A method and device for self-feedback control of a hot rolling mill profile

Abstract

The application discloses a self-feedback control method and device for a plate shape of a hot rolling mill, adopts a flatness gauge to measure a designated measuring point on a strip steel, and obtains height data of a plurality of longitudinal wave shapes on the strip steel measured by the flatness gauge; adopts a least square method according to the height data to fit a quadratic curve function of the whole strip steel; utilizes a fitting result of the quadratic curve function to calculate a bending roll force required to be adjusted by the hot rolling mill in real time; and compiles the calculation result of the bending roll force required to be adjusted by the hot rolling mill to automatically adjust the bending roll force of a press roll to control the plate shape of the whole strip steel. The application realizes automatic calculation and adjustment of the bending roll force of the rolling mill by taking the measuring data of the flatness gauge as feedback, realizes accurate feedback control on the plate shape, and improves the plate shape quality.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hot rolling, and particularly relates to a self-feedback control method and device for a plate shape of a hot rolling mill. BACKGROUND

[0002] A hot rolling mill, also known as a hot rolling production line, can heat metal materials to a high temperature and press them into shape, and is an important part of the metal manufacturing process, mainly used for producing various shaped metal plates, strips and profiles, and widely applied in the steel industry, construction industry, automobile manufacturing industry and other fields.

[0003] The basic working principle of a hot rolling mill is that the metal raw material is sent to the feeding roller table of the hot rolling mill and enters the heating furnace for heating. The heating temperature is usually between 1000℃ and 1300℃, and the specific temperature depends on the metal material to be produced and the processing effect required. Then, the heated metal raw material is sent to the roller table of the rolling mill and is pressed by the rollers in the middle of the roller table. Through the process of continuous rolling and pressing, the desired plate, strip or profile is finally formed.

[0004] At present, the traditional plate shape control mainly relies on the rolling mill operator to realize, and the rolling mill operator manually adjusts the bending roller force by observing the wave shape, which not only lacks accurate plate shape data feedback, but also leads to inaccurate plate shape control. SUMMARY

[0005] Therefore, the present application provides a self-feedback control method and device for a plate shape of a hot rolling mill to solve the problem of poor accuracy caused by manual adjustment relying on artificial.

[0006] In order to achieve the above purpose, the present application provides the following technical scheme: a self-feedback control method for a plate shape of a hot rolling mill, comprising:

[0007] The flatness gauge is used to measure the specified measurement point on the strip steel to obtain the height data of the several longitudinal wave shapes measured by the flatness gauge on the strip steel;

[0008] According to the height data, the least square method is used to fit the quadratic curve function of the entire strip steel;

[0009] The fitting result of the quadratic curve function is used to calculate the bending roller force required by the hot rolling mill in real time;

[0010] The calculation result of the bending roller force required by the hot rolling mill is compiled to automatically adjust the bending roller force of the press roller to control the plate shape of the entire strip steel.

[0011] As a preferred scheme of the self-feedback control method for the plate shape of the hot rolling mill, the quadratic curve function fitted for the entire strip steel is:

[0012] y=a2x 2+a1x + a0

[0013] In the formula, y represents the height data of the wave shape, x represents the horizontal coordinate of the measuring point, and a0, a1, and a2 represent the fitting coefficients.

[0014] As a preferred scheme of the self-feedback control method of the plate shape of the hot rolling mill, if a2>0, the wave shape is defined as a middle wave, and the operation of reducing the bending roller force is performed.

[0015] If a2<0, the wave shape is defined as a double-side wave, and the operation of increasing the bending roller force is performed.

[0016] As a preferred scheme of the self-feedback control method of the plate shape of the hot rolling mill, if a2>0, the adjustment amount of the bending roller force is a2 x 2 *k1, a2 x 2 represents the middle wave value, and k1 represents the middle wave coefficient, which is valued between -0.3 and -0.8 according to the steel type, thickness, and width.

[0017] As a preferred scheme of the self-feedback control method of the plate shape of the hot rolling mill, if a2<0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 x 2 represents the double-side wave value, and k2 represents the double-side wave coefficient, which is valued between -0.3 and -0.8 according to the steel type, thickness, and width.

[0018] As a preferred scheme of the self-feedback control method of the plate shape of the hot rolling mill, the control period of the automatic adjustment of the bending roller force of the press roller is:

[0019] The time τ from the start of the hot rolling mill to the measurement of the adjusted result by the flatness instrument.

[0020] The application also provides a self-feedback control device for the plate shape of a hot rolling mill, which comprises:

[0021] A wave shape data acquisition module, which is used for measuring the designated measuring points on the strip steel by using the flatness instrument, and acquiring the height data of a plurality of longitudinal wave shapes on the strip steel measured by the flatness instrument.

[0022] A strip steel fitting module, which is used for fitting the quadratic curve function of the whole strip steel by using the least square method according to the height data.

[0023] A bending roller force analysis module, which is used for calculating the bending roller force required to be adjusted by the hot rolling mill in real time by using the fitting result of the quadratic curve function.

[0024] A compiling control module, which is used for compiling the calculation result of the bending roller force required to be adjusted by the hot rolling mill, so as to automatically adjust the bending roller force of the press roller to control the plate shape of the whole strip steel.

[0025] As a preferred embodiment of the self-feedback control device for hot rolling mill strip profiles, the quadratic curve function used to fit the entire strip in the strip fitting module is:

[0026] y=a2x 2 +a1x+ a0

[0027] In the formula, y represents the height data of the wave shape, x represents the x-coordinate of the measurement point, and a0, a1, and a2 represent the fitting coefficients.

[0028] As a preferred embodiment of the self-feedback control device for hot rolling mill plate profiles, the bending roll force analysis module includes:

[0029] If a2>0, define the wave shape as a medium wave and perform the operation to reduce the bending roller force;

[0030] If a2 < 0, define the wave shape as a double-sided wave and perform the operation of adding bending roller force;

[0031] If a2 > 0, the adjustment amount of the bending roller force is a2 x 2 *k1, a2 x 2 The value represents the wave value, and k1 represents the wave coefficient. The wave coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width.

[0032] If a2 < 0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 ​​x 2 represents the two-sided wave value, and k2 represents the two-sided wave coefficient. The two-sided wave coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width.

[0033] As a preferred embodiment of the self-feedback control device for hot rolling mill plate profiles, the control cycle for automatically adjusting the bending force of the pressure rollers in the compilation control module is as follows:

[0034] The time τ from when the strip starts rolling at the hot rolling mill until the straightness instrument measures the adjusted result.

[0035] This invention has the following advantages: A flatness meter is used to measure designated points on the strip steel to obtain the height data of several longitudinal wavinesses on the strip steel as measured by the flatness meter; based on the height data, a quadratic curve function of the entire strip steel is fitted using the least squares method; the fitting result of the quadratic curve function is used to calculate the bending roll force that the hot rolling mill needs to adjust in real time; the calculated bending roll force of the hot rolling mill is compiled to automatically adjust the bending roll force of the pressure rolls to control the shape of the entire strip steel. This invention uses flatness meter measurement data as feedback to automatically calculate and adjust the bending roll force of the rolling mill, achieving precise feedback control of the strip shape and improving strip quality. Attached Figure Description

[0036] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the self-feedback control method for hot rolling mill plate shape provided in Embodiment 1 of the present invention;

[0038] Figure 2 This is a schematic diagram of the technical route of the self-feedback control method for hot rolling mill plate shape provided in Embodiment 1 of the present invention;

[0039] Figure 3 This is a schematic diagram of closed-loop control in the self-feedback control method for hot rolling mill plate shape provided in Embodiment 1 of the present invention;

[0040] Figure 4 This is a schematic diagram of wave shape fitting in the self-feedback control method for hot rolling mill plate shape provided in Embodiment 1 of the present invention;

[0041] Figure 5 The actual on-site control curve in the self-feedback control method for hot rolling mill plate shape provided in Embodiment 1 of the present invention;

[0042] Figure 6 This is a field data acquisition diagram from the self-feedback control method for hot rolling mill plate shape provided in Embodiment 1 of the present invention;

[0043] Figure 7 This is a schematic diagram of the self-feedback control device architecture for hot rolling mill plate shape provided in Embodiment 2 of the present invention. Implementation

[0044] The following specific embodiments 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. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0045] See Figure 1 , Figure 2 and Figure 3 This invention provides a self-feedback control method for hot rolling mill plate profiles, comprising the following steps:

[0046] S1. Use a flatness tester to measure the specified measurement points on the strip steel and obtain the height data of several longitudinal wavinesses on the strip steel measured by the flatness tester.

[0047] S2. Based on the height data, the least squares method is used to fit the quadratic curve function of the entire strip steel.

[0048] S3. Using the fitting results of the quadratic curve function, calculate in real time the bending roll force that the hot rolling mill needs to be adjusted;

[0049] S4. Compile the calculation results of the bending roll force that needs to be adjusted in the hot rolling mill, so as to automatically adjust the bending roll force of the pressure roll to control the shape of the entire strip.

[0050] In step S1 of this embodiment, the wave height data y1 to y9 at 9 positions on the strip are measured using a BPM120 flatness meter; at the same time, the abscissas of the 9 measurement points are set to x1 to x9 respectively, and the abscissa of the middle point x5 is set to 0.

[0051] In step S2 of this embodiment, the quadratic curve function fitted to the entire strip steel is:

[0052] y=a2x 2 +a1x+ a0

[0053] In the formula, y represents the height data of the wave shape, x represents the x-coordinate of the measurement point, and a0, a1, and a2 represent the fitting coefficients.

[0054] Specifically, taking the rolling of 1547.7mm wide strip steel as an example, based on the mechanical spot position distribution of the straightness instrument, the abscissas x1~x9 of its 9 points are calculated as follows:

[0055] -693.85mm, -513.85mm, -333.85mm, -153.85mm, 0,153.85mm, 333.85mm, 513.85mm, 693.85mm.

[0056] Then read the I values ​​of channels y1~y9 of the flatness instrument, such as: 200, 150, 100, 50, 30, 70, 90, 130, 188.

[0057] At this point, curve fitting can be performed using the least squares method. The solution obtained from the multivariate derivative formula is the best-fit quadratic function: y = 0.0003x² − 0.0107x + 51.78.

[0058] The coefficients a0, a1, a2 of the quadratic function can be found:

[0059] From the above formula, we know that a0 = 51.78, a1 = -0.0107, and a2 = 0.0003;

[0060] Finally, the quadratic polynomial function obtained is: y = a²x 2 +a1x+ a0.

[0061] Support Figure 4 In step S3 of this embodiment, if a2>0, the wave shape is defined as a medium wave, and the operation of reducing the bending roller force is performed;

[0062] If a2 < 0, the wave shape is defined as a double-sided wave, and the bending roller force is increased. If a2 > 0, the adjustment amount for decreasing the bending roller force is a2 x 2 *k1, a2 x 2 Here, k1 represents the wave value, and k1 represents the wave coefficient, which ranges from -0.3 to -0.8 depending on the steel grade, thickness, and width. If a2 < 0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 ​​x 2 represents the two-sided wave value, and k2 represents the two-sided wave coefficient. The two-sided wave coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width.

[0063] Specifically, if a2 > 0, it indicates a medium wave pattern, requiring the operation of reducing the bending roller force. The value of a medium wave pattern is a2x. 2 Substituting x9=693.85 into the equation, we get 693.85*693.85*0.0003=144.4, so the wave value in the system is 144.4.

[0064] Assuming a2 < 0, it indicates a double-sided wave, requiring the application of bending roller force. The value of a double-sided wave is a2x. 2 Substituting x9=693.85 into the equation, we get 693.85*693.85*0.0003=144.4. Therefore, the inverted bilateral wave value in the system is -144.4.

[0065] If a2>0, the adjustment amount is 4*k1, where k1 is the wave coefficient, with a value between -0.3 and -0.8. The value is determined based on the steel grade, thickness, and width. 144.4*-0.5=-72.2KN. The bending roll force of the last frame is reduced by 72.2 KN in this adjustment.

[0066] If a2 < 0, the adjustment amount is 4 * k1, where k1 is the wave coefficient, with a value between -0.3 and -0.8. The value is determined based on the steel grade, thickness, and width. -144.4 * -0.5 = 72.2 KN. This adjustment increases the bending roll force of the last frame by 72.2 KN compared to the current adjustment.

[0067] Support Figure 5The curves from top to bottom are as follows: red is the bending roll force adjustment curve; black is the F7 rolling force change trend *0.1; blue is the quadratic curve fitting value, which is negative on the graph, indicating double-sided wavy surface; and green is the mill loading sequence diagram.

[0068] Support Figure 6 In step S4 of this embodiment, the control cycle for automatically adjusting the bending force of the pressure roll is the time τ from when the strip starts rolling at the hot rolling mill until the straightness instrument measures the adjusted result. That is, using the method of this embodiment, the bending force of the rolling mill can be automatically calculated and adjusted based on the straightness instrument measurement data, achieving precise feedback control of the strip shape and improving strip quality.

[0069] In summary, this invention uses a flatness meter to measure designated points on the strip steel, obtaining height data of several longitudinal wavinesses on the strip steel as measured by the flatness meter; based on the height data, a quadratic curve function of the entire strip steel is fitted using the least squares method; the fitting result of the quadratic curve function is used to calculate the bending roll force that the hot rolling mill needs to adjust in real time; the calculation result of the bending roll force that the hot rolling mill needs to adjust is compiled to automatically adjust the bending roll force of the pressure roll to control the shape of the entire strip steel. The quadratic curve function fitted to the entire strip steel is: y=a²x 2 +a1x+ a0; If a2>0, define the wave shape as a medium wave and perform the operation of reducing the bending roller force; if a2<0, define the wave shape as a double wave and perform the operation of increasing the bending roller force. If a2>0, the adjustment amount of the bending roller force reduction is a2 x 2 *k1, a2 x 2 Here, k1 represents the wave value, and k1 represents the wave coefficient, which ranges from -0.3 to -0.8 depending on the steel grade, thickness, and width. If a2 < 0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 ​​x 2 The value represents the double-sided wave value, and k2 represents the double-sided wave coefficient, which ranges from -0.3 to -0.8 depending on the steel grade, thickness, and width. The control cycle for automatically adjusting the bending force of the pressure rolls is the time τ from when the strip starts rolling at the hot rolling mill until the straightness instrument measures the adjusted result. This invention uses the straightness instrument measurement data as feedback to automatically calculate and adjust the bending force of the rolling mill, achieving precise feedback control of the strip shape and improving strip quality.

[0070] It should be noted that the method of this embodiment can also be applied to a distributed scenario, where multiple devices cooperate to complete the task. In such a distributed scenario, one of these devices may execute only one or more steps of the method in this embodiment, and the multiple devices will interact with each other to complete the method described.

[0071] It should be noted that the above description describes some embodiments of this disclosure. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in a different order than that shown in the above embodiments and still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous. Example

[0072] See Figure 7 Embodiment 2 of the present invention also provides a self-feedback control device for hot rolling mill plate profile, comprising:

[0073] The wavy data acquisition module 1 is used to measure the specified measurement points on the strip using a flatness tester, and to acquire the height data of several longitudinal wavy shapes on the strip measured by the flatness tester.

[0074] The strip fitting module 2 is used to fit the quadratic curve function of the entire strip using the least squares method based on the height data.

[0075] The bending roll force analysis module 3 is used to calculate the bending roll force that the hot rolling mill needs to adjust in real time using the fitting result of the quadratic curve function.

[0076] The compilation control module 4 is used to compile the calculation results of the bending roll force that needs to be adjusted in the hot rolling mill, so as to automatically adjust the bending roll force of the pressure roll to control the shape of the entire strip.

[0077] In this embodiment, the quadratic curve function used to fit the entire strip in the strip fitting module 2 is:

[0078] y=a2x 2 +a1x+ a0

[0079] In the formula, y represents the height data of the wave shape, x represents the x-coordinate of the measurement point, and a0, a1, and a2 represent the fitting coefficients.

[0080] In this embodiment, the bending roller force analysis module 3 includes:

[0081] If a2>0, define the wave shape as a medium wave and perform the operation to reduce the bending roller force;

[0082] If a2 < 0, define the wave shape as a double-sided wave and perform the operation of adding bending roller force;

[0083] If a2 > 0, the adjustment amount of the bending roller force is a2 x 2 *k1, a2 x 2The value represents the wave value, and k1 represents the wave coefficient. The wave coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width.

[0084] If a2 < 0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 ​​x 2 represents the two-sided wave value, and k2 represents the two-sided wave coefficient. The two-sided wave coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width.

[0085] In this embodiment, the control cycle for automatically adjusting the bending force of the pressure roller in the compilation control module 4 is as follows:

[0086] The time τ from when the strip starts rolling at the hot rolling mill until the straightness instrument measures the adjusted result.

[0087] It should be noted that the information interaction and execution process between the modules of the above-mentioned device are based on the same concept as the method embodiment in Embodiment 1 of this application, and the resulting technical effects are the same as those in the method embodiment of this application. For details, please refer to the description in the method embodiment shown above in this application, and it will not be repeated here. Example

[0088] Embodiment 3 of the present invention provides a non-transitory computer-readable storage medium storing program code for a self-feedback control method for hot rolling mill plate shape. The program code includes instructions for executing the self-feedback control method for hot rolling mill plate shape of Embodiment 1 or any possible implementation thereof.

[0089] Computer-readable storage media can be any available medium that a computer can access, or a data storage device such as a server or data center that integrates one or more available media. The available medium can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state drives (SSDs)). Example

[0090] Embodiment 4 of the present invention provides an electronic device, including: a memory and a processor;

[0091] The processor and the memory communicate with each other via a bus; the memory stores program instructions that can be executed by the processor, and the processor can execute the self-feedback control method for hot rolling mill plate shape in Embodiment 1 or any possible implementation thereof by calling the program instructions.

[0092] Specifically, a processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. This memory can be integrated into the processor or located outside the processor and exist independently.

[0093] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0094] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0095] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A self-feedback control method for hot rolling mill plate profile, characterized in that, include: A flatness tester is used to measure the height of several longitudinal wavinesses on the strip at designated measurement points to obtain the height data of the flatness tester. Based on the height data, the least squares method is used to fit the quadratic curve function of the entire strip steel. Using the fitting results of the quadratic curve function, the bending roll force that needs to be adjusted in the hot rolling mill is calculated in real time; The calculation results of the bending roll force that needs to be adjusted in the hot rolling mill are compiled to automatically adjust the bending roll force of the pressure roll to control the shape of the entire strip. The quadratic curve function fitted to the entire strip of steel is: y=a2x 2 +a1x+a0 In the formula, y represents the height data of the wave shape, x represents the x-coordinate of the measurement point, and a0, a1, and a2 represent the fitting coefficients. If a2>0, define the wave shape as a medium wave and perform the operation to reduce the bending roller force; If a2 < 0, define the wave shape as a double-sided wave and perform the operation of adding bending roller force; If a2 > 0, the adjustment amount of the bending roller force is a2 x 2 *k1, a2 x 2 The value represents the wave length, and k1 represents the wave length coefficient. The wave length coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width. If a2 < 0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 ​​x 2 represents the two-sided wave value, and k2 represents the two-sided wave coefficient, which is between -0.3 and -0.8 depending on the steel grade, thickness, and width. The control cycle for the bending force of the automatically adjusting pressure roller is: The time τ from when the strip starts rolling at the hot rolling mill until the straightness instrument measures the adjusted result.

2. A self-feedback control device for hot rolling mill plate profile, characterized in that, include: The waviness data acquisition module is used to measure the height of several longitudinal wavinesses on the strip using a straightness meter at specified measurement points on the strip. The strip fitting module is used to fit the quadratic curve function of the entire strip using the least squares method based on the height data. The bending roll force analysis module is used to calculate the bending roll force that the hot rolling mill needs to adjust in real time using the fitting results of the quadratic curve function. The compilation control module is used to compile the calculation results of the bending roll force that needs to be adjusted in the hot rolling mill, so as to automatically adjust the bending roll force of the pressure roll to control the shape of the entire strip steel. In the strip fitting module, the quadratic curve function for fitting the entire strip is: y=a2x 2 +a1x+a0 In the formula, y represents the height data of the wave shape, x represents the x-coordinate of the measurement point, and a0, a1, and a2 represent the fitting coefficients. In the bending roller force analysis module: If a2>0, define the wave shape as a medium wave and perform the operation to reduce the bending roller force; If a2 < 0, define the wave shape as a double-sided wave and perform the operation of adding bending roller force; If a2 > 0, the adjustment amount of the bending roller force is a2 x 2 *k1, a2 x 2 The value represents the wave length, and k1 represents the wave length coefficient. The wave length coefficient is between -0.3 and -0.8 depending on the steel grade, thickness, and width. If a2 < 0, the adjustment amount of the bending roller force is a2 x 2 *k2, a2 ​​x 2 represents the two-sided wave value, and k2 represents the two-sided wave coefficient, which is between -0.3 and -0.8 depending on the steel grade, thickness, and width. In the compilation control module, the control cycle for automatically adjusting the bending force of the pressure roller is: The time τ from when the strip starts rolling at the hot rolling mill until the straightness instrument measures the adjusted result.

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