A method for determining and controlling the rolling-out of an intermediate blank based on a buckle head control system

Abstract

A kind of intermediate blank rolling-out determination and control method based on buckling head control system belongs to control field.The method includes image recognition and quantitative calculation of intermediate blank buckling head by buckling head control system, data communication of the results of image recognition and quantitative calculation with rough rolling L2, type determination of head shape data of intermediate blank entry steel side by rough rolling L2 automatically;Then rough rolling L2 issues head shape mark to rough rolling L1, rough rolling L1 issues different roller operation instruction combined with different marks, and rough rolling L2 makes further protection to equipment combined with rolling force interlocking determination of rough rolling horizontal roller.The method issues different roller operation instruction according to different head shape marks, which helps to improve the reliability and robustness of existing control system, and can reduce the damage of intermediate blank buckling head to rolling equipment to the greatest extent.The method can be widely used in the field of slab rolling process control.

Description

Technical Field

[0001] This invention belongs to the field of automatic control, and in particular relates to a method for determining and controlling the rolling out of intermediate billets in a rolling mill. Background Technology

[0002] During the rolling process, the temperatures of the upper and lower surfaces of the strip are different. At the beginning and end of the strip, the temperature drop is greater and the temperature difference is more obvious, resulting in unequal metal flow rates on the upper and lower surfaces during the rolling process, which leads to the phenomenon of tipping.

[0003] Severe "head lifting" phenomenon can affect the normal biting of the roughing mill, causing impact on related equipment and significant damage to the rolling mill equipment. It can easily lead to long-term downtime and the replacement of parts of the rolling mill equipment after equipment damage, resulting in significant economic losses. Therefore, how to identify the head shape of the roughing mill exit and realize the judgment and control of the roughing mill exit is an urgent problem to be solved on site.

[0004] Chinese invention patent application CN 111715703 A, published on September 29, 2020, discloses "A strip edge leveling device and method in the roughing rolling process." It proposes a leveling method after edge raising. The leveling device has arches installed on both sides of the roller table, with a pneumatic or hydraulic cylinder under each arch. The leveling roller is installed inside the arch via a bearing seat and connected to the piston rod of the pneumatic or hydraulic cylinder. The upward or downward movement of the piston rod causes the bearing seat of the leveling roller to slide up and down within the arch. The invention utilizes an edge raising detection device located beside the roller table to determine the edge raising height of the strip. Based on the height of the subsequent stand's entry equipment, it determines whether the edge raising strip can enter the stand for rolling. If the edge raising height exceeds the height of the subsequent stand's entry equipment, it automatically levels the strip before proceeding with subsequent rolling by controlling the roll gap and rolling mode of the first stand, thus reducing scrap and downtime.

[0005] Chinese invention patent application CN 113204029 A, published on August 3, 2021, discloses "a device and method for detecting warpage of hot-rolled slabs," comprising the following: The device includes a single-line lidar, a lidar mounting bracket, a water chiller, a lidar server, and a calibration plate. First, the single-line lidar is calibrated by scanning the calibration plate on the roller conveyor to obtain the extrinsic parameters of the single-line lidar relative to the world coordinate system. A pose transformation is then performed to convert the point cloud data from the single-line lidar coordinate system to the world coordinate system. Next, the single-line lidar scans the moving slab to capture the point cloud data of the slab head. Combined with the roller conveyor speed information, a pose transformation is performed to generate three-dimensional point cloud information. Then, point cloud processing and feature extraction are used to obtain the point cloud features of the slab head. Finally, the least squares method is used to fit the slab head curve, and the slab head features are obtained by solving for the extreme values ​​of the curve.

[0006] The above technical solutions are mainly for detecting the shape of the intermediate billet head, and do not involve the determination and control of the intermediate billet rolling out. Summary of the Invention

[0007] The technical problem to be solved by this invention is to provide a method for determining and controlling the rolling out of intermediate billets based on a billet head tilt control system. This method utilizes an existing billet head tilt control system to perform image recognition and quantitative calculation of the billet head tilting situation. Roughing mill L2 determines the type of the billet head shape data on the steel feed side and sends it to roughing mill L1. Roughing mill L1, combined with different markings, issues different roller table operation commands. Simultaneously, roughing mill L2, combined with the rolling force interlock determination of the roughing mill horizontal rolls, provides further protection for the equipment, minimizing the damage to the rolling equipment caused by billet head tilting.

[0008] The technical solution of this invention is: to provide a method for determining and controlling the rolling out of intermediate billets based on a billet tilt control system, including image recognition of the tilting condition of the intermediate billets using a billet tilt control system, characterized in that:

[0009] 1) The lifting head control system performs image recognition on the plate shape before each pass of steel feeding in the R1 and R2 areas of the roughing mill, and uploads it to the L2 roughing mill;

[0010] 2) Based on the process rules and the warping value obtained from image recognition, the rough rolling L2 determines whether the plate shape is normal;

[0011] 3) Based on the plate shape determination result, the rough rolling L2 generates plate shape data markers;

[0012] 4) Roughing mill L2 sends the plate shape data flag to roughing mill L1;

[0013] 5) The roughing mill L1 issues corresponding control commands to the roller speed based on the received plate shape data flag;

[0014] 6) If the "normal head tilt" plate data flag is received, the roughing mill L1 issues the "roller conveyor normal operation" command;

[0015] 7) If the "high head alarm" plate data flag is received, the roughing mill L1 will issue a "roller conveyor half speed operation" command;

[0016] 8) If the "high head alarm" plate data flag is received, the roughing mill L1 will issue a "roller conveyor stop running" command.

[0017] Specifically, the aforementioned warp head control system includes at least the following functions: image acquisition, image data processing, warp direction determination, warp degree calculation, speed difference correction calculation, and speed difference setpoint self-learning calculation.

[0018] Furthermore, after obtaining the image of the slab head, the aforementioned buckle head control system, based on the strong contrast between the slab image and the background, segments the shape curve of the upper surface edge of the slab by setting a threshold for light and dark changes, and calculates the coordinates of each point on the curve based on the actual distance represented by adjacent pixels determined in the image calibration, thereby calculating the specific value of the buckle head.

[0019] Specifically, the intermediate billet rolling judgment and control method uses the warping value obtained by the warping degree calculation function of the warping control system to determine whether the plate shape is normal.

[0020] Furthermore, when the roughing mill L1 receives the "high head" alarm sign, the roughing mill L2 calculates the time required from the start of the roller table to the steel feeding, and obtains the steel feeding time T0. If time T0 has elapsed after the roller table starts and the rolling force of the roughing mill horizontal roller is still 0, it is determined that the intermediate billet has jammed, and a "roller table stop" command is immediately issued.

[0021] The plate shape of the roughing R1 and R2 regions before each pass of steel feeding is obtained by the overhanging head control system after image recognition.

[0022] The intermediate billet rolling determination and control method based on the billet head control system described in this invention uses image recognition and quantification calculation of the billet head tilting situation through the billet head control system. The results of image recognition and quantification calculation are then communicated with the roughing mill L2. The roughing mill L2 automatically determines the type of the head shape data of the intermediate billet on the steel inlet side. Then, the roughing mill L2 sends the head shape mark to the roughing mill L1. The roughing mill L1, based on different marks, issues different roller table operation commands. At the same time, the roughing mill L2, combined with the rolling force interlock determination of the roughing mill horizontal rolls, further protects the equipment and can minimize the damage to the rolling equipment caused by the billet head tilting.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] 1. The tilting status of intermediate billets can be obtained based on the existing tilting control system without adding new hardware or systems. There is no hardware modification to the existing roughing control system, which is easy to implement and readily accepted.

[0025] 2. By determining the type of the head plate shape data on the steel feeding side of the intermediate billet, and issuing different roller conveyor operation instructions according to different head plate shape markings, it is simple and easy to implement, less prone to control logic errors, and helps to improve the reliability and robustness of the existing control system.

[0026] 3. While issuing different roller table operation commands, the roughing mill L2 combines the rolling force interlock judgment of the roughing mill horizontal roll to further protect the equipment, which can minimize the damage to the rolling equipment caused by the intermediate billet tip. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the hardware architecture of the button-lifting control system;

[0028] Figure 2 This is a schematic diagram of the intermediate billet rolling determination and control process of the present invention.

[0029] In the diagram, 1 is the rolling mill, 2 is the PLC and transmission system, 3 is the image processing and button head control computer, and 4 is the CCD black and white camera. Detailed Implementation

[0030] The invention will now be further described with reference to the accompanying drawings.

[0031] The technical solution of this invention provides a method for determining and controlling the rolling out of intermediate billets based on a tilting head control system. The inventive point is:

[0032] Based on the existing button-lifting control system (the hardware architecture of the button-lifting control system is as follows) Figure 1 As shown in the figure, 1 is the rolling mill, 2 is the PLC and transmission system, 3 is the image processing and tilting head control computer, and 4 is the CCD black and white camera. The system performs image recognition on the inlet side plate shape data of the slab each time it enters the rolling mill. After recognition, the relevant values ​​of the tilting head are transmitted to the roughing mill L2. The roughing mill L2 combines the plate shape data to determine the severity of the tilting head, which is classified into three types: normal tilting head, high tilting head alarm, and extremely high tilting head alarm.

[0033] The intermediate billet rolling determination and control method based on the overhang control system described in this invention includes the following steps:

[0034] S1: The lifting head control system performs image recognition on the plate shape before each steel feeding in the R1 and R2 areas of the roughing mill, and uploads it to the L2 roughing mill.

[0035] S2: Based on the existing process rules and the warp value obtained by image recognition, the rough rolling L2 determines whether the plate shape is normal and classifies the plate shape data into three types of plate shape data flags: "normal warp", "high warp" alarm and "high warp" alarm.

[0036] S3: Roughing mill L2 sends the plate shape data flag to roughing mill L1. Roughing mill L1 makes corresponding control commands on the roller speed according to the received plate shape data flag. Under the "high head" alarm command, it is also necessary to make corresponding judgments based on the roughing mill horizontal roll rolling force data to decide whether to stop the roller operation.

[0037] Furthermore, the plate shape of each pass in the R1 and R2 areas of the roughing mill is obtained by image recognition from the buckle head control system.

[0038] The main functions of the buckle head control system include: image acquisition, image data processing, warping direction determination, warping degree calculation, speed difference correction calculation, and speed difference setpoint self-learning calculation. The technical solution of this invention mainly utilizes the warping degree calculation function of existing buckle head control systems.

[0039] Before image acquisition, the camera must first be calibrated. The purpose of calibration is to obtain the actual distance represented by each two pixels. The calibration method is based on the distance between the camera's installation position and the object being measured. A standard image calibration board is placed at the same distance as the object being measured. The calibration board contains a standard image, the size of which is known. By calculating the number of pixels occupied by the standard image in the captured image, the actual length represented by each two pixels can be derived.

[0040] After obtaining the image of the slab head, based on the strong contrast between the slab image and the background, the shape curve of the upper surface edge of the slab is segmented by setting the threshold of light and dark changes. Based on the actual distance between adjacent pixels determined in the image calibration, the coordinates of each point on the curve are calculated, thereby calculating the specific value of the upturned buckle.

[0041] Based on this, the technical solution of the present invention is carried out according to the following steps:

[0042] The buckle head control system uploads the specific value of the buckle head to the roughing mill L2. The roughing mill L2 determines whether the plate shape is normal according to the existing process rules and identifies the plate shape data as one of three types of flags: "normal buckle head", "high buckle head" alarm, and "high buckle head" alarm.

[0043] Then, the roughing mill L2 sends the warp value judgment flag to the roughing mill L1.

[0044] After L1 receives the "normal tilting" flag, it issues a normal operation command for the roller conveyor.

[0045] When L1 receives the "high billet head" alarm flag, it assumes that the intermediate billet is seriously tilted and cannot feed steel normally, and issues a command to stop the roller conveyor.

[0046] When roughing mill L1 receives the "high billet head" alarm, it assumes that the intermediate billet is tilted upwards, posing a risk of difficulty in feeding. To prevent the intermediate billet from traveling too fast and causing a strong impact on related equipment, it issues a half-speed operation command for the roller conveyor. At the same time, roughing mill L2 calculates the time required for the intermediate billet to feed after the roller conveyor starts, obtaining the feeding time T0. If time T0 has elapsed after the roller conveyor starts and the rolling force of the roughing mill's horizontal rolls is still 0, it is determined that the intermediate billet is stuck. To avoid further impact, it immediately issues a roller conveyor stop command.

[0047] The technical solution of this invention uses a head-tilting control system to perform image recognition and quantification calculations on the head-tilting situation of intermediate billets. The results of image recognition and quantification calculations are then communicated with the roughing mill L2. The roughing mill L2 automatically determines the type of the head shape data of the intermediate billet on the steel inlet side. Then, the roughing mill L2 sends the head shape marking to the roughing mill L1. The roughing mill L1, based on different markings, issues different roller table operation commands. At the same time, the roughing mill L2, combined with the rolling force interlocking judgment of the roughing mill horizontal rolls, further protects the equipment, which can minimize the damage to the rolling equipment caused by the head-tilting of intermediate billets.

[0048] This invention can be widely used in the field of process control for slab rolling.

Claims

1. A method for determining and controlling the rolling out of intermediate billets based on a billet tilt control system, comprising using a billet tilt control system to perform image recognition of the billet tilting situation, characterized in that: 1) The lifting head control system performs image recognition on the plate shape before each pass of steel feeding in the R1 and R2 areas of the roughing mill, and uploads it to the L2 roughing mill; 2) Based on the process rules and the warping value obtained from image recognition, the rough rolling L2 determines whether the plate shape is normal; 3) Based on the plate shape determination result, the rough rolling L2 generates plate shape data markers; 4) Roughing mill L2 sends the plate shape data flag to roughing mill L1; 5) Based on the received plate shape data flag, the roughing mill L1 issues corresponding control commands to the roller speed; 6) If the "normal head tilt" plate data flag is received, the roughing mill L1 issues the "roller conveyor normal operation" command; 7) If the "high head angle alarm" plate data flag is received, the roughing mill L1 will issue a "roller conveyor half speed operation" command; 8) If the "high head alarm" plate data flag is received, the roughing mill L1 will issue a "roller conveyor stop running" command; The intermediate billet rolling determination and control method based on the billet head tilt control system uses image recognition and quantification calculation of the billet head tilting situation through the billet head tilt control system. The results of image recognition and quantification calculation are communicated with the roughing mill L2. The roughing mill L2 automatically determines the type of the head shape data of the intermediate billet on the steel inlet side. Then, the roughing mill L2 sends the head shape mark to the roughing mill L1. The roughing mill L1, based on different marks, issues different roller table operation commands. At the same time, the roughing mill L2, based on the rolling force interlock determination of the roughing mill horizontal rolls, further protects the equipment and minimizes the damage to the rolling equipment caused by the billet head tilting.

2. The intermediate billet rolling determination and control method based on the tilting head control system according to claim 1, characterized in that: The aforementioned buckle control system includes at least the following functions: image acquisition, image data processing, warping direction determination, warping degree calculation, speed difference correction calculation, and speed difference setpoint self-learning calculation.

3. The intermediate billet rolling determination and control method based on the tilting head control system according to claim 1, characterized in that: After obtaining the image of the slab head, the aforementioned buckle head control system, based on the strong contrast between the slab image and the background, segments the shape curve of the upper surface edge of the slab by setting a threshold for light and dark changes, and calculates the coordinates of each point on the curve according to the actual distance represented by adjacent pixels determined in the image calibration, thereby calculating the specific value of the buckle head.

4. The intermediate billet rolling determination and control method based on the tilting head control system according to claim 1 or 2, characterized in that: The intermediate billet rolling judgment and control method uses the warping value obtained by the warping degree calculation function of the warping control system to determine whether the plate shape is normal.

5. The intermediate billet rolling determination and control method based on the tilting head control system according to claim 1, characterized in that... When the roughing mill L1 receives the "high head" alarm, the roughing mill L2 calculates the time required from the start of the roller table to the steel feeding, and obtains the steel feeding time T0. If the rolling force of the roughing mill horizontal roll is still 0 after the roller table has started, it is determined that the intermediate billet has jammed, and the "roller table stop" command is immediately issued.

6. The intermediate billet rolling determination and control method based on the tilting head control system according to claim 1, characterized in that: The plate shape before each pass of the roughing R1 and R2 regions is obtained by the overhang head control system through image recognition.

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