JP6517705B2 - Micrometer Automatic Reader - Google Patents

Description

  The present invention relates to an automatic reading apparatus that automatically reads an indication value of a micrometer.

  In adjusting the angle of the mirror that constitutes the resonator of the laser device, an analog micrometer may be used. At this time, the operator visually reads the indicated value of the micrometer head. However, in the case of an unskilled worker, the reading operation may take time, or reading errors may occur.

  Various techniques have been proposed for reading the indicated value of the meter using image processing techniques without relying on visual inspection by the operator (Patent Documents 1 to 5).

Unexamined-Japanese-Patent No. 2003-242444 Unexamined-Japanese-Patent No. 2006-120133 JP, 2006-277608, A JP 2012-038195 A JP, 2014-032039, A

  There is a need for an automatic reading device that can automatically read the reading value of an analog micrometer.

According to a first aspect of the present invention, there is provided an automatic reading device for automatically reading an indication value of an analog micrometer, wherein the micrometer comprises a sleeve, a sleeve scale printed on the sleeve, and the sleeve And a thimble number printed on the thimble and a thimble scale printed on the thimble, and the automatic reading device acquires an image acquisition unit that acquires a scale image including at least the sleeve scale and the thimble scale. An image rotation unit that rotates the scale image so that the reference line of the sleeve is at a predetermined angle; a sleeve counting unit that counts the sleeve scale in the rotated scale image to obtain a sleeve count value; , Of the thimble numbers included in the rotated scale image, the most proximal to the reference line. The value of the thimble scale is determined on the basis of the positional relationship between the nearest distance number recognition unit, which recognizes the distance number by comparison with the matching image, the thimble scale and the reference line included in the rotated scale image. An automatic reading apparatus is provided, comprising: a thimble scale determination unit; and an indication value calculation unit that calculates an indication value of the micrometer based on the sleeve count value, the nearest distance numeral, and the value of the thimble scale. Ru.
According to a second aspect of the present invention, in the automatic reading device according to the first aspect, the nearest distance number recognition unit recognizes the nearest distance number by comparing a part of the thimble numbers with a reference image. Configured as.
According to a third aspect of the present invention, in the automatic reading device according to the first or second aspect, the thimble scale determination unit determines a thimble scale corresponding to the closest distance number and a thimble scale corresponding to the indicated value. Count the number of thimble ticks between them, and if the reference line is located on the side larger than the closest distance number, add the number of the thimble ticks counted to the closest distance number; It is arranged to subtract the number of thimble ticks counted from the closest distance number if the line is located on the smaller side of the closest distance number.
According to a fourth aspect of the present invention, in the automatic reading device according to any one of the first to third aspects, the indication value calculation unit predicts the range of the indication value of the micrometer according to the tolerance value. If the calculation result of the indication value calculation unit is larger than the upper limit value of the range of the indication value, a value corresponding to one thimble rotation is subtracted from the calculation result, and the calculation result of the indication value calculation unit is the indication When the value is smaller than the lower limit of the range of values, a value corresponding to one thimble rotation is added to the calculation result.
According to a fifth aspect of the present invention, the automatic reading device according to any one of the first to fourth aspects further comprises an output unit that outputs the micrometer indicated value calculated by the indicated value calculating unit.

  These as well as other objects, features and advantages of the present invention will become more apparent by referring to the detailed description of the exemplary embodiments of the present invention shown in the attached drawings.

  According to the automatic reading device according to the present invention, it is possible to automatically obtain the indicated value of the micrometer without relying on visual inspection by the operator. As a result, since the manual reading operation is not necessary, the efficiency of the setup operation or the maintenance operation at the time of manufacturing can be improved, and a reading error due to a human error can be prevented.

It is a figure showing the example of composition of the measuring system provided with the automatic reading device concerning one embodiment. It is a figure which expands and shows the micrometer head vicinity. It is a functional block diagram of an automatic reading device concerning one embodiment. It is a flowchart which shows the process performed in the automatic reader which concerns on one Embodiment. It is a figure which shows the example of the picked-up image of a micrometer. It is a figure which shows the image obtained by rotating the picked-up image of FIG. It is a figure which shows the result of having image-processed the image of FIG. It is a figure explaining the number identification function in the automatic reader concerning one embodiment. It is a figure explaining the thimble scale reading function in the automatic reader concerning one embodiment. It is a figure explaining the thimble scale reading function in the automatic reader concerning one embodiment. It is a figure explaining the thimble scale reading function in the automatic reader concerning one embodiment. It is a figure explaining the thimble scale reading function in the automatic reader concerning one embodiment. It is a figure explaining the indication value correction function in the automatic reading device concerning one embodiment. It is a figure explaining the indication value correction function in the automatic reading device concerning one embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The components of the illustrated embodiment have been scaled appropriately to aid in the understanding of the present invention. The same reference symbols are used for identical or corresponding components.

  FIG. 1 shows a configuration example of a measurement system provided with an automatic reading device according to an embodiment. The measurement system 100 includes a micrometer 20, a camera 50, an image processing device 60, and an automatic reading device 10.

  The measurement system 100 is not particularly limited, but can be used when adjusting the angle of the mirror that constitutes the resonator of the gas laser device during setup or maintenance work at the time of manufacturing the gas laser device.

  The measurement system 100 performs image processing of an image obtained by photographing the micrometer 20 with the camera 50 by the image processing device 60 and reads an instruction value of the micrometer 20 by the automatic reading device 10 using the result of the image processing. It is configured to measure an object.

  The micrometer 20 is an analog micrometer having a known configuration. FIG. 2 is an enlarged view of the vicinity of the micrometer head. The micrometer 20 comprises a fixed sleeve 30 and a thimble 40 rotatably mounted relative to the sleeve 30.

  A sleeve scale 32 is printed on the sleeve 30 together with the reference line 34. A thimble scale 42 is printed on the thimble 40. In the thimble 40, a thimble number N1 is printed adjacent to the thimble graduation 42 every five graduation lines.

  The configuration of the micrometer 20 is not particularly limited as long as the reading of the micrometer 20 can be obtained from the sleeve scale 32 and the thimble scale 42.

  The camera 50 is a digital camera provided with a known imaging device such as a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor).

  The image processing apparatus 60 is a digital computer configured to extract necessary information from a target image using a known image processing algorithm such as edge detection, binarization and the like. The image processing apparatus 60 is used for the purpose of processing a photographed image of the micrometer 20 as described later.

  The automatic reading device 10 is configured to automatically read the indicated value of the micrometer 20 in cooperation with the camera 50 and the image processing device 60. In one embodiment, the automatic reading apparatus 10 is connected to the image processing apparatus 60 via a network such as a LAN (local area network), a WAN (wide area network), the Internet, etc., which is separate from the image processing apparatus 60. It is a digital computer. Alternatively, the automatic reading device 10 and the image processing device 60 may be a single digital computer sharing the hardware configuration.

  In the present specification, a "digital computer" has a known hardware configuration such as a CPU, ROM, RAM, nonvolatile memory, various interfaces, etc., and executes predetermined operations according to an operation program stored in the nonvolatile memory. Machine that has the function to The digital computer may further include an input device connected via a known interface, such as a mouse and a keyboard, or a display device such as a liquid crystal display.

  FIG. 3 is a functional block diagram of the automatic reader 10. The automatic reading device 10 includes an image acquisition unit 11, an image rotation unit 12, an image processing unit 13, a sleeve counting unit 14, a recent distance number recognition unit 15, a thimble scale determination unit 16, an instruction value calculation unit 17, and an output unit 18. Have.

  The image acquisition unit 11 acquires an image of the micrometer 20 captured by the camera 50. The photographed image (hereinafter sometimes referred to as “scale image”) includes at least a sleeve scale 32 and a thimble scale 42. FIG. 5 shows an example of a scale image.

  The image rotation unit 12 rotates the scale image so that the reference line 34 of the sleeve 30 is at a predetermined angle. FIG. 6 shows an example of the scale image rotated by the image rotation unit 12. In this case, the scale image is rotated so that the reference line 34 of the sleeve 30 is directed horizontally.

  The image processing unit 13 processes the scale image by the image processing device 60. FIG. 7 shows the result of image processing of the rotated scale image of FIG. As shown, as a result of image processing, a sleeve scale 32, a thimble scale 42, a reference line 34 of the sleeve 30, a thimble number N1, etc. are extracted from the scale image.

  The sleeve counting unit 14 counts the sleeve graduations 32 using the image processing result of the graduation image to obtain a sleeve count value. In the example of FIG. 7, since four scale lines are detected from the sleeve scale 32 in addition to the scale line of “0”, the sleeve counting unit 14 outputs “4” as the sleeve count value.

  Among the thimble numbers N1 included in the scale image, the closest distance number recognition unit 15 recognizes the closest distance number N2 located at the closest distance from the reference line 34 of the sleeve 30 in comparison with the reference image. In the case of the example shown in FIG. 7, "45" is detected as the nearest distance number.

  In one embodiment, the closest distance number recognition unit 15 may be configured to recognize the closest distance number N2 by comparing a portion of the thimble number N1 with the match image. That is, if only a characteristic part of each numeral is compared with the collation image, the accuracy of numeral recognition can be improved, and the time required for numeral recognition can be shortened.

  For example, in the case of a common micrometer in which one rotation of the thimble corresponds to 0.5 mm, a number is printed on the thimble every time it increases by “5” from “0” to “45”. Therefore, in this case, the tens digit of the number printed on the thimble is either "1", "2", "3" or "4", while the one digit is "0" Or "5".

  The scale image may make it difficult to determine the detection target due to poor photographing conditions such as defocus or lack of light. For example, “2” and “3” are similar in shape to the upper half of the numbers, so the lower half image can not be identified for some reason, and the number that is actually “2” is mistaken as “3”. It may be detected or vice versa. Similarly, “1” and “4” and “0” and “5” are also prone to false detection.

  Therefore, according to the present embodiment, as shown in FIG. 8, only the lower half of the tens digit numbers “1”, “2”, “3” and “4” is recognized as the recognition area A1, A2, respectively. A3 and A4. In addition, for the numbers “0” and “5” in the first place, only the upper half of the numbers is set as the recognition areas B1 and B2, respectively. Then, the image included in the recognition area is compared with the corresponding matching image.

  By setting the recognition areas A1 to A4 or B1 and B2 in this manner, it is possible to prevent the number from being erroneously recognized due to a poor photographing condition.

  Referring again to FIG. 3, the thimble scale determination unit 16 determines the value of the thimble scale 42 based on the positional relationship between the thimble scale 42 and the reference line 34 included in the rotated scale image.

  The indicated value calculation unit 17 calculates the indicated value of the micrometer 20 based on the sleeve count value, the latest distance numeral N 2, and the value of the thimble scale 42.

  The output unit 18 outputs the indicated value of the micrometer 20 calculated by the indicated value calculation unit 17. If the indicated value of the micrometer 20 can be output to the outside, data collection and management become easy. Further, the output unit 18 may be configured to digitize and output the instruction value. In that case, the measurement system 100 including the analog micrometer 20 can be configured to be able to output digital data, which leads to cost reduction of the measurement system 100.

  In one embodiment, the thimble scale determination unit 16 counts the number of thimble scales 42 (the number of scale lines) between the thimble scale 42 corresponding to the most recent distance number N2 and the thimble scale 42 corresponding to the indicated value, If the reference line 34 of the sleeve 30 is positioned more recently than the distance number N2, then the number of thimble grid lines counted is added to the most recent distance number N2 and the reference line 34 is greater than the most recent distance number N2. If it is on the small side, it may be arranged to subtract the number of thimble scale lines counted from the recent distance number N2.

  When the operator visually reads the micrometer indicated value, the operator can recognize the thimble scale by looking at the thimble numbers. However, in a general micrometer, the relationship between the direction of rotation of the thimble and the increase or decrease of the indicated value is uniquely determined by the structure of the micrometer.

  Therefore, in the micrometer 20 according to the present embodiment, the number of thimble scale lines to be counted is calculated based on the positional relationship between the reference line 34 of the sleeve 30 and the nearest distance numeral.

  The thimble scale determination unit 16 according to the present embodiment will be described with reference to examples illustrated in FIGS. 9 to 12 respectively. In the case of the example of FIG. 9, the thimble number N1, which is the closest distance from the reference line 34 of the sleeve 30, that is, the recent distance number N2 is “40”. Therefore, "4.40" is determined as a reading based on the sleeve count "4" and the most recent distance number N2 (= 40).

  Further, the reference line 34 is located on the side where the thimble number N1 is larger than the recent distance number N2. In this case, the number of thimble scale lines between the thimble scale line 42a corresponding to the thimble number "40" which is the closest distance number N2 and the thimble scale line 42b corresponding to the indicated value is "1". Therefore, “4.41” (= 4.40 + 0.01) is determined as a reading based on the sleeve count value, the latest distance number N2, and the thimble graduation line 42b. Further, “4.417” is acquired as the indicated value of the micrometer 20 from the size of the interval between the graduation line 42 b and the adjacent graduation line 42 c.

  In the case of the example of FIG. 10, the nearest distance number N2 is "45". Therefore, "4.45" is determined as a reading based on the sleeve count "4" and the most recent distance numeral N2.

  The reference line 34 is located on the side where the thimble number N1 is smaller than the latest distance number N2. In this case, the number of thimble scale lines between the thimble scale line 42a corresponding to the thimble number "45" which is the closest distance number N2 and the thimble scale line 42b corresponding to the indicated value is "2". Therefore, it is recognized that the reading based on the sleeve count value, the latest distance number N2, and the thimble graduation line 42b is "4.43" (= 4.45-0.02). Furthermore, “4.438” is acquired as the indicated value of the micrometer 20 from the size of the interval between the graduation line 42 b and the adjacent graduation line 42 c.

  11 and 12 show an example where the micrometer 20 is a left-handed screw micrometer. It can be seen that the arrangement of the thimble numbers N1 is reversed, in contrast to FIGS.

  In the case of the example of FIG. 11, the nearest distance number N2 is "45". Therefore, "4.45" is determined as a reading based on the sleeve count "4" and the most recent distance numeral N2.

  The reference line 34 is located on the side where the thimble number N1 is smaller than the latest distance number N2. In this case, the number of thimble scale lines between the thimble scale line 42a corresponding to the thimble number "45" which is the closest distance number N2 and the thimble scale line 42b corresponding to the indicated value is "2". Therefore, it is recognized that the reading based on the sleeve count value, the latest distance number N2, and the thimble graduation line 42b is "4.43" (= 4.45-0.02). Further, “4.437” is acquired as the indicated value of the micrometer 20 from the size of the interval between the graduation line 42 b and the adjacent graduation line 42 c.

  In the example of FIG. 12, the nearest distance number N2 is "40". Therefore, "4.40" is determined as a reading based on the sleeve count "4" and the most recent distance number N2.

  Further, the reference line 34 is located on the side where the thimble number N1 is larger than the recent distance number N2. In this case, the number of thimble scale lines between the thimble scale line 42a corresponding to the thimble number "45" which is the closest distance number N2 and the thimble scale line 42b corresponding to the indicated value is "1". Therefore, it is recognized that the indicated value based on the sleeve count value, the latest distance numeral N2, and the thimble graduation line 42b is "4.41" (= 4.40 + 0.01). Further, “4.418” is acquired as the indicated value of the micrometer 20 from the size of the interval between the graduation line 42 b and the adjacent graduation line 42 c.

  According to the present embodiment, there is an advantage that it is possible to complete the number recognition that places a heavy load on the computer at one time. Moreover, even if it is a left-handed screw micrometer whose rotation direction is opposite to that of a general right-handed screw micrometer, the value of the thimble graduation 42 can be determined in the same manner as described above. Thus, the present embodiment is also applicable to a left-handed screw micrometer used for special applications.

  FIG. 4 is a flowchart showing the process executed by the automatic reading device 10 according to the present embodiment. In step S401, the image acquisition unit 11 captures an image of the micrometer 20 by the camera 50, and acquires a scale image (see FIG. 5).

  In step S402, the image rotation unit 12 rotates the scale image acquired in step S401 (see FIG. 6), and the image processing unit 13 executes image processing of the scale image (see FIG. 7).

  In step S403, the sleeve counting unit 14 acquires the read value of the sleeve scale 32. In step S404, the thimble scale determination unit 16 acquires the read value of the thimble scale 42.

  In step S <b> 405, the indicated value calculation unit 17 calculates the indicated value of the micrometer 20 based on the read value of the sleeve scale 32 and the read value of the thimble scale 42.

  In step S406, the output unit 18 outputs the indication value of the micrometer 20, and the indication value is displayed on the display device connected to the automatic reading device 10.

  The function of the thimble scale determination unit 16 in the automatic reading device 10 according to another embodiment will be described with reference to FIGS. 13 and 14.

  Due to the individual difference of the micrometer head or the difference in the angle of the camera 50 when acquiring the scale image, a reading error of the numerical value of the sleeve scale 32 may occur. For example, the edge (the area C shown in FIG. 13) of the thimble 40 may be recognized as a sleeve scale 32a (see FIG. 14). Thus, there is a possibility that the detection indication value of the micrometer 20 may increase or decrease by one rotation (0.5 mm) of the thimble 40 from the actual indication value due to the reading error of the sleeve graduation line.

  This will be described in more detail with reference to FIG. In the example of FIG. 14, the sleeve counting unit 14 recognizes the sleeve graduation 32 a as a valid graduation, and obtains the reading “4.5” of the sleeve graduation 32. On the other hand, the thimble scale determination unit 16 obtains the read value “0.442” of the thimble scale 42. Therefore, the indicated value of the micrometer 20 is “4.942” (= 4.5 + 0.442), which is larger than the actual indicated value by one rotation (0.5 mm) of the thimble 40.

  Therefore, according to the present embodiment, the indication value calculation unit 17 predicts the range of the indication value of the micrometer 20 according to the allowable value, and the calculation result of the indication value calculation unit 17 is higher than the upper limit value of the indication value range. If the value is also large, a value corresponding to one rotation (for example, 0.5 mm) of the thimble 40 is subtracted from the calculation result, and calculation is performed when the calculation result of the indication value calculation unit 17 is smaller than the lower limit of the indication value range. A value corresponding to one rotation (for example, 0.5 mm) of the thimble 40 may be added to the result.

  For example, assuming that the sleeve counting unit 14 can recognize up to 1/10 of the interval of the sleeve graduations, the tolerance of 0.2 mm corresponding to the width of the graduations of the sleeve 30 is set. In that case, a predicted range of 4.3 to 4.7 mm can be obtained from the sleeve count value.

  In the case of the example of FIG. 14 described above, the indicated value of the micrometer 20 exceeds the upper limit value of the prediction range. Therefore, the instruction value calculation unit 17 subtracts 0.5 mm corresponding to one rotation of the thimble 40 to calculate “4.442” as the instruction value.

  As described above, by adding or subtracting one rotation of the thimble 40 as a correction value, it is possible to prevent the occurrence of a reading error of the reading of the micrometer 20.

  While various embodiments of the present invention have been described above, those skilled in the art will recognize that other embodiments may achieve the intended effects of the present invention. In particular, without departing from the scope of the present invention, the components of the above-described embodiment can be deleted or replaced, or known means can be added. Further, it is obvious for those skilled in the art that the present invention can be practiced by arbitrarily combining the features of the plurality of embodiments explicitly or implicitly disclosed in the present specification.

DESCRIPTION OF SYMBOLS 10 Automatic reading apparatus 11 Image acquisition part 12 Image rotation part 13 Image processing part 14 Sleeve counting part 15 Recent distance number recognition part 16 Thimble scale determination part 17 Indicator value calculation part 18 Output part 20 micrometer 30 Sleeve 32 Sleeve graduation 34 Reference line 40 Thimble 42 Thimble Scales 42a, 42b, 42c Thimble Scale Lines 50 Cameras 60 Image Processing Unit 100 Measurement System N1 Thimble Numbers N2 Recent Distance Numbers

Claims (5)

An automatic reader (10) for automatically reading an indication value of an analog micrometer (20), wherein
The micrometer (20) comprises a sleeve (30), a sleeve scale (32) printed on the sleeve (30), a thimble (40) rotating relative to the sleeve (30), and the thimble (40). With the thimble numbers (N1) and thimble graduations (42) printed on
The automatic reader (10)
An image acquisition unit (11) for acquiring a scale image including at least the sleeve scale (32) and the thimble scale (42);
An image rotation unit (12) for rotating the scale image so that the reference line (34) of the sleeve (30) is at a predetermined angle;
A sleeve counting section (14) for counting the sleeve scale (32) in the rotated scale image to obtain a sleeve count value;
Among the thimble numbers (N1) included in the rotated scale image, the closest distance number recognition that recognizes the closest distance number (N2) located at the closest distance from the reference line (34) in comparison with the reference image Part (15),
A thimble scale determination unit (16) that determines the value of the thimble scale (42) based on the positional relationship between the thimble scale (42) and the reference line (34) included in the rotated scale image;
An indication value calculation unit (17) that calculates an indication value of the micrometer (20) based on the sleeve count value, the nearest distance numeral (N2), and the value of the thimble scale (42);
An automatic reader (10).   The system according to claim 1, wherein the closest distance number recognition unit (15) is configured to recognize the closest distance number (N2) by comparing a portion of the thimble number (N1) with a reference image. Automatic reader (10). The thimble scale determination unit (16)
Counting the number of thimble ticks (42) between the thimble tick (42) corresponding to the closest distance number (N2) and the thimble tick (42) corresponding to the indication value;
When the reference line (34) is located on the side larger than the nearest distance number (N2), the number of the thimble graduations (42) counted is added to the nearest distance number (N2);
If the reference line (34) is located on the smaller side than the closest distance number (N2), the number of the thimble tick marks (42) counted is subtracted from the closest distance number (N2). The automatic reader (10) according to claim 1 or 2, configured. The indicated value calculation unit (17)
Predict the range of indicated value of the micrometer (20) according to the tolerance value,
When the calculation result of the indication value calculation unit (17) is larger than the upper limit value of the range of the indication value, a value corresponding to one thimble rotation is subtracted from the calculation result,
The system according to claim 1, wherein when the calculation result of the indication value calculation unit (17) is smaller than the lower limit value of the range of the indication value, a value corresponding to one thimble rotation is added to the calculation result. 3. The automatic reader (10) according to any one of the preceding three.   The automatic reading device (10) according to any one of claims 1 to 4, further comprising an output unit (18) for outputting the indicated value of the micrometer (20) calculated by the indicated value calculation unit (17). ).