A method and system for controlling the shutter opening sequence of a thickness gauge

Abstract

This application provides a method and system for controlling the shutter opening timing of a thickness gauge. The method includes: acquiring the preset rolling speed of each finishing mill stand; determining a delay control strategy for the shutter opening of the thickness gauge based on the preset rolling speed of the last finishing mill stand, so as to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the shutter opening time; wherein the delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area. This application effectively solves the problem of the thickness gauge shutter opening 1-2 seconds earlier, and solves the problem of unreasonable timing in the existing thickness gauge shutter control logic. After the method is implemented, the shutter opening time is closer to the time when the strip head reaches the thickness gauge shutter; it effectively solves the problem that the premature opening of the existing thickness gauge shutter leads to inaccurate measured strip thickness deviation, affecting the accuracy of strip head thickness feedback control and thickness self-learning accuracy.

Description

Technical Field

[0001] This invention relates to the field of steel production applications, and in particular to a method and system for controlling the shutter opening sequence of a thickness gauge. Background Technology

[0002] Thickness gauges are typically installed after the F7 stand in the finishing mill of a hot strip rolling production line to detect strip thickness in real time and provide feedback to the control system for thickness control adjustments. In this case, the thickness gauge, located 4.17 meters from the centerline of the F7 stand, is installed after the finishing mill in the hot coil production line of a steel rolling mill. It uses X-rays for real-time strip thickness detection. Currently, the X-ray shutter opening command for the thickness gauge is issued by the primary control system. However, due to the simplicity of the existing shutter opening control logic and method, the shutter often opens 1-2 seconds prematurely. When the shutter opens but no actual strip is detected, the thickness deviation reported by the thickness gauge is -500µm. This forces the control system to avoid this section during thickness self-learning, affecting the accuracy of strip head thickness feedback control and the accuracy of thickness self-learning. Summary of the Invention

[0003] In view of the problems existing in the prior art, the present invention proposes a method and system for controlling the shutter opening sequence of a thickness gauge, which mainly solves the problem that the shutter of the existing thickness gauge usually opens about 1-2 seconds in advance, resulting in a large deviation in the detection of strip thickness, which in turn affects the thickness feedback control and thickness self-learning of the strip head.

[0004] To achieve the above and other objectives, the technical solution adopted by the present invention is as follows.

[0005] This application provides a method for controlling the shutter opening sequence of a thickness gauge, comprising: acquiring the preset rolling speed of each finishing mill stand; determining a delay control strategy for the shutter opening of the thickness gauge based on the preset rolling speed of the last finishing mill stand, so as to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the shutter opening time; wherein the delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area.

[0006] In one embodiment of this application, the step of determining the delay control strategy for opening the thickness gauge shutter based on the preset rolling speed of the finishing mill stand includes: recording the preset rolling speed of the finishing mill stand as the first speed; comparing the first speed with a preset speed threshold to determine the speed range into which the first speed falls; and calling a pre-associated delay control strategy based on the speed range to calculate the opening delay of the thickness gauge shutter.

[0007] In one embodiment of this application, when the first speed is greater than or equal to 9 m / s, the calculation method for the shutter opening delay of the thickness gauge includes:

[0008]

[0009] Wherein, T1: Delay time for the thickness gauge shutter to open after the F5 stand bites the steel; L1: Distance between the center line of the F5 stand and the thickness gauge shutter; V5: Preset rolling speed of the F5 stand; V6: Preset rolling speed of the F6 stand; V7: Preset rolling speed of the F7 stand; slip5: Forward slip value of the F5 stand; slip6: Forward slip value of the F6 stand; slip7: Forward slip value of the F7 stand.

[0010] In one embodiment of this application, when the first speed is greater than or equal to 4.5 m / s and less than 9 m / s, the calculation method for the shutter opening delay of the thickness gauge includes:

[0011]

[0012] Wherein, T2: Delay time for the thickness gauge shutter to open after the F6 stand bites the steel; L2: Distance between the center line of the F6 stand and the thickness gauge shutter; V6: Preset rolling speed of the F6 stand; V7: Preset rolling speed of the F7 stand; slip6: Forward slip value of the F6 stand; slip7: Forward slip value of the F7 stand.

[0013] In one embodiment of this application, when the first speed is less than 4.5 m / s, the calculation method for the shutter opening delay of the thickness gauge includes:

[0014]

[0015] Among them, T3: Delay time for the thickness gauge shutter to open after the F7 stand bites the steel; L3: Distance between the center line of the F7 stand and the thickness gauge shutter; V7: Preset rolling speed of the F7 stand; slip7: Forward slip value of the F7 stand.

[0016] This application also provides a thickness gauge shutter opening timing control system, including: a data acquisition module for acquiring the preset rolling speed of each finishing mill stand; and a shutter delay control module for determining a delay control strategy for the thickness gauge shutter based on the preset rolling speed of the last finishing mill stand, so as to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the shutter opening time; wherein the delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area.

[0017] As described above, the thickness gauge shutter opening timing control method and system proposed in this application have the following beneficial effects.

[0018] This application calculates the time it takes for the strip to reach the thickness gauge's measurement area based on the preset rolling speed of each stand before the final stand of the finishing mill. Then, it determines the shutter opening time of the thickness gauge based on the calculated time, avoiding the impact of the thickness gauge shutter opening prematurely on the strip thickness detection. This improves the thickness control accuracy of the strip head and the entire length, avoids the recurrence of scrap steel accidents caused by abnormal thickness feedback control, and enhances the threading stability of the finishing strip head. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the shutter opening timing control method for a thickness gauge in one embodiment of this application.

[0020] Figure 2 This is a block diagram of the shutter opening timing control system of a thickness gauge in one embodiment of this application. Detailed Implementation

[0021] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0022] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0023] The inventor discovered through research that:

[0024] The existing control logic for the shutter opening of the finishing mill thickness gauge is simple: when the pre-set rolling speed of F7 is ≥9m / s, the finishing mill F5 stand bites the steel, and the thickness gauge shutter opens; when the pre-set rolling speed of F7 is 4.5m / s ≤ F7 <9m / s, the finishing mill F6 stand bites the steel, and the thickness gauge shutter opens; when the pre-set rolling speed of F7 is <4.5m / s, the finishing mill F7 stand bites the steel, and the thickness gauge shutter opens. The existing control technology simply determines that the pre-set rolling speed of F7 controls the opening of the thickness gauge shutter based on the subsequent stand biting signal, causing the shutter of all thickness gauge specifications to open 1-2 seconds prematurely, resulting in inaccurate control timing and unreasonable control logic.

[0025] When the thickness gauge shutter opens prematurely and fails to detect the actual strip, the thickness deviation fed back to the control system is -500µm, which affects the thickness feedback control accuracy of the strip head and the accuracy of thickness self-learning, and also affects the threading stability of the finishing strip head.

[0026] Based on the problems existing in the prior art, this application proposes a method and system for controlling the shutter opening timing of a thickness gauge. The technical solution of this application will be described in detail below with reference to specific embodiments.

[0027] Please see Figure 1 , Figure 1 This is a flowchart illustrating a thickness gauge shutter opening timing control method according to an embodiment of this application. The method provided in this embodiment includes:

[0028] Step S100: Obtain the preset rolling speed of each finishing mill stand.

[0029] In one embodiment, the rolling speed of each finishing mill stand can be preset. During the finishing rolling process, each finishing mill stand rolls at the preset rolling speed. The preset rolling speeds of different finishing mill stands can be different, and can be set and adjusted according to actual application requirements, without limitation here. When controlling the shutter opening sequence of the thickness gauge, the preset rolling speed of the corresponding finishing mill stand can be read to calculate the time it takes for the strip head to pass through the corresponding finishing mill stand and reach the measurement area of ​​the thickness gauge based on the corresponding preset rolling speed.

[0030] Step S110: Determine the delay control strategy for the opening of the thickness gauge shutter based on the preset rolling speed of the final finishing mill stand, in order to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the shutter opening time. The delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area. The forward slip value of the corresponding mill stand can be calculated based on the forward slip value and the rolling speed of the corresponding finishing mill stand. By fully considering the forward slip value of the corresponding finishing mill stand when calculating the shutter opening time of the thickness gauge, the accuracy of the opening time calculation can be improved. A finishing mill unit typically has seven finishing mill stands, F1-F7, with F7 serving as the final finishing mill stand.

[0031] In one embodiment, the step of determining the delay control strategy for opening the thickness gauge shutter based on the preset rolling speed of the finishing mill stand includes: recording the preset rolling speed of the finishing mill stand as the first speed; comparing the first speed with a preset speed threshold to determine the speed range into which the first speed falls; and calling a pre-associated delay control strategy according to the speed range to calculate the shutter opening delay of the thickness gauge. Specifically, delay control strategies associated with different speed ranges can be preset, and the endpoints of the speed ranges can be used as thresholds to compare with the first speed, thereby determining which speed range the first speed falls into. The corresponding delay control strategy is called according to the speed range into which the first speed falls. The delay control strategy is mainly used to calculate the time from the strip to the thickness gauge measurement area, and this time is used as the delay to determine the shutter opening delay of the thickness gauge. Since the calculation starting point of the delay is different for different speed ranges, different delay control strategies need to be set accordingly.

[0032] In one embodiment, when the first speed is greater than or equal to 9 m / s, the calculation method for the shutter opening delay of the thickness gauge includes:

[0033]

[0034] Wherein, T1: Delay time for the thickness gauge shutter to open after the F5 stand bites the steel (i.e., how many seconds after the F5 stand bites the steel, the thickness gauge shutter opens); L1: Distance between the center line of the F5 stand and the thickness gauge shutter, for example, 15.17 meters; V5: Preset rolling speed of the F5 stand; V6: Preset rolling speed of the F6 stand; V7: Preset rolling speed of the F7 stand; slip5: Forward slip value of the F5 stand (the strip rolling speed is faster than the stand roll speed, a positive value); slip6: Forward slip value of the F6 stand; slip7: Forward slip value of the F7 stand.

[0035] When the preset rolling speed of F7 is greater than or equal to 9m / s, the thickness gauge shutter opening time point calculation is started when the steel is bitten on the F1 stand. After a delay of T1 seconds after the steel is bitten on the F5 stand, the control system sends a shutter opening command to the thickness gauge to control the opening of the thickness gauge shutter.

[0036] In one embodiment, when the first speed is greater than or equal to 4.5 m / s and less than 9 m / s, the calculation method for the shutter opening delay of the thickness gauge includes:

[0037]

[0038] Wherein, T2: Delay time for the thickness gauge shutter to open after the F6 stand bites the steel (i.e., how many seconds after the F6 stand bites the steel, the thickness gauge shutter opens); L2: Distance between the center line of the F6 stand and the thickness gauge shutter, for example, 9.67 meters; V6: Preset rolling speed of the F6 stand; V7: Preset rolling speed of the F7 stand; slip6: Forward slip value of the F6 stand (the strip rolling speed is faster than the stand roll speed, a positive value); slip7: Forward slip value of the F7 stand.

[0039] When the preset rolling speed of F7 is greater than or equal to 4.5 m / s and less than 9 m / s, the thickness gauge shutter opening time point calculation is started when the steel is bitten on the F1 stand. After a delay of T2 seconds after the steel is bitten on the F6 stand, the control system sends a shutter opening command to the thickness gauge to control the opening of the thickness gauge shutter.

[0040] In one embodiment, when the first speed is less than 4.5 m / s, the calculation method for the shutter opening delay of the thickness gauge includes:

[0041]

[0042] Wherein, T3: Delay time for the thickness gauge shutter to open after the F7 stand bites the steel (i.e., how many seconds after the F7 stand bites the steel, the thickness gauge shutter opens); L3: Distance between the center line of the F7 stand and the thickness gauge shutter, for example, 4.17 meters; V7: Preset rolling speed of the F7 stand; slip7: Forward slip value of the F7 stand (the strip rolling speed is faster than the stand roll speed, and is a positive value).

[0043] Based on the above technical solution of this application, the problem of the shutter opening 1-2 seconds too early in the existing thickness gauge is effectively solved, as is the unreasonable control logic and timing of the shutter opening time in the existing thickness gauge. After the control method is implemented, the shutter opening time of the thickness gauge is closer to the time when the strip head reaches the shutter of the thickness gauge. It also effectively solves the problem that the measured strip thickness deviation is inaccurate after the shutter of the existing thickness gauge opens too early, which affects the accuracy of the thickness feedback control and thickness self-learning of the strip head and the stability of the threading of the finishing strip head.

[0044] Please see Figure 2 , Figure 2 This is a block diagram of a thickness gauge shutter opening timing control system according to an embodiment of this application. The system includes: a data acquisition module for acquiring the preset rolling speed of each finishing mill stand; and a shutter delay control module for determining a delay control strategy for opening the thickness gauge shutter based on the preset rolling speed of the last finishing mill stand, so as to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the shutter opening time; wherein the delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area.

[0045] The specific system execution process has been described in detail in the aforementioned method embodiments, and will not be repeated here.

[0046] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for controlling the shutter opening timing of a thickness gauge, characterized in that, include: Obtain the preset rolling speed for each finishing mill stand; The delay control strategy for opening the thickness gauge shutter is determined based on the preset rolling speed of the finishing mill stand, so as to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the time when the shutter opens; wherein the delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area. The delay control strategy for determining the opening delay of the thickness gauge shutter based on the preset rolling speed of the finishing mill stand includes: recording the preset rolling speed of the finishing mill stand as the first speed; comparing the first speed with a preset speed threshold to determine the speed range into which the first speed falls; and calling a pre-associated delay control strategy based on the speed range to calculate the opening delay of the thickness gauge shutter.

2. The thickness gauge shutter opening timing control method according to claim 1, characterized in that, When the first speed is greater than or equal to 9 m / s, the calculation method for the shutter opening delay of the thickness gauge includes: Wherein, T1: Delay time for the thickness gauge shutter to open after the F5 stand bites the steel; L1: Distance between the center line of the F5 stand and the thickness gauge shutter; V5: Preset rolling speed of the F5 stand; V6: Preset rolling speed of the F6 stand; V7: Preset rolling speed of the F7 stand; slip5: Forward slip value of the F5 stand; slip6: Forward slip value of the F6 stand; slip7: Forward slip value of the F7 stand.

3. The thickness gauge shutter opening timing control method according to claim 1, characterized in that, When the first speed is greater than or equal to 4.5 m / s and less than 9 m / s, the calculation method for the shutter opening delay of the thickness gauge includes: Wherein, T2: Delay time for the thickness gauge shutter to open after the F6 stand bites the steel; L2: Distance between the center line of the F6 stand and the thickness gauge shutter; V6: Preset rolling speed of the F6 stand; V7: Preset rolling speed of the F7 stand; slip6: Forward slip value of the F6 stand; slip7: Forward slip value of the F7 stand.

4. The thickness gauge shutter opening timing control method according to claim 1, characterized in that, When the first speed is less than 4.5 m / s, the calculation method for the shutter opening delay of the thickness gauge includes: Among them, T3: Delay time for the thickness gauge shutter to open after the F7 stand bites the steel; L3: Distance between the center line of the F7 stand and the thickness gauge shutter; V7: Preset rolling speed of the F7 stand; slip7: Forward slip value of the F7 stand.

5. A shutter opening timing control system for a thickness gauge, characterized in that, include: The data acquisition module is used to obtain the preset rolling speed of each finishing mill stand; The shutter delay control module is used to determine the delay control strategy for opening the thickness gauge shutter based on the preset rolling speed of the finishing mill stand, so as to reduce the time difference between the time when the strip head enters the measurement area of ​​the thickness gauge and the time when the shutter opens; wherein the delay control strategy is determined based on the preset rolling speed of each finishing mill stand, the forward slip value of the corresponding finishing mill stand, and the distance between the corresponding finishing mill stand and the measurement area; The delay control strategy for determining the opening delay of the thickness gauge shutter based on the preset rolling speed of the finishing mill stand includes: recording the preset rolling speed of the finishing mill stand as the first speed; comparing the first speed with a preset speed threshold to determine the speed range into which the first speed falls; and calling a pre-associated delay control strategy based on the speed range to calculate the opening delay of the thickness gauge shutter.

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