JP2009198211A - Visual inspection apparatus and specimen visual inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the management of data for comparison as a standard as compared to conventional techniques. <P>SOLUTION: Standard image data, which are obtained by photographing a standard area 44 of a standard specimen as a standard for comparison (for example, a standard tire 42 formed with a character or symbol as a standard on its sidewall) with a camera 18, and which are continuous over the entire standard area 44, are stored in a HDD 40c. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a visual inspection apparatus and a visual inspection method for an inspection object.

  Conventionally, an appearance inspection apparatus for inspecting the appearance of an inspection object is known. For example, an appearance inspection apparatus including a camera that captures an image of a tire in order to inspect the appearance of a tire as an object to be inspected is known (for example, see Patent Document 1 and Patent Document 2).

In general, in an appearance inspection apparatus, for example, pattern matching data is obtained in advance for each character or symbol formed on a tire sidewall, and storage means (for example, an HDD) is obtained for each pattern matching data. (Hard Disk Drive)), a position information file including position data for each pattern matching data obtained in advance is obtained in advance for position matching data corresponding to each pattern matching data. Stored in advance. Then, the image of the sidewall image for one round of the tire is acquired by photographing the sidewall of the tire to be inspected by the camera while rotating the tire, and the character or symbol at a predetermined position of the acquired image And the pattern matching data and the pattern matching data corresponding to the predetermined position obtained on the basis of the position information file, a predetermined character or symbol is formed on the tire sidewall. It is determined whether or not. And the appearance inspection of a tire is performed by performing this determination about all the characters and symbols.
JP 2007-333531 A JP 2005-331274 A

However, in the inspection object inspection apparatus of the above example, pattern matching data (reference comparison data) is obtained in advance for each character or symbol and stored in the storage means for each pattern matching data. Since the data is stored, when there are a large number (for example, 600 or more) of data for pattern matching, there is a problem that management of the data for pattern matching is not easy. (For example, even if one pattern matching data disappears from the storage means, the operator does not notice immediately.)
The present invention has been made to solve the above-described problems, and is an appearance inspection apparatus that can easily manage pattern matching data (reference comparison data) as compared with the prior art. It is another object of the present invention to provide a method for inspecting the appearance of an inspection object.

  In order to achieve the above object, the visual inspection apparatus according to the invention described in claim 1 is an imaging unit that images the reference region of the reference inspection object and the inspection object region of the inspection object and outputs image data; Storage means for storing reference image data continuous over the entire reference area obtained by imaging by the imaging means, data on a predetermined part of the reference area represented by the reference image data, and the inspection object By comparing the data corresponding to the predetermined part of the inspection target area represented by the inspection target image data continuous over the entire inspection target area obtained by imaging the area by the imaging means, And inspection means for inspecting the appearance of the inspection object.

  According to the appearance inspection apparatus of the present invention, a reference region of a reference object to be compared (for example, a tire in which characters and symbols serving as a reference are formed on a sidewall) is used as a reference by an imaging unit (for example, a camera). Reference image data continuous over the entire reference area obtained by photographing is stored in a storage means (for example, HDD (Hard Disk Drive)). Therefore, according to the appearance inspection apparatus of the present invention, since one reference image data is stored as reference data for comparison, a large number of pattern matching data in the prior art is stored in the storage means. Compared to the case of setting, it becomes easier to manage reference data for reference. Further, compared with the conventional technique, the number of accesses to the storage means is reduced, and the amount of network traffic is reduced.

  In order to achieve the above object, the appearance inspection apparatus according to the second aspect of the present invention is an imaging means for imaging the reference area of the reference object and the inspection object area of the object and outputting image data. Storage means for storing reference image data continuous over the entire reference area obtained by photographing by the photographing means, photographing the reference image data and the inspection target area by the photographing means. The feature points of the reference area represented by the reference image data and the inspection object area represented by the inspection object image data based on the inspection object image data continuous over the entire inspection object area obtained by Control means for controlling the reference area and the inspection target area to be displayed on a display device in association with the feature points corresponding to the feature points. It is.

  According to the appearance inspection apparatus of the present invention, a reference region of a reference object to be compared (for example, a tire in which characters and symbols serving as a reference are formed on a sidewall) is used as a reference by an imaging unit (for example, a camera). Reference image data continuous over the entire reference area obtained by photographing is stored in a storage means (for example, HDD). Therefore, according to the appearance inspection apparatus of the present invention, since one reference image data is stored as reference data for comparison, a large number of pattern matching data in the prior art is stored in the storage means. Compared to the case of setting, it becomes easier to manage the reference data for reference. Further, according to the appearance inspection apparatus of the present invention, the reference area and the inspection target area can be displayed on the display device by a simple process. Thereby, the operator can perform an appearance inspection visually.

  In order to achieve the above object, the inspection method of the inspection object according to the third aspect of the present invention provides a continuous reference over the entire reference area by photographing the reference area of the reference inspection object. By obtaining image data in advance and photographing the inspection object area of the inspection object, continuous inspection object image data is obtained over the entire inspection object area, and a predetermined portion of the reference area represented by the reference image data is obtained. The appearance of the inspection object is inspected by comparing the data and data corresponding to the predetermined part of the inspection object region represented by the inspection object image data.

  According to the appearance inspection method for an object to be inspected according to the present invention, an image of a reference area of a reference object to be compared (for example, a tire in which characters and symbols serving as a reference are formed on a sidewall) is used as a reference. The appearance of the inspection object is inspected by comparing the reference image data continuously obtained over the entire reference region obtained in advance with the inspection target image data. Such management of reference image data is easier than in the case of managing a large number of pattern matching data in the prior art.

  As described above, according to the visual inspection apparatus and the visual inspection method of the inspection object of the present invention, it is possible to obtain an effect that management of comparative data serving as a reference becomes easy.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an example in which the present invention is applied to an appearance inspection apparatus that performs an appearance inspection of a sidewall of a tire as an inspection object will be described.

  FIG. 1 shows a state in which a tire 20 as an object to be inspected (shown in a sectional view) is mounted on an appearance inspection apparatus 10 according to an embodiment of the present invention. The appearance inspection apparatus 10 includes a holder 12 that holds the tire 20. The holder portion 12 has the same function as the wheel on which the tire 20 is mounted. In the holder portion 12, a pair of disk portions are arranged to face each other in parallel (only one side is shown in FIG. 1). At one center of the holder portion 12, a rotating shaft holder 14 to which the rotating shaft of the motor 16 is connected is attached. The motor 16 is connected to the controller 40.

  The controller 40 includes an I / O (input / output) port 40a, a ROM (Read Only Memory) 40b, an HDD (Hard Disk Drive) 40c, a CPU (Central Processing Unit) 40d, a RAM (Random Access Memory) 40e, and these I / Os. The bus 40f connects the O port 40a, the ROM 40b, the HDD 40c, the CPU 40d, and the RAM 40e to each other.

  A ROM 40b as a storage medium stores a basic program such as an OS.

  The HDD 40c as a storage medium stores a program for executing a processing routine of an appearance inspection process, which will be described in detail later.

  In addition, as shown in FIG. 2B, the HDD 40c stores in advance compressed image data over the entire reference area 46. Hereinafter, this image data may be referred to as reference image data or model data. The reference image data includes a predetermined range 44 of a predetermined region (reference region) 43 on the side wall of the reference tire 42 as a reference inspection object in which characters and symbols to be compared in the appearance inspection are formed on the side wall. A plurality of still images obtained by continuously shooting still images at predetermined intervals by the camera 18 while the reference tire 42 is rotated in a predetermined direction, for example, the arrow A direction shown in FIG. This can be obtained in advance. That is, the reference image data is continuous data over the entire reference area 44 obtained by photographing the reference area 44 of the reference tire 42 with the camera 18. In the present embodiment, for example, as shown in FIG. 2B, when the character “B” of “BRIDGESTONE” is set as a predetermined feature point, the character “B” is the head of the reference area 43. The reference area 43 is edited by correcting the reference image data so that the corrected reference image data is stored in the HDD 40c.

  Note that stitching still images can be performed using a known technique. For example, it is possible to detect a feature point in each of a plurality of still images, search for a common feature point, and connect the still images based on the common feature point.

  The CPU 40d reads the program from the ROM 40b and the HDD 40c and executes the program, and various data are temporarily stored in the RAM 40e.

  The I / O port 40a includes a display device 48, a camera 18 for photographing a predetermined region (inspection target region) where characters and symbols on the sidewalls of the tire 20 as an inspection object are formed, and a motor 16. It is connected.

  The camera 18 is installed so as to be capable of photographing the inspection target region of the sidewall of the tire 20 and outputs image data of the photographed image. That is, the camera 18 can take an image of an inspection target area of the tire 20 as an inspection object and output image data. Further, the camera 18 can capture a reference region 44 of a reference tire 42 as a reference inspection object and output image data.

  The motor 16 is driven to rotate in response to an instruction signal from the controller 40 so that the holder unit 12 and the camera 18 can be rotated relatively. With this configuration, it is possible to photograph the inspection target region of the tire 20 sidewall over the entire circumference by the camera 18.

  The display device 48 is composed of an LCD or a CRT that performs display based on input information.

  The tire 20 has a carcass 22 divided for each of a plurality of rubber members, and the carcass 22 is folded back by a bead 26. The carcass 22 includes various codes. The inner side of the carcass 22 is an inner liner 24, and a bead rubber 36 is disposed on the inner liner 24 so as to extend. A substantially triangular area formed by the folded carcass 22 is a bead filler 28. A belt 30 is disposed above the carcass 22, a tread rubber 32 having a groove is disposed on the outer side in the radial direction of the belt 30, and a side rubber 34 is disposed on the outer side in the axial direction of the carcass 22. Yes.

  Next, a processing routine for visual inspection processing executed by the CPU 40d of the controller 40 will be described with reference to FIG. In the present embodiment, the appearance inspection process is executed when an instruction to perform the appearance inspection process is input from an input device (not shown) by the operator.

  First, in step 100, the compressed model data is read from the HDD 40c.

  In the next step 102, the model data read in step 100 is decompressed.

  In the next step 104, an instruction signal is output to the motor 16 so as to be driven to rotate, and the camera 18 is continuously photographed at predetermined intervals for one round of the tire 20 in the inspection target area of the tire 20. To control.

  In the next step 106, the image data of each still image taken in step 104 is captured.

  In the next step 108, the images of the still images represented by the image data captured in step 106 are connected. As described above, it is possible to join images using a known technique.

  In the next step 110, the image of the inspection target region is edited so that a predetermined feature point of the inspection target region represented by the inspection target image data is at the head. Specifically, in the present embodiment, for example, as shown in FIG. 4A, a character “B” of “BRIDGESTONE” is a predetermined feature in the inspection target region 50 represented by the inspection target image data. In the case of a dot, as shown in FIG. 4B, the inspection target area 50 is edited by correcting the inspection target image data so that the character “B” is at the head of the image.

  Therefore, continuous image data can be obtained over the entire inspection target area by photographing the inspection target area of the tire 20 as the inspection object with the camera 18 by the processing in steps 104 to 110. Note that image data continuous over the entire inspection target area may be hereinafter referred to as inspection target image data.

  In the next step 112, based on the model data decompressed in step 102 and the inspection object image data corrected in step 110, the reference region 46 represented by the model data is displayed as shown in FIG. A feature point (for example, a letter “B”) and a feature point corresponding to the above-described feature point of the inspection target area 50 represented by the inspection target image data (for example, a character having a character “B” in the reference area 46) In some cases, the reference feature 46 and the inspection target area 50 are displayed on the display device 48 so that the corresponding feature point in the inspection target region 50 corresponds to the letter “B”). Control the display.

  In the next step 114, images of characters or symbols to be compared are cut out in a predetermined unit (for example, one character in the case of characters) from the inspection target area 50 edited in step 110 in order from the top.

  In the next step 116, an image having the same position and range as the position or range of the character or symbol cut out in the above step 114 on the inspection target area 50 is used as a reference represented by the model data decompressed in the above step 102. Cut out from region 46.

  In the next step 118, the image data represented by the character or symbol image cut out in the step 114 is compared with the image data of the image cut out in the step 116. It is determined whether the image of the character or symbol cut out at step 114 is the same as the image cut out at step 116.

  In the next step 120, it is determined whether or not the comparison has been performed on all the character and symbol images in the inspection target area 50 in the above step 118.

  If it is determined in step 120 that comparison has not been performed for all characters and symbols in the inspection target area 50, the process returns to step 114. When the process returns from step 120 to step 114, in step 114, images of characters or symbols that have not yet been cut out from the inspection target area 50 edited in step 110 in order from the top are displayed in predetermined units (for example, If it is a character, cut it out by 1 character).

  On the other hand, if it is determined in step 120 that all character and symbol images in the inspection target area 50 have been compared, the process proceeds to the next step 122.

  In step 122, it is determined whether or not there is a character or symbol extracted in step 114 that is determined not to be the same in step 118.

  If it is determined in step 122 that there is a character or symbol extracted in step 114 that is determined not to be the same in step 118, the process proceeds to the next step 124. In step 124, the display of the display device 48 is controlled so as to display the image of the character or symbol cut out in step 114 that is determined not to be the same. Thereby, the operator can grasp | ascertain the defect | deletion of the character and symbol which were formed in the sidewall of the tire 20. FIG. Then, the appearance inspection process ends.

  On the other hand, if it is determined in step 122 that there is no character or symbol extracted in step 114 that is determined not to be the same in step 118, the process proceeds to the next step 126. In step 126, the display of the display device 48 is displayed so as to display a message indicating that there is no loss of characters and symbols formed on the sidewalls of the tire 20, for example, a character string “no character or symbol is missing”. Control. Then, the appearance inspection process ends.

  As described above, by the processing in steps 114 to 120, the data of the predetermined part of the reference region 46 and the data of the predetermined part corresponding to the inspection target region 50 (that is, the data of the inspection target region 50, the reference region 46). The data of the predetermined part corresponding to the predetermined part) is inspected to inspect the appearance of the tire 20 as the inspection object. Note that the processing in steps 114 to 120 corresponds to an inspection unit.

  As described above, according to the appearance inspection apparatus 10 of the present embodiment, the reference inspection object (for example, the reference tire 42 in which the reference characters and symbols are formed on the sidewalls) is used as a reference for comparison. The reference image data continuous over the entire reference area 43 obtained by photographing the reference area 43 with the camera 18 is stored in the HDD 40c. Therefore, according to the appearance inspection apparatus 10 of the present embodiment, since the reference image data of one reference region 46 is stored as reference comparison data, a large number of pattern matching data in the prior art is stored. Compared with the case where the data is stored in the storage means, it becomes easier to manage the reference comparison data. In addition, compared with the conventional technique, the number of accesses to the storage means (in this embodiment, the HDD 40c) is reduced, and the amount of traffic on the network is reduced.

  In the present embodiment, the data of the predetermined part of the reference region 46 and the data of the predetermined part corresponding to the inspection target region 50 (that is, the data of the inspection target region 50 corresponding to the predetermined part of the reference region 46). The example of inspecting the appearance of the tire 20 as the inspection object has been described by comparing the data of the predetermined portion of the inspection target region 50 and the data of the predetermined portion corresponding to the reference region 46 ( That is, the appearance of the tire 20 as the object to be inspected may be inspected by comparing the data of the reference area 46 and data corresponding to a predetermined part of the inspection target area 50.

  In the present embodiment, the example in which the present invention is applied to the appearance inspection apparatus 10 that inspects the appearance of the sidewall of the tire 20 has been described. However, the reference data and the data to be inspected are compared. The present invention can be applied to any inspection apparatus that performs inspection by comparison.

  Various types of reference image data (model data) in the present embodiment are applied. For example, the reference image data in the present embodiment may be an 8-bit or 32-bit real image, a 2-bit character information image, or a 2-bit spew It may be a bent ridge image.

It is a schematic block diagram which shows an example of the external appearance inspection apparatus of this embodiment. It is a figure for demonstrating the reference | standard area | region in this Embodiment. It is a figure which shows the flowchart of the process routine of the external appearance inspection process which the controller in this Embodiment performs. It is a figure for demonstrating step 110 of the external appearance inspection process in this Embodiment. It is a figure for demonstrating step 112 of the external appearance inspection process in this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Appearance inspection apparatus 12 Holder part 14 Rotating shaft holder 16 Motor 18 Camera 40 Controller 40c HDD
40d CPU
48 display devices

Claims (3)

Imaging means for imaging the reference area of the reference inspection object and the inspection target area of the inspection object, and outputting image data;
Storage means for storing reference image data continuous over the entire reference area obtained by photographing by the photographing means;
It is represented by data of a predetermined part of the reference area represented by the reference image data, and inspection object image data continuous over the entire inspection object area obtained by imaging the inspection object area by the imaging means. Inspection means for inspecting the appearance of the inspection object by comparing data corresponding to the predetermined part of the inspection target area;
Visual inspection device including Imaging means for imaging the reference area of the reference inspection object and the inspection target area of the inspection object, and outputting image data;
Storage means for storing reference image data continuous over the entire reference area obtained by photographing by the photographing means;
The reference represented by the reference image data based on the reference image data and the inspection target image data continuous over the entire inspection target area obtained by imaging the inspection target area by the imaging unit. The reference region and the inspection target region are displayed on the display device by associating the feature point of the region with the feature point corresponding to the feature point of the inspection target region represented by the inspection target image data. Control means for controlling;
Visual inspection device including By photographing the reference area of the reference object, the reference image data continuous over the entire reference area is obtained in advance.
By imaging the inspection target area of the inspection object, obtaining continuous inspection target image data over the entire inspection target area,
By comparing the data of the predetermined part of the reference region represented by the reference image data with the data corresponding to the predetermined part of the inspection target region represented by the inspection target image data, the appearance of the inspection object Inspecting the appearance of the inspection object.

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