Cold-rolled plate shape feedback regulation and control dynamic allocation method, device and system and storage medium

Abstract

The invention discloses a cold-rolled plate shape feedback regulation dynamic distribution method, device and system and a storage medium, and the method comprises the steps: carrying out the Legendre decomposition of an actual plate shape deviation into a quartic polynomial, and calculating a quartic term coefficient and a quadratic term coefficient of the plate shape deviation; the regulation and control effects of working roll bending and middle roll bending are decomposed into quartic polynomials through Legendre decomposition; calculating a similarity index between the strip shape deviation and the regulation and control effects of working roll bending and middle roll bending execution mechanisms; and comparing the size of the similarity between the regulation and control efficacy of each execution mechanism and the plate shape deviation, and introducing a normalized exponential function for mapping to realize dynamic distribution control of each execution mechanism. By means of the technical scheme, dynamic distribution control can be achieved, and more accurate control over the plate shape is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of cold-rolled steel strips, and in particular relates to a method and device, a system, and a storage medium for dynamic allocation of cold-rolled plate shape feedback control. Background Art

[0002] With the improvement of technology, the quality of strips and plates has become more and more prominent, especially the plate shape quality problem which is difficult to control, which has become the focus of current research. Plate shape refers to the distribution of residual stress inside the strip after rolling along the width direction.

[0003] There are two common control strategies for closed-loop feedback control of plate shape in existing cold rolling mills: one is to adopt a sequential control strategy, that is, based on a predetermined priority list, the principle of least square method is used to solve the problem. However, this method of using one control method first cannot give full play to the effectiveness of multiple methods; the other is a proportional control strategy, that is, each control method is allocated according to a fixed ratio. The specific control process is as follows: Figure 1 As shown, for example, if there are two control methods, working roll bending and intermediate roll bending, generally a proportional coefficient of 0.5 is assigned to each. The proportional coefficient in the proportional control strategy is solidified into the control model, and the proportional coefficient remains unchanged. Although such a control strategy must have a solution, the mutual cooperation ratio of the actuators cannot be dynamically adjusted according to the rolling state and the plate shape of the rolled piece, and the solution is not the optimal solution of the current actuator. Therefore, it is urgent to analyze which allocation ratio is optimal under different rolling conditions and realize the dynamic adjustment of the cooperation proportional coefficient in order to give full play to the plate shape feedback control strategy of the unit. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method and device, system and storage medium for dynamic allocation of cold-rolled plate shape feedback regulation to achieve more precise control of the plate shape.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A method for dynamically allocating cold-rolled plate shape feedback control means, comprising:

[0007] The actual flatness deviation is decomposed into a 4th-order polynomial by Legendre, and the quartic term coefficient and quadratic term coefficient of the flatness deviation are calculated;

[0008] The control effects of working roll bending and intermediate roll bending are decomposed into a 4th-order polynomial by Legendre;

[0009] Calculate the similarity index between the plate shape deviation and the control efficiency of the working roll bending and intermediate roll bending actuators;

[0010] The similarity between the control efficiency of each actuator and the plate shape deviation is compared, and a normalized exponential function is introduced for mapping to realize the dynamic allocation control of each actuator.

[0011] As a preferred method, the calculation formula of the similarity index between the plate shape deviation and the control efficiency of the working roll bending roll and the intermediate roll bending roll actuator is:

[0012]

[0013] Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, λ 2 and λ 4 are the coefficients of the second and fourth basic modes of plate shape deviation, λ j4 is the fourth-order coefficient of the control efficiency of the j-th actuator, λ j2 is the quadratic coefficient of the control efficiency of the jth actuator.

[0014] As a preference, the allocation ratio of each execution structure is:

[0015]

[0016] Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

[0017] The present invention also provides a dynamic distribution device for cold-rolled plate shape feedback control means, comprising:

[0018] The first processing module is used to perform Legendre decomposition on the actual flatness deviation into a 4th-order polynomial, and calculate the quartic term coefficient and the quadratic term coefficient of the flatness deviation;

[0019] The second processing module is used to perform Legendre decomposition on the control effects of the working roll bending and the intermediate roll bending into a 4th-order polynomial;

[0020] The third processing module is used to calculate the similarity index between the plate shape deviation and the control effect of the working roll bending roll and the intermediate roll bending roll actuator;

[0021] The fourth processing module is used to compare the similarity between the control efficacy of each actuator and the plate shape deviation, introduce a normalized exponential function for mapping, and realize dynamic allocation control of each actuator.

[0022] As a preferred method, the calculation formula of the similarity index between the plate shape deviation and the control efficiency of the working roll bending roll and the intermediate roll bending roll actuator is:

[0023]

[0024] Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, λ 2 and λ 4 are the coefficients of the second and fourth basic modes of plate shape deviation, λ j4 is the fourth-order coefficient of the control efficiency of the j-th actuator, λ j2 is the quadratic coefficient of the control efficiency of the jth actuator.

[0025] As a preference, the allocation ratio of each execution structure is:

[0026]

[0027] Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

[0028] An embodiment of the present invention also provides a dynamic allocation system for cold-rolled plate shape feedback control means, comprising: a memory and a processor, wherein the memory stores a computer program run by the processor, and the computer program executes a dynamic allocation method for cold-rolled plate shape feedback control means when run by the processor.

[0029] An embodiment of the present invention further provides a storage medium, on which a computer program is stored, and when the computer program is run, a method for dynamically allocating cold-rolled plate shape feedback control means is executed.

[0030] In the plate shape closed-loop feedback control system of the present invention, the symmetrical plate shape deviation is controlled by the proportional control strategy of the working roll bending and the intermediate roll bending. The proportional control strategy distributes the working roll bending and the intermediate roll bending according to a fixed ratio, performs Legendre decomposition on the actual plate shape deviation, and maps the control efficacy of the working roll bending and the intermediate roll bending into coefficients of Legendre polynomials. By defining an evaluation index, the similarity between the actual plate shape deviation and the control efficacy of the working roll bending and the intermediate roll bending is evaluated, and a normalized exponential function is introduced for mapping. The greater the similarity between the control ability of the actuator and the plate shape deviation, the higher the distribution ratio, thereby realizing dynamic distribution control and achieving more precise control of the plate shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0032] Figure 1 Schematic diagram of the strategy for solving the proportional allocation of the units;

[0033] Figure 2 This is a flow chart of a method for dynamically allocating cold-rolled plate shape feedback control means according to an embodiment of the present invention;

[0034] Figure 3 Y is the basis mode of the Legendre orthogonal polynomial symmetric plate defect: 3 For the middle wave, Y 4 For double wave, Y 7 For the quarter wave, Y 8 It is a side-middle compound wave;

[0035] Figure 4 This is the plate shape control effect diagram under the fixed ratio allocation method;

[0036] Figure 5 This is the plate shape control effect diagram under the dynamic proportional allocation method;

[0037] Figure 6 This is a comparison chart of the plate shape control effects of the fixed proportion allocation method and the dynamic proportion allocation method. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] Embodiment 1:

[0041] An embodiment of the present invention provides a method for dynamically allocating cold rolling plate shape feedback control means. The control effect of the actuator in the cold rolling process is compared with the similarity of the plate shape deviation, an evaluation index is defined, and the similarity between the actual plate shape deviation and the control effect of the working roll bending roll and the intermediate roll bending roll is evaluated. A normalized exponential function is introduced for mapping, thereby dynamically changing the collaborative proportional coefficient, improving the plate shape control accuracy, and realizing intelligent control of the plate shape feedback.

[0042] In the proportional distribution control strategy, each actuator is allocated a fixed proportion of the flatness deviation, as shown in the following formula:

[0043] Δflat j =α jΔflat(j=1……m)

[0044] Among them, Δflat is the actual flatness deviation; Δflat j The plate shape deviation assigned to the jth actuator; α j Assign a proportionality coefficient to the j-th actuator, which is determined in advance by empirical selection and then solidified; m is the number of actuators.

[0045] The control amount of each actuator in the proportional distribution control strategy can be calculated by the following formula:

[0046]

[0047] Among them, eff ji is the control efficiency of the j-th actuator in the i-th section of the bandwidth direction; Δw j is the control amount of the jth actuator; Δflat ji is the i-th section plate shape change caused by the j-th actuator in the bandwidth direction; n is the number of sections of plate shape value.

[0048] It can be seen from the above formula that the control amount of the actuator is related to both the plate shape deviation and the control effect. The plate shape deviation changes dynamically with the actual plate shape, and the control effect also changes dynamically with the equipment and process status. To give full play to the control performance of the actuator, comprehensive consideration is required. A dynamic proportional allocation strategy is proposed. The basic idea of ​​the dynamic proportional allocation strategy is: the greater the similarity between the control effect of the actuator and the plate shape deviation, the better its control effect, and the larger the proportional coefficient assigned to it.

[0049] like Figure 2 As shown, the method for dynamically allocating cold-rolled plate shape feedback control means according to the embodiment of the present invention includes:

[0050] Step 1: Decompose the actual flatness deviation into a 4th-order polynomial by Legendre method, and calculate the quartic term coefficient and quadratic term coefficient of the flatness deviation.

[0051] The eight common wave shapes are represented by the basis modes of Legendre orthogonal polynomials, namely left wave, right wave, double wave, middle wave, left three-point wave, right three-point wave, side-middle composite wave and quarter wave. Figure 3 For the control of symmetrical wave shape, y=λ can be used 2 δ 2 +λ 4 δ 4 represents the plate shape (x∈[-1,1]), where λ 2 and λ 4 are the coefficients of the second and fourth basic modes of the plate shape deviation. The second and fourth basic modes include:

[0052] Double wave:

[0053] Middle Wave:

[0054] Edge-middle compound wave:

[0055] Quarter Wave:

[0056] Step 2: Decompose the control effects of the working roll bending and the intermediate roll bending into a 4th-order polynomial by Legendre. These two actuators adjust the plate shape defects of the symmetrical terms, so take their quadratic mode and quartic mode coefficients, that is, the quartic term coefficient λ of the control effect of the jth actuator j4 and the quadratic coefficient λ of the jth actuator control efficiency j2 , use these coefficients to judge the similarity between the control efficiency of the actuator and the plate shape deviation. 2 is the quadratic coefficient of plate shape deviation, λ 4 is the fourth-order coefficient of plate shape deviation.

[0057] Step 3: Define the similarity index between the plate shape deviation and the control efficiency of the working roll bending roll and intermediate roll bending roll actuators, and perform similarity calculation.

[0058]

[0059] Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation.

[0060] Step 4: Compare the similarity between the control efficiency of each actuator and the plate shape deviation, introduce the normalized exponential function for mapping, the larger the value, the higher the allocation ratio, thus realizing the dynamic allocation control of each actuator. That is, the allocation ratio of each actuator structure is:

[0061]

[0062] Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

[0063] The dynamic allocation strategy of the present invention can dynamically select the optimal proportional allocation coefficient according to the changing plate shape and the changing control effect. This method does not change the original proportional allocation control strategy of the unit, but dynamically optimizes the proportional allocation coefficient, avoiding the risk of fruitless solution when changing other optimization strategies. The dynamic proportional allocation method can safely and fully exert the plate shape control performance of the unit.

[0064] The method provided by the embodiment of the present invention is implemented in the description of the plate shape of a certain thin plate cold rolling mill.

[0065] The cold rolling mill is a five-stand six-roller UCM mill. The closed-loop feedback acts on the fifth stand. The closed-loop feedback control of the unit adopts a proportional distribution control strategy, which is based on a fixed proportional distribution, that is, the working roll bending distribution ratio is 0.5, and the intermediate roll bending distribution ratio is 0.5. Then the principle of least squares method is used to solve it. The control strategy of the unit is optimized.

[0066] Step 1: Decompose the actual flatness deviation into a 4th-order polynomial by Legendre. The symmetric terms of the flatness are mainly quadratic and quartic flatness defects. Use y=λ 2 δ 2 +λ 4 δ 4 represents a symmetrical plate defect, where λ 2 and λ 4 are the coefficients of the second and fourth basis modes of plate shape deviation.

[0067] Step 2: Map the control effects of the work roll bending and the intermediate roll bending into the coefficients of the Legendre polynomial. These two actuators adjust the symmetrical plate shape defects, so take their quadratic mode and quartic mode coefficients, that is, the quartic term coefficient λ of the control effect of the jth actuator j4 and the quadratic term coefficient of the j-th actuator control efficiency, and these coefficients are used to judge the similarity between the actuator control efficiency and the plate shape deviation.

[0068] Step 3: Define the similarity index between the plate shape deviation and the control efficiency of the working roll bending roll and intermediate roll bending roll actuators, and perform similarity calculation.

[0069]

[0070] Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation.

[0071] Step 4: Compare the similarity between the control effect of each actuator and the plate shape deviation, introduce the normalized exponential function for mapping, the larger the value, the higher the allocation ratio, so as to realize the dynamic allocation control of the working roll bending and the intermediate roll bending. That is, the allocation ratio of each actuator structure is:

[0072]

[0073] Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

[0074] The current proportional allocation control strategy is a static control strategy, that is, the proportional coefficient is fixed, solidified as 0.5 for the working roll bending and 0.5 for the intermediate roll bending. The dynamic allocation strategy can dynamically select the optimal proportional allocation coefficient for the changing plate shape and the changing control effect. This method does not change the original proportional allocation control strategy of the unit, but dynamically optimizes the proportional allocation coefficient, which can safely and fully exert the plate shape control performance of the unit and avoid the risk of fruitless solution when changing other optimization strategies.

[0075] Figure 4 The figure shows the plate shape control effect under the fixed ratio allocation method. Figure 5 The figure shows the plate shape control effect under the dynamic proportional allocation method. Figure 6 The figure shows the comparison of the plate shape control effect of the fixed proportion allocation method and the dynamic proportion allocation method. The results show that the control effect of the dynamic proportion allocation method is obvious. Due to the control effect of the fixed proportion allocation method, the plate shape deviation after control is smaller. Therefore, dynamically adjusting the proportional allocation coefficient of the actuator can better control the plate shape.

[0076] Embodiment 2:

[0077] The embodiment of the present invention further provides a cold-rolled plate shape feedback control means dynamic allocation device, comprising:

[0078] The first processing module is used to perform Legendre decomposition on the actual flatness deviation into a 4th-order polynomial, and calculate the quartic term coefficient and the quadratic term coefficient of the flatness deviation;

[0079] The second processing module is used to perform Legendre decomposition on the control effects of the working roll bending and the intermediate roll bending into a 4th-order polynomial;

[0080] The third processing module is used to calculate the similarity index between the plate shape deviation and the control effect of the working roll bending roll and the intermediate roll bending roll actuator;

[0081] The fourth processing module is used to compare the similarity between the control efficacy of each actuator and the plate shape deviation, introduce a normalized exponential function for mapping, and realize dynamic allocation control of each actuator.

[0082] As an implementation method of an embodiment of the present invention, the calculation formula of the similarity index between the plate shape deviation and the control effect of the working roll bending roll and the intermediate roll bending roll actuator is:

[0083]

[0084] Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, λ 2 and λ 4 are the coefficients of the second and fourth basic modes of plate shape deviation, λj4 is the fourth-order coefficient of the control efficiency of the j-th actuator, λ j2 is the quadratic coefficient of the control efficiency of the jth actuator.

[0085] As an implementation method of the embodiment of the present invention, the allocation ratio of each execution structure is:

[0086]

[0087] Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

[0088] Embodiment 3:

[0089] An embodiment of the present invention also provides a dynamic allocation system for cold-rolled plate shape feedback control means, comprising: a memory and a processor, wherein the memory stores a computer program run by the processor, and the computer program executes a dynamic allocation method for cold-rolled plate shape feedback control means when run by the processor.

[0090] Embodiment 4:

[0091] An embodiment of the present invention further provides a storage medium, on which a computer program is stored, and when the computer program is run, a method for dynamically allocating cold-rolled plate shape feedback control means is executed.

[0092] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for dynamically allocating cold-rolled plate shape feedback control means, characterized in that: include: The actual flatness deviation is decomposed into a 4th-order polynomial by Legendre, and the quartic term coefficient and quadratic term coefficient of the flatness deviation are calculated; The control effects of working roll bending and intermediate roll bending are decomposed into a 4th-order polynomial by Legendre; Calculate the similarity index between the plate shape deviation and the control efficiency of the working roll bending and intermediate roll bending actuators; The similarity between the control efficiency of each actuator and the plate shape deviation is compared, and a normalized exponential function is introduced for mapping to realize the dynamic allocation control of each actuator.

2. The method for dynamic allocation of cold-rolled plate shape feedback control means according to claim 1, characterized in that: The calculation formula for the similarity index between the plate shape deviation and the control efficiency of the working roll bending and intermediate roll bending actuators is: Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, λ2 and λ4 are the coefficients of the second and fourth basis modes of the plate shape deviation, λ j4 is the fourth-order coefficient of the control efficiency of the j-th actuator, λ j2 is the quadratic coefficient of the control efficiency of the jth actuator.

3. The method for dynamic allocation of cold-rolled plate shape feedback control means according to claim 2, characterized in that: The allocation ratio of each execution structure is: Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

4. A dynamic distribution device for cold-rolled plate shape feedback control means, characterized in that: include: The first processing module is used to perform Legendre decomposition on the actual flatness deviation into a 4th-order polynomial, and calculate the quartic term coefficient and the quadratic term coefficient of the flatness deviation; The second processing module is used to perform Legendre decomposition on the control effects of the working roll bending and the intermediate roll bending into a 4th-order polynomial; The third processing module is used to calculate the similarity index between the plate shape deviation and the control effect of the working roll bending roll and the intermediate roll bending roll actuator; The fourth processing module is used to compare the similarity between the control efficacy of each actuator and the plate shape deviation, introduce a normalized exponential function for mapping, and realize dynamic allocation control of each actuator.

5. The dynamic distribution device for cold-rolled plate shape feedback control means according to claim 4, characterized in that: The calculation formula for the similarity index between the plate shape deviation and the control efficiency of the working roll bending and intermediate roll bending actuators is: Among them, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, λ2 and λ4 are the coefficients of the second and fourth basis modes of the plate shape deviation, λ j4 is the fourth-order coefficient of the control efficiency of the j-th actuator, λ j2 is the quadratic coefficient of the control efficiency of the jth actuator.

6. The dynamic distribution device for cold-rolled plate shape feedback control means according to claim 5, characterized in that: The allocation ratio of each execution structure is: Among them, α j is the allocation ratio coefficient of the jth actuator, h j is the similarity between the control efficiency of the jth actuator and the plate shape deviation, and m is the number of actuators.

7. A dynamic distribution system for cold-rolled plate shape feedback control means, characterized in that: include: A memory and a processor, wherein the memory stores a computer program executed by the processor, and when the computer program is executed by the processor, the method for dynamically allocating cold-rolled plate shape feedback control means as described in any one of claims 1 to 3 is executed.

8. A storage medium, characterized in that: The storage medium stores a computer program, which, when running, executes the method for dynamically allocating cold-rolled plate shape feedback control means as described in any one of claims 1 to 3.

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