JP4984078B2 - Inspection method for FIPG coating line - Google Patents

Description

  The present invention relates to a method for inspecting a FIPG application line for accurately inspecting a line on which a work surface FIPG (Formed In Place Gasket) is applied.

There is a FIPG method as a method for performing on-site molding and construction of gaskets on engines, mission-related parts, or electronic equipment (work). This is a technique in which a liquid resin is applied to a predetermined position of a workpiece in a predetermined shape by a robot or the like, and a gasket is formed on the spot.
In such a FIPG method, the line on which the work surface FIPG is applied (FIPG application line) needs to be accurately inspected in order to have a necessary gasket function.

Conventionally, the application surface of a substance “determines the difference in reflected light from the application area and non-application area, and determines whether or not the application state is good compared to previously recorded application pattern information”. An inspection device has been proposed (see Patent Document 1).
However, with this inspection method using this apparatus, it has been difficult to perform an accurate inspection for satisfying the gasket function required in the FIPG method, in particular, to accurately inspect the FIPG coating line for breakage and protrusion. Therefore, in the end, the FIPG application line was inspected for defects or protrusions by hand, that is, visually by an inspector.

Japanese Patent Laid-Open No. 11-2610

  However, in the visual inspection, it is difficult to measure a quantitative value, and an accurate inspection cannot be performed due to a large variation in measurement results. Also, in the mass production line, when the occurrence of defects in the FIPG coating line formed for a large number of workpieces increases with time, it is impossible to accurately grasp from which point the defect has increased. There was a problem.

  The present invention has been made to solve the above-described problems, and it is possible to measure a quantitative value in the inspection of the FIPG coating line, to perform an accurate inspection without variation in the measurement result, and to a mass production line. In the FIPG coating line inspection method, it is possible to accurately capture changes over time in the inspection results of the FIPG coating line, such as from which point the occurrence of defects in the FIPG coating line formed on a large number of workpieces has increased. The issue is to provide.

The said subject is solved by making the inspection method of a FIPG application line into the structure of each following aspect.
As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the present invention, and the technical features described in this specification and combinations thereof should not be construed as being limited to those described in the following sections. . In addition, when a plurality of items are described in one section, it is not always necessary to employ the plurality of items together, and it is also possible to take out only a part of the items and employ them.

  Of the following items, (1) corresponds to claim 1, (2) corresponds to claim 2, and (3) corresponds to claim 3.

(1) A binarized image of a surface image to be inspected obtained by imaging a surface to be inspected including a FIPG application line, and a binary repeated pattern shape in which pattern positions and pattern component dimensions are set in advance. A method for inspecting a FIPG coating line, wherein the quality of the FIPG coating line is determined based on a determination image obtained by performing a logical product operation with the pattern image.
(2) a first step of binarizing the inspection surface image obtained by imaging the inspection surface including the FIPG application line, and a binary value in which the position of the pattern and the dimension of the pattern component are set in advance A second step of obtaining a first determination image by performing a logical product operation between the repetitive pattern image and the binarized image obtained in the first step; an inverted image of the pattern image; A third step of obtaining a second determination image by performing a logical AND operation with the binarized image, and a fourth step of determining whether the FIPG coating line is good or bad based on the first determination image and the second determination image. A FIPG coating line inspection method comprising:
(3) In the fourth step, the quality of the FIPG application line is determined by comparing the dimensions of the pattern components of the FIPG application line measured from the first determination image and the second determination image with design values. The FIPG coating line inspection method according to item (2), wherein

  According to the present invention, a quantitative value can be measured in the inspection of the FIPG application line, and an accurate inspection can be performed without variation in the measurement result. In addition, in the mass production line, when inspection results such as the occurrence of defects on the FIPG coating line formed on a large number of workpieces change over time, it is possible to accurately grasp from which point the change has occurred. Can be demonstrated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. FIG. 1 is a flowchart showing an embodiment of the FIPG coating line inspection method according to the present invention.
The present invention accurately inspects the good and defective (good / bad) coating state, such as the presence or absence of cut, squeezing (necking), or protrusion of the line on which the work surface is coated with FIPG (FIPG coating line) In the mass production line, it is intended to accurately capture the temporal change in the inspection result (good or bad) of the FIPG application line for each workpiece. For this reason, these inspections are quantitatively performed using images (data) rather than visual inspection by an inspector.

As can be seen from FIG. 1, in the present embodiment, first, an image of the surface to be inspected is obtained by imaging the surface to be inspected including the FIPG application line, that is, the work surface after FIPG application (step 101).
The inspection surface image is preferably acquired by a CCD (Charge Coupled Device) frame camera (hereinafter abbreviated as a CCD camera), but the CCD line sensor may be moved on the inspection surface to acquire the inspection surface image. Good. Or you may acquire using another imaging device. In short, it is only necessary that the work surface after FIPG application is imaged and an image including the FIPG application line can be acquired.

In step 102, the reference position of the workpiece is determined from the inspected surface image obtained in step 101, and the position of the image is corrected.
In step 103 (first process), the binarization process is performed on the inspection surface image whose position has been corrected in step 102 to extract only the FIPG application line from the inspection surface. Specifically, an appropriate luminance value (a change point of the feature value) for distinguishing the FIPG application line and the other work surface is selected from each pixel value (pixel luminance value) of the inspection surface image, and this is set as a threshold value. Then, binarization processing is performed to extract the FIPG coating line.
Since the FIPG coating line and the other work surface have different reflected light intensities and a clear difference appears in the luminance value on the inspection surface image, the extraction of the FIPG coating line by the above binarization processing is performed. Easy. Hereinafter, the extracted binarized image is referred to as a FIPG application line image.

  When the line brightness of the FIPG application line image is black, the FIPG application line image is inverted to white before the logical product operation described later, and the inverted image is used as the FIPG application line image. FIG. 2 shows an example of the FIPG application line image after this inversion. In FIG. 2, reference numeral 21 denotes a portion corresponding to the FIPG coating line (curved portion), and 22 denotes a portion corresponding to the protruding portion (excess portion), which is determined to be defective through the following processing. .

In step 104 (second step), a binary repeated pattern image, in this embodiment a stripe pattern image (see FIG. 3), and the binarized image shown in FIG. That is, the first determination image is obtained by performing a logical product operation with the FIPG application line image.
In the example shown in FIG. 3, the stripe pattern image is a black and white binary stripe image, and the luminance of the white portion is matched to the line luminance (white) of the FIPG application line image shown in FIG.
FIG. 4 shows an example of the first determination image. In FIG. 4, reference numeral 41 denotes a bend portion corresponding to the FIPG application line bend (the bend portion 21 in FIG. 2), and reference numeral 42 is an overhang portion corresponding to the protrusion (the protruded portion 22 in FIG. 2). This is a portion determined to be defective in step 108 described later.
If the logical product operation is not performed in a state where the FIPG application line image (binarized image) and the stripe pattern image are aligned, an accurate determination result cannot be obtained. This is the reason why the position of the inspection surface image is corrected in step 102.

FIPG application is performed by an operator or a robot, but in any case, it is performed according to a design value (drawing value). The FIPG application line is an actual line applied according to the design value, and does not necessarily match the design value (design line).
Therefore, the FIPG coating line is inspected. The stripe pattern image shown in FIG. 3 is preset in such a manner that the position (shape) of the entire pattern matches the design value.
Dimensions of pattern components (stripe), specifically, stripe length L (stripe pattern width W), stripe spacing (dimensions between black and white portions) D1 and D2, and further, stripe pattern corner portions A bending angle, an R value, and the like are also set in advance according to the design value.
The width W of the stripe pattern is set to a predetermined value larger than the width of the design value in consideration of tolerances and variations with respect to the design value. According to this, it is possible to measure at least the entire line width (stripe length) at the design value with high robustness.

Note that the length L of the stripes constituting the stripe pattern, in other words, the width W of the stripe pattern, and the stripe intervals D1 and D2 can be increased or decreased in units of one pixel of the stripe pattern image.
Also, the dimension between the white parts (dimension in the short direction of the black part) D1 and the dimension between the black parts (dimension in the short direction of the white part) D2 must always be matched. It is not a thing.
Further, the repeated pattern image is not limited to the stripe pattern image, and may be a mesh pattern image, for example.

In step 105, the next measurement is performed on the first determination image acquired in step 104.
That is, in the first determination image, the length of the white portion (element of the first determination image) corresponding to the white portion in the pattern component (stripe), in other words, the FIPG application line width at that position is set. Measure for each white part. The measured value is stored in a storage device.

In step 106 (third step), the black-and-white inverted image of the stripe pattern image (hereinafter referred to as the inverted stripe pattern image; see FIG. 5) and the FIPG coating line image shown in FIG. A second determination image is obtained by performing an AND operation between them.
FIG. 6 shows an example of the second determination image. In FIG. 6, 61 is a bend corresponding to the FIPG application line bend (the bend 21 in FIG. 2 and the bend 41 in FIG. 4), and 62 is the same (the protrude 22 in FIG. 2). ) And is a portion determined to be defective in step 108 described later.

In step 107, the next measurement is performed on the second determination image acquired in step 106.
That is, in the second determination image, the length of the white portion (element of the second determination image) corresponding to the white portion in the pattern component (stripe), in other words, the FIPG application line width at that position is set. Measure for each white part. The measured value is stored in a storage device.
The addition of step 106 and step 107 as well as step 104 and step 105 is to measure the length of the portion (element) corresponding to the black portion of the black and white stripe in the first determination image that is not acquired by step 104 and step 105. This is because the FIPG coating line width is measured over the entire length of the FIPG coating line.

In step 108 (fourth process), the measured value in step 105 and step 107, that is, the length of each white portion (each element) in the first determination image and the second determination image is used to determine the FIPG coating line portion and the entire portion. Judge the quality.
Specifically, using the line width at the design value (each position of the design line) as a reference value, the length of each white portion (each element) in the first determination image and the second determination image corresponding to that position ( Each measured value is compared. Based on the result of the comparison, the presence / absence, extent, and frequency of FIPG application line breakage (measurement value = 0), dripping (measurement value <reference value), or protrusion (measurement value> reference value) are quantified. To determine whether or not the FIPG coating line part or the whole is good or bad.

According to such quantitative determination (inspection), an extremely accurate inspection result can be obtained as compared with visual inspection.
In addition, by sequentially storing the inspection results of the FIPG coating line formed on a large number of workpieces in the mass production line, for example, when the occurrence of defects increases with time, it is often from what point in time. I can grasp exactly what has become.

FIG. 7 is a block diagram illustrating an example of an apparatus to which the above-described embodiment is applied.
As can be seen from this figure, the apparatus comprises a CCD camera 71, an amplifier 72, an A / D converter 73, and a computer 74.
The CCD camera 71 is a camera that picks up an image of the work surface (surface of the work 81) 82 after FIPG application and captures the image, that is, the inspection surface image. In the figure, reference numeral 83 denotes FIPG applied to the work surface 82.
The amplifier 72 is a circuit that amplifies the image signal from the CCD camera 71, and the A / D converter 73 is a circuit that converts the image signal (analog signal) from the amplifier 72 into a digital signal.

The computer 74 includes an input unit 74a, an arithmetic processing unit 74b, an external storage unit 74c, and a display unit 74d.
Here, the input unit 74a is used for executing the above-described embodiment in which an operator manually inputs data such as an initial value to the arithmetic processing unit 74b or gives an instruction to the arithmetic processing unit 74b and is stored in the external storage unit 74c. It is an apparatus unit that performs a desired process such as starting a program. In the embodiment shown in FIG. 1, the data manually input by the input unit 74 a includes position data for correcting the position of the inspection surface image in step 102.

  The display unit 74d is a device unit that displays various processing results such as a program execution result by the arithmetic processing unit 74b. In the embodiment shown in FIG. 1, the good / bad (good / bad) judgment result in step 108 is displayed. Further, the FIPG application line image obtained in step 103 (see FIG. 2), the pattern image in steps 104 and 106 (see FIGS. 3 and 5), the determination image (see FIGS. 4 and 6), and further in step 105 and Intermediate processing results such as measurement values obtained in step 107 can also be displayed. The display unit 74d also performs display for confirming the data and commands input by the input unit 74a.

  The external storage unit 74c is a device unit that stores the program and the pattern image (see FIGS. 3 and 5). In the present embodiment, the inspection surface image (data) from the A / D converter 73, the image (data) illustrated in FIGS. The result can also be stored in the external storage unit 74c.

  In such a configuration, the arithmetic processing unit 74b reads the data input by the input unit 74a, the program stored in the external storage unit 74c, and the pattern image in response to a command from the input unit 74a, and performs the processing shown in FIG. Specifically, step 102 to step 108 are executed. Then, the execution result, that is, the determination result of the quality of the FIPG application line is displayed on the display unit 74d and stored and stored in the external storage unit 74c.

It is a flowchart which shows one Embodiment of the inspection method of the FIPG application line by this invention. It is a figure which shows an example of the binarization process image (FIPG application | coating line image) calculated by logical product operation in step 104 in FIG. It is a figure which expands and partially shows an example of the stripe pattern image which carries out a logical product operation between the binarization process images in the step 104. It is a figure which shows an example of the logical product image (1st image for a determination) obtained by the logical product operation in the same step 104. FIG. It is a figure which shows an example of the inversion stripe pattern image by which a logical product is calculated between the binarization process images in step 106 in FIG. It is a figure which shows an example of the logical product image (2nd image for a determination) obtained by the logical product calculation in the same step 106. FIG. It is a block diagram which shows an example of the apparatus with which the method of this invention was applied.

Explanation of symbols

  21, 41, 61: Drowning part, 22, 42, 62: Overhanging part, 103: Binarization processing step (first process), 104: AND operation step (second process) for obtaining a first determination image , 106: AND operation step for obtaining a second determination image (third step), 108: FIPG application line pass / fail determination step (fourth step).

Claims (3)

  A binarized image of a surface image to be inspected obtained by imaging the surface to be inspected including the FIPG application line, and a binary pattern image having a binary pattern in which the position of the pattern and the dimensions of the pattern components are preset. A FIPG coating line inspection method, wherein the quality of the FIPG coating line is determined based on a determination image obtained by performing a logical product operation between the first and second images. A first step of binarizing the inspection surface image obtained by imaging the inspection surface including the FIPG application line;
For the first determination, a logical AND operation is performed between a binary repeated pattern image in which the position of the pattern and the dimension of the pattern component are set in advance and the binarized image obtained in the first step. A second step of obtaining an image;
A third step of obtaining a second determination image by performing an AND operation between the inverted image of the pattern image and the binarized image;
And a fourth step of determining whether the FIPG coating line is good or bad based on the first determination image and the second determination image.   In the fourth step, the quality of the FIPG coating line is determined by comparing the dimensions of the FIPG coating line measured from the first determination image and the second determination image for each pattern component with a design value. The method for inspecting a FIPG coating line according to claim 2.

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