TW202328468A - Method and system for controlling thickness of galvanized film of steel strip - Google Patents

Abstract

A method of controlling a thickness of galvanized film of a steel strip includes: passing the steel strip through a zinc liquid tank to achieve hot-dip galvanization; utilizing an air knife device to blow off the excess zinc liquid on the steel strip; measuring a front surface zinc layer thickness and a back surface zinc layer thickness of the metal strip; determining whether the air knife device has the air knife lip retraction according to the front surface zinc layer thickness and the back surface zinc layer thickness; and correcting the position of the air knife device relative to the metal strip when determining that the air knife device has the air knife lip retraction.

Description

Steel strip galvanized film thickness control method and system

The present invention relates to a control method and its system, and in particular to a steel strip galvanized film thickness control method and its system.

Hot-dip galvanized steel sheet is currently the most widely used and most effective steel corrosion protection method, and the corrosion resistance of galvanized steel strip mainly depends on the thickness of the galvanized layer of the steel strip. In the traditional production method, after the hot-dip galvanizing of the steel plate is completed, the thickness of the galvanized layer will be measured by X-ray (X-ray) through the measuring device after the zinc liquid is solidified, and then according to the thickness of the galvanized layer on the front and rear surfaces Manually adjust the position of the centerline of the steel strip according to the difference in thickness until the difference in the thickness of the zinc layer on the front and rear surfaces is the smallest. However, this method of adjusting the center line of the steel strip cannot immediately adjust the center position of the steel strip, which may easily cause the thickness of the zinc layer of some steel strips to fail to meet the target. In addition, when there is an abnormality in the production line, it is necessary to wait for the thickness of the zinc layer at the back end Only the measurement results of the measuring device can be relatively dealt with, which cannot be predicted in real time. Furthermore, manual adjustments will lead to inconsistent judgment standards and large variations, making it impossible to establish adjustment standards.

In addition, in order to maintain the stability of the zinc tank equipment in the galvanizing production line, after about 3 weeks of operation, there is a period of 1 week for equipment maintenance. During the maintenance period, all related equipment in the zinc tank, such as immersion rollers, correction rollers, stabilization rollers, etc. will be removed for replacement and maintenance. As a result, when the equipment is reinstalled, the parameters may have offset errors, such as the center position parameters have not been corrected , will cause the thickness of the zinc layer on the front and rear surfaces of the steel strip to deviate. The correction method of the center position parameter is also manually adjusted by the measurement results of the rear-end zinc layer thickness measuring device as mentioned above. In addition to the problems discussed above, the thickness of the zinc layer on the front and rear surfaces of the steel strip The inconsistency is not limited to the position of the center line, but other factors also affect it. It is difficult for manpower to accurately judge and correct the process parameters.

Another example is the roller bearings in the zinc tank. During the production process, the continuous wear will cause the position of each roller to shift, which will also increase the variability of process parameters during the production process.

Another important piece of equipment is the air knife. During the galvanizing process, zinc liquid will adhere to the air knife and block the air outlet, causing uneven air flow. Therefore, it is necessary to use a scraper to clean the lip of the air knife during the production process. Accumulation will cause the lip of the air knife to shrink, resulting in a longer distance between the actual air knife and the steel strip, and greater variation in the thickness of the zinc layer. However, at present, the problem of retraction of the air knife lip can only be corrected by manual measurement when the machine is shut down for maintenance, and cannot be predicted immediately.

The object of the present invention is to propose a method for controlling the galvanized film thickness of a steel strip, which is suitable for a galvanized steel strip production line. The above-mentioned galvanized steel strip production line includes a zinc liquid tank and an air knife device. The strip passes through the zinc bath to achieve hot-dip galvanizing and blows air through the air knife device to scrape off excess zinc on the strip. The method for controlling the galvanized film thickness of the steel strip includes: measuring the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface of the steel strip; judging whether the air knife device has an air knife lip Retraction; and when it is judged that the air knife device has a retraction of the air knife lip, correct the position of the air knife device relative to the steel belt.

In some embodiments, the method for controlling the galvanized film thickness of the steel strip further includes: when the thickness of the zinc layer on the front surface or the thickness of the zinc layer on the rear surface is greater than the target zinc layer thickness, judging that the air knife device has an air knife lip retraction.

In some embodiments, the method for controlling the galvanized film thickness of the steel strip further includes: before the steel strip passes through the air knife equipment, transmitting a plurality of process parameters of the steel strip to the calculation device for the center position of the steel strip to calculate the center position of the steel strip ; And when judging that the air knife equipment has the air knife lip retraction, move the correcting roller in the zinc liquid tank to correct the air knife equipment relative to The position of the steel belt.

In some embodiments, the method for controlling the galvanized film thickness of the steel strip further includes: when the difference between the thickness of the zinc layer on the current surface and the thickness of the zinc layer on the rear surface is not zero, judging that the center position deviates; and when judging the center position When there is a deviation, move the correction roller to correct the center position according to the center position, the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface.

In some embodiments, the said device for calculating the central position of the steel strip performs prediction according to the forecasting model to calculate the central position, and the learning process of the said forecasting model includes a data collection step, a data analysis step and a model training step. The data collection step is to obtain process parameters and production line process parameters related to the production line. The data analysis step is to integrate the production line speed with time to calculate the current position of the steel strip. The model training step is to establish a predictive model through artificial intelligence learning methods of classification, grouping and regression.

The purpose of the present invention is to propose another steel strip galvanized film thickness control system, which is applicable to the galvanized steel strip production line. The above-mentioned galvanized steel strip production line includes zinc liquid tank and air knife equipment. The above-mentioned galvanized steel strip production line will The steel strip passes through the zinc bath to achieve hot-dip galvanizing and blows air through the air knife device to scrape off the excess zinc liquid on the steel strip. The above-mentioned galvanized film thickness control system for the steel strip includes: a zinc layer thickness measuring device and a correcting device. The zinc layer thickness measuring device is used for measuring the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface of the steel strip. The calibration device is used to: judge whether the air knife device has the air knife lip retraction according to the thickness of the front surface zinc layer and the rear surface zinc layer thickness; and when the calibration device judges that the air knife device has the air knife lip retraction, the calibration device corrects the air knife device Relative to the position of the steel belt.

In some embodiments, when the thickness of the zinc layer on the front surface or the thickness of the zinc layer on the rear surface is greater than the target thickness of the zinc layer, the correction device determines that the air knife device has an air knife lip retraction.

In some embodiments, the above-mentioned steel strip galvanized film thickness control system further includes a steel strip center position calculation device for: before the steel strip passes through the air knife equipment, a plurality of process parameters of the steel strip are transmitted to the steel strip center position calculation device to calculate the center position of the steel strip. Among them, the correction device is more used: when the correction device judges that the air knife device has the retraction of the air knife lip, the correction device moves the zinc liquid tank according to the center position, the thickness of the zinc layer on the front surface, the thickness of the zinc layer on the rear surface, and the thickness of the target zinc layer. Calibration rollers are used to correct the position of the air knife device relative to the steel belt.

In some embodiments, the correction device is further used: when the difference between the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface is not zero, the correction device judges that the center position deviates; and when the correction device judges that the center position has a deviation When it deviates, the correction device moves the correction roller according to the center position, the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface to correct the center position.

In some embodiments, the said device for calculating the central position of the steel strip performs prediction according to the forecasting model to calculate the central position, and the learning process of the said forecasting model includes a data collection step, a data analysis step and a model training step. The data collection step is to obtain process parameters and production line process parameters related to the production line. The data analysis step is to integrate the production line speed with time to calculate the current position of the steel strip. The model training step is to establish a predictive model through artificial intelligence learning methods of classification, grouping and regression.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Embodiments of the invention are discussed in detail below. It should be appreciated, however, that the embodiments provide many applicable concepts that can be implemented in a wide variety of specific contexts. The discussed and disclosed embodiments are for illustration only, and are not intended to limit the scope of the present invention. The terms “first”, “second”, etc. used herein do not specifically refer to a sequence or sequence, but are only used to distinguish elements or operations described with the same technical terms.

Fig. 1 is a configuration diagram of the relative positions of a plurality of devices in a galvanized steel strip production line according to an embodiment of the present invention. Fig. 2 is a configuration diagram of relative positions of a plurality of devices of a galvanized steel strip production line according to another viewing angle of an embodiment of the present invention. Fig. 3 is a structural schematic diagram of a galvanized steel strip production line according to an embodiment of the present invention.

The galvanized steel strip production line includes an air knife device 110 and a zinc bath 120 . First, the steel strip 100 is passed through the zinc bath 120 of molten zinc to achieve hot-dip galvanizing. At this time, the surface of the steel strip 100 will be attached with molten zinc, and when the steel strip 100 passes through the zinc bath 120, The gas is blown out through the air knife device 110 , and the excess zinc liquid on the steel strip 100 is scraped off by the gas, so that the thickness of the zinc liquid coating attached to the surface of the steel strip 100 reaches a preset thickness.

In an embodiment of the present invention, the air knife device 110 includes a first air knife and a second air knife respectively disposed on different sides of the steel strip 100 . In the embodiment of the present invention, the adjustable air knife equipment parameter values of the air knife equipment 110 include: air knife pressure, the distance value between the first air knife and the steel strip, the distance between the second air knife and the steel strip For the distance value, the parameter value of the above-mentioned air knife equipment can be adjusted so that the thickness of the zinc liquid coating attached to the surface of the steel strip 100 reaches a preset thickness.

In an embodiment of the present invention, the steel strip galvanized film thickness control system includes a zinc layer thickness measuring device 200 . After the steel strip 100 passes through the air knife device 110, the steel strip galvanized film thickness control system measures the front surface zinc layer thickness of the front surface of the steel strip 100 and the thickness of the rear surface of the steel strip 100 through the zinc layer thickness measuring device 200. The thickness of the zinc layer on the rear surface. In an embodiment of the present invention, the zinc layer thickness measuring device 200 may be, for example, a coating thickness gauge (coating thickness gauge), which may, for example, use X-rays (X-ray) to measure the thickness of the galvanized layer.

In the embodiment of the present invention, the steel strip galvanized film thickness control system further includes a steel strip center position calculation device 210 and a correction device 220 connected by communication. The steel strip center position calculating device 210 is used for calculating the center position of the steel strip 100 . As shown in FIG. 2 and FIG. 3 , the zinc tank 120 includes a zinc tank roll 121 , a calibration roll 122 and a stabilizing roll 123 , and the calibration roll 122 is connected to the calibration device 220 in communication. In the embodiment of the present invention, when the center position of the steel strip 100 deviates, the correcting device 220 adjusts the position of the steel strip 100 through the movement of the correcting roller 122 .

The strip center position calculating device 210 is used to: before the steel strip 100 passes through the air knife device 110 , transmit a plurality of process parameters of the steel strip 100 to the strip center position calculating device 210 to calculate the center position of the steel strip 100 .

The calibration device 220 is used for judging whether the air knife device 110 has air knife lip retraction according to the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface measured by the zinc layer thickness measuring device 200 . When the calibration device 220 determines that the air knife device 110 has an air knife lip retraction, the calibration device 220 corrects the position of the air knife device 110 relative to the steel strip 100 through the movement of the calibration roller 122 .

Regarding the strip center position calculation device 210 , before the steel strip 100 passes through the air knife device 110 , a plurality of process parameters of the steel strip 100 are sent to the strip center position calculation unit 210 to calculate the center position of the steel strip 100 . Specifically, the calculation device 210 for calculating the center position of the steel strip 100 calculates the center position of the steel strip 100 according to a plurality of process parameters of the steel strip 100 and uses a prediction model to predict.

In the embodiment of the present invention, the learning process of the prediction model used by the steel strip center position calculation device 210 includes a data collection step, a data analysis step and a model training step.

Among them, the data collection step can obtain multiple production line process parameters related to the production line according to the conditions of the field equipment, such as: production line speed, steel strip type, steel strip size (such as width, length), equipment status (such as roll diameter, roll position, etc.), air knife opening, pressure, distance, etc. Identify the object of use of the steel strip, which needs to be adjusted in different processes), the serial number of the parent steel coil (connecting data to determine the source of the steel coil), and upstream related process parameters (such as annealing temperature or annealing time, etc.), etc. Any information or parameters that may affect the thickness of the zinc layer, such as the production line process parameters that may affect the thickness of the zinc layer, the process parameters of the steel strip 100, and material information, can be captured. It depends on the user’s understanding of the zinc coating. The requirement of the thickness prediction model, and the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface measured by the zinc layer thickness measuring device 200 . Among them, the establishment of the prediction model still needs to be based on practical needs. For example, if the quality of the steel strip surface is required, it must refer to the relevant rolling conditions (such as: pressure, roll diameter, etc.), and put these relevant data into the establishment of the prediction. The parameters of the model are then measured through the corresponding front surface zinc layer thickness and rear surface zinc layer thickness as a relative basis for predictive model training.

Among them, with regard to the data analysis step, the above-mentioned collected parameter data must be processed before the prediction model training can be carried out. Because the thickness data of the surface layer of the steel strip 100 usually has a problem of distance delay with the process parameters, Therefore, it is necessary to make corrections according to the delayed part of the data. The data are mainly time series, but the speed of the production line may change at any time, and the required time cannot be accurately estimated. The line speed is integrated with time to calculate the current position of the steel belt, the formula is as follows: Among them, V _{steel belt} is the production line speed, and Local is the current position of the steel belt.

In addition to correcting the delay in zinc layer thickness measurement, screening data with fewer influencing parameters is also one of the methods to improve the accuracy of the prediction model. For example, data screening can be performed based on the variation of zinc layer width (for example, filtering out those with large variation ), the variation in width, direction, and thickness of the zinc layer is small, which means that the steel strip 100 itself has less deformation and is relatively smooth. A flat steel strip is easier to judge the position of the centerline. The center position of the steel strip 100 is defined.

Finally, the model training step is carried out. After the data is collected and sorted, the collected data can be used to train the prediction model through the regression model. Through the artificial intelligence learning methods of classification, grouping and regression (such as machine learning, deep learning) to Build predictive models. The prediction model of the steel strip center position calculation device 210 is to predict a specific value, which belongs to the regression method.

In the embodiment of the present invention, through the supervised learning method of support vector machine (SVM), the principle of statistical risk minimization is used to estimate a classified hyperplane (hyperplane), the concept of which is to find a A hyperplane can separate two different types of data. The support vector regression (SVR) is a deformation of SVM, assuming that the data is expressed as ,in Indicates the input process parameters, Indicates the corresponding regression value, the thickness of the zinc layer is ,if , then we know that such can from , accurately predicting ,this It is the plane that SVR is looking for. In terms of calculation, it can be found from the collected production line process parameters and the corresponding thickness of the zinc layer on the front surface of the steel strip 100 and the thickness of the rear surface zinc layer, plus a certain error range. , that is, the relationship between the production line process parameters and the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface can be trained, and then the prediction model can be trained based on the center position of the steel strip 100 and the difference between the thickness of the zinc layer on the front surface and the thickness of the rear surface zinc layer .

Another training method in the model training step is gradient boosting regression (GBR). The main method is to classify through many weak classifiers, and finally collect the classification results of all weak classifiers into an answer. Weak classification is a kind of A simple classifier can first distinguish answers according to different conditions, and finally gather all weak classifiers to vote for the best answer. In GBR's prediction model, the data is assumed to be , first calculate it with a simple formula (it can be a linear function or a polynomial, etc.) , the goal is to have , if it is not 0, continue to Bring it into the second weak classifier to calculate ,until ,at last The total is the required model, and finally the forecast model can be established by adding the program of the parameter input method.

Combining the above methods, as long as there are process parameters, production line-related process parameters and corresponding information such as the thickness of the front surface zinc layer and the thickness of the rear surface zinc layer, the prediction model can be trained in different ways.

Fig. 4 is a schematic diagram of the difference between the center position and the surface zinc layer thickness of the steel strip with or without the retracted air knife lip of the air knife equipment according to the embodiment of the present invention. As shown in Figure 4, _before the air knife device 110 includes the first air knife 110, it is arranged on this side of the front surface of the steel strip 100 _; that side of the . As shown in FIG. 4 , the thickness of the zinc layer on the front surface of the steel strip 100 is represented by _CWfront , and the thickness of the zinc layer on the rear surface of the steel strip 100 is represented by _CWback . As shown in FIG. 4 , the distance between _{the front of} the first air knife 110 and the steel strip 100 is represented by _dfront , and the distance between _{the rear} of the second air knife 110 and the steel strip 100 is represented by _dback .

As shown in Figure 4, when the second air knife ₁₁₀ of the air knife device 110 has an air knife lip retraction, it will cause the distance d _between the second air knife 110 of the air knife device 110 and the steel strip 100 _to become farther, As a result, the _rear surface zinc layer thickness CW is not equal to the target zinc layer thickness but greater than the target zinc layer thickness. In the embodiment of the present invention, the target zinc layer thickness is the preset zinc layer thickness of the galvanized steel strip production line or the target zinc layer thickness of the galvanized steel strip production line obtained by using historical data.

In other words, as shown in FIG. 4 , the front surface zinc layer thickness CW is equal to the target zinc layer thickness, but _when the rear surface zinc layer thickness CW is greater than the target zinc layer thickness, the calibration device 220 can judge the second value of the air knife device 110 _accordingly . The air knife lip retracts _behind the air knife 110 . Then, the correction device 220 corrects the second air knife 110 of the air knife device 110 _relative to the steel strip according to the center position of the steel _strip 100, the front surface zinc layer thickness CW, _the rear surface zinc layer thickness CW, and the target zinc layer thickness. The position of 100 is to correct the problem that the lip of the air knife _behind the second air knife 110 retracts. In the embodiment of the present invention, the target of correcting the position of the air knife device 100 relative to the steel strip 100 is to reduce the distance value d _between the second air knife 110 of the air knife device ₁₁₀ and the steel strip 100, so that The rear surface zinc layer thickness CW _is equal to the target zinc layer thickness, and _the specific method can be (1) _after the second air knife 110 of the mobile air knife device 110 to reduce d; and/or (2) in the mobile zinc liquid tank 120 The correction roller 122.

Specifically, _when the thickness CW of the current surface zinc layer is greater than the target zinc layer thickness, the calibration device 220 judges that there is an air knife lip retraction _before the first air knife 110 of the air knife device 110; _when the rear surface zinc layer thickness CW is greater than the target zinc layer thickness When the layer thickness is measured, the calibration device 220 judges that there is an air knife lip retraction _behind the second air knife 110 of the air knife device 110 .

Specifically, when the correction device 220 judges that the air knife device 110 has an air knife lip retraction, the correction device 220 according to the center position of the steel strip, the thickness of the zinc layer _{on the} front surface CW, the thickness of the zinc layer _on the rear surface CW, the target zinc layer thickness To move the air knife device 110 or move the correcting roller 122 in the zinc bath 120 to correct the position of the air knife device 110 relative to the steel strip 100 .

Fig. 5 is a comparative schematic diagram of the difference between the central position of the steel strip and the thickness of the surface zinc layer according to the embodiment of the present invention, whether the central position of the steel strip deviates or not. Specifically, as shown in FIG. 5 , the central position of the steel strip 100 is the relative position of the steel strip 100 relative to the air knife device 110 . As shown in Figure 5, _before the air knife device 110 includes the first air knife 110, it is arranged on this side of the front surface of the steel strip 100 _; that side of the .

As shown in Figure 5, when the central position of the steel strip 100 does not deviate, the thickness of the zinc layer on the front surface of the front surface of the steel strip 100 expressed _as CW is equal to the thickness of the zinc layer on the rear surface of the rear surface of the steel strip 100 expressed as _CW . In other words, when the difference between the _front surface zinc layer thickness CW and the _rear surface zinc layer thickness CW is zero, the calibration device 220 judges that the center position of the steel strip 100 is not deviated.

As shown in Figure 5, when the center position of the offset steel strip 100' deviates, the front surface zinc layer thickness of the front surface of the offset steel strip 100' is not equal to the rear of the offset steel strip 100' in terms of CW _front' The rear surface zinc layer thickness of the surface is given in CW _post' . In other words, when the difference between the front surface zinc layer thickness CWbefore _' and the rear surface zinc layer thickness _CWafter' is not zero, the calibration device 220 can determine that the center position of the offset steel strip 100' deviates. When the correcting device 220 judges that the central position of the offset steel strip 100' deviates, the correcting device 220 calculates according to the central position of the offset steel strip 100', the thickness of the zinc layer on the front surface CWfront _' and the thickness of the zinc layer on the rear surface CWback _'. The correction roller 122 in the zinc bath 120 is moved to correct the center position of the offset steel strip 100'. The goal of the above-mentioned movement of the correcting roller 122 is to make the difference between the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface zero, so that the center position of the steel strip 100 does not deviate.

Specifically, when the correction device 220 judges that the center position of the steel strip deviates, the correction device 220 moves the correction roller 122 in the zinc liquid tank 120 according to the center position of the steel strip, the thickness of the zinc layer on the front surface, and the thickness of the zinc layer on the rear surface. To correct the center position of the steel strip 100.

Fig. 6 is a flow chart of a method for controlling the thickness of a galvanized steel strip according to an embodiment of the present invention. In step S1, the steel strip 100 is passed through the zinc bath 120 to achieve hot-dip galvanizing. In step S2 , air is blown out through the air knife device 110 to scrape excess zinc liquid on the steel strip 100 . In step S3 , the zinc layer thickness measuring device 200 measures the zinc layer thickness on the front surface and the zinc layer thickness on the rear surface of the steel strip 100 . In step S4 , the calibration device 220 judges whether the air knife device 110 has air knife lip retraction according to the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface. In step S5 , when the calibration device 220 judges that the air knife device 110 has an air knife lip retraction, the calibration device 220 calibrates the position of the air knife device 110 relative to the steel strip 100 .

FIG. 7 is a schematic flowchart of a manufacturing method of a galvanizing production line according to an embodiment of the present invention. In step U1, various process parameters of the current galvanizing production line are obtained. In step U2, verify the state of the equipment to determine whether there is an error, the specific way is to compare various process parameters of the current galvanizing production line with various process parameters of the historical production line. If it is judged in step U2 that there is no error, then go to step U4, and if it is judged in step U2 that there is an error, then go to step U3 to update the process parameters. The specific method is to update the process parameters of the historical production line. In step U4, use the prediction model to perform prediction to calculate the center position of the steel strip. In step U5, the optimization calculation of the process parameters is carried out. The specific method is to use the center position of the steel strip calculated in the step U4 to optimize the process parameters. In step U6, the process parameters are set, specifically by using the optimized process parameters in step U5 to reset the process parameters. In step U7, the zinc layer thickness feedback judges whether there is an error in the thickness of the zinc layer. If it is judged in step U7 that there is no error, the production line production will be carried out. If it is judged in step U7 that there is an error, it will return to step U2 for correction.

To sum up the above, the present invention provides a zinc layer thickness measurement device and correction device and production line process parameters through machine learning and deep learning through machine learning and deep learning, and a steel strip galvanized film thickness control system, as well as production line process parameters. Using the prediction model for calculating the center position of the steel strip and comparing the measured front surface zinc layer thickness and rear surface zinc layer thickness, the prediction model can be used to automatically judge the status of important equipment in the current galvanizing production line, and automatically correct the deviation of the equipment To stabilize the production of the galvanizing production line, and automatically set the process parameters according to the order specifications to achieve accurate, fast and stable production control. Finally, the thickness of the zinc layer and the thickness of the zinc layer can be reported according to the zinc layer thickness measuring device on the production line. Comparing the prediction value of the prediction model, automatically correcting the error between the prediction value and the actual measurement, and at the same time providing on-site personnel to monitor the steel strip process in real time, reducing the plating on the front and rear surfaces of the steel strip caused by the deviation of the steel strip or the retraction of the air knife lip of the air knife equipment The zinc thickness is different, and through the steel strip galvanized film thickness control system, a galvanized steel strip intelligent manufacturing system that can automatically judge and produce is realized, achieving the purpose of intelligent production and fully automatic steel strip center position control.

The features of several embodiments are outlined above, so those skilled in the art can better understand aspects of the present invention. Those skilled in the art should appreciate that they can easily use the present invention as a basis to design or modify other processes and structures, thereby achieving the same goals and/or achieving the same advantages as the embodiments described herein . Those skilled in the art should also understand that these equivalent constructions do not depart from the spirit and scope of the present invention, and that they can make various changes, substitutions and alterations without departing from the spirit and scope of the present invention.

100: steel belt 100': offset steel belt 110: air knife equipment 110 _before : first air knife 110 _after : second air knife 120: zinc liquid tank 121: zinc tank roll 122: correction roll 123: stabilizing roll 200: Zinc layer thickness measurement device 210: steel strip center position calculation device 220: correction device CW _front , CW _front' : front surface zinc layer thickness CW _rear , CW _rear' : rear surface zinc layer thickness d _front , d _rear : distance value S1~S5, U1~U7: steps

A better understanding of aspects of the present invention can be obtained from the following detailed description in conjunction with the accompanying drawings. It is to be noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion. [ Fig. 1 ] is an arrangement diagram of relative positions of a plurality of devices of a galvanized steel strip production line according to an embodiment of the present invention. [ FIG. 2 ] is an arrangement diagram of relative positions of a plurality of devices of a galvanized steel strip production line according to an embodiment of the present invention from another viewing angle. [ Fig. 3 ] is a structural schematic diagram of a galvanized steel strip production line according to an embodiment of the present invention. [ Fig. 4 ] is a comparison schematic diagram of the difference between the central position of the steel strip and the thickness of the surface zinc layer with or without the retraction of the air knife lip of the air knife equipment according to the embodiment of the present invention. [ Fig. 5 ] is a schematic diagram showing the difference between the central position of the steel strip and the thickness of the surface zinc layer according to the embodiment of the present invention. [ Fig. 6 ] is a flowchart of a method for controlling the thickness of a galvanized steel strip according to an embodiment of the present invention. [ Fig. 7 ] is a schematic flowchart of a manufacturing method of a galvanizing line according to an embodiment of the present invention.

S1~S5: steps

Claims (10)

A method for controlling the galvanized film thickness of a steel strip is applicable to a galvanized steel strip production line, wherein the galvanized steel strip production line includes a zinc liquid tank and an air knife device, wherein the galvanized steel strip production line uses a steel strip Hot-dip galvanizing is achieved by passing through the zinc liquid tank and blowing gas through the air knife device to scrape off excess zinc liquid on the steel strip, wherein the method for controlling the thickness of the steel strip galvanized film includes: Measuring the thickness of a front surface zinc layer and a rear surface zinc layer thickness of the steel strip; According to the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface, it is judged whether the air knife device has an air knife lip retraction; and When it is judged that the air knife device has an air knife lip retraction, the position of the air knife device relative to the steel strip is corrected. The method for controlling the thickness of the steel strip galvanized film as described in claim 1 further includes: When the thickness of the zinc layer on the front surface or the thickness of the zinc layer on the rear surface is greater than a target thickness of the zinc layer, it is determined that the air knife device has an air knife lip retraction. The method for controlling the thickness of the steel strip galvanized film as described in claim 2 further includes: Before the steel strip passes through the air knife device, a plurality of process parameters of the steel strip are transmitted to a steel strip center position calculating device to calculate a center position of the steel strip; and When it is judged that the air knife device has an air knife lip retraction, a correction roller in the zinc liquid tank is moved to correct according to the center position, the thickness of the zinc layer on the front surface, the thickness of the zinc layer on the rear surface, and the thickness of the target zinc layer. The position of the air knife device relative to the steel strip. The method for controlling the thickness of the steel strip galvanized film as described in claim 3 further includes: When the difference between the thickness of the front surface zinc layer and the thickness of the rear surface zinc layer is not zero, the center position is judged to be deviated; and When it is judged that the center position deviates, the correcting roller is moved to correct the center position according to the center position, the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface. The method for controlling the thickness of the steel strip galvanized film as described in claim 3, Wherein the center position calculation device of the steel strip performs prediction according to a prediction model to calculate the center position, wherein the learning process of the prediction model includes a data collection step, a data analysis step and a model training step; The data collection step is to obtain the process parameters and a plurality of production line process parameters related to the production line; The data analysis step is to integrate the production line speed with time to calculate the current position of the steel strip; Wherein the model training step is to establish the predictive model through artificial intelligence learning methods of classification, grouping and regression. A steel strip galvanized film thickness control system, suitable for a galvanized steel strip production line, wherein the galvanized steel strip production line includes a zinc liquid tank and an air knife device, wherein the galvanized steel strip production line uses a steel strip Hot-dip galvanizing is achieved through the zinc bath, and gas is blown through the air knife device to scrape off excess zinc liquid on the steel strip, wherein the steel strip galvanized film thickness control system includes: a zinc layer thickness measuring device for measuring the thickness of a front surface zinc layer and a rear surface zinc layer of the steel strip; and A calibration device for: According to the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface, it is judged whether the air knife device has an air knife lip retraction; and When the correcting device judges that the air knife device has an air knife lip retraction, the correcting device corrects the position of the air knife device relative to the steel strip. The steel strip galvanized film thickness control system as described in Claim 6, wherein when the thickness of the zinc layer on the front surface or the thickness of the zinc layer on the rear surface is greater than a target zinc layer thickness, the calibration device judges that the air knife device has an air knife Lips flinch. The steel strip galvanized film thickness control system as described in claim 7 further includes: A steel belt center position calculation device, used for: Before the steel strip passes through the air knife device, a plurality of process parameters of the steel strip are transmitted to the steel strip center position calculation device to calculate a center position of the steel strip; and Among them, the calibration device is more used for: When the correction device judges that the air knife lip retracts in the air knife device, the correction device moves the zinc liquid tank according to the center position, the thickness of the zinc layer on the front surface, the thickness of the zinc layer on the rear surface, and the target zinc layer thickness. A correction roller to correct the position of the air knife device relative to the steel strip. The steel strip galvanized film thickness control system as described in Claim 8, wherein the calibration device is further used for: When the difference between the thickness of the front surface zinc layer and the thickness of the rear surface zinc layer is not zero, the calibration device judges that the center position is deviated; and When the correction device judges that the center position deviates, the correction device moves the correction roller according to the center position, the thickness of the zinc layer on the front surface and the thickness of the zinc layer on the rear surface to correct the center position. The steel strip galvanized film thickness control system as described in claim item 8, Wherein the center position calculation device of the steel strip performs prediction according to a prediction model to calculate the center position, wherein the learning process of the prediction model includes a data collection step, a data analysis step and a model training step; The data collection step is to obtain the process parameters and a plurality of production line process parameters related to the production line; The data analysis step is to integrate the production line speed with time to calculate the current position of the steel strip; Wherein the model training step is to establish the predictive model through artificial intelligence learning methods of classification, grouping and regression.

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