KR20200057286A - Inspection method for discharge state of sealer - Google Patents

Abstract

The present invention relates to a method for inspecting the discharge state of a sealer and, more specifically, to a method for inspecting the discharge state of a sealer, capable of significantly improving work efficiency since an operation of resetting a region of interest is not required even if changes in work information and a work object occur. According to the present invention, the method for inspecting the discharge state of a sealer comprises an image acquisition step, a region of interest setting step, an excluded region setting step, a binarization step, a start point setting step, a sealer region detection step, and a sealer state analysis step.

Description

Inspection method for discharge state of sealer

The present invention relates to a method for inspecting the discharge state of a sealer, and more specifically, even when the work information and the work object are changed, a reset operation of the region of interest is not required, so that the work efficiency can be greatly improved, and based on the tip portion of the sealer discharge unit. The present invention relates to a method for inspecting a discharge state of a sealer that can not only accurately detect shape information of a sealer, but also significantly improve a calculation speed by detecting a sealer area within an area where an exclusion area is located in an area of interest.

In general, during the production process of automobiles, sealing is performed to secure watertightness and airtightness between inner and outer parts, or for bonding between materials, as well as for the purpose of rust prevention, dustproofing and heat dissipation of automobile bodies. For this purpose, a sealing gun for applying a sealer was used.

This, the sealing gun (sealing gun) can be divided into a manual type in which the discharge amount is set by the operator's grip and an automatic type in which the sealer is automatically drawn at a pressure set by compressed air when the operator operates such that the discharge port of the coating gun is opened. Previously, a method of manually applying a sealer to a work object such as a panel, a bracket, and a gasket using the above-described application gun has been widely used.

However, the above method has a problem in that it is difficult to perform a uniform operation because the sealer must be applied manually, and a difference occurs in the degree of completion of the work object according to the skill of the operator.

Accordingly, recently, a sealer coating device for automatically applying a sealer to a work object due to automation of equipment is used, an example of which is illustrated in FIG. 1.

1 is a view showing a conventional sealer coating device, Figure 2 is a flow chart showing a discharge method of the conventional sealer in order.

As shown in FIG. 1, the conventional sealer application device 100 includes a supporter 110, a sealer discharging unit 120 that is movably installed on an upper portion of the supporter 110, and discharges a sealer downward, and a sealer discharging unit It is installed on one side of (120) and consists of an inspection device that checks for defects in the discharge state of the sealer, and the robot arm holding the object is driven, and the work object is placed at a position corresponding to the sealer discharge part (120). When the sealer discharge unit 120 moves along a position to discharge the sealer based on preset work information, the sealer discharge unit 120 discharges the sealer to a predetermined sealer discharge target area.

At this time, the conventional tester for sealer application device 130 is installed on one side of the sealer nozzle unit, the camera 131 for acquiring a plurality of images of one side of the discharged sealer in real time, and analyzes the acquired image for the sealer discharge state. Consists of an analysis unit 132 that analyzes for defects, and analyzes the defects of the discharger of the sealer by acquiring and analyzing a number of images of the discharged sealers while moving along with the movement of the sealer discharge unit. More detailed description with reference to FIG. 2 is as follows.

First, the camera 131 acquires a plurality of images of the discharged sealer in real time while moving along with the movement operation of the sealer discharging unit, (S210) binarizing a preset region of interest among the acquired images, and (S220) binarizing Detects the sealer within the image of the region of interest, and (S230) analyzes the presence or absence, length and width of the detected sealer and compares the analyzed analysis information with a previously stored reference value to determine whether the sealer is defective. Inspect. (S240)

Here, in the conventional method for inspecting the discharge state of the sealer, as described above, a partial area in which the sealer is to be located is estimated and set as a region of interest in advance, and the image in the region of interest is analyzed to examine the discharge state of the sealer.

However, in the conventional method for inspecting the discharge state of the sealer, when the work information is changed or the work object is changed, the operator needs to re-specify the region of interest each time, and it takes considerable time to reset the region of interest, thereby significantly increasing the working time. There was a problem in that work efficiency and productivity were significantly reduced.

In addition, the conventional method for inspecting the discharge state of the sealer acquires an image of a part of the discharged sealer, and analyzes the shape information of the sealer due to noise generated by various environmental factors among the sealer detection areas among the areas acquired from the binarized image. Therefore, it is difficult to accurately analyze information on the shape of the sealer because the analysis reference point is ambiguous.

In addition, the conventional sealer discharge state inspection method analyzes only a specific region of interest, that is, a specific region of the acquired images in order to analyze images acquired in real time while the camera 131 moves, thereby reducing the computation amount and thereby improving the computational speed. However, in the process of detecting the sealer region in the region of interest, as all the pixels in the region of interest are analyzed, there is a limit to the efficiency of saving computation amount and improving computation speed.

The present invention has been devised to solve the above problems, and the object of the present invention is that a reset operation of the region of interest is not required even if the work information and the work object are changed, so that the work efficiency can be greatly improved, and the tip of the sealer discharge part The present invention provides a method for inspecting the discharge state of a sealer that can accurately detect the shape information of a sealer based on a negative as well as significantly improve a calculation speed by detecting a sealer area within an area in which an exclusion area is located within a region of interest.

According to an aspect of the present invention for achieving the above object, while discharging the sealer to the predetermined area of the work object while moving along the sealer discharge target area, the image obtained from the camera installed in the sealer discharge section is analyzed to discharge the sealer. In the discharge state inspection method of the sealer for inspecting whether or not the defect, the image that acquires a plurality of images of the discharge area of the sealer including the tip portion of the sealer discharge portion from the camera that moves together as the sealer discharge portion moves Acquisition step, a tip portion of the sealer discharging portion of the image, a region of interest setting step of setting a peripheral region of the tip portion as a region of interest, and an exclusion region for setting a region corresponding to the sealer discharging portion of the region of interest as an exclusion region A setting step, a binarization step of binarizing the region of interest, a pixel corresponding to the outer periphery of the sealer discharge unit within the excluded area, a pixel corresponding to the color of a pre-stored sealer among the detected pixels, and extraction A start point setting step of setting a pixel as a start point, and a sealer area detection step of detecting a pixel corresponding to the color of a pre-stored sealer in an area where the exclusion area is located among the plurality of images and detecting a sealer area from the start point And analyzing the shape information of the detected sealer area, and comparing the analyzed detection value with a preset reference value to determine whether the sealer is defective or not, and a sealer state analysis step. Provides a method for checking the condition.

In addition, it is preferable to further include a complementary step of removing noise from the region of interest binarized through morphological operation and compensating for the region lost due to binarization.

In addition, before the starting point setting step, a resolution converting step of converting the resolution of the region of interest to a lower resolution than the original may be further included.

In addition, it is preferable to further include an automatic region of interest setting step of automatically resetting the region corresponding to one side of the detected sealer to the region of interest.

In addition, the region of interest and the region of exclusion may be set in a circular shape.

According to the present invention as described above, even if the work information and the work object are changed, a reset operation of the region of interest is not required, thereby greatly improving the work efficiency, and accurately detecting the shape information of the sealer based on the tip portion of the sealer discharge unit. As well as, in the region of interest, by detecting the sealer region within the region where the exclusion region is located, there is an effect that can significantly improve the computational speed.

1 is a view showing a conventional sealer coating device,
Figure 2 is a flow chart showing the discharge method of the conventional sealer in order,
3 is a view schematically showing an apparatus for inspecting a discharge state of a sealer and a method for inspecting a discharge state of a sealer using the sealer according to an embodiment of the present invention;
Figure 4 is a block diagram schematically showing the connection relationship between each configuration of the tester using the discharge state inspection device of the sealer and the discharge state inspection method of the sealer according to an embodiment of the present invention,
Figure 5 is a flow chart showing a method for inspecting the discharge state of the sealer according to an embodiment of the present invention,
6 is a view showing a state of acquiring an image for a sealer discharged from a camera according to an embodiment of the present invention;
7 is a photograph of a state in which the region of interest and the region of exclusion are set according to an embodiment of the present invention,
8 is a view showing a state in which a pixel corresponding to a predetermined color of a sealer is extracted from pixels forming an outer circumference of the sealer discharge unit according to an embodiment of the present invention;
9 is a view showing a state of detecting a sealer area according to an embodiment of the present invention;
10 is a flowchart illustrating a method for inspecting a discharge state of a sealer according to another embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a view schematically showing an apparatus for inspecting a discharge state of a sealer and an inspection apparatus using a method for inspecting a discharge state of a sealer according to an embodiment of the present invention, and FIG. 4 is a sealer according to an embodiment of the present invention It is a block diagram schematically showing the connection relationship between each configuration of the discharge state inspection device and the inspection device using the discharge state inspection method of the sealer using the same.

First, as shown in Figures 3 and 4, looking at each configuration of the discharge state inspection device (1) of the sealer according to an embodiment of the present invention, it is installed on one side of the outer surface of the sealer discharge section (S) as an image recording area A lighting unit 10 for irradiating light and a camera 20 installed on the other side of the outer surface of the sealer discharging unit S to capture a plurality of images by capturing the sealer discharging area while moving as the sealer discharging unit S moves together ) And a controller 30 that receives an image acquired from the camera 20 and analyzes it to determine whether the sealer is in a defective state.

The lighting unit 10 is installed on one side of the outer surface of the sealer discharging unit S as described above, and a plurality of light sources are formed on one side to irradiate light to the image capturing area, so that the camera 20 to be described later is used for imaging the sealinger discharging area. It serves to provide the required light.

The camera 20 serves to acquire an image of a sealer application target area and provide it to the control unit 30, and a general CCD camera 20 can be used, which is common in the art. It is obvious that those who have knowledge are known to be able to purchase and use commercially available ones, and detailed configuration descriptions will be omitted.

The control unit 30 sets the peripheral region of the tip portion of the sealer discharge portion as the region of interest among the images applied from the camera 20 and sets the region corresponding to the sealer discharge portion in the region of interest as an excluded region, and discharges the region of interest. It detects the sealer area corresponding to the sealed sealer and analyzes the shape of the detected sealer area to determine whether the sealer is defective.

The operation of the control unit 30 will be described in more detail in the operation description to be described later.

5 is a flowchart illustrating a method for inspecting a discharge state of a sealer according to an embodiment of the present invention, and FIG. 6 is a view showing a state of acquiring an image of a sealer discharged from a camera according to an embodiment of the present invention 7 is a photograph of a state in which a region of interest and an exclusion region according to an embodiment of the present invention are set, and FIG. 8 is a color of a predetermined sealer from a pixel forming the outer periphery of the sealer discharge unit according to an embodiment of the present invention. FIG. 9 is a view showing a state in which a corresponding pixel is extracted, and FIG. 9 is a view showing a state in which a sealer region is detected according to an embodiment of the present invention.

A method for inspecting a sealer discharge state according to an embodiment of the present invention using the above-described device will be described with reference to FIGS. 5 to 9 as follows.

First, a method for inspecting a discharge state of a sealer according to an embodiment of the present invention includes a lighting control step, an image acquisition step, an interest area setting step, an exclusion area setting step, a binarization step, a complementation step, and a resolution conversion step. And, starting point setting step, sealer area detection step, and sealer state analysis step. The detailed operation of each step will be described below.

Prior to the description, the method for inspecting the discharge state of the sealer described below is actually performed at the same time as the sealer discharge operation of the sealer discharge robot S, but will be sequentially described at each step to help understanding.

Lighting control stage (S10)

First, when a work object is loaded into a jig installed under the sealer discharge part S, the sealer discharge part S discharges the sealer to the sealer application target area among the work objects while moving along the set virtual trajectory. In step 10), light required for image acquisition is provided by irradiating light to the shooting area.

Image acquisition stage (S20)

The camera 20 acquires an image by capturing the sealer discharge area while moving with the sealer discharge part S, but acquires an image including a tip portion of the sealer discharge part S and a sealer discharge area around it.

On the other hand, in the present embodiment, although it is described as acquiring an image from the camera 20, the acquisition operation of the actual image is obtained by acquiring a plurality of frames as the camera 20 continuously photographs the sealer discharge area. The expression of conceptually expresses any one of a plurality of frames to help understand the operation of the present invention.

In addition, the camera 20 transmits the acquired image to the control unit 30 and simultaneously transmits it to a database outside to store and collect the original image.

Interest area setting step and exclusion area setting step (S30, S40)

The controller 30 receives the image acquired from the camera 20 and sets the tip portion of the sealer discharge portion and the peripheral region of the tip portion as the region of interest.

In addition, the region corresponding to the sealer discharge portion in the region of interest is set as an excluded region.

In the case of setting the region of interest and the region of exclusion, the region of interest and the region of exclusion can be set as a rectangular region, but in this embodiment, these regions are set in a circle, which is a specific region centered on the tip portion of the sealer discharge section. To inspect and perform the sealer's starting point analysis.

Binarization stage (S50)

In the binarization step, the first and second images are converted into black and white images by binarizing the first image and the second image in order to detect sealer, that is, to detect the shadow. Before the binarization step, the RGB-type first and second images acquired by the camera 20 are The operation of converting the image to the YUV method may be preceded. The operation of converting the RGB method image to the YUV method image is generally used in the vision inspection method, and a detailed description thereof will be omitted.

Complementary stage (S60)

The complementary step is a step for removing the noise generated by various factors during the above-described binarization step and compensating for the missing area, and the noise removing and the missing area supplementing operation is performed through a known morphological operation. .

Here, the morphological operation (morphological operation) is a technique that deals with images from a morphological point of view, and has a background in the set theory of mathematics. Since it is used, a detailed description thereof will be omitted.

Resolution conversion step (S70)

In this embodiment, the resolution of the region of interest including the excluded region in the image is converted to a low resolution.

As an example, as the original image of the region of interest having a resolution of 1980x720 is changed to a low resolution of 640x320, the number of pixels in the analysis area is reduced, and thus the computational amount to process it is greatly reduced, thereby significantly improving the computational speed.

Starting point setting step (S80, S90)

Next, the control unit 30 extracts the pixels forming the outer periphery of the sealer discharge unit in the excluded region, and sequentially extracts the extracted pixels as a candidate sealer group if they fall within a preset reference color range, and extracts the extracted sealer candidate group. Set it as a starting point.

In other words, the present invention can accurately detect the discharge start point of the sealer by detecting pixels of a color corresponding to the sealer based on the outer circumference of the sealer discharge portion where the actual sealer is discharged, and thereby accurately analyze the length of the sealer. .

Sealer area detection step (S100)

In the sealer region detection step, the sealer region is detected based on the discharge start point of the set sealer. In this embodiment, the sealer region may be detected using a chain code.

Here, the chain code is a method of expressing through the unit distance moving in the east, west, south, and north directions from the starting point of the data, all of the words that can be expressed in N bits (2n kinds), or Some of them are arranged in a cyclical sequence, where each word is generated from neighboring words, by discarding the leftmost and rightmost bits and adding new bits to the end.

Such a method of detecting a specific region using a chain code is already well known and used, and a description of a method of detecting a sealer region using a chain code will be omitted.

On the other hand, a number of starting point candidates may be detected due to various environmental factors such as a sealer remaining on the surface of the sealer discharging portion in the starting point setting step. In this case, all sealer regions starting from each starting point are detected.

Sealer status analysis step (S110)

In the sealer state analysis step, the length of each detected sealer area is analyzed from a plurality of starting points, and a sealer area having the longest length among the analyzed multiple sealer areas is selected as a final analysis target.

Then, the shape information such as the length and width of the sealer area selected as the final analysis target, and the discharge position of the sealer are analyzed, and the analyzed analysis value is compared with a preset reference value to determine whether the sealer is defective.

Accordingly, when the discharging operation is completed, the presence or absence of a defect is indicated on the prepared display, and the defect location is guided so that the operator can correct the area.

10 is a flowchart illustrating a method for inspecting a discharge state of a sealer according to another embodiment of the present invention.

The basic configuration of the embodiment of FIG. 10 is the same as that of the embodiments of FIGS. 3 to 9, but the automatic setting of the region of interest (S120) in which one of the sealer regions selected as the final analysis target in the sealinger analysis step is automatically designated as the region of interest More are added.

This automatic setting step (S120) can be used in a conventional sealer discharge state inspection method.

The conventional sealer ejection state inspection method in which a part of the sealer ejection area is set as a rectangular region of interest has the advantage of analyzing more information regarding the ejector state of the sealer than the present embodiment, but inspects the sealer ejection state. Before, the operator had to set the region corresponding to the discharge area of the sealer in advance as the region of interest, and there was a hassle of resetting the region of interest when the work object was changed or the work information was changed.

Accordingly, when the sealer discharge state inspection according to the present embodiment is performed during the first sealer discharge state inspection, one side of the last detected sealer area is automatically set as a region of interest, and then a conventional sealer discharge state inspection method is used.

That is, when an operator selects a conventional sealer discharge state inspection method to analyze a large amount of information, the conventional sealer discharge state is inspected by allowing the region of interest to be automatically reset according to the present embodiment even if the work object is changed or the work information is changed. The problem of the method can be solved, and the convenience can be greatly improved.

Other structures are the same as the above-described basic embodiment, and the rest of the description will be omitted.

Although the invention has been described in connection with the preferred embodiments mentioned above, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the scope of the appended claims will include such modifications or variations that fall within the gist of the present invention.

10: lighting unit 20: camera
30: control unit

Claims (5)

A method for inspecting a discharge state of a sealer that analyzes an image acquired from a camera installed in a sealer discharge unit that discharges a sealer to a predetermined area of a work object while moving along the sealer discharge target area, and inspects whether the sealer is discharged or not.
An image acquiring step of acquiring a plurality of images of a discharge area of the sealer including a tip portion of the sealer discharge portion from the camera moving together as the sealer discharge portion moves;
A region of interest setting step of setting a tip portion of the sealer discharge portion and a peripheral region of the tip portion as the region of interest in the image;
An exclusion area setting step of setting an area corresponding to the sealer discharging part of the region of interest as an exclusion area;
A binarization step of binarizing the region of interest;
A starting point setting step of detecting a pixel corresponding to the outer periphery of the sealer discharge portion in the exclusion area, extracting a pixel corresponding to a color of a pre-stored sealer among the detected pixels, and setting the extracted pixel as a starting point
A sealer area detecting step of detecting a sealer area from the starting point by detecting a pixel corresponding to a color of a pre-stored sealer in an area where the exclusion area is located among the plurality of images; And
And a sealer state analyzing step of analyzing the detected shape information and positional information of the sealer area, and comparing the analyzed detection value with a preset reference value to determine whether the sealer is defective or not. How to check the discharge state.
According to claim 1,
A method for inspecting a discharge state of a sealer, further comprising a complementary step of removing noise from the region of interest binarized through a morphological operation and compensating for a region lost due to binarization.
According to claim 1,
And a resolution conversion step of converting the resolution of the region of interest to a lower resolution than the original before the setting of the starting point.
According to claim 1,
And automatically setting a region of interest for automatically resetting the region corresponding to one side of the detected sealer to the region of interest.
According to claim 1,
The region of interest and the region of exclusion are characterized in that they are set in a circular shape.

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