KR20110061300A - Control apparatus and method of spangle size at continuous hot-dip galvanizing line that easy spray position control - Google Patents

Abstract

PURPOSE: A device and method for controlling spangle of a molten galvanizing steel plate are provided to control the spray area of spangle miniaturizing material. CONSTITUTION: A device for controlling spangle of a molten galvanizing steel plate comprises a injecting device(20), a moving device(30), and a high speed camera(40) and a control device(50). The injecting device comprises an injection nozzle(21) for spraying spangle minimization material to the plated steel sheet in which molten zinc is plated. The moving device transfers the injection nozzle of the injecting device to the spray position. The high speed camera takes an image of the surface of the plated steel sheet in which the molten zinc is plated.

Description

Control Apparatus and Method of Spangle Size at Continuous Hot-Dip Galvanizing Line That Easy Spray Position Control}

The present invention relates to a sequin control device and method for continuous hot-dip galvanized steel sheet easy to control the injection position, and more particularly to analyze the image to determine the position of the sequins, and to inject the sequins micronized material to the position where the sequins are formed It is an apparatus and method for sequin refinement of a hot dip galvanized steel sheet.

 In general, hot-dip galvanized steel sheet is used for interior and exterior materials of home appliances due to excellent corrosion resistance, and is used for interior and exterior materials of buildings and components of electrical and electronic products.

When zinc is corroded earlier than iron by the sacrificial method, zinc oxide is thinly formed on the surface, which prevents zinc from being corroded anymore, thereby inhibiting corrosion of the base metal.

In the manufacturing method of the hot-dip galvanized steel sheet, the metal zinc is melted in a ceramic pot to form a molten liquid state, and a thin steel sheet is deposited on one side of the pot and continuously drawn out to the other side of the pot so that the molten zinc is deposited on the surface of the steel sheet. I use a lot.

The apparatus for producing hot dip galvanized steel sheet may include: an unwinding frame (1) on which a coil in which a hot dip galvanized steel sheet is wound in a roll form is mounted; A cleaning facility (3) for washing the surface storage of the entrance storage frame (2) through which the front end of the steel sheet released from the coil of the release frame and the surface residue of the steel sheet passing through the entrance storage frame (2); A heat treatment facility 4 for softening the steel sheet material having passed through the cleaning facility; A plating facility (5) provided with a hot dip plating port to bury the molten zinc on the surface of the steel sheet passing through the heat treatment facility (4); An air knife facility (6) through which the hot dip galvanizing is excessively buried on the surface of the steel sheet while passing through the plating facility (5); A fine material injection device (7) which passes through the air knife device (6) and injects a fine material to the surface of the steel sheet to refine the sequin size of the floral pattern formed on the surface when the molten zinc solidifies; A cooling installation (8) for cooling the steel sheet; A temper rolling facility 9 for stretching the steel sheet by several percent to improve the mechanical properties of the cooled steel sheet; A post-treatment facility 10 for applying anti-rust oil or a material to perform a special function on the stretched steel sheet surface; An exit storage frame 11 through which the steel sheet passed through the after-treatment facility 10 passes, and a winding frame 12 for winding the steel sheet passing through the exit storage frame 11 and storing it in a coil form.

The hot-dip galvanized steel sheet is a steel sheet is released from the above-mentioned rim (1), the storage tank 2, the cleaning equipment (3), heat treatment equipment (4), plating equipment (5), air knife equipment (6), miniaturization The manufacturing is completed while winding the winding mold 12 through the material spraying equipment 7, the cooling equipment 8, the tempered rolling equipment 9, the aftertreatment equipment 10, and the exiting storage frame 11.

The steel sheet is deposited on molten zinc and gradually cooled in the air while zinc crystals develop dendritic on the surface to form flower-shaped zinc crystals called sequins.

The sequins may cause the appearance deterioration of the surface of the hot-dip galvanized steel sheet to be completely removed in the hot-dip galvanizing process of the steel sheet. Even distribution is most desirable.

In the sequin refinement distribution method described above, it is common to inject the sequin refinement material in the refinement injection device 7.

As described above, the micronizing method of spraying the sequin micronized material on the surface of the steel plate deposited and plated in molten zinc uses a method of spraying the micronized material on the surface before the molten metal material of the steel plate surface is solidified.

In the sequin refining method, it is most important that the micronized material acts as nucleation site of the molten metal to inhibit nucleus growth by minimizing the sequin size by spraying the micronized material immediately before the molten metal material solidifies.

That is, since the melting point of zinc is 419.6 ° C, spraying micronized material at a temperature higher than 419.6 ° C causes defects on the surface of the molten metal, and if it is sprayed at a temperature lower than 419.6 ° C, it is already melted. Metals begin to solidify and promote nuclear growth, resulting in no sequin refinement.

Therefore, it is very important technique to inject micronized material by measuring that the temperature of the molten zinc is 419.6 ° C. on the surface of the steel sheet, but it is difficult to accurately measure the temperature of the molten zinc.

In general, a method of measuring temperature includes a contact method and a non-contact method of a temperature meter.

In the case of measuring the zinc temperature in the molten state by the contact method for the sequin refinement operation, it is difficult to measure by contacting the temperature sensor to the surface of the steel sheet continuously moving at a rate of about 200 mpm (meter per minute) during the continuous hot dip galvanizing process In this case, when the temperature sensor is contacted, contact marks remain on the non-solidified molten zinc, which causes a lot of surface defects during the hot dip galvanizing operation.

In addition, a method of measuring the temperature of the non-solidified zinc on the surface of the steel sheet with a non-contact thermometer has been proposed.

However, the above-mentioned non-contact type thermometer uses non-contact temperature measurement principle of several tens to tens of micro-infrared rays, and the measured temperature value varies according to the infrared radiation rate. The emissivity of the non-solidified zinc surface is less than 0.1. As the surface is high reflectivity like a mirror, the ambient light or object is reflected on the molten zinc surface to be measured, so that the emissivity value of the non-contact infrared thermometer is changed from time to time. There was a problem that was difficult to do.

Therefore, it is difficult to precisely inject the sequin fine material when the temperature of the molten zinc is 419.6 ° C. on the surface of the steel sheet to determine the injection point of the sequin fine material by using a non-contact thermometer. This is actually a technology that is not used in the field.

The present invention is a continuous molten zinc easy to control the injection position to increase the degree of miniaturization of sequins by accurately spraying the sequin micronized material to the optimum temperature of the molten zinc through image analysis of the image taken by a high-speed camera The present invention provides a device and a method for controlling a sequin of a coated steel sheet.

The object of the present invention is an injection device having an injection nozzle for injecting a sequin fine material on the plated steel sheet coated with molten zinc;

A mobile device for moving the injection nozzle of the injection device to an injection point;

A high speed camera for photographing the surface of the plated steel sheet plated with molten zinc;

Analyze the image taken by the high-speed camera to identify the point where the sequins are formed on the plated steel sheet and to facilitate the injection position control including a control device for moving the injection device to the mobile device to spray the sequin fine material to the sequin formation point It is solved by providing a sequin control apparatus for a continuous hot dip galvanized steel sheet.

The high speed camera has a shooting speed of 1,000 to 5,000 fps (frame per second).

The high speed camera is connected to and integrated with the spray nozzle, and the mobile device moves the integrated high speed camera and the spray nozzle together.

The high speed camera is disposed on an upper side of the spray nozzle of the spray apparatus,

The injection device is to spray the sequin fine material 300 to 1,000mm before the position where the sequins are formed.

The control device includes a filtering unit for removing unnecessary images and signals from images captured by the high speed camera;

An image processing unit for finding and confirming an image of a sequin from the filtered image by the filtering unit;

It is connected to the injection device, a high speed camera, a mobile device and includes an operation control unit for controlling each operation.

And a camera elevating device for elevating the high speed camera.

In another aspect, the present invention is the photographing step of photographing the plated steel sheet plated with molten zinc with a high speed camera;

An image analysis step of identifying a point where sequins are formed on the coated steel sheet by analyzing the image photographed in the photographing step;

It is solved by providing a sequin control method of a continuous hot dip galvanized steel sheet which is easy to control the injection position, including an injection step of injecting a sequin fine material into the identified sequin formation point.

The shooting step is to shoot at a shooting speed of 1,000 ~ 5,000fps (frame per second).

The image analyzing step may include an image filtering process of removing unnecessary images from a plurality of images photographed by the high speed camera;

It includes a sequins confirmation process for confirming that the sequins are formed on the surface of the plated steel sheet in the selected image through the image filtering process.

When the sequin formation is not confirmed in the image analysis step, the method further includes a high speed camera moving step of moving the high speed camera and performing a shooting step, wherein the high speed camera moving step moves the high speed camera and the spray nozzle together.

The spraying step is to spray the sequin fine material from 300 ~ 1,000mm before the sequin formation position confirmed in the image analysis step.

The present invention has the effect of minimizing the sequins, evenly and widely distributed by analyzing the image by precisely spraying the sequins micronized material to the formation point of the sequins.

Therefore, the present invention significantly improves the gloss quality of the hot dip galvanized steel sheet, maintains the quality of the hot dip galvanized steel sheet uniformly, and reduces the defective rate.

When described in detail with reference to the accompanying drawings a preferred embodiment of the present invention.

Fig. 2 is a schematic diagram of a sequin control device of a continuous hot dip galvanized steel sheet in which injection position control of the present invention is easy, and shows an example in which the present invention is disposed after an air knife facility and sprays a sequin fine material on the surface of the coated steel sheet.

Figure 3 is a front view showing an embodiment of a sequin control device of the continuous hot-dip galvanized steel sheet easy to control the injection position of the present invention, the mobile device moves the nozzle of the high speed camera and the spraying device together and sequins on the surface of the plated steel sheet The example which injects refine | miniaturized substance is shown.

4 is a block diagram showing a procedure of a method for controlling a sequin control of a continuous hot dip galvanized steel sheet which is easy to control the injection position of the present invention, and shows an example in which a photographing step, an image analyzing step, and a spraying step are sequentially performed.

Figure 5 is a flow chart according to the sequin control method of the continuous hot-dip galvanized steel sheet easy to control the injection position of the present invention, showing the flow according to the sequins refinement method in more detail.

6A to 6C are photographs taken with the high speed camera of the present invention, and FIG. 6A is a photograph before the sequins are formed on the surface of the coated steel sheet, and FIG. 6B is a photograph at which the sequins are formed on the surface of the coated steel sheet. 6c is a photograph in a state where sequins are completely formed on the surface of the coated steel sheet.

Hereinafter, as shown in FIG. 2, the sequin control apparatus of the continuous hot-dip galvanized steel sheet which is easy to control the spraying position of the present invention is filled with molten zinc in the continuous production line of the hot-dip galvanized steel sheet, and the ceramic plate is deposited through the ceramic. It is provided in the rear side of the plating equipment 5 including a pot, and the air knife equipment 6 which blows air to the surface of the steel plate which passed the said plating equipment 5, and adjusts the surface plating amount of molten zinc.

The spraying device 20 of the present invention is disposed on the rear side of the air knife facility 6 to inject a sequin fine material to the surface of the plated steel sheet 60 in the state of molten zinc plated.

The injection device 20 includes a plurality of injection nozzles 21 for injecting the sequin fine material and a supply unit for supplying the sequin fine material to the injection nozzle 21.

The plurality of spray nozzles 21 are disposed to be spaced apart in the width direction of the steel sheet so as to be close to the point where the sequin formation is confirmed in the image captured by the high speed camera 40 to be described later. It is controlled by the device 50.

The sequin micronized material may be selected from any one of sodium acetate solution, sodium chloride solution, sodium phosphate solution, and ammonium phosphate solution, and has excellent cooling ability, considering the effects on spray stability, post-treatment and paintability In this case, an aqueous ammonium phosphate solution is preferably used.

Examples of the ammonium phosphate include ammonium dihydrogen phosphate (NH ₄ H ₂ PO ₄ ), diammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ), triammonium phosphate ((NH ₄ ) ₃ PO ₄ ), and the like.

The injection nozzle 21 of the injection device 20 is moved to the injection point by the mobile device 30, and the injection point is determined by the image of the high speed camera 40 photographing the surface of the plated steel sheet 60. do.

The moving device 30 reciprocates the spray nozzle 21 to correspond to the moving direction of the plated steel sheet 60.

The mobile device 30 is controlled by the control device 50, which will be described later, and moves and positions the injection nozzle 21 at the sequin formation position determined as the image of the high speed camera 40.

The high speed camera 40 photographs the surface of the plated steel sheet 60 and transmits an image signal to the control device 50 to be described later. The high speed camera 40 uses a high speed shooting camera having a shooting speed of 500 fps (frame per second) or more. The speed is 1,000 to 5,000 fps (frame per second).

As can be seen in Example 1 below, if the shooting speed per second of the high-speed camera 40 is less than 1,000 sheets, even if the plated molten zinc is solidified to form sequins, the image may distinguish the sequins due to the moving speed of the steel sheet. It is blurred so that it is impossible to determine the shape of the sequins.

In addition, when the shooting speed of the high speed camera 40 is more than 5,000, a clear and clear image capable of classifying sequins may be taken regardless of the moving speed of the steel sheet, but a large amount of the control device 50 will be described later. Since the data must be processed, the processing speed is slow, and the time to be injected to the injection point is delayed, thereby reducing the sequin refinement efficiency and increasing the defective rate.

[Example 1]

Experiment number Line speed (mpm) Shooting Speed (fps) Sequin judgment Data processing status One 200 900 Undetermined Great 2 200 1,000 Judgment Great 3 200 3,000 Judgment Great 4 200 5,000 Judgment Great 5 200 5,900 Judgment Bad 6 150 6,500 Judgment Bad

The image of the high speed camera 40 is transmitted to the control device 50, and the control device 50 includes: a filtering unit 51 for removing unnecessary images and signals from the image captured by the high speed camera 40;

An image processing unit 52 for finding and confirming an image of a sequin from the filtered image by the filtering unit 51;

It is connected to the injection device 20, the high speed camera 40, the mobile device 30 includes an operation control unit 53 for controlling each operation.

The image processing unit 52 finds the sequins from which the sequins are formed in the filtered image and checks the sequin formation points where the sequins are formed, and the operation controller 53 controls the injection nozzles of the injection device 20. 21) is moved to the sequin formation point to spray the sequin fine material to the sequin formation point.

The present invention is to spray the sequin fine material while confirming the point where the sequins are formed with an image.

In the sequin refining operation, when the temperature of the molten zinc is 419.6 ° C. on the surface of the plated steel sheet 60, a sequin fine material may be sprayed onto the sequins formed on the plated steel sheet 60 to obtain an optimal refinement effect.

The molten zinc of the plated steel sheet 60 starts to solidify at 419.6 ° C., and as the solidification starts, sequins are formed.

That is, in the present invention, since the temperature of the sequin formation point at which the sequins are formed is 419.6 ° C., the image processing unit 52 checks the point where the sequins are formed by the image photographed by the high speed camera 40, thereby reducing the It is to know the exact injection point and injection timing.

The present invention further comprises a separate high speed camera moving device (not shown) for moving the high speed camera 40 to move the high speed camera 40 at a speed faster than the moving speed of the steel sheet to photograph the surface of the steel sheet. Preferably, the high speed camera 40 is integrated with the injection nozzle 21 of the injection device 20 as shown in FIG. 3 so as to be moved together by the mobile device 30.

When the spray nozzle 21 of the high speed camera 40 and the spray device 20 are moved separately, after confirming the sequin formation with the high speed camera 40, the spray nozzle 21 is moved to the mobile device 30 at the sequin forming point. It is difficult to spray the sequin micronized material at the exact time when the sequins are formed due to the shifting time.

The moving device 30 includes a moving guide rail member 31 disposed on both sides of the plated steel sheet 60 so as to correspond to a moving direction of the plated steel sheet 60;

A plurality of injection nozzles 21 of the injection device 20 mounted on the moving guide rail member 31 and moving along the moving guide rail member 31 across the width direction of the plated steel sheet 60; And a moving frame member 32 to which the high speed camera 40 is mounted.

Although not shown, the moving frame member 32 may be provided to be reciprocated within a predetermined period by being connected to a chain or a belt that receives a rotational force of the motor and moves in a circular orbit. The rotational force of the motor using the rack gear and the pinion gear may be provided. It can be provided to be reciprocated in a structure that converts to a linear reciprocating movement, in addition to that it can be found that it can be carried out by transforming into a variety of known moving structures.

The operation control unit 53 moves the surface of the plated steel plate 60 with the high speed camera 40 while moving the high speed camera 40 and the spray nozzle 21 of the injection device 20 together to the mobile device 30. Photographing, and when it is confirmed that the sequins are formed in the photographed image, the sequin fine material is sprayed through the spray nozzle 21 at the sequin forming point.

The operation control unit 53 selects the spray nozzle 21 disposed at a position corresponding to the sequin formation point among the plurality of spray nozzles 21 and injects the sequin fine material.

In addition, the operation control unit 53 is a spray nozzle of the high speed camera 40 and the injection device 20 to the mobile device 30 when the point where the sequins are formed in the image photographed by the high speed camera 40 is not confirmed Moving the 21 to photograph the surface of the plated steel sheet 60, and to repeat the process of confirming the sequin formation point in the image taken again.

The high speed camera 40 is preferably disposed on the upper side of the injection nozzle 21 of the injection device 20.

When the position where the sequins are formed through the image of the high speed camera 40 is confirmed, the spraying device 20 may spray the sequin fine material 300 to 1,000 mm before the position where the sequins are formed.

This is because the sequin refinement material has the greatest sequin refinement effect only when the sequin refinement material is sprayed just before the sequins are formed on the surface.

The present invention further includes a camera elevating device 41 for elevating the high speed camera 40 to adjust the photographing position of the high speed camera 40, and to confirm the image confirming position of the high speed camera 40 and the ejection device. By adjusting the interval between the spray nozzles 21 of 20, the position where the sequin fine material is injected before the position where the sequins are formed can be adjusted.

The elevating device 41 is an example of using a hydraulic cylinder, in addition to the high-speed camera 40 to move up and down, it turns out that it can be implemented in various modified examples of the structure.

In addition, the injection section of the injection device 40 is 2,000 ~ 4,000mm, which can be variously modified according to the thickness, line speed, galvanized thickness of the plated steel sheet (60).

On the other hand, sequin control method of the continuous molten galvanized steel sheet easy to control the injection position of the present invention includes a photographing step (100) for photographing the galvanized steel sheet 60 is plated with a high-speed camera 40;

An image analysis step (200) of analyzing a photographed image in the photographing step (100) to identify a point where sequins are formed on the coated steel sheet (60);

And a spraying step 300 for spraying the sequin refinement material to the identified sequin formation point.

The sequin refinement process by the sequin control method of the continuous hot-dip galvanized steel sheet which is easy to control the injection position of the present invention is a plating process during the continuous plating manufacturing process of the hot-dip galvanized steel sheet 60, that is, the hot-dip zinc filled in the ceramic pot It is just before the cooling process after the deposition process to pass through the deposition, the plating amount adjustment process to control the zinc plating amount by air sprayed from the air knife installation 6 during the movement of the steel plate coated with molten zinc on the surface. .

The photographing step 100 is to photograph the surface of the plated steel sheet 60 is plated on the surface of the plated steel plate 60 being moved to the next process, that is, the cooling process at a high speed, preferably 1,000 to 5,000 fps (frame per second) Shooting at a shooting speed.

As can be seen in Example 1, if the shooting speed per second of the high-speed camera 40 is less than 1,000 sheets, even if the plated molten zinc is solidified to form sequins, the image may distinguish sequins due to the moving speed of the steel sheet. It is blurred so that it is impossible to determine the shape of the sequins.

In addition, when the shooting speed of the high speed camera 40 is more than 5,000, a clear and clear image capable of classifying sequins may be taken regardless of the moving speed of the steel sheet, but a large amount of the control device 50 will be described later. Since the data must be processed, the processing speed is slow, and the time to be injected to the injection point is delayed, thereby reducing the sequin refinement efficiency and increasing the defective rate.

The image analyzing step 200 includes an image filtering process 210 for removing unnecessary images from a plurality of images captured by the high speed camera 40;

And a sequin check process 220 for confirming that the sequins are formed on the surface of the plated steel plate 60 in the selected image through the image filtering process 210.

The sequin confirmation process 220 is to check the sequin shape of the polygon formed in a triangle or a pentagon with a size of 0.5 ~ 5mm.

In the spraying step 300, when it is confirmed that the sequins are formed in the image analyzing step 200, the sequin fine material is sprayed on the sequin forming points.

In this case, the spraying step 300 preferably sprays the sequin fine material 300 to 1,000 mm before the sequins formed in the image analysis step 200.

The injection section of the injection step 300 is 2,000 ~ 4,000mm, which can be variously modified according to the thickness, line speed, galvanized thickness of the plated steel sheet 60.

This is because the sequin refinement material has the greatest sequin refinement effect only when the sequin refinement material is sprayed just before the sequins are formed on the surface.

The present invention further includes a high speed camera moving step 400 for moving the high speed camera 40 and performing the shooting step 100 when the sequin formation is not confirmed in the image analysis step 200.

In the high speed camera movement step 400, if the sequin shape of the polygonal shape of 0.5 to 5 mm is not confirmed, the high speed camera 40 is moved upward by 50 mm and photographed again to confirm the sequin formation.

That is, according to the present invention, the plated steel sheet 60 is photographed by the high speed camera 40, and when the formation of the sequins is confirmed in the photographed image (FIG. 6B), the sequin fine material is sprayed correctly on the sequin forming point.

In addition, when the sequin formation is not confirmed in the image photographed by the high speed camera 40, that is, when the polygonal sequin shape of 0.5-5 mm is not confirmed (FIG. 6A), the high speed camera 40 is moved to Since the sequins are repeatedly formed by photographing the other surface part, the sequin formation point is quickly confirmed on the surface of the plated steel sheet 60, and the sequin fine material is sprayed accurately to the sequin formation point.

As described above, when the sequin fine material is injected onto the surface of the steel sheet, the sequins are minutely and evenly distributed on the surface of the plated steel sheet 60 as shown in FIG. 6C.

The present invention analyzes the image taken by the high-speed camera 40 to determine the optimum time point and the point of spraying the sequin fine material as described above, so that no error of judgment occurs.

And the high-speed camera 40 and the spray nozzle 21 is moved integrally to confirm the sequin formation point and at the same time spraying the sequin fine material to the sequin formation point it is possible to further maximize the sequin fine effect.

The present invention is not limited to the above-described embodiments, and various changes can be made without departing from the gist of the present invention, which is understood to be included in the configuration of the present invention.

1 is a schematic view showing a continuous production line of a typical hot dip galvanized steel sheet

Figure 2 is a schematic diagram of a sequin control device of the continuous hot-dip galvanized steel sheet easy to control the injection position of the present invention

Figure 3 is a front view showing an embodiment of the sequin control device of the continuous hot-dip galvanized steel sheet easy to control the injection position of the present invention

Figure 4 is a block diagram showing the procedure of the sequin control apparatus method of the continuous hot-dip galvanized steel sheet easy to control the injection position of the present invention

Figure 5 is a flow chart according to the sequin control method of the continuous hot-dip galvanized steel sheet easy to control the injection position

6a to 6c is a photograph taken with a high speed camera of the present invention

* Description of the major symbols in the drawings *

20: injection machine 21: injection nozzle

30: mobile device 40: high speed camera

50: control device 60: filtering unit

52: image processing unit 53: operation control unit

Claims (11)

An injector having an injector nozzle for injecting a sequin fine material into the plated steel sheet plated with molten zinc; A mobile device for moving the injection nozzle of the injection device to an injection point; A high speed camera for photographing the surface of the plated steel sheet plated with molten zinc; An injection position including a control device for analyzing the image photographed by the high speed camera to identify a point where sequins are formed on the plated steel sheet, and moving the injector to a moving device to inject a sequined micronized material at the sequin formation point Sequin control device of continuous hot dip galvanized steel sheet for easy control. The method according to claim 1, The high-speed camera has a sequin control device of the continuous hot dip galvanized steel sheet easy to control the injection position, characterized in that having a shooting speed of 1,000 ~ 5,000fps (frame per second). The method according to claim 1, The high speed camera is connected to the injection nozzle and integrated, and the mobile device moves the integrated high speed camera and the injection nozzle together. The method according to claim 1 or 3, The high speed camera is disposed on an upper side of the spray nozzle of the spray apparatus, The spraying device is a sequin control device of the continuous hot-dip galvanized steel sheet easy to control the injection position, characterized in that for spraying the sequin fine material from 300 ~ 1,000mm before the position where the sequins are formed. The method according to claim 1, The control device includes a filtering unit for removing unnecessary images and signals from images captured by the high speed camera; An image processing unit for finding and confirming an image of a sequin from the filtered image by the filtering unit; And an operation control unit connected to the injection device, the high speed camera, and the mobile device to control each operation. The method of claim 3, And a camera elevating device for elevating the high-speed camera. A photographing step of photographing a plated steel sheet coated with molten zinc with a high speed camera; An image analysis step of identifying a point where sequins are formed on the coated steel sheet by analyzing the image photographed in the photographing step; And a spraying step of spraying a sequin fine material with the spraying nozzle at the identified sequin forming point. The method of claim 7, The photographing step is a sequin control method of the continuous hot-dip galvanized steel sheet easy to control the injection position, characterized in that shooting at a shooting speed of 1,000 ~ 5,000fps (frame per second). The method according to claim 7 or 8, The image analyzing step may include an image filtering process of removing unnecessary images from a plurality of images photographed by the high speed camera; Sequin control method of the continuous hot-dip galvanized steel sheet easy to control the spray position, characterized in that it comprises a sequins confirmation process for confirming that the sequins are formed on the surface of the coated steel sheet in the selected image through the image filtering process. The method of claim 7, If the sequin formation is not confirmed in the image analysis step, further comprises a high speed camera moving step of moving the high speed camera and performing as a shooting step, wherein the high speed camera moving step is characterized by moving the high speed camera and the spray nozzle together Sequin control method of continuous hot dip galvanized steel sheet for easy injection position control. The method of claim 7, wherein The spraying step is a sequin control method of the continuous hot-dip galvanized steel sheet easy to control the injection position, characterized in that for spraying the sequin fine material from 300 ~ 1,000mm before the sequin formation position confirmed in the image analysis step.

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