the Z-axis direction (Z) at each measurement position of the workpiece 12 from the measurement position information in the XY direction of the first imaging device 17a or the second imaging device 17b and the contrast information of each minute range of the image obtained at that position. Value). The displacement in the Z-axis direction can be detected by a white interferometer in addition to detecting from such contrast information. The white interferometer, for example, guides white light having a wideband spectrum to the work 12 and the reference surface, interferes with each reflected light, acquires a position where the peak value of the interference signal for each pixel is observed, and obtains a peak for each pixel. The displacement of the workpiece 12 in the Z-axis direction is detected according to the position and the position of the reference plate constituting the reference surface.

  The computer 20 includes a computer main body 21, a keyboard 22, a joystick box (J / S) 23, a mouse 24, a display 25, and a printer 26. The computer main body 21 is configured, for example, as shown in FIG. That is, the image information of the workpiece 12 input from the imaging unit 17 is stored in the image memory 32 via the interface (I / F) 31.

  The CAD data of the work 12 is input to the CPU 35 via the I / F 33, subjected to predetermined processing by the CPU 35, and stored in the image memory 32. The image information stored in the image memory 32 is displayed on the display 25 via the display control unit 36.

  On the other hand, code information and position information input from the keyboard 22, J / S 23, and mouse 24 are input to the CPU 35 via the I / F 34. The CPU 35 executes various processes according to the macro program stored in the ROM 37 and the program stored in the RAM 40 from the HDD 38 via the I / F 39.

  The CPU 35 controls the image measuring device 10 via the I / F 41 according to the program. The HDD 38 is a recording medium for storing various data. The RAM 40 provides a work area for various processes.

[Operation]
Next, a measurement method of the image measurement apparatus according to this embodiment will be described. FIG. 3 is a flowchart for explaining the manufacturing method of the image measuring apparatus according to this embodiment.

  In step S11, imaging by the second imaging device 17b is performed, and preliminary image information 50 as shown in FIG. However, it is also possible to further select a measurement range from the image information acquired by the second imaging device 17 b and use it as the preliminary image information 50. In this case, the preliminary image information 50 can be designated by setting, for example, predetermined coordinates corresponding to the image information as the measurement start position 51 and the measurement end position 52.

  In step S12, a rectangular map 53 is generated from the preliminary imaging information 50 and displayed on the display 25 as shown in FIG. The rectangular map 53 is coordinate data obtained by arranging the main measurement visual field range 54 corresponding to the visual field range of the first imaging device 17 a on the preliminary image information 50. Further, it can be said that the rectangular map 53 is formed by dividing the preliminary image information 50 into a plurality of main measurement visual field ranges 54. Here, the measurement visual field ranges 54 can be arranged so as to overlap each other by a predetermined amount. As a result, the stitching process can be performed with high accuracy.

  In step S13, as shown in FIG. 6, one or more main measurement visual field ranges 54 are selected from the rectangular map 53 based on the input from the mouse 24 or the keyboard 22, and the measurement target range 541 and the non-measurement target range 542 are selected. And classify. In this selection process, for example, the user visually recognizes the rectangular map 53 displayed on the display 25, moves the cursor to the main measurement visual field range 54 to be selected as the measurement target range 541 or the non-measurement target range 542, and selects with the mouse 24. You can also select from the keyboard. Further, it may be possible to classify the measurement visual field range 54 that clearly does not include the workpiece 3 into the non-measurement target range 532 in advance by edge detection processing or the like.

  In step S14, measurement by the first imaging device 17a is executed according to a predetermined condition. That is, the visual field range of the first imaging device 17 a is sequentially moved to the coordinate position corresponding to the measurement target range 541 by the X-axis drive mechanism 16 a and the Y-axis drive mechanism 18. Further, the Z-axis drive mechanism 17c and the first imaging device 17a are controlled to perform imaging at each coordinate position.

[Second Embodiment]
Next, an image measurement method according to the second embodiment of the present invention will be described. In the first embodiment, a rectangular map 53 is generated by imaging with the second imaging device 17 b and arranging the first visual field range 54 on the preliminary image information 50. In the present embodiment, as shown in FIG. 7, coordinate data such as CAD data is input to the PC 20 (step S21), preliminary image information 50 is generated from the CAD data, and a main measurement visual field range 54 is arranged to form a rectangular shape. A map 53 is generated (step S22). The method for selecting the measurement target range 541 can be performed by the same method as in the first embodiment (step S13). Further, in the measurement using the first imaging device 17a in the present embodiment (step S24), the X-axis drive mechanism 16a is referred to while referring to the position of the marker provided on the workpiece 12 by the first imaging device 17a or the like. And after controlling the Y-axis drive mechanism 18 and performing alignment etc., the imaging of the coordinate corresponding to each measurement object visual field range 541 is started.

  DESCRIPTION OF SYMBOLS 10 ... Image measuring machine, 11 ... Mount, 12 ... Workpiece (measurement object), 13 ... Stage, 14, 15 ... Support arm, 16 ... X-axis guide, 16a ... X-axis drive mechanism, 17 ... Imaging unit, 17a ... First imaging device, 17b ... second imaging device, 17c ... Z-axis drive mechanism, 18 ... Y-axis drive mechanism, 20 ... computer (PC), 53 ... rectangular map.

Claims (8)

A stage on which a measurement object is placed;
An imaging device provided so as to be relatively movable with respect to the stage, and imaging the measurement object in a predetermined imaging range narrower than the measurement range and outputting image information;
A position control device that moves the imaging device to a plurality of measurement positions within the measurement range and scans the measurement devices in a direction perpendicular to the stage at each measurement position;
An arithmetic processing unit that performs measurement processing for calculating displacement in the scanning direction at each measurement position based on image information of the predetermined imaging range at each measurement position obtained by scanning of the imaging device;
The arithmetic processing unit divides the measurement range into a plurality of main measurement visual field ranges, and performs measurement processing only for the main measurement visual field range selected as a measurement target range among the plurality of main measurement visual field ranges. Image measuring device. The arithmetic processing unit includes:
Based on the imaging range of the imaging device, generate a rectangular map in which the plurality of main measurement visual field ranges are arranged in the measurement range,
The image measurement apparatus according to claim 1, wherein one or two or more main measurement visual field ranges are selected from the plurality of main measurement visual field ranges to be the measurement target range. The imaging device is configured to be able to image a preliminary measurement range wider than the predetermined imaging range prior to the main measurement for measuring the displacement in the scanning direction at each measurement position,
The image processing device according to claim 2, wherein the arithmetic processing unit generates the rectangular map from image information obtained by the imaging device scanning the preliminary measurement range during the preliminary measurement. The arithmetic processing unit includes:
Enter the specified comparison target data,
The image measurement apparatus according to claim 2, wherein a rectangular map in which the main measurement visual field ranges are arranged on an image corresponding to the comparison target data is generated. A stage on which a measurement object is placed;
An imaging device provided so as to be relatively movable with respect to the stage, and imaging the measurement object in a predetermined imaging range narrower than the measurement range and outputting image information;
A position control device that moves the imaging device to a plurality of measurement positions within the measurement range and scans the measurement devices in a direction perpendicular to the stage at each measurement position;
An image measurement apparatus comprising: an arithmetic processing unit that performs measurement processing for calculating a displacement in the scanning direction at each measurement position based on image information of the predetermined imaging range at each measurement position obtained by scanning of the imaging device. A device control program,
The measurement range is divided into a plurality of main measurement visual field ranges, and only the main measurement visual field range selected as a measurement target range among the plurality of main measurement visual field ranges is subjected to measurement processing. Program. Based on the imaging range of the imaging device, generate a rectangular map in which the plurality of main measurement visual field ranges are arranged in the measurement range,
6. The program for controlling an image measurement apparatus according to claim 5, wherein one or more main measurement visual field ranges are selected from the plurality of main measurement visual field ranges and set as the measurement target range. The imaging device is configured to be capable of imaging a preliminary imaging range wider than the predetermined imaging range prior to the main measurement for measuring the displacement in the scanning direction at each measurement position,
The control of the image measurement device according to claim 6, wherein the image measurement device generates the rectangular map from image information obtained by scanning the image pickup device in the preliminary measurement range during the preliminary measurement. Program. Enter the specified comparison target data,
The control program for an image measurement apparatus according to claim 6, wherein a rectangular map in which the main measurement visual field ranges are arranged on an image corresponding to the comparison target data is generated.

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