Strip steel tension loss control method and device and medium

Abstract

The invention provides a strip steel tension loss control method and device and a medium, and the method comprises the steps that in the actual production process of hot-rolled strip steel, in response to strip steel entering a downstream rack corresponding to a loop, the downstream rack completes steel biting, and loop rising of the loop is controlled in a forced moment loop rising control mode; when the loop lifting torque of the loop reaches the set forced loop lifting torque, the control stage of the loop is converted into a tension control stage from a forced torque loop lifting stage; and in the tension control stage, open-loop control is conducted on the loop within the preset duration, and when the preset duration is over, the loop is controlled in a closed-loop control mode so that tension adjustment of the strip steel can be achieved. According to the method, the device and the medium, the problems that in the prior art, when a hot rolling strip steel production line adopts a forced torque loop for loop rising and then tension control is conducted, the tension of the strip steel is too high and detection lag influences, the loop is controlled for strip steel tension adjustment, strip steel tension loss is likely to be caused, and the rolling stability of the production line is seriously affected can be solved.

Description

Technical Field

[0001] This invention relates to the field of strip steel production technology, and in particular to a method, device and medium for controlling strip steel tension loss. Background Technology

[0002] The looper operation in the actual production of hot-rolled strip steel is divided into the following stages: waiting process, looper raising process, tension and looper adjustment process, tail looper lowering process, and looper lowering process. In the waiting position, the looper maintains a fixed position at a certain angle to ensure smooth strip threading. When the strip enters the downstream stand of the looper, the looper moves to its highest position at a certain speed to form tension upon contact with the strip. When the angle of the looper and the tension of the strip reach a certain amplitude, the looper raising process ends, and the tension and looper adjustment stage begins. The strip tension is calculated by using a pressure head or pressure sensor mounted on the looper arm, combined with an angle encoder to detect pressure, angle, and the physical dimensions of the looper's mechanical structure. The difference between this calculated tension and the tension set in the secondary model is used to adjust the opening of the servo valve via PI control. This tension adjustment enables the looper to be raised or lowered. To achieve constant strip tension during this process, the looper adjustment is achieved by using the difference between the looper height set by the secondary model and the actual looper height, which is then controlled by PI regulation to increase or decrease the speed of the upstream stand, thus stabilizing the looper at a certain height. Before the tail of the strip leaves the upstream mill, precise calculations can control the looper to enter a small-loop state at a set position. During this stage, the looper tension and looper amount decrease at a set speed to a set value suitable for the tail of the strip to be thrown out. Finally, through strip tracking, when it is expected that the tail of the strip is about to leave the upstream stand, the looper switches from tension control to position control, falling from the current position to the waiting position of the next strip, thus completing the control process of one looper.

[0003] However, in the existing technology, when the hot-rolled strip steel production line adopts the forced torque looper to switch to tension control after the looper starts, it is affected by the high strip steel tension at this time and the detection lag. Controlling the looper to adjust the strip steel tension is prone to causing strip steel loss of tension, which seriously affects the rolling stability of the production line. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the above-mentioned deficiencies of the prior art by providing a strip tension control method, device and medium to solve the problem that in the prior art, when the hot-rolled strip production line uses a forced torque looper to control the tension after the looper starts, the strip tension is too high at this time and the detection is delayed, which makes it easy for the control looper to adjust the strip tension and cause strip tension loss, which seriously affects the rolling stability of the production line.

[0005] In a first aspect, the present invention provides a method for controlling strip tension loss, comprising: In the actual production process of hot-rolled strip steel, in response to the strip steel entering the downstream stand corresponding to the looper so that the downstream stand can complete the steel biting, the looper is controlled to lift the looper by a forced torque lifting control method. When the lifting torque of the looper reaches the set forced lifting torque, the control phase of the looper is switched from the forced torque lifting phase to the tension control phase. During the tension control phase, the looper is controlled in an open-loop manner for a preset time period, and when the preset time period ends, the looper is controlled in a closed-loop manner to achieve tension adjustment of the strip steel. The preset time period is obtained based on field equipment data analysis.

[0006] Furthermore, the field equipment data includes loop tension curve data collected by the field equipment; Before the tension control phase, in which the looper is controlled in an open-loop manner for a preset time period, and then controlled in a closed-loop manner when the preset time period ends, to achieve tension adjustment of the strip steel, the method further includes: The preset duration is obtained by analyzing the loop tension curve data collected by the field equipment under the strip tension loss condition.

[0007] Furthermore, the step of analyzing the looper tension curve data collected by the field equipment under strip tension loss conditions to obtain the preset duration specifically includes: The points corresponding to the highest tension during the forced torque starting stage and the lowest tension during the tension control stage are obtained from the looper tension curve data collected by the field equipment under strip tension loss conditions. The time interval between the point corresponding to the highest tension value and the point corresponding to the lowest tension value is determined as the preset duration.

[0008] Furthermore, in the tension control phase, the looper is subjected to open-loop control for a preset time period, and when the preset time period ends, the looper is controlled through closed-loop control to achieve tension adjustment of the strip steel, specifically including: Calculate the target torque when the forced torque start-up stage transitions to the tension control stage, wherein the target torque when the forced torque start-up stage transitions to the tension control stage is less than the forced torque start-up stage. Based on the target torque and the forced lifting torque, determine whether the strip has a tension problem; In response to the strip tension loss problem, during the tension control phase, the looper is controlled in an open-loop manner based on the forced lifting torque for a preset time period, and when the preset time period ends, the looper is controlled in a closed-loop manner based on the forced lifting torque to achieve tension adjustment of the strip.

[0009] Furthermore, the target torque for calculating the forced torque during the transition from the initial tension stage to the tension control stage specifically includes: The actual tension of the strip is obtained when the forced torque sleeve-starting stage transitions to the tension control stage; Based on the actual tension of the strip and the preset tension, the target torque is calculated when the forced torque starting stage transitions to the tension control stage, wherein the actual tension of the strip when the forced torque starting stage transitions to the tension control stage is greater than the preset tension.

[0010] Furthermore, determining whether the strip has a tension problem based on the target torque and the forced lifting torque specifically includes: If the difference between the forced lifting torque and the target torque is greater than a preset threshold, it is determined that the strip has a tension problem.

[0011] Furthermore, the actual production process of the hot-rolled strip includes the actual production process of 1580mm hot continuous rolling strip.

[0012] In a second aspect, the present invention provides a strip tension control device, comprising: The control module is used to control the looper to lift in response to the strip entering the downstream stand corresponding to the looper so that the downstream stand can complete the steel biting, in the actual production process of hot-rolled strip steel; It is converted into a module and connected to the control module. When the torque of the looper reaches the set forced looper torque, the control phase of the looper is switched from the forced torque looper phase to the tension control phase. A control and adjustment module, connected to the conversion module, is used to perform open-loop control on the looper within a preset time period during the tension control phase, and to control the looper through closed-loop control when the preset time period ends, so as to realize the tension adjustment of the strip steel. The preset time period is obtained based on the analysis of field equipment data.

[0013] Thirdly, the present invention provides a strip tension control device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to implement the strip tension control method described in the first aspect above.

[0014] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the strip tension control method described in the first aspect.

[0015] The strip tension control method, device, and medium provided by this invention firstly, in the actual production process of hot-rolled strip steel, in response to the strip steel entering the downstream stand corresponding to the looper to enable the downstream stand to complete the steel biting, the looper is controlled to start using a forced torque starting control method; then, when the looper starting torque reaches the set forced starting torque, the control stage of the looper is switched from the forced torque starting stage to the tension control stage; finally, in the tension control stage, the looper is controlled in an open-loop manner for a preset time, and when the preset time ends, the looper is controlled in a closed-loop manner to achieve the tension adjustment of the strip steel, wherein the preset time is obtained based on the analysis of field equipment data. This invention employs a forced torque method to control the looper's lifting after the strip enters the downstream stand of the looper and completes the gripping process. When the looper's lifting torque reaches a set value, it switches to the tension control stage. During the tension control stage, the looper is first subjected to open-loop control based on a preset duration determined by on-site equipment data analysis. During this period, the strip tension is not adjusted, thus avoiding tension loss caused by detection lag when adjusting tension during periods of high strip tension. After the preset duration ends, the looper is controlled in a closed loop to adjust the strip tension, thereby significantly reducing the probability of strip tension loss and effectively lowering the scrap rate caused by tension loss. This ensures the rolling stability of the production line and solves the problem in existing hot-rolled strip steel production lines where, when switching from forced torque looper lifting to tension control, the high strip tension and detection lag at this time can easily lead to strip tension loss when adjusting the looper's strip tension, severely affecting the rolling stability of the production line. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this drawing. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a flowchart of a strip tension control method according to Embodiment 1 of the present invention; Figure 2 This is a looper tension curve diagram before optimization of the hot strip rolling production line according to an embodiment of the present invention; Figure 3 This is an optimized looper tension curve of the hot strip rolling production line according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of a strip tension control device according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of a strip tension control device according to Embodiment 3 of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0019] It is understood that the specific embodiments and accompanying drawings described herein are merely for explaining the invention and are not intended to limit the invention.

[0020] It is understood that, without conflict, the various embodiments and features in the embodiments of the present invention can be combined with each other.

[0021] It is understood that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, while the parts unrelated to the present invention are not shown in the drawings.

[0022] It is understood that each unit or module involved in the embodiments of the present invention may correspond to only one entity structure, or may be composed of multiple entity structures, or multiple units or modules may be integrated into one entity structure.

[0023] It is understood that, without conflict, the functions and steps marked in the flowcharts and block diagrams of this invention may occur in a different order than that marked in the accompanying drawings.

[0024] It is understood that the flowcharts and block diagrams of this invention illustrate the possible architecture, functions, and operations of systems, apparatuses, devices, and methods according to various embodiments of this invention. Each block in the flowchart or block diagram may represent a unit, module, program segment, or code, containing executable instructions for implementing the specified function. Furthermore, each block or combination of blocks in the block diagram and flowchart can be implemented using a hardware-based system to achieve the specified function, or using a combination of hardware and computer instructions.

[0025] It is understood that the units and modules involved in the embodiments of the present invention can be implemented by software or by hardware. For example, the units and modules can be located in a processor.

[0026] Application Overview The main function of the hot-rolled strip looper is to maintain constant tension between stands and coordinate speed differences. It balances instantaneous speed fluctuations by storing or releasing strip steel, ensuring the stability of the continuous rolling process. The looper dynamically adjusts its angle via hydraulic / pneumatic devices. When the upstream stand speed decreases, it stores strip steel; when the downstream stand speed increases, it releases strip steel, controlling tension fluctuations within ±5%. This prevents strip breakage due to excessive tension or strip piling due to insufficient tension, thus maintaining constant tension. When adjacent stands have inconsistent speeds (e.g., upstream stand decelerating or downstream stand accelerating), the looper stores or releases strip steel through lifting and lowering movements, eliminating tension fluctuations caused by speed differences and preventing strip breakage at the head or tail slippage. This compensates for speed differences. Through an automatic adjustment mechanism, the looper can absorb changes in metal flow, coordinate the rolling speed of each stand, and reduce problems such as deviation and strip piling caused by fluctuations in process parameters, ensuring stable production.

[0027] The looper operation in actual production consists of the following stages: waiting process, looper raising process, tension and looper weight adjustment process, tail looper reduction process, and looper lowering process. In the waiting position, the looper maintains a fixed position at a certain angle to ensure smooth strip threading. When the strip enters the downstream frame of the looper, the looper moves to its highest position at a certain speed to form tension upon contact with the strip. When the angle of the looper and the tension of the strip reach a certain amplitude, the looper raising process ends, and the tension and looper weight adjustment stage begins. The strip tension is calculated by using a pressure head or pressure sensor mounted on the looper arm, combined with an angle encoder to detect pressure, angle, and the physical dimensions of the looper's mechanical structure. The difference between this calculated tension and the tension set in the secondary model is used to adjust the opening of the servo valve via PI control. This tension adjustment enables the looper to be raised or lowered. To achieve constant strip tension during this process, the looper adjustment is achieved by using the difference between the looper height set by the secondary model and the actual looper height, which is then controlled by PI regulation to increase or decrease the speed of the upstream stand, thus stabilizing the looper at a certain height. Before the tail of the strip leaves the upstream mill, precise calculations can control the looper to enter a small-loop state at a set position. During this stage, the looper tension and looper amount decrease at a set speed to a set value suitable for the tail of the strip to be thrown out. Finally, through strip tracking, when it is expected that the tail of the strip is about to leave the upstream stand, the looper switches from tension control to position control, falling from the current position to the waiting position of the next strip, thus completing the control process of one looper.

[0028] The core of hot-rolled strip tension control lies in maintaining stable strip tension through dynamic balance to ensure a smooth rolling process. Its control system typically consists of three parts: mechanical structure, hydraulic system, and electrical control. The mechanical part includes the looper rolls and support arms, responsible for guiding the strip path and storing metal; the hydraulic system adjusts the looper roll lifting speed in real time through servo valves and displacement sensors; the electrical control system collects the mill speed signal and uses a PID algorithm to calculate the hydraulic cylinder's actuation.

[0029] Currently, existing hot-rolled strip steel production lines use forced torque for looper retrieval control, followed by conventional tension control. The aim is rapid retrieval to quickly establish strip tension. However, a problem arises: the forced torque for rapid retrieval causes a momentary spike in strip tension. When the looper switches from forced torque to tension control, the lag in tension detection means the control system still detects or calculates the excessively high tension, significantly reducing the output torque. This results in a large torque difference at the switchover moment, ultimately causing a momentary loss of strip tension. This problem is particularly severe when rolling thin strip steel, easily causing the strip head to break, generating scrap, and seriously affecting the rolling stability of the production line.

[0030] In summary, when the hot-rolled strip steel production line uses a forced torque looper to control tension after the looper starts, the high strip tension at this time and the detection lag can easily cause strip tension loss when the looper is used to adjust the strip tension, which seriously affects the rolling stability of the production line.

[0031] To address the aforementioned technical problems, this application provides a strip tension control method, device, and medium. After the strip enters the downstream stand of the looper and completes the gripping process, a forced torque method is used to control the looper's lifting. When the looper's lifting torque reaches a set value, the process switches to a tension control stage. During the tension control stage, the looper is first subjected to open-loop control based on a preset duration determined by analysis of field equipment data. During this period, no adjustment is made to the strip tension, thus avoiding tension loss caused by detection lag when tension adjustment is performed during periods of high strip tension. After the preset duration, closed-loop control of the looper is then implemented to adjust the strip tension, significantly reducing the probability of strip tension loss and effectively lowering the scrap rate caused by tension loss. This ensures the rolling stability of the production line and at least solves the problem in existing hot-rolled strip production lines where, after the forced torque looper lifts and switches to tension control, the high strip tension and detection lag at this time easily lead to strip tension loss during looper tension adjustment, severely impacting the rolling stability of the production line.

[0032] After introducing the basic principles of this application, various non-limiting embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0033] Example 1: This embodiment provides a method for controlling strip tension loss, such as... Figure 1As shown, the method includes: Step S101: In the actual production process of hot-rolled strip steel, in response to the strip steel entering the downstream stand corresponding to the looper so that the downstream stand completes the steel biting, the looper is controlled to lift the looper by a forced torque lifting control method.

[0034] It should be noted that the actual production process of hot-rolled strip includes the actual production process of 1580mm hot continuous rolling strip, etc. The forced torque starting control method refers to the control method of directly outputting a preset forced torque command to drive the looper to start the looper quickly with a fixed torque, thereby realizing the rapid starting of the strip and the establishment of tension.

[0035] Specifically, in the actual production process of hot-rolled strip steel, when the strip steel enters the downstream stand corresponding to the looper and completes the steel biting action of the downstream stander, the looper moves to the highest position at a set speed under the forced torque looper control mode. After the looper contacts the strip steel, it causes tension to form on the strip steel, thereby controlling the looper to start.

[0036] Step S102: When the torque of the looper reaches the set forced looper torque, the control stage of the looper is switched from the forced torque looper stage to the tension control stage.

[0037] It should be noted that the forced torque start-up stage refers to the stage where the looper is started up by the forced torque start-up control method described above. The set forced torque start-up torque is the torque value preset in the forced torque start-up stage. When the actual torque output by the looper during the start-up process reaches this value, it indicates that the looper has completed the start-up.

[0038] Specifically, when the torque of the looper reaches the set forced looper torque after a certain period of time, so that the looper angle and strip tension reach the set amplitude, the control stage of the looper is changed from the forced torque looper stage to the tension control stage.

[0039] Step S103: In the tension control stage, the looper is controlled in an open loop for a preset time period, and when the preset time period ends, the looper is controlled in a closed loop to adjust the tension of the strip steel. The preset time period is obtained based on the analysis of field equipment data.

[0040] It should be noted that the field equipment data includes the loop tension curve data collected by the field equipment.

[0041] It is worth mentioning that the preset duration is determined by analyzing the actual production data collected by the on-site equipment. It can accurately adapt to the on-site rolling conditions and match the differences in detection lag and tension excess during the tension control stage of different rolling equipment. This effectively avoids the adjustment errors caused by detection lag and tension excess, and fundamentally reduces the risk of strip tension loss.

[0042] In an optional embodiment, before the tension control phase involves open-loop control of the looper for a preset time period and closed-loop control of the looper at the end of the preset time period to achieve tension adjustment of the strip, the method further includes: The preset duration is obtained by analyzing the loop tension curve data collected by the field equipment under the strip tension loss condition.

[0043] Specifically, by statistically analyzing the loop tension curve data collected by the on-site equipment under the condition of strip loss of tension, the preset duration suitable for the on-site production conditions is determined.

[0044] In one optional embodiment, the step of analyzing the loop tension curve data collected by the field equipment under strip tension loss conditions to obtain the preset duration specifically includes: The points corresponding to the highest tension during the forced torque starting stage and the lowest tension during the tension control stage are obtained from the looper tension curve data collected by the field equipment under strip tension loss conditions. The time interval between the point corresponding to the highest tension value and the point corresponding to the lowest tension value is determined as the preset duration.

[0045] It should be noted that the looper tension curve data directly corresponds to and reflects the tension of the strip steel corresponding to the looper.

[0046] Specifically, in the case of strip tension loss, the characteristic points corresponding to the peak value of strip tension during the forced torque starting stage and the characteristic points corresponding to the trough value of strip tension during the tension control stage are located and obtained from the looper tension curve data (such as the looper tension curve diagram) collected by the field equipment under the condition of strip tension loss. The time interval between the above tension peak characteristic points and tension trough characteristic points (this time period is the dangerous period when strip tension is most likely to lose tension under the rolling equipment corresponding to the looper tension curve data) is determined as the preset duration.

[0047] In an optional embodiment, during the tension control phase, the looper is subjected to open-loop control for a preset duration, and when the preset duration ends, the looper is controlled via closed-loop control to achieve tension adjustment of the strip steel, specifically including: Calculate the target torque when the forced torque start-up stage transitions to the tension control stage, wherein the target torque when the forced torque start-up stage transitions to the tension control stage is less than the forced torque start-up stage. Based on the target torque and the forced lifting torque, determine whether the strip has a tension problem; In response to the strip tension loss problem, during the tension control phase, the looper is controlled in an open-loop manner based on the forced lifting torque for a preset time period, and when the preset time period ends, the looper is controlled in a closed-loop manner based on the forced lifting torque to achieve tension adjustment of the strip.

[0048] In this embodiment, the calculation of the target torque when the forced torque sleeve-setting stage transitions to the tension control stage specifically includes: obtaining the actual tension of the strip steel when the forced torque sleeve-setting stage transitions to the tension control stage; calculating the target torque when the forced torque sleeve-setting stage transitions to the tension control stage based on the actual tension of the strip steel and a preset tension, wherein the actual tension of the strip steel when the forced torque sleeve-setting stage transitions to the tension control stage is greater than the preset tension.

[0049] Specifically, the actual tension of the strip can be calculated at the instant of switching from the forced torque start-up stage to the tension control stage by using the pressure head or pressure sensor installed on the looper arm in combination with the pressure, angle and physical dimensions of the looper mechanical structure detected by the angle encoder. Based on the difference between the actual tension of the strip and the preset tension of the strip, the target torque when the forced torque start-up stage turns into the tension control stage can be calculated.

[0050] In this embodiment, determining whether the strip has a tension problem based on the target torque and the forced lifting torque specifically includes: if the difference between the forced lifting torque and the target torque is greater than a preset threshold, then it is determined that the strip has a tension problem. The preset threshold is specifically determined by the corresponding technical personnel based on the on-site rolling process, strip specifications, historical working condition data, on-site experience, etc.

[0051] In this embodiment, in response to the strip tension loss problem, during the tension control phase, the looper is subjected to open-loop control based on the forced lifting torque for a preset time period, and when the preset time period ends, the looper is controlled through closed-loop control based on the forced lifting torque to achieve strip tension adjustment. Specific steps may include: Step 1: When it is determined that the strip has a tension problem (that is, controlling the looper to adjust the strip tension at this time is likely to cause the strip to lose tension), then during the tension control stage, the looper is continuously controlled with a forced lifting torque in an open-loop control mode for a preset time period (that is, no strip tension adjustment is performed). Step 2: When the preset timeout ends, exit the open-loop control mode and switch to the closed-loop control mode. At this time, the forced lifting torque is still used as the control basis to adjust the looper action and achieve stable adjustment of strip tension.

[0052] It is worth mentioning that the strip tension control method provided by this invention, after the strip enters the downstream stand corresponding to the looper and completes the gripping process, adopts a forced torque looper control method to control the looper's lifting. When the looper's lifting torque reaches the set forced lifting torque, it switches to the tension control stage. During the tension control stage, the looper is first subjected to open-loop control according to a preset duration determined by on-site equipment data analysis. During this period, no strip tension adjustment is performed, thereby avoiding tension loss caused by detection lag when the strip tension is too high. After the preset duration ends, the looper is then regulated through closed-loop control to achieve stable strip tension adjustment. This method can significantly reduce the probability of strip tension loss, effectively reduce the scrap rate caused by tension loss, and ensure the production stability of the rolling production line.

[0053] In one specific embodiment, the present invention provides a strip tension control method relating to hot-rolled strip production, used to reduce strip tension during hot-rolled looper shearing of the tension ring (that is, the control stage of the looper is changed from the forced torque looper stage to the tension control stage).

[0054] This method is based on the control method of transitioning to tension control after the start-up process. For the head start-up control, a forced torque start-up is used. The advantage of forced torque start-up is that it can quickly build up tension. The core of this method is the timing of the connection of the torque calculation entry point in the initial stage of tension ring control and the torque calculation. The torque calculation entry point refers to the time starting point when the tension closed-loop algorithm officially takes effect after the hot-rolled looper cuts the tension ring. The torque value calculated by the closed loop is used to control the looper torque.

[0055] The strip tension control method may specifically include: In the actual production process of hot-rolled strip steel, when the strip steel enters the downstream stand corresponding to the looper and completes the steel biting, the looper is started with a large torque through a forced torque starting control method. By analyzing the data (such as the torque output curve and the control loop transition point), it is determined whether there is a tension drop problem at the moment of cutting into the tension loop after the large torque starting (after the large tension starting, the tension control is cut, and the field sensor detects a large tension, and there is a certain lag between the detection and the actual situation. The control setpoint will reduce the torque output, which can easily lead to tension loss). If there is a tension drop problem, a preset delay time can be selected after cutting into the tension control for closed-loop torque control of the tension loop. The specific preset time is changed according to the actual situation on site (i.e., based on the analysis of field equipment data).

[0056] In another specific embodiment, taking loopers 1-6 of a 1580mm seven-stand hot strip mill as an example (this embodiment omits the step of determining whether the strip has a tension problem): When the looper starts to lift the strip after the lower stand of the finishing mill bites the steel, reaching the set forced lifting torque (acting for approximately 0.3 seconds), the tension control is then switched with an appropriate delay of about 0.2 seconds (the specific duration is determined based on the actual data analysis of the on-site equipment and adjusted adaptively; in this embodiment, the calculated value is 0.2 seconds). The actual effect is as follows: after lifting the looper, tension control is switched approximately 0.3 seconds later. This is divided into two stages: during the 0.2-second delay, tension open-loop control is implemented: no adjustment operations are performed on the looper's movement or strip tension during this stage, and the looper's operating status and strip tension change naturally with the on-site working conditions; after the 0.2-second delay, tension closed-loop control is entered: during this stage, the looper's movement is adjusted in real time through closed-loop control to achieve precise and stable control of the strip tension.

[0057] It is worth mentioning that by using the delay time (i.e., the preset time) as the boundary during tension control, and first executing the open-loop tension control and then the closed-loop tension control, the probability of the head strip losing tension can be greatly reduced, and the scrap steel caused by the head tension loss can be effectively reduced.

[0058] Specifically, Figure 2 The original data curve (i.e., looper tension curve) of the 1580mm hot strip production line before optimization is shown in the figure. The phenomenon shown in the figure is that the looper of different stands is forced to start with a large torque. When switching to tension control later, the tension low points of different degrees are significantly lower than the straight line corresponding to the set tension value (the specific location of each tension low point is marked in the figure). This results in low tension on site, frequent strip loss of tension, and strip surface tearing. Figure 3 The actual tension curve of the finishing looper for a 1580mm hot strip steel production line after optimization according to the method in this embodiment is shown in the figure. It can be clearly seen that during the forced torque to tension ring control stage, the tension of the looper did not fall significantly below the set tension value, that is, there was no obvious loss of tension in the actual tension of the looper.

[0059] It is worth mentioning that the strip tension control method provided by the present invention is used to solve the tension control problem after the looper starts and the tension control is switched, and to avoid the strip being crushed or scrapped at the moment of threading.

[0060] The strip tension control method provided in this embodiment of the invention firstly, in the actual production process of hot-rolled strip, in response to the strip entering the downstream stand corresponding to the looper to enable the downstream stand to complete the steel biting, the looper is controlled to start using a forced torque starting control method; then, when the looper starting torque reaches the set forced starting torque, the control stage of the looper is switched from the forced torque starting stage to the tension control stage; finally, in the tension control stage, the looper is controlled in an open-loop manner for a preset time, and when the preset time ends, the looper is controlled in a closed-loop manner to achieve the tension adjustment of the strip, wherein the preset time is obtained based on the analysis of field equipment data. This invention employs a forced torque method to control the looper's lifting after the strip enters the downstream stand of the looper and completes the gripping process. When the looper's lifting torque reaches a set value, it switches to the tension control stage. During the tension control stage, the looper is first subjected to open-loop control based on a preset duration determined by on-site equipment data analysis. During this period, the strip tension is not adjusted, thus avoiding tension loss caused by detection lag when adjusting tension during periods of high strip tension. After the preset duration ends, the looper is controlled in a closed loop to adjust the strip tension, thereby significantly reducing the probability of strip tension loss and effectively lowering the scrap rate caused by tension loss. This ensures the rolling stability of the production line and solves the problem in existing hot-rolled strip steel production lines where, when switching from forced torque looper lifting to tension control, the high strip tension and detection lag at this time can easily lead to strip tension loss when adjusting the looper's strip tension, severely affecting the rolling stability of the production line.

[0061] Example 2: like Figure 4 As shown, this embodiment provides a strip tension control device for executing the above-described strip tension control method, including: Control module 11 is used to control the looper to lift in response to the strip entering the downstream stand corresponding to the looper so that the downstream stand can complete the steel biting, in the actual production process of hot-rolled strip steel; The switch module 12 is connected to the control module 11 and is used to switch the control phase of the looper from the forced torque release phase to the tension control phase when the torque of the looper reaches the set forced release torque. The control and adjustment module 13, connected to the conversion module 12, is used to perform open-loop control on the looper within a preset time during the tension control phase, and to control the looper through closed-loop control when the preset time ends, so as to realize the tension adjustment of the strip steel. The preset time is obtained based on the analysis of field equipment data.

[0062] Furthermore, the field equipment data includes loop tension curve data collected by the field equipment; The device further includes: The analysis module is used to analyze the loop tension curve data collected by the field equipment under the strip tension loss condition to obtain the preset duration.

[0063] Furthermore, the analysis module specifically includes: The first acquisition unit is used to acquire the point corresponding to the highest tension value during the forced torque start-up stage and the point corresponding to the lowest tension value during the tension control stage from the looper tension curve data collected by the field equipment under strip tension loss conditions. The determining unit is used to determine the time period between the point corresponding to the highest tension value and the point corresponding to the lowest tension value as the preset duration.

[0064] Furthermore, the control and adjustment module 13 specifically includes: The first calculation unit is used to calculate the target torque when the forced torque start-up stage transitions to the tension control stage, wherein the target torque when the forced torque start-up stage transitions to the tension control stage is less than the forced torque start-up stage. The judgment unit is used to determine whether the strip has a tension problem based on the target torque and the forced lifting torque; The control implementation unit is used to respond to the strip's tension loss problem, and during the tension control phase, to perform open-loop control on the looper based on the forced lifting torque within a preset time period, and when the preset time period ends, to control the looper through closed-loop control based on the forced lifting torque, so as to achieve tension adjustment of the strip.

[0065] Furthermore, the first computing unit specifically includes: The second acquisition unit is used to acquire the actual tension of the strip when the forced torque sleeve-starting stage is switched to the tension control stage. The second calculation unit is used to calculate the target torque when the forced torque starting stage is switched to the tension control stage based on the actual tension of the strip and the preset tension, wherein the actual tension of the strip when the forced torque starting stage is switched to the tension control stage is greater than the preset tension.

[0066] Furthermore, the determination unit is specifically used for: If the difference between the forced lifting torque and the target torque is greater than a preset threshold, it is determined that the strip has a tension problem.

[0067] Furthermore, the actual production process of the hot-rolled strip includes the actual production process of 1580mm hot continuous rolling strip.

[0068] Example 3: refer to Figure 5This embodiment provides a strip tension control device, including a memory 21 and a processor 22. The memory 21 stores a computer program, and the processor 22 is configured to run the computer program to execute the strip tension control method in Embodiment 1.

[0069] The memory 21 is connected to the processor 22. The memory 21 can be a flash memory, a read-only memory or other memory, and the processor 22 can be a central processing unit or a microcontroller.

[0070] Example 4: This embodiment provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the strip tension control method in Embodiment 1 above.

[0071] The computer-readable storage medium includes volatile or non-volatile, removable or non-removable media implemented in any method or technology for storing information, such as computer-readable instructions, data structures, computer program modules or other data. Computer-readable storage media include, but are not limited to, RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory or other memory technologies, CD-ROM (Compact Disc Read-Only Memory), DVD or other optical disc storage, cartridges, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer.

[0072] In summary, the strip tension control method, device, and medium provided in this embodiment of the invention firstly, in the actual production process of hot-rolled strip, in response to the strip entering the downstream stand corresponding to the looper to enable the downstream stand to complete the steel biting, the looper is controlled to start using a forced torque starting control method; then, when the looper starting torque reaches the set forced starting torque, the control stage of the looper is switched from the forced torque starting stage to the tension control stage; finally, in the tension control stage, the looper is controlled in an open-loop manner within a preset time, and when the preset time ends, the looper is controlled in a closed-loop manner to achieve the tension adjustment of the strip, wherein the preset time is obtained based on the analysis of field equipment data. This invention employs a forced torque method to control the looper's lifting after the strip enters the downstream stand of the looper and completes the gripping process. When the looper's lifting torque reaches a set value, it switches to the tension control stage. During the tension control stage, the looper is first subjected to open-loop control based on a preset duration determined by on-site equipment data analysis. During this period, the strip tension is not adjusted, thus avoiding tension loss caused by detection lag when adjusting tension during periods of high strip tension. After the preset duration ends, the looper is controlled in a closed loop to adjust the strip tension, thereby significantly reducing the probability of strip tension loss and effectively lowering the scrap rate caused by tension loss. This ensures the rolling stability of the production line and solves the problem in existing hot-rolled strip steel production lines where, when switching from forced torque looper lifting to tension control, the high strip tension and detection lag at this time can easily lead to strip tension loss when adjusting the looper's strip tension, severely affecting the rolling stability of the production line.

[0073] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for controlling strip tension loss, characterized in that, The method includes: In the actual production process of hot-rolled strip steel, in response to the strip steel entering the downstream stand corresponding to the looper so that the downstream stand can complete the steel biting, the looper is controlled to lift the looper by a forced torque lifting control method. When the lifting torque of the looper reaches the set forced lifting torque, the control phase of the looper is switched from the forced torque lifting phase to the tension control phase. During the tension control phase, the looper is controlled in an open-loop manner for a preset time period, and when the preset time period ends, the looper is controlled in a closed-loop manner to achieve tension adjustment of the strip steel. The preset time period is obtained based on field equipment data analysis.

2. The method according to claim 1, characterized in that, The field equipment data includes loop tension curve data collected by the field equipment; Before the tension control phase, in which the looper is controlled in an open-loop manner for a preset time period, and then controlled in a closed-loop manner when the preset time period ends, to achieve tension adjustment of the strip steel, the method further includes: The preset duration is obtained by analyzing the loop tension curve data collected by the field equipment under the strip tension loss condition.

3. The method according to claim 2, characterized in that, The process of analyzing the looper tension curve data collected by the field equipment under strip tension loss conditions to obtain the preset duration specifically includes: The points corresponding to the highest tension during the forced torque starting stage and the lowest tension during the tension control stage are obtained from the looper tension curve data collected by the field equipment under strip tension loss conditions. The time interval between the point corresponding to the highest tension value and the point corresponding to the lowest tension value is determined as the preset duration.

4. The method according to claim 1, characterized in that, In the tension control phase, the looper is subjected to open-loop control for a preset time period, and when the preset time period ends, the looper is controlled through closed-loop control to achieve tension adjustment of the strip steel, specifically including: Calculate the target torque when the forced torque start-up stage transitions to the tension control stage, wherein the target torque when the forced torque start-up stage transitions to the tension control stage is less than the forced torque start-up stage. Based on the target torque and the forced lifting torque, determine whether the strip has a tension problem; In response to the strip tension loss problem, during the tension control phase, the looper is controlled in an open-loop manner based on the forced lifting torque for a preset time period, and when the preset time period ends, the looper is controlled in a closed-loop manner based on the forced lifting torque to achieve tension adjustment of the strip.

5. The method according to claim 4, characterized in that, The calculation of the target torque when the forced torque stage transitions to the tension control stage specifically includes: The actual tension of the strip is obtained when the forced torque sleeve-starting stage transitions to the tension control stage; Based on the actual tension of the strip and the preset tension, the target torque is calculated when the forced torque starting stage transitions to the tension control stage, wherein the actual tension of the strip when the forced torque starting stage transitions to the tension control stage is greater than the preset tension.

6. The method according to claim 4, characterized in that, The step of determining whether the strip has a tension problem based on the target torque and the forced lifting torque specifically includes: If the difference between the forced lifting torque and the target torque is greater than a preset threshold, it is determined that the strip has a tension problem.

7. The method according to claim 1, characterized in that, The actual production process of hot-rolled strip steel includes the actual production process of 1580mm hot continuous rolling strip steel.

8. A strip tension control device, characterized in that, include: The control module is used to control the looper to lift in response to the strip entering the downstream stand corresponding to the looper so that the downstream stand can complete the steel biting, in the actual production process of hot-rolled strip steel; It is converted into a module and connected to the control module. When the torque of the looper reaches the set forced looper torque, the control phase of the looper is switched from the forced torque looper phase to the tension control phase. A control and adjustment module, connected to the conversion module, is used to perform open-loop control on the looper within a preset time period during the tension control phase, and to control the looper through closed-loop control when the preset time period ends, so as to realize the tension adjustment of the strip steel. The preset time period is obtained based on the analysis of field equipment data.

9. A strip tension control device, characterized in that, It includes a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to implement the strip tension control method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the strip tension control method as described in any one of claims 1-7.

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