A method for automatically converting slab into steel

Abstract

The present invention relates to a slab automatic steel transfer method, and relates to the field of steel rolling and metallurgical automation, which comprises the following steps: when the slab enters the steel transfer area, confirming the current position of the slab; the system issues instructions to control the operation of different camera processes; performing perspective transformation on the acquired photos; detecting the brightness value of the slab; identifying the slab contour and calculating the angle between the long side of the minimum circumscribed rectangle and the positive direction of the X-axis; ensuring that the calculated steel transfer angle is 90 degrees through logical control; sending the angle information and position information to the primary automation system in real time; associating steel transfer parameters, and using different accelerations to control the tapered rollers; determining the slab angle range for successful steel transfer according to the aspect ratio of the slab; monitoring the slab position to ensure that it is within the steel transfer area; and controlling the side guide plate to clamp the slab when the slab angle and position meet the requirements. The present invention is conducive to improving the automation level, reducing the labor intensity of operators, and improving production efficiency.

Description

Technical Field

[0001] The invention relates to the field of steel rolling and metallurgical automation, and in particular to a slab automatic steel-transforming method. Background Art

[0002] In the production process of wide and thick plates, the slabs are treated with high-pressure water for dephosphorization and then enter the rolling mill for rolling. According to the requirements of the rolling process, the slabs need to undergo widening rolling and extension rolling. In the rough rolling stage, the slabs need to undergo widening rolling, which includes horizontal and vertical widening, and the slabs need to be adjusted in length and width. In actual operation, the first-level automation system will determine whether the slab needs to be rotated in the current rolling stage. The process of rotating the slab may occur in the steel transfer area before or after the rolling mill.

[0003] At present, most wide and thick plate mills have installed security cameras in the steel transfer area before and after the rolling mill. When the slab needs to be turned, the operator will monitor the camera screen in real time and manually control the forward and reverse rotation of the tapered roller in the steel transfer roller area by the hand lever to achieve a rotation of the slab about 90 degrees. The slab will then be clamped by the side guide plate and sent to the rolling mill for rolling. This operation method is labor-intensive and workers need to keep an eye on the monitoring screen, which limits the realization of production process automation.

[0004] Although some wide and thick plate mills have adopted automatic steel turning systems, these systems usually have high installation requirements and require the camera to be fixed directly above the slab or ensure that it is parallel to the direction of travel of the slab, which may lead to problems such as unstable recognition angle and complex installation. Summary of the invention

[0005] The purpose of the present invention is to provide a slab automatic steel-transforming method to improve the automation level, reduce the labor intensity of operators, and improve production efficiency.

[0006] In order to achieve the above object, the technical solution of the present invention provides a slab automatic steel conversion method, comprising the following steps:

[0007] When the slab enters the steel transfer area, the first-level automation system confirms the current position of the slab;

[0008] According to the location information, the system issues instructions to control the process operation of the cameras before and after the rolling mill respectively, so as to obtain photos of the steel transfer area before and after the rolling mill;

[0009] Perform perspective transformation on the acquired photos to correct the image deformation caused by the camera installation angle;

[0010] Based on the perspective transformed image, the brightness value of the slab is detected to determine whether the slab is in the steel transfer area;

[0011] Use the deep learning instance segmentation algorithm to identify the slab outline and calculate the angle between the long side of the minimum circumscribed rectangle of the slab outline and the positive direction of the X-axis;

[0012] Through logical control, ensure that the calculated steel turning angle is 90 degrees;

[0013] Send angle information and position information to the primary automation system in real time to control the slab steel transfer;

[0014] According to the size and weight of the slab, related to the steel turning parameters, different accelerations are used to control the speed and forward and reverse rotation of the tapered roller;

[0015] Determine the slab angle range for successful steel transfer based on the slab's aspect ratio;

[0016] Monitor the position of the slab based on the camera image to ensure it is within the steel transfer area;

[0017] When the angle and position of the slab meet the requirements, the side guide plates are controlled to clamp the slab and send it into the rolling mill.

[0018] Preferably, the perspective transformation step includes:

[0019] Determine the coordinates of the four corner points of the original image and the four corner points of the target image;

[0020] Apply a perspective transformation function to convert the original image to an image that corresponds to the actual angle.

[0021] Preferably, the step of angle logic control includes:

[0022] When the slab does not enter the steel transfer area, the slab angle is forced to be set to 0 degrees;

[0023] Angle compensation is performed based on the difference between the current angle and the previous angle.

[0024] Preferably, the step of position monitoring comprises:

[0025] The coordinates of the center point, leftmost point, rightmost point, topmost point and bottommost point of the slab are sent to the system. If the slab deviates from the steel turning area during rotation, the system will adjust the speed of the conical roller motor in time to move the slab back to the set steel turning position.

[0026] Preferably, the method includes the following steps for abnormal steel turning: if the steel turning angle is not in place or exceeds the defined maximum angle, the angle is corrected by controlling the speed of the conical roller motor.

[0027] Preferably, the processing steps for the situation where the slab cannot be rotated due to the buckle head include: simulating manual operation, moving the slab forward and backward by a specific distance, and then continuing to control the speed of the conical roller motor.

[0028] Preferably, it includes a processing step for touching the edge of the side guide plate during rotation: by real-time monitoring the coordinates of the edge points of the slab, determining whether the slab touches the edge of the side guide plate, and triggering a software system alarm and a first-level automation system alarm.

[0029] Preferably, the alarm step includes: triggering a software system alarm and a first-level automation system alarm when an angle does not meet the steel turning requirements or a buckle head causes the slab to be unable to rotate during the steel turning process.

[0030] Preferably, the step of recording the appropriate steel turning position during each slab rotation process includes: avoiding positions where rollers are worn based on the results of extracting a large amount of steel turning data, and automatically turning the slab at a position with a high steel turning success rate.

[0031] Preferably, at any time during the automatic steel transfer of the slab, manual intervention is allowed, and the first-level automation system exits the automatic steel transfer mode and switches to the manual mode.

[0032] In summary, the present invention includes the following beneficial technical effects:

[0033] In order to improve the level of automation, an industrial camera can be used to take pictures of the steel transfer area. The first-level automation system controls the camera's shooting time and transmits the image to the industrial computer. The visual system analyzes and processes the image to obtain the angle and position information of the slab. This information is then sent back to the first-level automation system, which controls the corresponding roller speed based on this data to achieve the rotation of the slab, thereby achieving automatic steel transfer. This method can reduce the labor intensity of operators and improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of an acute angle situation in a slab automatic steel-transforming method of the present invention;

[0035] Figure 2 It is a structural schematic diagram of an obtuse angle situation in a slab automatic steel-transforming method of the present invention;

[0036] Figure 3 It is an original schematic diagram of a slab automatic steel conversion method of the present invention;

[0037] Figure 4 It is a schematic diagram after perspective transformation in a slab automatic steel conversion method of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] The embodiment of the present invention discloses a method for automatic steel transfer of slabs. The present invention provides a method for realizing automatic steel transfer of slabs in a wide and thick plate production line, thereby improving production efficiency, liberating human resources, and controlling the steel transfer angle more accurately.

[0040] When the slab enters the steel-transfer area, the first-level automation system will identify the current position of the slab to determine whether it is located in the steel-transfer area in front of or behind the rolling mill, and issue corresponding instructions accordingly to start the corresponding camera process to capture photos containing the slab information.

[0041] The calculation of the slab angle involves the following:

[0042] 1 Since the installation angle of the industrial camera may not be parallel to the slab, the corresponding angle relationship in the original image does not match the actual angle, so the original image needs to be perspective transformed. In the image after perspective transformation, the four edges of the slab and the two side guide edges will correctly reflect the actual angle. Figure 3 and Figure 4 The original image and the image after perspective transformation are shown respectively. The mathematical model of perspective transformation is

[0043] Image'=F[Image,(p1, p2, p3, p4),(p1', p2', p3', p4')],

[0044] Where Image' represents the transformed image, F is the perspective transformation function, p1, p2, p3, p4 are the coordinates of the four corner points of the original image, and p1', p2', p3', p4' are the coordinates of the four corner points of the perspective transformed target image.

[0045] 2 All subsequent image processing is based on the perspective transformed image. When the slab enters the steel transfer area, the system detects the brightness value of the image to determine whether the slab is within the field of view of the steel transfer area. If the slab is not detected, the system sets the slab angle α to 0.

[0046] 3 Using deep learning instance segmentation technology, the system will identify the slab contour and calculate its minimum circumscribed rectangle. Then, the system will calculate the angle between the long side of the minimum circumscribed rectangle and the positive direction of the X-axis, where the positive direction of the X-axis is parallel to the side guide edge and is the direction of travel of the slab on the roller. Angle calculation needs to consider both acute angles and obtuse angles (such as Figure 1 and Figure 2 ), the angle range is limited to 0 to 179.99 degrees.

[0047] 4 In order to ensure that the PLC can set the steel turning target angle to a unique 90 degrees, the system will perform logical control on the steel turning angle.

[0048] 5 Angle logic control: Slabs are sometimes rolled into approximate squares. Conventional calculation methods may result in an erroneous angle calculation result of 90 degrees. To prevent this error, angle logic control is used. When the slab has not entered the steel transfer area, the slab angle is forced to be set to 0 degrees. The difference between the current angle and the previous angle is judged to perform angle compensation. If the current angle is greater than the previous angle and the change is greater than 60 degrees and less than 150 degrees, the current angle is -90 degrees. If the current angle is less than the previous angle and the change is greater than 60 degrees and less than 150 degrees, the current angle is +90 degrees.

[0049] 6. Level 1 automation controls the steel transfer of slabs: The visual system sends angle information and position information to the level 1 automation system in real time. The algorithm of the visual system takes 20ms, the image acquisition and transmission time is 30ms in total, and the data transmission interval is 10ms. Therefore, the cycle of updating the angle of the level 1 automation system is 60ms. When the initial angle of the slab is detected as an acute angle, the steel transfer roller is controlled to rotate the slab counterclockwise and set the target angle to 90 degrees; when the initial angle of the slab is detected as an obtuse angle, the steel transfer roller is controlled to rotate the slab clockwise and set the target angle to 90 degrees.

[0050] 7. Association of steel turning parameters: The success rate of steel turning of the original slab in one time is the key to the success of the steel turning system. Therefore, the system needs to associate the length, width, thickness and weight of the slab with the acceleration of the conical roller that controls the steel turning to meet the steel turning requirements of different slab sizes.

[0051] In order to adjust the new acceleration value according to the length, width, height and current rotation angle of the slab, the acceleration setting is corrected by the moment of inertia I related to the geometric dimensions of the slab, thereby achieving precise control. The specific steps are as follows:

[0052] The moment of inertia I of the slab can be calculated from its length l, width w, and height h. The formula for the moment of inertia of the slab rotating around the central vertical axis (Z axis) is:

[0053] I Z =(1 / 12)m(l 2 +w 2 )

[0054] In the above formula, m is the mass of the slab, which can be calculated from the volume of the slab and the material density ρ:

[0055] m=ρlwh

[0056] Set the acceleration adjustment factor k, which is based on the slab's moment of inertia I and a standard moment of inertia I ref To define:

[0057] K = I ref / I Z

[0058] 8 The speed of the tapered roller is controlled according to the set acceleration value: In order to improve the efficiency and accuracy of the slab automatic steel transfer process, the system will use different accelerations to control the speed of the tapered roller motor in different angle ranges. The specific acceleration setting depends on the initial angle of the slab and the slab specifications.

[0059] When the initial slab angle is an acute angle, the slab needs to be rotated counterclockwise to around 90 degrees. Set the acceleration of the tapered roller motor of the rotating roller to (1.2*K) m / s in the range of 0 to 30 degrees. 2 In the range of 30 to 60 degrees, the acceleration is set to 0, and in the range greater than 60 degrees, the acceleration is set to -(1.2*K)m / s 2 , reduce the speed of the forward and reverse conical roller motors to 0, and use inertia to rotate the slab angle to around 90 degrees.

[0060] When the initial slab angle is an obtuse angle, the slab needs to be rotated clockwise to around 90 degrees. At about 179 degrees to 150 degrees, the acceleration of the tapered roller motor of the rotating roller is set to (1.2*K) m / s 2 In the range of 150 to 120 degrees, the acceleration is set to 0, and in the range less than 120 degrees, the acceleration is set to -(1.2*K)m / s 2 , reduce the speed of the forward and reverse conical roller motors to 0, and use inertia to rotate the slab angle to around 90 degrees.

[0061] 9 Marking whether the slab steel transfer is successful: When the slab steel transfer is completed and the angle meets the side guide plate clamping, the slab can be accurately fixed to 90 degrees. Different specifications of slabs have different requirements for whether the side guide plate can be successfully clamped. Whether the side guide plate can be clamped is determined based on the length-to-width ratio of the slab. When the length-to-width ratio of the slab is greater than 3, the angle requirement for the slab that has been successfully transferred is 85 to 95 degrees. When the length-to-width ratio is greater than 2 and less than 3, the required slab angle is 80 to 100 degrees. When the length-to-width ratio is greater than 1 and less than 2, the required slab angle is in the range of 75 to 105 degrees.

[0062] 10 Position monitoring: The vision system will send five position information to the first-level automation system, including the coordinates of the center point, leftmost point, rightmost point, topmost point and bottommost point of the slab. If the slab deviates from the steel turning area during rotation, the system will adjust the speed of the conical roller motor in time to move the slab back to the set steel turning position.

[0063] 11 When the system continuously monitors that the speed is constant and the angle is within the angle range for successful steel turning, the first-level automation system will control the side guide plate to clamp and feed the slab into the rolling mill.

[0064] 12 Abnormal steel turning operation: If the steel turning angle does not meet the angle range defined for successful steel turning, there are two situations. The first is that the steel turning angle is not in place: for example, 85 to 95 degrees is the angle range defined for successful steel turning, but when the angle is detected to be 80 degrees and has not changed, the first-level automation system will continue to rotate the billet at the speed of the rotating conical roller motor for a specific time until the angle definition is met. The second is that the steel turning angle exceeds the maximum angle defined for successful steel turning: At this time, it is necessary to control the speed of the conical roller motor and rotate the billet in the opposite direction according to a specific time until the angle definition is met.

[0065] 13 For the situation where the slab cannot rotate due to the buckled head: when the first-level automation system gives the rotating motor roller speed value, but the angle of the slab does not change within a specific time, it will simulate the manual operation method and move the slab forward or backward a specific distance. After the movement, it will continue to control the speed of the conical roller motor until the slab rotates to about 90 degrees.

[0066] 14 Hitting the edge of the side guide plate during rotation: The edge position of the side guide plate is fixed during the rotation of the slab. By real-time monitoring the coordinates of the edge points of the slab, it can be determined whether the slab touches the edge of the side guide plate during rotation. If it touches the edge of the side guide plate and the angle does not change within a certain period of time, the software system alarm and the first-level automation system alarm will be triggered, and the operator will be reminded to take over and intervene manually in time.

[0067] 15 Alarm mechanism: When the angle of the slab during rotation does not meet the definition of successful steel rotation or the slab cannot be rotated due to the buckle head, the system will correct the angle by simulating manual methods. If the angle still does not meet the requirements after a certain period of time, the software system alarm and the first-level automation system alarm will be triggered.

[0068] 16 Record the appropriate steel turning position: The system will record the appropriate steel turning position during each slab rotation process to avoid steel turning failure caused by roller wear, and automatically turn the steel at a position with a high steel turning success rate based on the results of a large amount of data extraction.

[0069] 17 Manual intervention: At any stage of the slab automatic steel transfer, manual intervention has the highest priority. Once manual intervention is made, the first-level automation system will exit the automatic steel transfer mode and switch to manual mode. To restart the automatic steel transfer, just click the automatic mode in the first-level automation system interface.

[0070] The present invention provides a method for realizing automatic steel transfer of slabs, which belongs to the field of metallurgical technology. The method comprises: installing an industrial camera with a field of view covering the steel transfer area in the steel transfer area of ​​a rough rolling mill of a thick plate production line, extracting and calculating the angle information and position information of the slab using the slab image captured by the industrial camera, and sending the information to a primary automation system; when the slab needs to be transferred in the pass to which it belongs, the primary automation system controls the forward and reverse rotation of the tapered roller to realize the rotation of the slab by 90 degrees; when the angle of the slab meets the clamping condition of the side guide plate, the side guide plate is controlled to clamp the slab to complete the automatic steel transfer process.

[0071] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for automatic steel conversion of slabs, characterized in that: The following steps are involved: When the slab enters the steel transfer area, the first-level automation system confirms the current position of the slab; According to the location information of the slab, the system issues instructions to control the operation of different camera processes to obtain photos containing slab information; Perform perspective transformation on the acquired photos to correct the image deformation caused by the camera installation angle; Based on the perspective transformed image, the visual system detects the brightness value of the slab to determine whether the slab is within the steel transfer area; Use deep learning instance segmentation technology to identify the slab contour and calculate the angle between the long side of the minimum circumscribed rectangle and the positive direction of the X-axis; Through logical control, ensure that the calculated steel turning angle is 90 degrees; Send angle information and position information to the primary automation system in real time to control the slab steel transfer; According to the size and weight of the slab, the acceleration of the tapered roller of the steel turning is controlled in a linked manner, and different accelerations are used to control the speed and forward and reverse rotation of the tapered roller; Determine the slab angle range for successful steel transfer based on the slab's aspect ratio; Monitor the position of the slab to ensure it is within the steel transfer area; When the angle and position of the slab meet the requirements, the side guide plates are controlled to clamp the slab and send it into the rolling mill.

2. The method for automatic slab steel conversion according to claim 1, characterized in that: The steps of perspective transformation include: Determine the coordinates of the four corner points of the original image and the four corner points of the target image; Apply a perspective transformation function to convert the original image to an image that corresponds to the actual angle.

3. The method for automatic slab steel conversion according to claim 2, characterized in that: The steps of angle logic control include: When the slab does not enter the steel transfer area, the slab angle is forced to be set to 0 degrees; Angle compensation is performed based on the difference between the current angle and the previous angle.

4. The method for automatic slab steel conversion according to claim 3, characterized in that: The steps of location monitoring include: The coordinates of the center point, leftmost point, rightmost point, topmost point and bottommost point of the slab are sent to the system. If the slab deviates from the steel turning area during rotation, the system will adjust the speed of the conical roller motor in time to move the slab back to the set position.

5. The method for automatic slab steel conversion according to claim 4, characterized in that: The method includes the following steps for abnormal steel turning: if the steel turning angle is not in place or exceeds the defined maximum angle, the angle is corrected by controlling the speed of the conical roller motor.

6. The method for automatic slab steel conversion according to claim 5, characterized in that: The method includes steps for handling the situation where the slab cannot be rotated due to the buckled head: simulating manual operation, moving the slab forward and backward by a specific distance, and then continuing to control the speed of the conical roller motor to realize the slab steel rotation.

7. The method for automatic slab steel conversion according to claim 6, characterized in that: The process includes the following steps for handling the edge of the side guide plate encountered during rotation: by real-time monitoring of the coordinates of the edge points of the slab, it is determined whether the slab touches the edge of the side guide plate, and the software system and the first-level automation system are triggered to alarm.

8. The method for automatic slab steel conversion according to claim 7, characterized in that: Including alarm mechanism: when the angle does not meet the requirements or the slab cannot be rotated due to the buckle head during the steel transfer process, the software system alarm and the first-level automation system alarm are triggered.

9. The method for automatic slab steel conversion according to claim 8, characterized in that: The method includes the steps of recording the appropriate steel turning position during each slab turning process: avoiding the position where the roller is worn according to the results of a large amount of data extraction, and automatically turning the slab at the position with a high steel turning success rate.

10. The method for automatic slab steel conversion according to claim 9, characterized in that: At any time during the automatic steel transfer of the slab, manual intervention is allowed, and the first-level automation system exits the automatic steel transfer mode and switches to manual mode.

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