JP3288902B2 - Seal inspection system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal inspection system, and more particularly, to an improvement in a seal inspection system for judging the application state of a seal material applied in a bead shape using an automatic seal application device or the like.

[0002]

2. Description of the Related Art In recent years, a sealing method using a silicone resin or the like has been adopted for sealing between various mechanical parts.

[0003] In particular, in an assembly process of an engine or the like, since it can be easily applied to an assembly line and can improve a working environment, a nozzle provided movably along a joint surface of a workpiece can be used. 2. Description of the Related Art Apparatuses for discharging a liquid sealing material and automatically applying the liquid sealing material to a joint surface have become widespread.

In the above-described coating apparatus, when air or the like is mixed in the sealing material for some reason, air is ejected when the sealing material is discharged from the nozzle.
There is an inconvenience that a so-called idling state is caused to partially obstruct continuous ejection of the sealing material, or to cause a partial application width abnormality or the like.

For this reason, after the automatic application, it is necessary to inspect the state of the sealing material applied to the joint surface. In this inspection, visual observation by an operator is adopted.
A coating inspection by image processing using an imaging means such as a CD camera has also been adopted.

[0006]

However, since a coating abnormality or a defect rarely occurs, if a defect actually occurs due to the assumption that there is no defect in the visual inspection, Is likely to be overlooked.

Further, in the visual inspection, since the abnormality of the coating is determined by the examiner's subjectivity, it is difficult to make the standard for determining whether the coating state is normal or abnormal. That is, in the visual inspection, the application state determined to be abnormal by one inspector may be determined to be normal by another inspector, and the evaluation of the application state of the sealing material cannot be quantified.

On the other hand, in an inspection by image processing, the density value in a captured image tends to vary, and in an inspection in which image processing is performed on binarized image data, it is difficult to ensure the accuracy of the inspection result. There was an inconvenience. More specifically, as shown in FIG. 4 (A), an image in the case where there is no irregular reflection of illumination at the time of photographing is obtained.
The seal material 41 can be clearly identified from 0. This is because the bonding surface 40 is normally imaged brightly, while the sealing material is imaged darker than this brightness.

Therefore, when the image shown in FIG. 4A is binarized by a predetermined threshold value, the joining surface 40 and the sealing material 41 are satisfactorily separated as shown in FIG. 4B. Therefore, the sealing material 41 on the bonding surface 40 can be captured. Further, by counting the number of pixels in the dotted frame in the figure and comparing the number of pixels with a set value, it is possible to capture the area on which the sealing material has been applied and to inspect the applied state.

[0010] However, at the site where the sealing material is applied, it is a part of the manufacturing process, and the installation position of the lighting is limited. Therefore, the inspection environment such as the ambient brightness is not always good. For this reason, in actual shooting,
As shown in FIG. 4C, the illumination is reflected by a part of the sealing material 41 and becomes bright, and the brightness of the bonding surface 40 may be approximated to the part of the sealing material 41. Therefore, when the image shown in FIG. 4C is binarized,
As shown in (D), the portion separated as the sealing material 41 is smaller than the actual sealing material 41, and even if the number of pixels surrounded by a dotted line in the figure is counted, the number of pixels is smaller than the set number. It is determined to be defective.

That is, depending on the inspection environment, there is a problem that illumination is reflected on the sealing material 41 and erroneous determination of the application state is caused by the reflection of the sealing material. Therefore, when the bonding surface 40 is imaged in an ideal state, the coating state can be determined by image processing. However, in the actual manufacturing process, the reflection of the sealing material 41 causes the automatic inspection without visual inspection. Was unreliable.

In the method of determining the presence or absence of an inspection object based on the number of pixels in a window of a binarized image as shown in FIG. 4, it is difficult to set a threshold value for binarization. This causes a disadvantage that a threshold value that works well in one inspection environment does not separate the sealing material portion and the joint surface portion in another environment. Setting the threshold every time the illumination position or the intensity is changed is too complicated and hinders the automatic inspection of the application state of the sealing material by image processing. Further, in the automatic setting of the threshold value by the discriminant analysis method or the like, the processing requires a long time.

As described above, the inspection system for the application state of the sealing material is not limited to the sealing material even if the density in the image data is not uniform and slightly changed due to the change of the illumination position or the illuminance depending on the inspection environment. Even if external light is reflected by a part of the image and the brightness is the same as that of the bonding surface, a method capable of separating the sealing material portion in the image data is desired.

It has been found that the portion where the sealing material cannot be identified by reflection is likely to actually occur in the central portion along the coating direction of the sealing material. That is, due to the thickness of the sealing material and the like, both ends in the width direction of the sealing material 41 are hardly reflected by illumination, and are imaged dark. That is, the sealing material 41
Is unstable due to the influence of illumination, while the density at the both ends is stably different from the bonding surface 40. Therefore, the density at both ends in the width direction of the sealing material can be clearly identified with respect to the density at the joining surface.

[0015]

SUMMARY OF THE INVENTION It is an object of the present invention to detect the presence or absence of a sealing material based on a change in density distribution along both ends in the width direction of the sealing material with respect to image data of a work joining surface, and to determine this detection in advance. It is an object of the present invention to provide a seal inspection system capable of performing the application state of the sealing material at high speed and with high accuracy by performing the inspection for each inspection point.

[0016]

In order to achieve the above object, the present invention provides a means for capturing an image of a workpiece joint surface to which a sealing material has been applied, and an image for storing data captured by the image capturing means as image data. A memory, and a processing device connected to the image memory and performing grayscale image processing on the image data. The processing device further includes an inspection width portion centered on a predetermined inspection point on the image data. Inspection part specifying function to search for the pixel position of, and the position of the pixel whose density change value is equal to or larger than the set value among the pixels from the both ends of the inspection width in the image data to the inspection point are both ends in the width direction of the sealing material A two-side detection function for determining a position, and a cut for determining a seal break for the inspection point when both ends in the width direction are not detected by the two-side detection function. And a color determination function, and employs a configuration that.

Further, the processing apparatus in the seal inspection system has a configuration in which a coating state determining function for determining that the coating state is defective when a break error occurs continuously at a plurality of inspection points is adopted. Preferably, the inspection point is set at the center in the width direction of the normally applied sealing material, and both ends of the inspection width are set on the work bonding surface.

Further, the processing device calculates the width of the sealing material at the inspection point based on the both end positions in the width direction detected by the both-side detection function, and calculates the width of the sealing material at the inspection point. And an application width error determination function of determining an application width error for the inspection point when the application width is smaller than a predetermined minimum setting width.

Further, the processing apparatus is provided with a coating state determining function for determining that the coating state is defective when a coating width error occurs continuously at a plurality of inspection points.

Further, the processing device includes a shift amount calculating function for determining a shift amount of the coating position based on the both ends in the width direction detected by the both side detecting functions and the position of the inspection point, and a shift amount calculating function. A deviation error determination function for determining a deviation error for the inspection point when the calculated deviation amount is larger than a predetermined deviation amount. Can be inspected. In this case, the processing apparatus may be provided with a coating state determining function for determining that the coating state is defective when the coating width error occurs continuously at a plurality of inspection points.

[0021]

Before performing the gradation image processing, the inspection points are taught using the reference work to which the sealing material is normally applied, and each inspection point is stored in the processing device. After that, image data is captured by the imaging means for the inspection target having the sealing material applied to the work bonding surface, and the image data is stored in the image memory. The processing device performs grayscale image processing on the image data in the image memory for each inspection point in the seal width direction. Here, whether or not both ends of the sealing material are detected is determined by comparing the density of the work joining surface with the density of both ends of the sealing material. The density difference is set based on the color of the work bonding surface and the seal material, the reflectance of light, or the like, and the presence or absence of both ends of the seal can be determined based on the set value of the density difference.

When both ends of the seal material at a specific inspection point cannot be detected, the number of seal breaks at the inspection point is counted. If the detection of both ends of the seal material cannot be performed at the next inspection point, the count of the seal breakage is added. When the count value of the continuous seal break exceeds the allowable set number, it is determined that the seal is broken and the application is determined to be abnormal.

Further, in a configuration in which the processing device is provided with a function of detecting the minimum set width of the seal material, it is possible to simultaneously detect the seal application width and the width deviation at each inspection point in addition to the seal break.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a seal inspection system according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of the seal inspection system. In this figure, inspection work 1
Numeral 0 designates an automobile engine head cover or the like, and a sealing material 41 such as a silicone resin is applied to a joint surface 40 of the work 10. The application of the sealing material 41 is performed by a robot (not shown) for applying the sealing material 41. The sealing material application robot includes a nozzle for discharging a sealing material 41 on the bonding surface 40 and a nozzle for connecting the nozzle to the bonding surface 4.
Nozzle driving means for moving along 0.
The nozzle driving means is driven and controlled by the robot controller 11. The robot controller 11 teaches the nozzle on the application locus along the joining surface 40 of the workpiece 10, and the workpiece 1 that is continuously produced
A function of sequentially applying the sealing material 41 to the bonding surface 40 of the “0” is provided.

Above the inspection position of the work 10,
A plurality of CCD cameras 12 and illuminating devices 13 constituting the image pickup means are arranged. In the present embodiment, the CCD camera 12 has an effective pixel number of 768 (H) × 494 (V), and captures a monochrome image of the joint surface 40 in the inspection work 10. The photographing distance between the CCD camera 12 and the work 10 is set such that the sticker can be photographed to a size of, for example, about 4 to 6 pixels within the effective number of pixels. The positions of the work to be inspected and the CCD camera 12 are fixed,
The joining surface 40 of the work 10 is always imaged at the same position.

The CCD camera 12 has an image switch 14
The image switch 14 sequentially switches the CCD camera 12 according to the position of the imaging target, and inputs analog image data captured by the connected CCD camera 12 to the digitizer 15.

The digitizer 15 includes an A / D converter 16 for converting analog image data output from the CCD camera 12 into digital image data, and an image memory 17 for storing image data output from the A / D converter 16. And a D / A converter 18 for converting the image data in the image memory 17 into analog data for monitor display. Here, the A / D converter 16 converts the analog image data into two.
It is converted into digital image data of 56 tones (density values “0” to “255”). Hereinafter, the digital image data of 256 gradations is simply referred to as image data.

On the other hand, the internal / external monitors 19 and 20 and the printer 21 are connected to the D / A converter 18. Since the image data once stored in the image memory 17 is D / A converted and displayed on the monitors 19 and 20, the coordinates of the image displayed on the monitor correspond to the coordinates of the address of the image memory 17. Therefore, the position indicated by the operator with respect to the images displayed on the monitors 19 and 20 corresponds to the address of the image memory 17, and furthermore, the CCD camera 1
2 corresponds to the position of the bonding surface 40 imaged.

Further, since the position of the CCD camera 12 is fixed here, it is specified how many mm of the vertical and horizontal lengths of one pixel of the image data in the image memory 17 correspond to the bonding surface 40. You. Further, since the actual size of one pixel is specified, the actual length of the image data on the monitor can be displayed together.

The D / A converter 18 has a printer 21
Are provided so that image data and inspection results can be printed out as needed.

A microcomputer 25 as a processing device is connected to the image memory 17. The microcomputer 25 performs grayscale image processing on the image data stored in the image memory 17 and instructs the timing of drive control by the robot controller 11 and the like. Actually, the microcomputer 25 is provided with storage means such as a hard disk or a ROM (not shown) in which a program in which a control procedure is described is stored in advance.

The microcomputer 25 outputs a predetermined application start signal and an inspection end signal to the robot controller 11 and inputs a photographing start signal output from the robot controller 11 via the I / O board 26. And In addition, predetermined parameters are input to the microcomputer 25 by the keyboard 24 connected to the outside. Specifically, an inspection start position, an inspection start direction, an inspection end position, an allowable cutting width, an allowable width, and the like according to an inspection target when executing the teaching program can be arbitrarily set as variable information.

According to various programs, the microcomputer 25 defines an inspection position specifying section 25A for defining the inspection point of the application state of the sealing material on the image data, and a seal for the inspection point p defined by the inspection position specifying section 25A. The apparatus includes an application state inspection unit 25B that determines the application state of the material by image processing.

The inspection position specifying section 25A specifies a position where the sealing material must be applied. That is,
In the 512 × 512 image data picked up by the CCD camera 12, the coordinates at which the presence of the sealing material must be detected are specified. When the sealing material is successfully extracted, a continuous line having a thickness of 4 to 6 pixels is detected in this image data. The position of this line is determined by the shape of the work and the position where the sealing material 41 is applied to the joining surface 40.

The inspection position specifying unit 25A first monitors the image data of the joint surface 40 on which the sealing material has been normally applied by using the monitor 1.
Displayed at 9, 20. Alternatively, the position where the sealing material should be normally applied is painted black, for example, and the joining surface 40
Is displayed on the monitor. Next, the inspection start position and the inspection end position are received from the operator as coordinate information on the monitor. Further, when an instruction of a search direction is received from the operator, the application position of the sealing material according to the shape of the work is automatically detected as the coordinates of the image memory by the search processing.

Here, the process is performed by tracing the pixels determined as the seal material in the image data one by one. In this search processing, first, the number of continuous pixels in the search direction is determined, and if the number of continuous pixels is larger than the reference value, the coordinate is recorded by moving one pixel in that direction.

Further, when the number of the continuations is smaller than the reference value, it is determined that the seal is a bent portion, and a new search direction is determined. If the vehicle cannot go straight, the direction at 45 degrees to the left and right is checked, and a new direction is determined by comparing the density values.

Next, the average of the density of the current position and the density of the pixel adjacent in the traveling direction is set as a reference density value, and the average of the densities of the second and third pixels ahead of the current position is set as a comparison density value. If the reference density value is equal to or greater than the comparison density value, the pixel advances in that direction by one pixel, and the advanced position is recorded as the current position.

Each time a search is made and the coordinates are recorded, it is checked whether or not the position is within the range of the end position. If the position is within the end range, it is determined that the position is normal and the process is terminated. On the other hand, the search was for sealing material 4
Considering the case where the search deviates from 1 and cannot be normally performed, if the search does not reach the end position even if the search is repeated a fixed number of times, it is determined to be abnormal and the process ends.

Thus, the line on which the sealing material is applied is extracted. Further, points at regular intervals on this line are inspected to specify coordinates. At this time, the inspection point is set at the center of a certain width.

The coating state inspection unit 25B determines the position where the density change value in the width direction of the sealing material 41 at the inspection point defined in advance on the image data is equal to or more than the set value, at both ends in the width direction of the sealing material. Both side detection function to determine
When both ends in the width direction are not detected by the both-side detection function, a break error determination function of determining that the inspection point is a seal break is provided.

The application state inspection section 25B calculates an application width calculation function for calculating the width of the sealing material at the inspection point based on the both ends in the width direction detected by the both-side detection function, and an application width calculation function. When the application width calculated by the above is smaller than a predetermined minimum setting width, an application width error determination function of determining an application width error for the inspection point is provided.

Further, the coating state inspection unit 25B has a shift amount calculating function for determining a shift amount of the coating position based on the both ends in the width direction detected by the both side detecting function and the position of the inspection point, and a shift amount calculating function. A shift error determining function is provided for determining a shift error for the inspection point when the shift amount calculated by the amount calculating function is larger than a predetermined set shift amount.

In this embodiment, when each error occurs continuously at a plurality of inspection points, it is determined that the coating state is defective. Therefore, the coating state inspection unit 25B counts the number of each error. It has an error counter.

Next, the application state inspection section 25B will be described in more detail.

The coating state inspection unit 25B is provided with an image memory 17
The presence of the sealing material is confirmed by detecting a portion having a large change in shading with respect to the image data stored in. Here, as shown in FIG. 2, as the inspection of the application state, three elements of a break in the seal material, an application width, and a shift of the seal material application position are confirmed. First, a method of extracting a seal material portion by image processing will be described with reference to FIG. 3, and then a processing step of the application state inspection unit 25B that inspects the application state of the seal material will be described.

The inspection point p is defined at the center position in the width direction of the sealing material 41 applied to the work joining surface 40. The inspection points p are arranged at regular intervals along the application direction of the sealing material 41. Further, an inspection width w is defined for the inspection point p. this is,
The inspection point is set to be wider by a certain distance in the width direction of the sealing material from the inspection point, and both ends of the inspection width w are located within the work bonding surface 40 in this case.

The application state inspection unit 25B detects a change in density from the pixels at both ends of the inspection width w to the pixel at the inspection point p. As described above, since the edge portion in the width direction of the sealing material 41 is hardly affected by the reflection of illumination, the coating state inspection unit 25B determines the pixel adjacent to the inspection point p direction from the density of the pixels at both ends of the inspection width w. Is calculated, and if this density change is equal to or more than the set value, it is determined that the edge is the edge of the sealing material.

Since the position of the pixel whose density change is equal to or greater than the set value among the pixels from both ends of the inspection width w to the inspection point p is determined to be the both ends of the sealing material, the coating state inspection unit 25B In addition, the width at one point (inspection point) of the sealing material applied on the bonding surface 40 captured by the CCD camera 12 can be extracted. Since the detected width of the sealing material is calculated as the number of pixels, by comparing with the number of pixels corresponding to the width in the case of normal application, this C is calculated.
It is possible to quantitatively determine whether the width of the sealing material at the inspection point p captured by the CD camera 12 is smaller or larger than normal.

Further, since the inspection point p is set at the center position in the width direction of the normally applied sealing material, it is determined that the inspection point p is located on both sides (edges) of the sealing material. By comparing with the positions of the pixels, it is possible to quantitatively determine how much the seal material deviates from the position where the seal material should be applied.
Since the CCD camera 12 captures an image of the work bonding surface 40 so that the width of the normally applied sealing material is 4 to 6 pixels, the width and the amount of displacement of the sealing material can be detected in millimeters.

The application state inspection unit 25B detects the width of the sealing material at each inspection point arranged at a constant interval in the application direction of the sealing material. At this time, when the detection of the width of the sealing material has failed successively for a plurality of inspection points p, the application state inspection unit 25B determines that a break has occurred in the application direction of the sealing material.

Here, the inspection process of the application state of the sealing material with the configuration shown in FIG. 1 will be described with reference to the flowchart of FIG.

First, an illuminance inspection is performed (step S).
1). This is because when the illumination is dark, the sealing material 41
Since the density of the edge portion and the density of the joining surface 40 portion are close to each other and detection of both ends (both sides) in the width direction of the sealing material based on the density change cannot be performed satisfactorily, the illuminance before the imaging by the CCD camera 12 is performed. An inspection is performed. If the illuminance test is NG, the process is terminated without performing the test as a defective illumination (step S2).

Next, detection processing of both sides of the sealing material is performed on the inspection point p defined in advance for the image data picked up by the CCD camera 12. further,
An inspection of the application state is performed based on the detection result.

Steps S3 to S1 shown in FIG.
8 is the flow of processing for one inspection point p. Since a plurality of inspection points p are defined for the image data along the workpiece joint surface 40, the process of detecting both sides of all the inspection points p defined for this image data is completed in step S18. It is determined whether or not it has been performed.

In the inspection of the application state shown in FIG. 2, a break in the application of the sealing material (steps S3 to S6).
And the width of the applied sealing material (steps S8 to S8).
9), deviation of the application position of the sealing material (Steps S13 to S13)
The inspection of 16) is performed. In the present embodiment, in each inspection, if a break or the like occurs not at one inspection point but at consecutive inspection points, it is determined that an error (defective coating state) has occurred.

In step S3, it is detected whether or not there is a pixel from the inspection width w to the inspection point p in which the density has changed more than the set value. If both sides of the seal width are not detected, the value of the break error counter is increased by "1" (step S4). If the value of the break error counter is equal to or greater than the set value (step S5), that is, if it is determined that there is a break at inspection points p equal to or greater than a predetermined number of inspection points, the NG flag is set to “ON”.
As a break / shift error (step S6).
The reason for the possibility of a displacement error is that it is assumed that the sealing material 41 is applied outside the inspection width w.

If both sides of the sealing material are detected in step S3, first, a break error counter is initialized (step S7). Further, the number of pixels between both sides of the sealing material is calculated, and it is confirmed whether or not the width of the sealing material is equal to or larger than the minimum set width based on the number of pixels (step S).
8). If the width is less than the minimum set width, that is, if the number of pixels is 4 to 6 pixels or less in the above example, the value of the width error counter is increased by "1" (step S9). Next, it is checked whether or not the value of the width error counter is equal to or larger than a set value (step S10). That is, it is checked whether the inspection points p smaller than the minimum set width are continuous. When it is determined that the width of the sealing material is small continuously at the inspection points p equal to or larger than the preset number of inspection points, the NG flag is set to “ON” and a width error is caused (step S11).

If it is determined in step S8 that the width is equal to or larger than the minimum set width, first, the value of the width error counter is initialized (step S12). Further, based on the pixel positions on both sides of the sealing material and the position of the pixel at the inspection point, it is confirmed whether or not both sides are located within the set deviation (step S13). If the deviation exceeds the set deviation range, the value of the deviation error counter is set to “1” as in the other cases.
It increases (step S15). Further, when it is determined that the displacement of the application position occurs at the consecutive inspection points p (step S15), the NG flag is set to “ON” and a displacement error is caused (step S11).

If it is determined in step S13 that both side positions of the sealing material are within the set deviation, first, a deviation error counter is initialized (step S17). If each error is not equal to or greater than the set number of times in the processing of steps S3 to S17, the application state is determined to be good, the next inspection point is selected, and the processing returns to step S3.

On the other hand, if it is determined that the seal material is unacceptable, the fact that the application state of the sealing material is NG may be displayed as it is, and the process may be terminated. In order to obtain information as to whether or not an error has occurred, the next inspection point is selected, and the process returns to step S3. In this embodiment, the operation failure of the coating robot is specified based on the error information for each inspection point. Further, based on this error information, the operation of the application robot may be controlled to apply the sealant again. That is, the microcomputer 25 may cause the robot controller 11 to control the application of the sealing material again based on the position corresponding to the inspection point and the error type of the inspection point.

When the processing is completed for all the inspection points (step S18), the state of the NG flag is confirmed (step S19). If the NG flag is ON, NG is output (step S20). If is not ON, OK is output (step S21). The inspection result of the application state of the sealing material automatically performed by the image processing can be externally displayed. This external display is displayed on the monitors 19 and 20.
Alternatively, printing can be performed by the printer 21.

The CCD camera 12 according to the size of the work
In the case where there are a plurality of image data, after the processing for one image data is completed, the input of the CCD camera 12 is switched by the image switch 14, and the processing for the next image data is performed.

As described above, according to the inspection process shown in FIG. 2, the presence or absence of the seal material is detected by detecting the edge portion of the seal material. Of the sealing material can be detected by image processing without setting an ideal illumination environment.

Furthermore, since the pixels in which the density change from the both ends of the inspection width toward the inspection point exceeds the set value are determined as both ends of the sealing material, the width of the sealing material can be quantitatively captured by the number of pixels. By specifying the position of the CCD camera, it is specified how many millimeters of one pixel correspond to the actual bonding surface 40. Therefore, how many millimeters of the width of the sealing material defined by the number of pixels are actually obtained. Can be accurately calculated.

Further, since the both ends of the inspection width are set as the start positions and the density change amount is detected based on the density value of the pixel at the position, even if the brightness on the inspection target surface is not uniform, that is, the illumination environment is Accurate determination can be stably performed even if some irregular reflection occurs on the bonding surface 40 due to poor quality.

Further, since the inspection points correspond to the actual positions on the bonding surface 40, the application of the sealing material by the robot controller based on the error situation at each inspection point is not performed so that the application is not performed satisfactorily. It is possible to automatically and accurately apply the sealing material again at the position where the seal material has been set.

[0069]

The present invention is configured as described above, and
According to this, according to this, both sides detection function determines the position of the pixel whose density change value is equal to or larger than the set value among the pixels from both ends of the inspection width in the image data to the inspection point in the width direction of the sealing material. Since it is determined that both end positions are present, it is possible to detect the presence or absence of the seal material 41 based on the portions of the seal material 41 that are always imaged dark. When both ends in the width direction are not detected, the inspection point is determined to be a seal break, so that a seal break, which is a defective application state of the sealing material 41, can be automatically detected by image processing, which is an unprecedented superiority. An effective seal inspection system can be provided.

Further, since both ends of the inspection width are set on the work bonding surface 40, when the processing apparatus searches the image data for a pixel position of the inspection width portion centered on a predetermined inspection point, this inspection is performed. Both end positions of the width are pixels on the bonding surface 40. Therefore, a grayscale value on the bonding surface 40 can be used as a reference grayscale value for obtaining a density change value. Even when the density value changes due to illumination, the seal material 41 can be detected based on the changed density value.
Can be inspected stably without being affected by changes in the inspection environment.

Further, since the coating width calculating function calculates the width of the sealing material at the inspection point based on the both end positions in the width direction detected by the both-side detecting function, the sealing material on the joint surface 40 photographed is used. 41 can be calculated as the number of pixels.
In order to correspond to the above size, the application width of the sealing material 41 on the bonding surface 40 can be calculated based on the number of pixels, and the application width error calculation function is calculated by the application width calculation function. When the application width is smaller than the predetermined minimum setting width, the inspection point is determined to be an application width error. Therefore, the state of the application width can be determined by high-speed image processing of comparing the number of pixels.

In order to judge that the coating state is defective when an error in the coating width occurs continuously at a plurality of inspection points, the case where the necessary amount of the sealing material 41 is not applied at the time of bonding is determined by using the bonding surface 40. Can be detected satisfactorily according to the shape and the like of the application, and when it is determined that the application state is defective when the inspection occurs continuously at a plurality of inspection points, an error in the application width due to noise or the like is detected at one inspection point. Even when the determination is made, this is not determined as a defective application state, so that the defective application state can be determined without being affected by noise.

Further, the shift amount calculating function determines the shift amount of the coating position based on the width-direction both end positions detected by the both-side detection function and the position of the inspection point. Thus, it is possible to provide a seal inspection system having an unprecedented excellent effect that the shift amount of the seal material 41 actually applied can be quantitatively determined as the number of pixels.

Further, the processing apparatus has a coating state determining function,
Conventionally, the application state is determined without being affected by noise or the like at one inspection point because it is determined that the application state is defective when an application error occurs continuously at a plurality of inspection points. It is possible to provide a seal inspection system that has an excellent effect that cannot be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a seal inspection system according to the present invention.

FIG. 2 is an inspection flowchart of the seal inspection system.

FIG. 3 is a schematic plan view of a seal inspection point.

FIGS. 4A to 4D are explanatory views of a conventional example in which image data is binarized and a seal inspection is performed.

[Explanation of symbols]

 12 CCD camera 15 Digitizer 17 Image memory 25 Microcomputer as processing device 40 Joining surface 41 Sealing material

Continuation of the front page (72) Inventor Hiroyuki Okamoto 14-4, Nishi-Imamachi, Matsue-shi, Shimane Matsue College of Technology (56) References JP-A-5-5606 (JP, A) JP-A-5-26621 ( JP, A) JP-A-6-58732 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/84-21/958 G01B 11/00-11/30 G06T 1 / 00

Claims (7)

(57) [Claims] 1. A means for capturing an image of a workpiece joint surface to which a seal material has been applied, an image memory for storing data taken in by the image capturing means as image data, and a memory connected to the image memory and for storing the image data. A processing unit for performing a grayscale image processing on the seal inspection system, wherein the processing device specifies an inspection portion for searching for a pixel position of an inspection width portion centered on a predetermined inspection point on the image data. A function and both sides for determining the position of a pixel whose density change value is equal to or larger than a set value among pixels from both end positions of the inspection width to the inspection point in the image data as both end positions in the width direction of the sealing material. A detection function, and a cut that is determined to be a seal break for the inspection point when both ends in the width direction are not detected by the both-side detection function. Seal inspection system is characterized in that a color determination function. 2. The seal according to claim 1, wherein the processing device has a coating state determining function for determining that the coating state is defective when the break error occurs continuously at a plurality of inspection points. Inspection system. 3. The inspection point is set at the center in the width direction of the normally applied sealing material, and both ends of the inspection width are set on the work bonding surface. Item 2. The seal inspection system according to Item 1. 4. An application width calculation function for calculating a width of a sealing material at the inspection point based on the width direction both end positions detected by the both side detection functions, 4. An application width error determination function for determining an application width error for the inspection point when the calculated application width is smaller than a predetermined minimum set width.
The seal inspection system described. 5. The processing apparatus according to claim 4, wherein the processing apparatus has a coating state determining function for determining that the coating state is defective when the coating width error occurs continuously at a plurality of inspection points. Seal inspection system. 6. A shift amount calculating function for determining a shift amount of a coating position based on both end positions in the width direction detected by the both side detection functions and a position of the inspection point, and the processing unit includes: 4. The apparatus according to claim 1, further comprising: a shift error determining function for determining a shift error for the inspection point when the shift amount calculated by the calculating function is larger than a predetermined shift amount. The seal inspection system described. 7. The processing apparatus according to claim 6, wherein the processing apparatus has a coating state determining function for determining that the coating state is defective when the coating shift error occurs continuously at a plurality of inspection points. Seal inspection system.