A method and system for controlling the difference between the pressures on the two sides of the finishing stand of a hot continuous rolling mill

Abstract

The present application relates to a kind of hot continuous rolling finishing stand roll double-side pressure differential collaborative control method and system, the method is by first executing first control stage after the head of strip enters finishing stand roll area, then switch to second control stage according to stage end information, avoid the unstable form of strip head directly into pressure control;By obtaining the actual pressure of operating side and the actual pressure of transmission side, the deviation between the actual pressure of both sides and the corresponding target pressure is decomposed into common pressure deviation and differential pressure deviation, and common roll gap adjustment and differential roll gap adjustment are generated respectively, so that common roll gap adjustment is used to maintain strip width constraint, and differential roll gap adjustment is used to correct the center line deviation of finishing caused by uneven stress of both sides;By obtaining the width deviation of finishing outlet and the center line deviation of finishing outlet, the target pressure and differential roll gap adjustment parameter are feedback corrected, so that finishing stand roll control forms collaborative closed loop between width accuracy and deviation suppression.

Description

Technical Field

[0001] This invention relates to the field of hot-rolled strip steel production technology, and in particular to a method and system for differential pressure control on both sides of hot continuous rolling mill vertical rolls. Background Technology

[0002] In the hot strip mill production process, the finishing mill's small vertical rolls are located on both sides of the strip's width direction, used to apply lateral constraints to the strip's edges as it enters the finishing mill. The control state of the finishing mill's small vertical rolls directly affects the strip's width accuracy, the position of the finishing mill exit centerline, and the camber at the strip's head and deviation at its tail. As downstream users increase their requirements for strip dimensional stability and shape quality, the finishing mill's small vertical rolls are no longer just simple edge limiting mechanisms, but need to continuously provide appropriate lateral constraints under complex conditions such as changes in rolling load, changes in strip head and tail shape, and changes in steel grade and specifications.

[0003] Existing finishing mill vertical rolls typically employ position control, meaning that the operating side and drive side vertical rolls are controlled to reach predetermined positions based on a set roll gap position. This method provides basic width constraints when rolling conditions are relatively stable, but its control is primarily based on the roll gap position and cannot adaptively adjust to changes in actual pressure on both sides during rolling. When fluctuations occur in strip material, temperature, entry thickness, rolling speed, or head and tail morphology, fixed position control may result in excessive pressure on one side of the vertical roll while insufficient pressure on the other, causing unbalanced lateral forces on the strip.

[0004] To address these issues, some production lines have introduced vertical roll pressure control. This involves using pressure sensors to detect the rolling pressure on the vertical rolls and adjusting the roll gap based on the deviation between the actual and target pressures to maintain the vertical roll pressure within a set range. However, conventional constant pressure control typically treats the pressure on both sides as a single control target or only focuses on whether the average pressure reaches the target value. It fails to adequately distinguish the impact of the average clamping force on width accuracy and the effect of uneven force on the finishing mill centerline offset. When there is a force difference between the operating and drive sides of the strip, simply maintaining a stable average pressure may not be enough to suppress deviation. Furthermore, when the strip itself exhibits a wedge-shaped offset tendency, directly relying on differential adjustment based on centerline deviation may lead to erroneous adjustments. Summary of the Invention

[0005] The main objective of this invention is to provide a method and system for differential pressure control on both sides of the vertical roll of hot continuous rolling mill, so as to solve the technical problem that it is difficult to simultaneously achieve width accuracy and suppress centerline deviation of the finishing mill in the existing technology.

[0006] To achieve the above objectives, the present invention provides a method for differential pressure coordinated control of both sides of the vertical roll of a hot continuous rolling mill, comprising the following steps: S1. Obtain the current strip steel production process information, and determine the target pressure of the operating side vertical roll, the target pressure of the transmission side vertical roll, and the initial differential roll gap adjustment parameters based on the current strip steel production process information; S2. Obtain entry information of the strip head into the finishing mill vertical roll area, and control the operation side vertical roll and the transmission side vertical roll to perform the first control stage according to the entry information; S3. Obtain the phase end information of the first control phase, and switch the operation side vertical roller and the transmission side vertical roller from the first control phase to the second control phase according to the phase end information; S4. Obtain the actual pressure on the operating side and the actual pressure on the transmission side, and determine the common pressure deviation and differential pressure deviation based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the vertical roller on the operating side, and the target pressure of the vertical roller on the transmission side. S5. Determine the common roll gap adjustment amount based on the common pressure deviation, call the differential roll gap adjustment parameters, and determine the differential roll gap adjustment amount based on the differential pressure deviation and the differential roll gap adjustment parameters; S6. Generate the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount according to the common roll gap adjustment amount and the differential roll gap adjustment amount, and control the hydraulic roll gap adjustment device to adjust the operating side vertical roll gap and the transmission side vertical roll gap respectively according to the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount. S7. Obtain the finishing mill exit width deviation and the finishing mill exit centerline deviation, and correct the target pressure of the operating side vertical roll and / or the target pressure of the transmission side vertical roll based on the finishing mill exit width deviation and the finishing mill exit centerline deviation.

[0007] Furthermore, step S1 specifically includes the following steps: Obtain information on the current strip steel grade, target width, finishing mill entry thickness, finishing mill exit thickness, and rolling speed; Obtain the historical width deviation and historical centerline deviation of historical strips that have the same steel type information and the same target width information as the current strip; The basic target pressure is determined based on the steel grade information, the target width information, the finishing mill inlet thickness information, the finishing mill outlet thickness information, and the rolling speed information; The basic target pressure is corrected based on the historical width deviation and the historical centerline deviation to obtain the target pressure of the operating side vertical roller and the target pressure of the drive side vertical roller.

[0008] Furthermore, the first control stage is the head import control stage, and step S2 specifically includes the following steps: After obtaining the entry information, control the operation side vertical roller and the transmission side vertical roller to move to the entry roller gap position; The actual pressure on the operating side and the actual pressure on the transmission side are continuously acquired. When the actual pressure on either side reaches the preset upper limit of the input pressure, the vertical roller on the corresponding side stops moving towards the edge of the strip. The length of the strip head passing through the finishing mill vertical roll area is obtained, and the stage end information is determined based on the length of the passing.

[0009] More preferably, the second control stage includes a pressure control stage and a full-load coordinated control stage, and step S3 specifically includes the following steps: The continuous and effective acquisition status of the actual pressure on the operating side and the actual pressure on the transmission side during the first control phase is obtained. Obtain the roll gap position status of the operating side vertical roller gap and the transmission side vertical roller gap; When the continuous effective acquisition status indicates that the pressure on both sides is effectively acquired, and the roll gap position status indicates that neither of the vertical rolls on both sides has reached the mechanical limit, the pressure pipe control stage is entered. During the pressure control phase, the proportion of position control output in roll gap control is reduced, while the proportion of pressure control output in roll gap control is increased. When both the actual pressure on the operating side and the actual pressure on the transmission side enter the allowable deviation range of the corresponding target pressure, the full-load coordinated control stage is entered.

[0010] Furthermore, the following steps are included before step S4: Acquire the operating-side pressure sampling sequence and the transmission-side pressure sampling sequence collected according to a preset sampling period; The operating-side pressure sampling sequence and the transmission-side pressure sampling sequence are respectively subjected to moving average processing to obtain the operating-side smoothed pressure and the transmission-side smoothed pressure. Obtain the pressure change rate in the operation-side pressure sampling sequence and the transmission-side pressure sampling sequence, and determine the sampling points whose pressure change rate exceeds a preset pressure change rate threshold as abnormal sampling points; After removing the abnormal sampling points, the smoothing pressure on the operating side is taken as the actual pressure on the operating side, and the smoothing pressure on the transmission side is taken as the actual pressure on the transmission side.

[0011] Furthermore, in step S4, the method for determining the common pressure deviation and the differential pressure deviation includes the following steps: Calculate the average target pressure on both sides based on the target pressure of the operating side vertical roller and the target pressure of the transmission side vertical roller; Based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the vertical roller on the operating side, and the target pressure of the vertical roller on the transmission side, the deviation of the average clamping force on both sides relative to the average target pressure on both sides is determined, and the deviation is taken as the common pressure deviation. Based on the actual pressure difference between the actual pressure on the operating side and the actual pressure on the transmission side, and the target pressure difference between the target pressure of the vertical roller on the operating side and the target pressure of the vertical roller on the transmission side, the uneven force state on both sides is determined, and the uneven force state on both sides is taken as the differential pressure deviation.

[0012] More preferably, step S5 specifically includes the following steps: When the common pressure deviation indicates that the average clamping force on both sides is lower than the average target pressure on both sides, a common roll gap adjustment amount is generated to simultaneously reduce the roll gap of the operating side vertical roll and the roll gap of the transmission side vertical roll. When the common pressure deviation indicates that the average clamping force on both sides is higher than the average target pressure on both sides, a common roll gap adjustment amount is generated to simultaneously increase the roll gap of the operating side vertical roll and the roll gap of the transmission side vertical roll. When the differential pressure deviation indicates that the force on the operating side is greater than the force on the transmission side, a differential roll gap adjustment amount is generated to increase the roll gap of the vertical roll on the operating side and decrease the roll gap of the vertical roll on the transmission side. When the differential pressure deviation indicates that the force on the transmission side is greater than the force on the operating side, a differential roll gap adjustment amount is generated to increase the roll gap of the vertical roll on the transmission side and decrease the roll gap of the vertical roll on the operating side.

[0013] Furthermore, step S6 specifically includes the following steps: Obtain the pressure dead zone judgment results corresponding to the common pressure deviation and the differential pressure deviation; When the pressure dead zone determination result indicates that the common pressure deviation and / or the differential pressure deviation do not exceed the corresponding pressure dead zone, the corresponding roll gap adjustment amount remains unchanged; When the pressure dead zone determination result indicates that the common pressure deviation and / or the differential pressure deviation exceed the corresponding pressure dead zone, the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount are subject to segmented step size restrictions. The mechanical limit states of the operating side vertical roller gap and the transmission side vertical roller gap are obtained. When the mechanical limit state of either side indicates that the corresponding side vertical roller is close to the mechanical limit, the corresponding side vertical roller is stopped from moving further in the mechanical limit direction.

[0014] Furthermore, step S7 specifically includes the following steps: When the deviation of the finishing mill exit width exceeds the preset allowable width range, and the deviation of the finishing mill exit centerline is within the preset allowable centerline range, the target pressure of the operating side vertical roll and the target pressure of the transmission side vertical roll are synchronously corrected according to the positive and negative directions of the finishing mill exit width deviation. When the deviation of the center line of the finishing mill exit exceeds the preset center line allowable range, and the actual pressure difference on both sides exceeds the preset pressure difference allowable range, the differential roll gap adjustment parameter is corrected according to the offset direction of the center line deviation of the finishing mill exit, so as to change the determination direction and / or determination amplitude of the differential roll gap adjustment amount. When the deviation of the center line of the finishing mill exit exceeds the preset center line allowable range, and the actual pressure difference on both sides is within the preset pressure difference allowable range, it is determined that the current strip has a wedge-shaped offset state, and the differential roll gap adjustment parameters are kept unchanged.

[0015] The present invention also provides a dual-side pressure differential collaborative control system for hot continuous rolling mill finishing vertical rolls, used to implement the above-described dual-side pressure differential collaborative control method for hot continuous rolling mill finishing vertical rolls. The system includes a production process information acquisition module, a stage control module, a pressure acquisition module, a pressure deviation determination module, a roll gap adjustment amount determination module, a hydraulic roll gap adjustment device, and an outlet feedback verification module. The production process information acquisition module is used to acquire the current strip steel production process information, and determine the target pressure of the operating side vertical roll, the target pressure of the transmission side vertical roll, and the initial differential roll gap adjustment parameters based on the current strip steel production process information; The stage control module is used to acquire entry information of the strip head entering the finishing mill vertical roll area, and control the operating side vertical roll and the drive side vertical roll to perform the first control stage according to the entry information. It is also used to acquire the stage end information of the first control stage, and switch the operating side vertical roll and the drive side vertical roll from the first control stage to the second control stage according to the stage end information. The pressure acquisition module is used to acquire the actual pressure on the operating side and the actual pressure on the transmission side. The pressure deviation determination module is used to determine common pressure deviation and differential pressure deviation based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the vertical roller on the operating side, and the target pressure of the vertical roller on the transmission side. The roll gap adjustment determination module is used to determine the common roll gap adjustment amount based on the common pressure deviation, and to call the differential roll gap adjustment parameters to determine the differential roll gap adjustment amount based on the differential pressure deviation and the differential roll gap adjustment parameters; it is also used to generate the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount based on the common roll gap adjustment amount and the differential roll gap adjustment amount. The hydraulic roll gap adjustment device is used to adjust the roll gap of the operating side vertical roller and the roll gap of the driving side vertical roller according to the adjustment amount of the operating side roll gap and the adjustment amount of the driving side roll gap, respectively. The exit feedback verification module is used to obtain the finishing mill exit width deviation and the finishing mill exit centerline deviation, and to correct the target pressure of the operating side vertical roll, the target pressure of the transmission side vertical roll, and / or the differential roll gap adjustment parameters based on the finishing mill exit width deviation and the finishing mill exit centerline deviation.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves a first control stage after the strip head enters the finishing mill vertical roll area, and switches to a second control stage after acquiring the end information of the first stage. This allows the pressure control of the finishing mill vertical roll to avoid the initial impact range where the strip head shape is unstable. By acquiring the actual pressure on the operating side and the actual pressure on the transmission side, and decomposing the deviation of the pressure on both sides relative to the corresponding target pressure into common pressure deviation and differential pressure deviation, the common pressure deviation corresponds to the constraint effect of the average clamping force on the strip width on both sides, and the differential pressure deviation corresponds to the correction effect of uneven force on both sides on the finishing mill centerline offset. By synthesizing the common roll gap adjustment amount and the differential roll gap adjustment amount, the roll gap adjustment amount on both sides is combined, enabling the operating side vertical roll and the transmission side vertical roll to perform synchronous pressure correction and differential pressure correction simultaneously. By using the finishing mill exit width deviation and the finishing mill exit centerline deviation to provide feedback verification of the target pressure and differential roll gap adjustment parameters, the vertical roll control is transformed from a single pressure closed loop to a synergistic closed loop of width accuracy and deviation suppression. This improves the strip width stability and finishing mill centerline stability when the rolling load, material, and strip head and tail shape change. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating the differential pressure control method on both sides of the hot continuous rolling mill vertical roll in one embodiment of the present invention. Figure 2 This is a schematic diagram of the centerline deviation of the double-sided pressure differential collaborative control method for the vertical roll of the hot continuous rolling mill without hot rolling mill in one embodiment of the present invention; Figure 3 This is a schematic diagram of the centerline deviation after the implementation of the double-sided differential pressure collaborative control method for hot continuous rolling mill vertical rolls in one embodiment of the present invention. Figure 4This is a schematic diagram of the width deviation of a multi-function instrument in an embodiment of the present invention, illustrating the differential pressure control method for the vertical rolls of a hot continuous rolling mill without hot rolling mill operation. Figure 5 This is a schematic diagram of the width deviation of a multi-function instrument after implementing the differential pressure control method on both sides of the hot continuous rolling mill vertical roll in one embodiment of the present invention. Figure 6 This is a schematic diagram of the width hit rate of the 2250 line of the hot rolling mill before and after the implementation of the double-sided pressure differential collaborative control method for the vertical rolls of the hot continuous rolling mill in one embodiment of the present invention. Figure 7 This is a schematic diagram of the overall deviation rate of the finishing mill line 2250 in a hot rolling mill before and after the implementation of the dual-side pressure differential collaborative control method for the hot continuous rolling mill vertical rolls in one embodiment of the present invention.

[0019] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0023] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0024] In the following embodiments, the hot-rolled finishing mill includes an operating-side vertical roll, a drive-side vertical roll, an operating-side pressure detection device, a drive-side pressure detection device, a hydraulic roll gap adjustment device, a finishing mill exit detection device, and a controller. The operating-side and drive-side vertical rolls are respectively arranged on both sides of the strip width direction to apply lateral constraints to the edges of the strip. The operating-side pressure detection device detects the actual pressure exerted by the operating-side vertical roll on the strip edges, and the drive-side pressure detection device detects the actual pressure exerted by the drive-side vertical roll on the strip edges. The hydraulic roll gap adjustment device is connected to both the operating-side and drive-side vertical rolls and is used to adjust the position of the two vertical rolls relative to the strip edges. The finishing mill exit detection device is located on the exit side of the finishing mill and is used to detect the finishing mill exit width deviation and the finishing mill exit centerline deviation.

[0025] Please see Figures 1 to 7 This embodiment provides a method for differential pressure coordinated control of both sides of the vertical roll of a hot continuous rolling mill, including the following steps: S1. Obtain the current strip steel production process information, and determine the target pressure of the operating side vertical roll, the target pressure of the drive side vertical roll, and the initial differential roll gap adjustment parameters based on the current strip steel production process information. Specifically, the current strip steel production process information can be obtained by the hot continuous rolling secondary process control system, rolling planning system, or finishing mill controller, including the current strip steel grade information, target width information, finishing mill inlet thickness information, finishing mill outlet thickness information, rolling speed information, historical width deviation, and historical centerline deviation. The target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll are the target pressure values ​​used to control the operating side vertical roll and the drive side vertical roll to apply lateral constraints to the edge of the strip steel, respectively. The differential roll gap adjustment parameters are control parameters used to determine the differential roll gap adjustment amount based on the differential pressure deviation, and include at least one of the following: differential adjustment direction, differential adjustment step size, allowable pressure difference range, and differential adjustment limit. Taking a 2250 hot strip mill production line as an example, the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll can be set within the range of 20kN to 60kN, preferably 30kN; the differential adjustment step size is set to 0.05mm to 0.50mm, the differential adjustment limit is set to 0.50mm to 1.00mm, and the allowable pressure difference range is set to 5kN to 15kN. The above pressure range is set with reference to the on-site control requirements when the finishing mill vertical roll applies lateral constraint to the edge of the hot-rolled strip, achieving both width constraint and preventing overpressure at the edge. The above roll gap adjustment range is set with reference to the action resolution and anti-over-adjustment requirements of the hydraulic roll gap adjustment mechanism of the finishing mill vertical roll. Through the above methods, the finishing mill vertical roll control can establish an initial control basis that matches the current strip specifications and historical rolling conditions before the strip enters the mill.

[0026] Further, step S1 specifically includes the following steps: acquiring the current strip's steel grade information, target width information, finishing mill inlet thickness information, finishing mill outlet thickness information, and rolling speed information; acquiring the historical width deviation and historical centerline deviation corresponding to historical strips with the same steel grade information and target width information as the current strip; determining the basic target pressure based on the steel grade information, target width information, finishing mill inlet thickness information, finishing mill outlet thickness information, and rolling speed information; correcting the basic target pressure based on the historical width deviation and historical centerline deviation to obtain the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll. Specifically, the steel grade information is used to reflect the deformation resistance of the strip material, the target width information is used to determine the geometric reference for the lateral constraint of the vertical roll, the finishing mill inlet thickness information and the finishing mill outlet thickness information are used to reflect the degree of reduction deformation during the finishing mill process, and the rolling speed information is used to reflect the response time requirement of the vertical roll pressure control. Historical width deviation can be taken as the average value or fluctuation range of the exit width deviation of the most recent 5 to 20 coils of strip steel with the same steel grade and target width. Historical centerline deviation can be taken as the average value or statistical result of the exit centerline deviation of the most recent 5 to 20 coils of strip steel with the same steel grade and target width. When the historical width deviation indicates that the width deviation of strip steel of the same specification is continuously large, the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll are increased simultaneously. When the historical width deviation indicates that the width deviation of strip steel of the same specification is continuously small, the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll are decreased simultaneously. When the historical centerline deviation indicates that there is a stable offset direction of strip steel of the same specification, the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll are differentiated based on the stable offset direction. Through the above methods, the determination process of target pressure can simultaneously consider material deformation characteristics, target width, thickness variation, rolling speed, and historical deviation trend, avoiding the problem that a single fixed pressure value is difficult to adapt to different strip steel working conditions.

[0027] S2. Obtain entry information of the strip head into the finishing mill vertical roll area, and control the operating side vertical roll and the drive side vertical roll to execute the first control stage based on the entry information. Specifically, the entry information can be generated by a hot metal detector, a stand entry position tracking signal, the rolling line speed integral result, or a strip head tracking model. When the controller obtains the entry information of the strip head into the finishing mill vertical roll area, it does not immediately execute pressure closed-loop control, but first controls the operating side vertical roll and the drive side vertical roll to execute the first control stage. The first control stage is used to introduce constraints on the strip head, so that when there is a camber, irregular edge, or head posture fluctuation, the strip head will not be subjected to excessive transient lateral force due to premature closure of the vertical roll. In this way, the unstable region of the strip head can be distinguished from the subsequent pressure collaborative control region, providing a prerequisite for the stable calculation of subsequent common pressure deviation and differential pressure deviation.

[0028] Further, the first control stage is the head introduction control stage, and step S2 specifically includes the following steps: after obtaining the entry information, controlling the operating side vertical roll and the driving side vertical roll to move to the introduction roll gap position; continuously obtaining the actual pressure of the operating side and the actual pressure of the driving side, and stopping the corresponding side vertical roll from moving towards the edge of the strip when the actual pressure on either side reaches the preset introduction pressure upper limit; obtaining the length of the strip head passing through the finishing vertical roll area, and determining the stage end information based on the length of ... The above method enables continuous monitoring of pressure on both sides during the strip head introduction stage, and timely cessation of the vertical roller on that side from approaching the strip edge when an overpressure trend appears on either side, thereby reducing the risk of head impact and misalignment.

[0029] S3. Obtain the stage end information of the first control stage, and switch the operating side vertical roll and the drive side vertical roll from the first control stage to the second control stage according to the stage end information. Specifically, the stage end information may include the strip head passing length reaching the preset head inlet length, both sides pressure being in a continuous and effective acquisition state, both side vertical rolls not reaching the mechanical limit, and both sides actual pressure not exceeding the preset inlet pressure upper limit. The second control stage is used to take over the strip full-load rolling process after the first control stage, so that the operating side vertical roll and the drive side vertical roll gradually enter the pressure coordinated control from the head inlet control. In this way, the vertical roll control can avoid abruptly changing from the inlet roll gap to the pressure closed loop, improving the smoothness of the control stage switching.

[0030] Further preferably, the second control stage includes a pressure control stage and a full-load collaborative control stage. Step S3 specifically includes the following steps: acquiring the continuous and effective acquisition status of the actual pressure on the operating side and the actual pressure on the transmission side in the first control stage; acquiring the roll gap position status of the vertical roll gap on the operating side and the vertical roll gap on the transmission side; when the continuous and effective acquisition status indicates that the pressure on both sides is effectively acquired, and the roll gap position status indicates that neither vertical roll on either side has reached the mechanical limit, the pressure control stage is entered; in the pressure control stage, the proportion of position control output in the roll gap control quantity is reduced, and the proportion of pressure control output in the roll gap control quantity is increased; when the actual pressure on the operating side and the actual pressure on the transmission side both enter the allowable deviation range of the corresponding target pressure, the full-load collaborative control stage is entered. Specifically, the continuous and effective acquisition status can indicate that the pressure detection device on the operating side and the pressure detection device on the transmission side both output effective pressure data within 0.5s to 2s, and there are no breakpoints, over-range, or sensor fault signs. The roll gap position status can be acquired by the position sensor or hydraulic cylinder displacement sensor of the hydraulic roll gap adjustment device. The duration of the pressure control phase can be set from 3m to 15m, or from 0.5s to 2s. Initially, the position control output can account for 70% to 90% of the pressure control output, while the pressure control output can account for 10% to 30%. At the end of the pressure control phase, the position control output percentage decreases to 0% to 20%, while the pressure control output percentage increases to 80% to 100%. The allowable deviation range for the target pressure can be set to ±5% to ±15% of the corresponding target pressure. This method allows for a smooth transition between position control and pressure control, reducing abrupt changes and pressure oscillations in the hydraulic roller gap adjustment device.

[0031] S4. Obtain the actual pressure on the operating side and the actual pressure on the transmission side. Based on these pressures, determine the common pressure deviation and differential pressure deviation. Specifically, the actual pressure on the operating side is detected by the operating side pressure detection device, and the actual pressure on the transmission side is detected by the transmission side pressure detection device. The common pressure deviation characterizes the deviation of the average clamping force on both sides relative to the average target pressure on both sides, reflecting whether the overall constraint of the vertical rollers on the strip width direction is too strong or insufficient. The differential pressure deviation characterizes the uneven force distribution between the operating side and the transmission side, reflecting whether the lateral resultant force on the strip in the width direction is biased to one side. This method avoids the problem of not being able to identify the difference in force between the left and right sides when only average pressure control is used.

[0032] Further, before step S4, the following steps are included: acquiring the operating-side pressure sampling sequence and the transmission-side pressure sampling sequence collected according to a preset sampling period; performing moving average processing on the operating-side pressure sampling sequence and the transmission-side pressure sampling sequence respectively to obtain the operating-side smooth pressure and the transmission-side smooth pressure; acquiring the pressure change rate in the operating-side pressure sampling sequence and the transmission-side pressure sampling sequence, and determining the sampling points with pressure change rates exceeding a preset pressure change rate threshold as abnormal sampling points; after removing the abnormal sampling points, using the operating-side smooth pressure as the actual operating-side pressure and the transmission-side smooth pressure as the actual transmission-side pressure. Specifically, the preset sampling period can be set to 10ms to 50ms, which is set with reference to the real-time requirements of pressure feedback control in the hot strip finishing section. The moving average processing window can be set to 5 to 20 sampling points, which is set with reference to the balance between pressure sensor noise suppression and control hysteresis. The preset pressure change rate threshold can be set to 5kN / s to 30kN / s, which is set with reference to the requirements of strip head and tail transition, hydraulic system impact, and sensor abnormal fluctuation identification. When the rate of pressure change at a sampling point relative to the previous sampling point exceeds a preset threshold, the sampling point is identified as an abnormal sampling point and removed. This method suppresses pressure noise and transient shocks before calculating common and differential pressure deviations, improving the stability of subsequent roll gap adjustment calculations.

[0033] Further, in step S4, the method of determining the common pressure deviation and differential pressure deviation includes the following steps: calculating the average target pressure on both sides based on the target pressure of the operating side vertical roller and the target pressure of the transmission side vertical roller; determining the deviation of the average clamping force on both sides relative to the average target pressure on both sides based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the operating side vertical roller, and the target pressure of the transmission side vertical roller, and taking the deviation as the common pressure deviation; determining the uneven force state on both sides based on the actual pressure difference between the actual pressure on the operating side and the actual pressure on the transmission side, and the target pressure difference between the target pressure of the operating side vertical roller and the target pressure of the transmission side vertical roller, and taking the uneven force state on both sides as the differential pressure deviation. Specifically, the average target pressure on both sides can be obtained by averaging the target pressure of the operating side vertical roller and the target pressure of the transmission side vertical roller, and the average clamping force on both sides can be obtained by averaging the actual pressure on the operating side and the actual pressure on the transmission side. The common pressure deviation represents the deviation of the average clamping force on both sides relative to the average target pressure on both sides. The actual pressure difference represents the difference between the actual pressure on the operating side and the actual pressure on the drive side, while the target pressure difference represents the difference between the target pressure of the vertical roll on the operating side and the target pressure of the vertical roll on the drive side. The differential pressure deviation represents the deviation of the actual pressure difference from the target pressure difference. When the actual pressure on the operating side is greater than the actual pressure on the drive side, the lateral resultant force on the strip tends to shift towards the drive side; conversely, when the actual pressure on the drive side is greater than the actual pressure on the operating side, the lateral resultant force on the strip tends to shift towards the operating side. This method establishes a clear physical causal relationship for determining the subsequent differential roll gap adjustment.

[0034] S5. Determine the common roll gap adjustment amount based on the common pressure deviation, call the differential roll gap adjustment parameters, and determine the differential roll gap adjustment amount based on the differential pressure deviation and the differential roll gap adjustment parameters. Specifically, the common roll gap adjustment amount is used to synchronously change the roll gap of the operating side vertical roll and the drive side vertical roll, so that the average clamping force on both sides returns to the corresponding target pressure allowable deviation range. The differential roll gap adjustment amount is used to adjust the roll gap of the operating side vertical roll and the drive side vertical roll in opposite directions to correct the uneven force on both sides. The differential roll gap adjustment parameters may include the pressure difference allowable range, the differential adjustment direction, the differential adjustment step size, and the differential adjustment limit. The pressure difference allowable range is used to determine whether a differential roll gap adjustment amount needs to be generated, the differential adjustment direction is used to determine the reverse adjustment direction of the operating side vertical roll gap and the drive side vertical roll gap, the differential adjustment step size is used to determine the single reverse adjustment amplitude, and the differential adjustment limit is used to limit the maximum reverse adjustment amplitude. By using the above method, the width constraint can be borne by the common roll gap adjustment, and the centerline correction can be borne by the differential roll gap adjustment, thereby avoiding mutual interference between width control and deviation control.

[0035] Further preferably, step S5 specifically includes the following steps: when the common pressure deviation indicates that the average clamping force on both sides is lower than the average target pressure on both sides, a common roll gap adjustment amount is generated to simultaneously reduce the roll gap of the operating side vertical roll and the roll gap of the driving side vertical roll; when the common pressure deviation indicates that the average clamping force on both sides is higher than the average target pressure on both sides, a common roll gap adjustment amount is generated to simultaneously increase the roll gap of the operating side vertical roll and the roll gap of the driving side vertical roll; when the differential pressure deviation indicates that the force on the operating side is greater than the force on the driving side, a differential roll gap adjustment amount is generated to increase the roll gap of the operating side vertical roll and decrease the roll gap of the driving side vertical roll; when the differential pressure deviation indicates that the force on the driving side is greater than the force on the operating side, a differential roll gap adjustment amount is generated to increase the roll gap of the driving side vertical roll and decrease the roll gap of the operating side vertical roll. Specifically, when the average clamping force on both sides is lower than the average target pressure on both sides, it indicates insufficient overall lateral constraint of the vertical rolls. In this case, the roll gaps on both the operating side and the drive side of the vertical rolls should be reduced simultaneously to bring both vertical rolls closer to the edge of the strip. When the average clamping force on both sides is higher than the average target pressure on both sides, it indicates excessive overall lateral constraint of the vertical rolls. In this case, the roll gaps on both the operating side and the drive side of the vertical rolls should be increased simultaneously to move both vertical rolls away from the edge of the strip. When the differential pressure deviation indicates that the force on the operating side is greater than that on the drive side, the pressure on the operating side should be reduced and the pressure on the drive side increased by increasing the roll gap on the operating side and decreasing the roll gap on the drive side. When the differential pressure deviation indicates that the force on the drive side is greater than that on the operating side, the pressure on the drive side should be reduced and the pressure on the operating side increased by increasing the roll gap on the drive side and decreasing the roll gap on the operating side. Through the above methods, the difference in force on both sides can be reduced while maintaining the overall width constraint of the strip, thereby suppressing the centerline offset caused by uneven force on the vertical rolls on both sides.

[0036] S6. Generate operating-side roll gap adjustment and transmission-side roll gap adjustment based on the common roll gap adjustment and the differential roll gap adjustment, and control the hydraulic roll gap adjustment device to adjust the roll gap of the operating-side vertical roller and the transmission-side vertical roller respectively according to the operating-side roll gap adjustment and the transmission-side roll gap adjustment. Specifically, the operating-side roll gap adjustment is synthesized by the common roll gap adjustment and the differential roll gap adjustment, and the transmission-side roll gap adjustment is also synthesized by the common roll gap adjustment and the differential roll gap adjustment. When the common roll gap adjustment is a synchronous reduction in roll gap, and the differential roll gap adjustment is an increase in the operating-side vertical roller roll gap and a decrease in the transmission-side vertical roller roll gap, the operating-side roll gap adjustment is the result of the superposition of the synchronous reduction component and the differential increase component, and the transmission-side roll gap adjustment is the result of the superposition of the synchronous reduction component and the differential reduction component. The hydraulic roll gap adjustment device includes an operating-side hydraulic actuator unit and a transmission-side hydraulic actuator unit. The output end of the operating-side hydraulic actuator unit is connected to the operating-side vertical roller drive, and the output end of the transmission-side hydraulic actuator unit is connected to the transmission-side vertical roller drive. The above method can be used to convert the control results of common pressure deviation and differential pressure deviation into the actual mechanical displacement of the two vertical rollers.

[0037] Further, step S6 specifically includes the following steps: obtaining the pressure dead zone judgment results corresponding to the common pressure deviation and the differential pressure deviation; when the pressure dead zone judgment result indicates that the common pressure deviation and / or the differential pressure deviation does not exceed the corresponding pressure dead zone, keeping the corresponding roll gap adjustment amount unchanged; when the pressure dead zone judgment result indicates that the common pressure deviation and / or the differential pressure deviation exceeds the corresponding pressure dead zone, segmented step size limits are applied to the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount; obtaining the mechanical limit status of the operating side vertical roll gap and the transmission side vertical roll gap, and when the mechanical limit status on either side indicates that the corresponding side vertical roll is close to the mechanical limit, stopping the corresponding side vertical roll from continuing to move in the mechanical limit direction. Specifically, the pressure dead zone can be set to ±1kN to ±3kN, which is set with reference to the normal fluctuation of the pressure sensor and the requirement to suppress frequent actions of the hydraulic actuator. When the common pressure deviation or the differential pressure deviation does not exceed the corresponding pressure dead zone, no new roll gap adjustment action is generated. The segmented step size limit can include: when the pressure deviation is within the first deviation range, the single roll gap adjustment amount is set to 0.05mm to 0.20mm; when the pressure deviation is within the second deviation range, the single roll gap adjustment amount is set to 0.20mm to 0.50mm; when the pressure deviation exceeds the safety deviation range, the maximum single roll gap adjustment amount is limited to 0.50mm to 1.00mm, and a control alarm is triggered. The mechanical limit status can be obtained through a hydraulic cylinder displacement sensor, a vertical roller position sensor, or a limit signal from the control system. This method avoids frequent adjustments caused by minor pressure fluctuations and prevents over-adjustment of the hydraulic actuator through segmented step size and mechanical limit protection.

[0038] S7. Obtain the finishing mill exit width deviation and the finishing mill exit centerline deviation, and correct the target pressure of the operating side vertical roll and / or the target pressure of the drive side vertical roll based on the finishing mill exit width deviation and the finishing mill exit centerline deviation. Specifically, the finishing mill exit width deviation and the finishing mill exit centerline deviation can be obtained by a finishing mill exit detection device, which can be a multi-function instrument, a width gauge, a centerline detection device, an image detection device, or a combination thereof. The finishing mill exit width deviation is used to evaluate the effect of common pressure control on the strip width constraint, and the finishing mill exit centerline deviation is used to evaluate the correction effect of differential pressure control on the strip centerline offset. The preset allowable width range can be set to ±5mm to ±15mm, which is set with reference to the accuracy requirements of hot-rolled strip width control; the preset allowable centerline range can be set to ±10mm to ±30mm, which is set with reference to the stability and deviation control requirements of the finishing mill exit centerline. In the above way, the exit detection results can be fed back to the target pressure setting process, so that the vertical roll pressure control of the next control cycle or the next coil of strip of the same specification has a quality verification basis.

[0039] Further, step S7 specifically includes the following steps: when the deviation of the finishing mill exit width exceeds the preset allowable width range, and the deviation of the finishing mill exit centerline is within the preset allowable centerline range, the target pressure of the operating side vertical roll and the target pressure of the transmission side vertical roll are simultaneously corrected according to the positive and negative directions of the finishing mill exit width deviation; when the deviation of the finishing mill exit centerline exceeds the preset allowable centerline range, and the actual pressure difference on both sides exceeds the preset allowable pressure difference range, the differential roll gap adjustment parameter is corrected according to the offset direction of the finishing mill exit centerline deviation, so as to change the determination direction and / or determination amplitude of the differential roll gap adjustment amount; when the deviation of the finishing mill exit centerline exceeds the preset allowable centerline range, and the actual pressure difference on both sides is within the preset allowable pressure difference range, it is determined that the current strip has a wedge-shaped offset state, and the differential roll gap adjustment parameter remains unchanged. Specifically, when the finishing mill exit width deviation indicates that the exit width is greater than the target width, the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll are simultaneously increased to strengthen the width constraint of the two vertical rolls in subsequent control. When the finishing mill exit width deviation indicates that the exit width is less than the target width, the target pressure of the operating side vertical roll and the target pressure of the drive side vertical roll are simultaneously decreased to weaken the width constraint of the two vertical rolls in subsequent control. When the centerline deviation of the finishing mill exit exceeds the preset centerline allowable range, and the actual pressure difference between the two sides exceeds the preset pressure difference allowable range, it indicates that there is a corresponding relationship between the centerline offset and the uneven force on the two vertical rolls. At this time, the differential adjustment direction, differential adjustment step size, or differential adjustment limit is corrected according to the offset direction. When the centerline deviation of the finishing mill exit exceeds the preset centerline allowable range, but the actual pressure difference between the two sides is still within the preset pressure difference allowable range, it indicates that the centerline offset is not mainly caused by the uneven force on the two vertical rolls, but may be caused by the wedge-shaped offset state of the rolled piece. At this time, the differential roll gap adjustment parameters are kept unchanged to avoid erroneously expanding the roll gap difference between the two vertical rolls. By using the above method, we can distinguish the different effects of width deviation, uneven force on both sides, and wedge-shaped offset of the rolled piece on the exit quality, thus avoiding attributing all exit offsets to differential pressure control.

[0040] In this embodiment, the controller employs a PI controller, which regulates the system through proportional (P) and integral (I) control actions. The proportional action quickly adjusts the output based on the deviation, but suffers from steady-state error; the integral action eliminates steady-state error by accumulating the deviation. The PI controller combines the advantages of both, achieving rapid response and error-free control.

[0041] PI regulator control quantity It consists of a proportional term and an integral term, as shown in the formula below.

[0042] in For error signals, For proportional gain, This is the integration time constant. Parameter tuning requires adjustment. and .

[0043] The present invention also provides a dual-side pressure differential collaborative control system for hot continuous rolling mill finishing vertical rolls, used to implement the above-mentioned dual-side pressure differential collaborative control method for hot continuous rolling mill finishing vertical rolls. The system includes a production process information acquisition module, a stage control module, a pressure acquisition module, a pressure deviation determination module, a roll gap adjustment amount determination module, a hydraulic roll gap adjustment device, and an outlet feedback verification module. Specifically, the production process information acquisition module is used to acquire the current strip steel production process information and determine the target pressure of the operating side vertical roll, the target pressure of the drive side vertical roll, and the initial differential roll gap adjustment parameters based on the current strip steel production process information; the stage control module is used to acquire the entry information of the strip head into the finishing rolling vertical roll area and control the operating side vertical roll and the drive side vertical roll to execute the first control stage based on the entry information, and is also used to acquire the stage end information of the first control stage and switch the operating side vertical roll and the drive side vertical roll from the first control stage to the second control stage based on the stage end information; the pressure acquisition module is used to acquire the actual pressure on the operating side and the actual pressure on the drive side; the pressure deviation determination module is used to determine the actual pressure on the operating side, the actual pressure on the drive side, the target pressure of the operating side vertical roll, and the target pressure of the drive side vertical roll based on the actual pressure on the operating side, the actual pressure on the drive side, and the target pressure of the operating side vertical roll. The system determines the common pressure deviation and differential pressure deviation; the roll gap adjustment determination module is used to determine the common roll gap adjustment amount based on the common pressure deviation, and to call the differential roll gap adjustment parameters to determine the differential roll gap adjustment amount based on the differential pressure deviation and the differential roll gap adjustment parameters; it is also used to generate the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount based on the common roll gap adjustment amount and the differential roll gap adjustment amount; the hydraulic roll gap adjustment device is used to adjust the operating side vertical roll gap and the transmission side vertical roll gap respectively according to the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount; the exit feedback verification module is used to obtain the finishing mill exit width deviation and the finishing mill exit centerline deviation, and to correct the operating side vertical roll target pressure, the transmission side vertical roll target pressure and / or the differential roll gap adjustment parameters based on the finishing mill exit width deviation and the finishing mill exit centerline deviation. Through the above methods, the current strip steel production process information acquisition, stage switching, pressure deviation decomposition, roll gap adjustment generation, hydraulic execution, and exit feedback verification can be realized in a modular manner, so that the hot strip mill finishing roll double-sided pressure differential collaborative control method has a deployable system structure.

[0044] Furthermore, the signal output terminal of the operating-side pressure detection device is electrically connected to the pressure signal input terminal of the controller; the signal output terminal of the transmission-side pressure detection device is electrically connected to the pressure signal input terminal of the controller; the detection signal output terminal of the finishing mill exit detection device is electrically connected to the detection signal input terminal of the controller; and the control signal output terminal of the controller is electrically connected to the control signal input terminal of the hydraulic roll gap adjustment device. The operating-side execution terminal of the hydraulic roll gap adjustment device is connected to the operating-side vertical roll drive, and the transmission-side execution terminal of the hydraulic roll gap adjustment device is connected to the transmission-side vertical roll drive. Through the above interface-level connection relationships, the signal flow and mechanical execution path between pressure detection, exit detection, controller calculation, and hydraulic execution can be clearly defined.

[0045] The hot strip mill finishing roll double-sided pressure differential collaborative control method and system provided in this embodiment can complete the setting of target pressure and differential roll gap adjustment parameters before the strip enters the finishing roll area. After the strip head enters, the head introduction control stage is used to reduce transient impact. In the pressure pipe control stage, the smooth transition between position control and pressure control is achieved. In the full-load collaborative control stage, the pressure on both sides is decomposed into common pressure deviation and differential pressure deviation, which are used for width constraint and centerline correction, respectively. At the same time, the finishing roll exit width deviation and finishing roll exit centerline deviation are used to reverse correct the control parameters, so that the finishing roll control is transformed from single position control or single constant pressure control into collaborative closed-loop control with stage identification, pressure decomposition, differential adjustment, execution protection and exit verification.

[0046] For the above embodiments, under the premise of the same steel grade and specifications, the deviation of the center line and width of the finishing mill exit before and after the implementation of the hot continuous rolling finishing mill vertical roll double-sided pressure differential collaborative control method was compared. Figure 2 The centerline deviation was due to the absence of vertical roller pressure control. The strip head deviated by 80mm, the strip deviated by 40mm during rolling, and the strip tail deviated by -40mm. The entire rolling centerline was out of control. Figure 3 To control the centerline deviation of the vertical roll pressure, the strip head offset was reduced to -20mm, a reduction of about 75%, significantly improving centerline stability. The middle offset was 40mm, reducing the offset fluctuation range and enhancing rolling stability. The tail offset was only -10mm, a reduction of about 75%, effectively curbing the tail deviation problem. Figure 4 Before the vertical roller pressure control is implemented, the width deviation range of the MFG test is 10mm-38mm. Figure 5 The width deviation after the pressure control of the vertical roller is shown. The fluctuation range of the entire strip width deviation is controlled within 12mm-22mm, which is significantly narrower than the width deviation range before the input, and the accuracy and stability are significantly improved.

[0047] Figure 6To improve the width hit rate of the 2250 line of the hot rolling mill from January to August 2025, the single position control method of the small vertical roll was changed to the method described in the above embodiment in early May. The width hit rate was significantly improved, with an average width hit rate of over 97%. Figure 7 The overall deviation rate of a certain shift in the finishing mill of the 2250 line of the hot rolling mill from January to August 2025 was calculated. After the single position control of the small vertical roll was changed to the method described in the above embodiment in early May, the deviation control of the finishing mill of this shift was significantly improved, and the average deviation rate exceeded 97%.

[0048] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for differential pressure coordinated control of two sides of a hot continuous rolling mill vertical roll, characterized in that, Includes the following steps: S1. Obtain the current strip steel production process information, and determine the target pressure of the operating side vertical roll, the target pressure of the transmission side vertical roll, and the initial differential roll gap adjustment parameters based on the current strip steel production process information; S2. Obtain entry information of the strip head into the finishing mill vertical roll area, and control the operation side vertical roll and the transmission side vertical roll to perform the first control stage according to the entry information; S3. Obtain the phase end information of the first control phase, and switch the operation side vertical roller and the transmission side vertical roller from the first control phase to the second control phase according to the phase end information; S4. Obtain the actual pressure on the operating side and the actual pressure on the transmission side, and determine the common pressure deviation and differential pressure deviation based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the vertical roller on the operating side, and the target pressure of the vertical roller on the transmission side. S5. Determine the common roll gap adjustment amount based on the common pressure deviation, call the differential roll gap adjustment parameters, and determine the differential roll gap adjustment amount based on the differential pressure deviation and the differential roll gap adjustment parameters; S6. Generate the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount according to the common roll gap adjustment amount and the differential roll gap adjustment amount, and control the hydraulic roll gap adjustment device to adjust the operating side vertical roll gap and the transmission side vertical roll gap respectively according to the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount. S7. Obtain the finishing mill exit width deviation and the finishing mill exit centerline deviation, and correct the target pressure of the operating side vertical roll and / or the target pressure of the transmission side vertical roll based on the finishing mill exit width deviation and the finishing mill exit centerline deviation.

2. The method for differential pressure coordinated control of the double-sided pressure of the hot continuous rolling mill vertical rolls according to claim 1, characterized in that, Step S1 specifically includes the following steps: Obtain information on the current strip steel grade, target width, finishing mill entry thickness, finishing mill exit thickness, and rolling speed. Obtain the historical width deviation and historical centerline deviation corresponding to historical strips that have the same steel type information and the same target width information as the current strip; The basic target pressure is determined based on the steel grade information, the target width information, the finishing mill inlet thickness information, the finishing mill outlet thickness information, and the rolling speed information; The basic target pressure is corrected based on the historical width deviation and the historical centerline deviation to obtain the target pressure of the operating side vertical roller and the target pressure of the transmission side vertical roller.

3. The method for differential pressure control on both sides of the hot continuous rolling mill vertical roll according to claim 1, characterized in that, The first control phase is the head import control phase, and step S2 specifically includes the following steps: After obtaining the entry information, control the operation side vertical roller and the transmission side vertical roller to move to the entry roller gap position; The actual pressure on the operating side and the actual pressure on the transmission side are continuously acquired. When the actual pressure on either side reaches the preset upper limit of the input pressure, the vertical roller on the corresponding side stops moving towards the edge of the strip. The length of the strip head passing through the finishing mill vertical roll area is obtained, and the stage end information is determined based on the length of the passing.

4. The hot continuous rolling mill finishing vertical roll double-sided pressure differential coordinated control method according to claim 3, characterized in that, The second control phase includes a pressure take-off control phase and a full-load coordinated control phase. Step S3 specifically includes the following steps: The continuous and effective acquisition status of the actual pressure on the operating side and the actual pressure on the transmission side during the first control phase is obtained. Obtain the roll gap position status of the operating side vertical roller gap and the transmission side vertical roller gap; When the continuous effective acquisition status indicates that the pressure on both sides is effectively acquired, and the roll gap position status indicates that neither of the vertical rolls on both sides has reached the mechanical limit, the pressure pipe control stage is entered. During the pressure control phase, the proportion of position control output in roll gap control is reduced, while the proportion of pressure control output in roll gap control is increased. When both the actual pressure on the operating side and the actual pressure on the transmission side enter the allowable deviation range of the corresponding target pressure, the full-load coordinated control stage is entered.

5. The method for differential pressure coordinated control of the vertical rolls of hot continuous rolling mill according to claim 1, characterized in that, The following steps precede step S4: Acquire the operating-side pressure sampling sequence and the transmission-side pressure sampling sequence collected according to a preset sampling period; The operating-side pressure sampling sequence and the transmission-side pressure sampling sequence are respectively subjected to moving average processing to obtain the operating-side smoothed pressure and the transmission-side smoothed pressure. Obtain the pressure change rate in the operation-side pressure sampling sequence and the transmission-side pressure sampling sequence, and determine the sampling points whose pressure change rate exceeds a preset pressure change rate threshold as abnormal sampling points; After removing the abnormal sampling points, the smoothing pressure on the operating side is taken as the actual pressure on the operating side, and the smoothing pressure on the transmission side is taken as the actual pressure on the transmission side.

6. The method for differential pressure coordinated control of both sides of the hot continuous rolling mill vertical roll according to claim 1, characterized in that, In step S4, the method for determining the common pressure deviation and the differential pressure deviation includes the following steps: Calculate the average target pressure on both sides based on the target pressure of the operating side vertical roller and the target pressure of the transmission side vertical roller; Based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the vertical roller on the operating side, and the target pressure of the vertical roller on the transmission side, the deviation of the average clamping force on both sides relative to the average target pressure on both sides is determined, and the deviation is taken as the common pressure deviation. Based on the actual pressure difference between the actual pressure on the operating side and the actual pressure on the transmission side, and the target pressure difference between the target pressure of the vertical roller on the operating side and the target pressure of the vertical roller on the transmission side, the uneven force state on both sides is determined, and the uneven force state on both sides is taken as the differential pressure deviation.

7. The method for differential pressure control on both sides of the hot continuous rolling mill vertical roll according to claim 6, characterized in that, Step S5 specifically includes the following steps: When the common pressure deviation indicates that the average clamping force on both sides is lower than the average target pressure on both sides, a common roll gap adjustment amount is generated to simultaneously reduce the roll gap of the operating side vertical roll and the roll gap of the transmission side vertical roll. When the common pressure deviation indicates that the average clamping force on both sides is higher than the average target pressure on both sides, a common roll gap adjustment amount is generated to simultaneously increase the roll gap of the operating side vertical roll and the roll gap of the transmission side vertical roll. When the differential pressure deviation indicates that the force on the operating side is greater than the force on the transmission side, a differential roll gap adjustment amount is generated to increase the roll gap of the vertical roll on the operating side and decrease the roll gap of the vertical roll on the transmission side. When the differential pressure deviation indicates that the force on the transmission side is greater than the force on the operating side, a differential roll gap adjustment amount is generated to increase the roll gap of the vertical roll on the transmission side and decrease the roll gap of the vertical roll on the operating side.

8. The method for differential pressure coordinated control of both sides of the vertical roll of hot continuous rolling mill according to claim 1, characterized in that, Step S6 specifically includes the following steps: Obtain the pressure dead zone judgment results corresponding to the common pressure deviation and the differential pressure deviation; When the pressure dead zone determination result indicates that the common pressure deviation and / or the differential pressure deviation do not exceed the corresponding pressure dead zone, the corresponding roll gap adjustment amount remains unchanged; When the pressure dead zone determination result indicates that the common pressure deviation and / or the differential pressure deviation exceed the corresponding pressure dead zone, the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount are subject to segmented step size restrictions. The mechanical limit states of the operating side vertical roller gap and the transmission side vertical roller gap are obtained. When the mechanical limit state of either side indicates that the corresponding side vertical roller is close to the mechanical limit, the corresponding side vertical roller is stopped from moving further in the mechanical limit direction.

9. The method for differential pressure coordinated control of both sides of the vertical roll of hot continuous rolling mill according to claim 1, characterized in that, Step S7 specifically includes the following steps: When the deviation of the finishing mill exit width exceeds the preset allowable width range, and the deviation of the finishing mill exit centerline is within the preset allowable centerline range, the target pressure of the operating side vertical roll and the target pressure of the transmission side vertical roll are synchronously corrected according to the positive and negative directions of the finishing mill exit width deviation. When the deviation of the center line of the finishing mill exit exceeds the preset center line allowable range, and the actual pressure difference on both sides exceeds the preset pressure difference allowable range, the differential roll gap adjustment parameter is corrected according to the offset direction of the center line deviation of the finishing mill exit, so as to change the determination direction and / or determination amplitude of the differential roll gap adjustment amount. When the deviation of the center line of the finishing mill exit exceeds the preset center line allowable range, and the actual pressure difference on both sides is within the preset pressure difference allowable range, it is determined that the current strip has a wedge-shaped offset state, and the differential roll gap adjustment parameters are kept unchanged.

10. A differential pressure control system for both sides of a hot continuous rolling mill vertical roll, characterized in that, The system is used to implement the hot continuous rolling finishing vertical roll double-sided pressure differential collaborative control method according to any one of claims 1 to 9, the system comprising a production process information acquisition module, a stage control module, a pressure acquisition module, a pressure deviation determination module, a roll gap adjustment amount determination module, a hydraulic roll gap adjustment device, and an outlet feedback verification module; The production process information acquisition module is used to acquire the current strip steel production process information, and determine the target pressure of the operating side vertical roll, the target pressure of the transmission side vertical roll, and the initial differential roll gap adjustment parameters based on the current strip steel production process information; The stage control module is used to acquire entry information of the strip head entering the finishing mill vertical roll area, and control the operating side vertical roll and the drive side vertical roll to perform the first control stage according to the entry information. It is also used to acquire the stage end information of the first control stage, and switch the operating side vertical roll and the drive side vertical roll from the first control stage to the second control stage according to the stage end information. The pressure acquisition module is used to acquire the actual pressure on the operating side and the actual pressure on the transmission side. The pressure deviation determination module is used to determine common pressure deviation and differential pressure deviation based on the actual pressure on the operating side, the actual pressure on the transmission side, the target pressure of the vertical roller on the operating side, and the target pressure of the vertical roller on the transmission side. The roll gap adjustment determination module is used to determine the common roll gap adjustment amount based on the common pressure deviation, and to call the differential roll gap adjustment parameters to determine the differential roll gap adjustment amount based on the differential pressure deviation and the differential roll gap adjustment parameters; it is also used to generate the operating side roll gap adjustment amount and the transmission side roll gap adjustment amount based on the common roll gap adjustment amount and the differential roll gap adjustment amount. The hydraulic roll gap adjustment device is used to adjust the roll gap of the operating side vertical roller and the roll gap of the driving side vertical roller according to the adjustment amount of the operating side roll gap and the adjustment amount of the driving side roll gap, respectively. The exit feedback verification module is used to obtain the finishing mill exit width deviation and the finishing mill exit centerline deviation, and to correct the target pressure of the operating side vertical roll, the target pressure of the transmission side vertical roll, and / or the differential roll gap adjustment parameters based on the finishing mill exit width deviation and the finishing mill exit centerline deviation.

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