A hot rolling looper tension control method based on cyber-physical system

Abstract

The present application provides a hot rolling looper tension control method based on an information-physical system, which relates to the field of control system technology, including: step 1 deriving an incremental model of tension and looper height, and establishing a state space model of the looper tension control system; step 2 constructing an ILQ controller based on the state space model of the looper tension control system; step 3 real-time acquisition of actual rolling process parameters, immediate input into the ILQ controller to calculate various gains; step 4 recording multiple groups of rolling process parameters and various calculated gains to form a database of the hot rolling looper tension control system; step 5 establishing a digital virtual body that completely corresponds to the looper working process based on the database established in the previous step. Through the interactive feedback loop between the computational process and the physical process, the deep integration and real-time interaction of the physical space and the information space are realized, thereby enhancing the control capability of the looper system, reducing the thickness fluctuation of the strip steel product, and improving the product quality.

Description

Technical Field

[0001] The present application belongs to the technical field of data processing, and relates to rolling process automation control system technology, and specifically is a hot rolling looper tension control method based on information physical system. Background Art

[0002] The Cyber-Physical System (CPS) integrates advanced information technologies such as perception, computing, communication, and control, as well as automatic control technologies, to build a complex system in which elements such as people, machines, objects, environment, and information in the physical space and cyber space are mapped to each other, interact in real time, and collaborate efficiently, thereby achieving on-demand response, rapid iteration, and dynamic optimization of resource allocation and operation within the system.

[0003] The quality of the looper control system can directly affect the quality of hot-rolled strip products and plays a pivotal role in the finishing mill. The purpose of controlling the looper height is to keep the amount of looping between adjacent finishing stands constant to avoid steel pulling and steel piling; the purpose of controlling the tension is to keep the tension acting on the strip constant to ensure product quality.

[0004] Aiming at the problems of hot-rolled strip looper and thickness control, some relevant studies done by domestic researchers were retrieved.

[0005] The patent "CN109865749 B A hot rolling thickness-loop integrated system inverse linear quadratic control method" takes the hot rolling thickness-loop integrated system as the research object, designs a controller based on the inverse linear quadratic theory, and tests the performance of the controller, providing guidance for actual production and theoretical research.

[0006] The patent "CN112792140 B A strip thickness and plate convexity control method based on inverse linear quadratic form" proposes a strip thickness and plate convexity control method based on inverse linear quadratic form theory in order to solve the problem of reduced system control ability due to interaction of hot rolling thickness and plate convexity control systems, and proves the feasibility of the method through simulation and experiments.

[0007] The above research has the following shortcomings: the traditional ILQ strategy is modeled near the working point, assuming that the system is in equilibrium. Because external interference factors are not considered, the controller gain parameters are all fixed values, resulting in low control accuracy in the actual rolling process. After adding the CPS strategy, the key parameters such as the rolling force, roll speed, roll gap, looper roll force, looper angle and tension of each stand in the rolling process can be detected in real time through the on-site measurement device, and the various feedback and integral gain parameters of the ILQ controller can be recalculated, greatly improving the control performance of the system. Summary of the invention

[0008] This application provides a hot rolling looper tension control method based on cyber-physical system. The following technical solutions are adopted:

[0009] A hot rolling looper tension control method based on cyber-physical system, comprising:

[0010] Step 1: Based on the actual rolling process parameters collected, the incremental model of tension and looper height is derived; combined with the incremental model of tension and looper height, the state space model of the looper tension control system is established;

[0011] Step 2: Construct an ILQ controller based on the state space model of the looper tension control system;

[0012] Step 3: Collect the actual rolling process parameters in real time and input them into the ILQ controller to calculate the various gains;

[0013] Step 4: Record the rolling process parameters and the calculated gain parameters, repeat step 3 and record multiple sets of parameters, and establish a database for the hot rolling looper tension ILQ control system;

[0014] Step 5: Based on the database established in the previous step, establish a digital virtual body corresponding to the looper working process.

[0015] By adopting the above technical solution, it is possible to achieve deep integration and real-time interaction between physical space and information space through the interactive feedback loop between the computing process and the physical process, improve model parameters, make the established digital virtual body more realistically conform to the actual production process, and enhance the control ability of the loop system, thereby improving the accuracy of the loop system control, reducing the thickness fluctuation of the strip steel product, and improving product quality.

[0016] Preferably, the tension increment in step 1 is composed of two parts: the tension change caused by the change in the looper amount, and the tension change caused by the change in the outlet speed of the rolled piece at the i frame and the change in the inlet speed of the i+1 frame;

[0017] The increment of the tension is expressed by the model:

[0018] Where: ; ; is the tension of the rolled piece; E is Young's modulus; L is the distance between the i and i+1 stands; is the looper angle; is the forward sliding distance of the strip on the i frame; is the rear sliding distance of the i+1 rack; is the sleeve amount between the i and i+1 frames; F2 is the influence coefficient of the angle on the sleeve amount; K 10v is the influence coefficient of tension on strip speed; i is the rolling mill speed of stand i; v i+1 is the rolling mill speed of the i+1 stand; t is the time.

[0019] By adopting the above technical solution, the change of the looper tension is derived, the two-part composition is considered, and the factors affecting the tension in production are fully considered, so that the incremental calculation model of the tension is accurate.

[0020] Preferably, the incremental model of the looper height in step 1 is established by the following steps:

[0021] The equation for the rate of change of the angular velocity of the looper is:

[0022] Where: F1 is the influence coefficient of angle on the moment of the looper, ; F3 is the influence coefficient of tension on the gravity moment of the strip steel, ; T is the output torque of the hydraulic cylinder; T t is the strip tension moment; is the strip steel gravity moment; is the gravity moment of the looper; is the strip bending moment; is the viscosity coefficient of the looper; J is the moment of inertia of the looper; is the angular velocity of the loop, ;

[0023] The equation model for the looper angle is:

[0024] Where: θ is the looper angle; ω is the looper angular velocity; is the loop transmission ratio.

[0025] By adopting the above technical solution, the incremental model of the active height is derived. The change of the looper height H1 is mainly related to the movement of the looper hydraulic cylinder. When the looper moves, since the position of the fulcrum O and the looper arm length R1 remain unchanged, the control of the looper height H1 is essentially the control of the looper angle. The output torque of the looper hydraulic cylinder is related to the tension torque of the strip, the weight moment of the strip, the weight moment of the looper, the bending moment of the strip, and the dynamic moment generated during the movement of the looper. According to the relationship between them, the equation for the change rate of the looper angular velocity can be obtained.

[0026] Preferably, the state space model of the looper tension control system in step 1 is:

[0027] ; ; ;

[0028] Where: ; ; ; A is the system matrix, B is the input matrix, C is the output matrix, x is the state variable, y is the output variable, u is the input variable, and V is the rolling mill speed.

[0029] By adopting the above technical solution, the state space model of the looper height and tension is obtained by using three simultaneous incremental equations. The first task in designing the ILQ controller is to combine the main dynamic mathematical incremental models to obtain the corresponding state space equations.

[0030] Preferably, step 2 is specifically:

[0031] First, according to the ILQ theory, the optimal and stable feedback control rate K is obtained;

[0032] Then, using the mathematical relationship between the feedback control rate K and the constructed system, the feedback gain matrix K is derived F and K I ;

[0033] Solve the feedback gain matrix K F and K I Able to obtain various gains.

[0034] By adopting the above technical solution, the optimal and stable feedback control rate K is first obtained. When the extended system reaches a steady state, the extended system is constructed by the state equation through integral solution, and the feedback gain matrix K is derived. F and K I , each gain parameter can be calculated.

[0035] Preferably, the various gains described in step 3 include: tension ring tension integral gain; tension ring tension feedback gain; angle ring loop speed feedback gain; angle ring angle integral gain; angle ring angle feedback gain; angle ring tension integral gain.

[0036] Preferably, the parameters of the database in step 4 include:

[0037] The rolling process parameters measured include: strip exit and entry speeds of each stand and rolling mill speed, strip tension, looper angle, geometric position relationship of looper device, strip weight, looper moment of inertia, and looper transmission ratio;

[0038] Parameters to be calculated: Calculate the forward slip of the strip in stand i based on the strip exit and entry speeds and the mill speed , slide back Value, and the influence coefficient of strip tension on strip speed ;

[0039] According to the geometric position relationship between the loop angle and the loop device, calculate the influence coefficient of the loop angle on the loop amount ;

[0040] Calculate the influence coefficient of the looper height on the looper torque based on the strip tension, strip gravity and looper angle ;

[0041] According to the geometric position relationship of the strip steel weight, the looper device and the strip steel tension, the influence coefficient of the strip steel tension on the strip steel weight moment is calculated. ;

[0042] According to the geometric position relationship of the loop device, the forward slide As well as the desired response of the loop tension ILQ control system, calculate the tension loop tension integral gain ;

[0043] According to the geometric position relationship of the loop device, the forward slide , calculate the tension feedback gain of the tension ring ;

[0044] Calculate the angle loop loop speed feedback gain based on the loop loop's rotational inertia ;

[0045] Calculate the angle loop angle integral gain based on the loop transmission ratio and the loop rotation inertia ;

[0046] Calculate the angle loop angle feedback gain based on the looper transmission ratio, looper moment of inertia, and the desired response of the looper tension ILQ control system And the angle loop tension integral gain .

[0047] By adopting the above technical solution, the values ​​of various feedback and integral gain parameters in the ILQ controller are calculated and used to construct a database.

[0048] Preferably, the process of establishing the digital virtual body in step 5 is as follows: using the established database, taking the rolling process parameters and the calculated gain as input, taking the looper angle and tension as output, and taking 0.05s as a sampling interval to construct a hot rolling looper angle tension prediction model, the specific steps are as follows:

[0049] Define the fitness function as follows:

[0050] in, is the coefficient, n is the number of nodes, is the expected output value, is the predicted output value;

[0051] Assume that the probability of the target individual being selected There are the following forms:

[0052] in, is the front sliding distance of the rack i, , N is the population size;

[0053] Calculate chromosomes using real crossover method and :

[0054] in, is a random number between [0,1];

[0055] The mutation operation method is as follows:

[0056] in, , and are the upper and lower critical value scores of the gene, respectively; is a random coefficient between [0,1]; x is the current iteration number; is the maximum number of evolutions.

[0057] By adopting the above technical solution, a hot rolling looper angle-tension prediction model is constructed with mechanism fusion data that completely corresponds to the looper working process. Through the interactive feedback loop between the computational process and the physical process, the deep fusion and real-time interaction of the physical space and the information space are realized, thereby enhancing the control capability of the looper system, thereby reducing the thickness fluctuation of the strip product and improving the product quality.

[0058] An electronic device comprises a processor and a memory, wherein the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory so that the electronic device executes any one of the methods described above.

[0059] A computer-readable storage medium stores instructions, and when the instructions are executed, any one of the above methods is executed.

[0060] In summary, the technical solutions provided in the embodiments of the present application have the following technical effects or advantages:

[0061] By deeply integrating the physical process of actual production with the calculation process obtained by model calculation, the two are repeatedly circulated to enhance the fit between the model and reality, thereby improving the accuracy of looper tension control and further improving the product quality of rolled strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1Flowchart of this method.

[0063] Figure 2 It is a plan view of the looper.

[0064] Figure 3 It is the ILQ control block diagram for tracking issues.

[0065] Figure 4 It is the principle diagram of the hot rolling looper angle-tension prediction model based on mechanism fusion data.

[0066] Figure 5 It is the loop angle prediction curve of the established model.

[0067] Figure 6 is the tension prediction curve of the established model.

[0068] Figure 7 It is the actual strip exit thickness deviation curve. DETAILED DESCRIPTION

[0069] In order to enable technicians in this field to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this application, not all of the embodiments.

[0070] In the description of the embodiments of the present application, words such as "for example" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "for example" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "for example" or "for example" is intended to present related concepts in a specific way.

[0071] In the description of the embodiments of the present application, the term "multiple" means two or more. For example, multiple systems refer to two or more systems, and multiple screen terminals refer to two or more screen terminals. In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0072] In this embodiment, a 1580mm hot rolling production line of a certain factory is taken as an example, and its process flow is as follows: first, the continuous casting billet is heated in a heating furnace, and then transported to the rough rolling mill, and after repeated rolling in the rough rolling mill, the irregular head and tail are cut off by a flying shear and enter the finishing mill for processing; finally, the strip passes through a laminar cooling device and enters the coiler for coiling.

[0073] The present invention controls the looper tension system in the stable rolling stage of the finishing rolling zone. The rolling mill rolls are all flat rolls. Some rolling mill parameters are shown in Table 1.

[0074] Table 1 Parameters of 1580 mm hot rolling mill

[0075]

[0076] A hot rolling looper tension control method based on cyber-physical system, see Figure 1 As shown, including:

[0077] Step 1: Based on the rolling mechanism and mathematical and dynamic relationships, a dynamic incremental model of tension and looper height is derived. The step 1 is specifically as follows:

[0078] Step 1.1: Solve the strip tension increment equation.

[0079] The change in strip tension consists of two parts: one is the change in the tension of the rolled piece caused by the change in the amount of the looper, and the other is the change in the tension of the rolled piece caused by the change in the exit speed of the rolled piece at the i frame and the change in the entrance speed of the i+1 frame.

[0080] According to the geometric relationship of the loop, the mathematical model of the loop amount can be obtained; according to the definition of front and rear slip and Fink's front slip formula, the mathematical model of the change of the exit speed of the rolled piece at the i stand and the entrance speed of the i+1 stand can be obtained. In the finishing rolling stage, since the thickness of the strip has been reduced to a certain extent, the influence of the roll gap and the strip thickness is ignored. In addition, when studying the rolling tension of a single-stage double-stand, the influence of the tensile stress of the front and rear sections is ignored.

[0081] The incremental model of tension is obtained as follows:

[0082] Where: ; ;

[0083] is the tension of the rolled piece; E is Young's modulus; L is the distance between the i and i+1 stands; is the looper angle; is the front sliding distance of the i rack; is the rear sliding distance of the i+1 rack; is the amount of loops between racks i and i+1.

[0084] Step 1.2: Solve the looper angle increment equation.

[0085] See Figure 1 The geometric position relationship of the looper device can be obtained from the plane diagram of the looper shown in the figure. Among them, the change of the looper height is mainly related to the movement of the looper hydraulic cylinder. Figure 2 It can be seen from the plane diagram of the looper that when the looper moves, since the position of the fulcrum O and the length R1 of the looper arm remain unchanged, the control of the looper height H1 is essentially the control of the looper angle control.

[0086] The output torque of the hydraulic cylinder of the looper is related to the tension torque of the strip, the gravity moment of the strip, the gravity moment of the looper, the bending moment of the strip, and the dynamic moment generated during the movement of the looper. According to the relationship between them, the equation for the change rate of the angular velocity of the looper can be obtained as follows:

[0087] Where: ; ; T is the output torque of the hydraulic cylinder; is the strip tension moment; is the strip steel gravity moment; is the gravity moment of the looper; is the strip bending moment; is the viscosity coefficient of the looper (the value is very small and often ignored); J is the moment of inertia of the looper; is the angular velocity of the loop, .

[0088] According to the relationship between the rate of change of the looper angle and the angular velocity of the looper, we can get:

[0089] Where: is the loop transmission ratio.

[0090] Establish the state space model of the looper-tension control system. Specifically:

[0091] The first task in designing an ILQ controller is to combine the main dynamic mathematical incremental models to obtain the corresponding state space equations. The three incremental equations can be combined to obtain the state space model of the looper height and tension.

[0092] ;

[0093] ; ; .

[0094] Where: ; ;

[0095] Step 2: Design the ILQ controller of the looper-tension control system and clarify the calculation method of the gain parameters of the designed controller. The specific steps of step 2 are:

[0096] The construction extension system is as follows:

[0097] in:

[0098]

[0099] , is the steady-state value.

[0100] For the extended system, according to the ILQ theory, the optimal and stable feedback control rate K is obtained.

[0101]

[0102] make:

[0103] but:

[0104] When this expansion system reaches a steady state, , .

[0105] Therefore, we can get:

[0106] Integrating both sides of the above equation yields:

[0107] The design process of ILQ controller for tracking problem is:

[0108] Step 1: According to the ILQ theory, find the optimal and stable feedback control rate K;

[0109] Step 2: Ask and ;

[0110] Step 3: Establish a control system.

[0111] Tracking problem ILQ control block diagram as Figure 3 shown.

[0112] Construct an extended system from the state equation:

[0113] , , ,

[0114] Then we have:

[0115]

[0116]

[0117]

[0118]

[0119] Solve the A-BF matrix and establish an equivalent relationship

[0120] Substituting F into A-BF, we get

[0121] In the formula

[0122]

[0123]

[0124]

[0125] Assume the characteristic equation of the closed-loop system is

[0126]

[0127]

[0128] By making the corresponding elements in the two matrices equal, we can obtain:

[0129] , .

[0130] According to the derived feedback gain matrix and , we can calculate: tension loop tension integral gain ; Tension loop tension feedback gain ; Angle loop speed feedback gain ; Angle loop angle integral gain ; Angle loop angle feedback gain ; Angle loop tension integral gain .

[0131] Step 3: Use the measuring devices in the production line to monitor the key parameters of the rolling process in real time and instantly calculate the values ​​of various feedback and integral gain parameters in the ILQ controller.

[0132] The step 3 is specifically as follows:

[0133] The values ​​of the feedback and integral gain parameters in the ILQ controller are calculated as follows: According to the strip exit and entrance speeds and the mill speed, the strip forward and backward slip values, as well as the strip tension influence coefficient on the strip speed are calculated. ; According to the geometric position relationship between the loop angle and the loop device, calculate the influence coefficient of the loop angle on the loop amount ; According to the strip tension, strip gravity and looper angle, calculate the influence coefficient of looper height on looper torque , according to the strip steel gravity, the geometric position relationship of the looper device and the strip steel tension, calculate the influence coefficient of the strip steel tension on the strip steel gravity moment ; Calculate the tension ring tension integral gain based on the geometric position relationship of the looper device, the forward slide, and the expected response of the looper-tension ILQ control system ; Calculate the tension feedback gain of the tension ring according to the geometric position relationship and forward sliding of the loop device ; Calculate the angle loop loop speed feedback gain based on the loop loop moment of inertia ; Calculate the angle loop angle integral gain based on the loop transmission ratio and the loop rotation inertia ; Calculate the angle loop angle feedback gain based on the loop transmission ratio, loop moment of inertia, and the desired response of the loop-tension ILQ control system And the angle loop tension integral gain .

[0134] Step 4: Record the partial differential coefficients, controller gain parameters and rolling process parameters in each mechanism model in the above steps to form a database of the hot rolling looper-tension control system. 10 The parameters in the calculation process of F2, F1, and F3 are all partial differential coefficients.

[0135] The database of step 4 specifically includes the parameters calculated in step 3, as well as the steel grade composition, intermediate billet thickness, width, and the outlet temperature of the finishing zone, the outlet thickness of the strip, the speed of each stand and the rolling mill speed, tension, rolling force, roll gap, looper roll force, and looper angle. The details are shown in Table 2.

[0136] Table 2 Parameters contained in the database

[0137]

[0138] Step 5: Establish a digital virtual body that fully corresponds to the looper working process, and through the interactive feedback loop between the computing process and the physical process, achieve deep integration and real-time interaction between the physical space and the information space, thereby enhancing the control ability of the looper system and improving product quality. The specific steps of step 6 are:

[0139] Utilizing the established database, the rolling process parameters and the calculated partial differential coefficients and gains are taken as input, and the looper angle and tension are taken as output. With a sampling interval of 0.05s, a hot rolling looper angle-tension GA-BP prediction model is constructed based on the mechanism fusion data that completely corresponds to the looper working process.

[0140] Among them, the principle of the hot rolling looper angle-tension prediction model based on mechanism fusion data is as follows: Figure 4 As shown, the specific steps are:

[0141] Define the fitness function as follows:

[0142] in, is the coefficient, n is the number of nodes, is the expected output value, is the predicted output value.

[0143] Assume that the probability of the target individual being selected There are the following forms:

[0144] in, , N is the population size.

[0145] Calculate chromosomes using real crossover method and .

[0146] in, is a random number between [0,1].

[0147] The mutation operation method is as follows:

[0148] in , and are the upper and lower critical value scores of the gene, respectively; is a random coefficient between [0,1]; x is the current iteration number; is the maximum number of evolutions.

[0149] 10,000 sets of data from the database established in step 4 were selected for model training, and 3,000 sets were selected for testing. The looper angle prediction curve of the established model is shown in Figure 5 As shown; the tension prediction curve of the established model is as follows Figure 6 shown.

[0150] Through the interactive feedback loop between the computational process and the physical process, the deep integration and real-time interaction of the physical space and the information space are realized, the model parameters are improved, and the control ability of the loop system is enhanced, thereby reducing the thickness fluctuation of the strip steel product and improving the product quality. The actual strip steel outlet thickness deviation curve is as follows: Figure 7 shown.

[0151] The present application also provides an electronic device, which may include: at least one processor and at least one memory. The processor may include one or more processing cores. The processor uses various interfaces and lines to connect various parts of the entire server, and executes various functions of the server and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory, and calling data stored in the memory.

[0152] Optionally, the processor can be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The processor can integrate one or a combination of a central processing unit (CPU), a graphics processing unit (GPU), and a modem. Among them, the CPU mainly processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display; and the modem is used to process wireless communications. It is understandable that the above-mentioned modem may not be integrated into the processor, but may be implemented separately through a chip.

[0153] The memory may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory may also be at least one storage device located away from the aforementioned processor. The memory as a computer storage medium may include an operating system, a network communication module, a user interface module, and an application for a hot rolling looper tension control method based on an information-physical system.

[0154] The present application also provides a computer-readable storage medium, which stores instructions. When executed by one or more processors, the electronic device executes one or more of the methods described in the above embodiments.

[0155] In addition, each functional unit in the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0156] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a memory and includes several instructions for a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: various media that can store program codes, such as USB flash drives, mobile hard drives, magnetic disks or optical disks.

[0157] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the disclosure of the specification and the truth of practice, it will be easy for those skilled in the art to think of other embodiments of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field that are not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A hot rolling looper tension control method based on cyber-physical system, characterized in that: include: Step 1: Based on the actual rolling process parameters collected, the incremental model of tension and looper height is derived; combined with the incremental model of tension and looper height, the state space model of the looper tension control system is established; Step 2: Construct an ILQ controller based on the state space model of the looper tension control system; Step 3: collect the actual rolling process parameters in real time, and input them into the ILQ controller to calculate various gains immediately; the various gains in step 3 include: tension ring tension integral gain; tension ring tension feedback gain; angle ring loop speed feedback gain; angle ring angle integral gain; angle ring angle feedback gain; angle ring tension integral gain; Step 4: Record the rolling process parameters and the calculated gain parameters, repeat step 3 and record multiple sets of parameters, and establish a database for the hot rolling looper tension ILQ control system; Step 5: Based on the database established in the previous step, establish a digital virtual body corresponding to the looper working process.

2. The hot rolling looper tension control method based on cyber-physical system according to claim 1 is characterized in that: The tension increment in step 1 is composed of two parts: the tension change caused by the change in the looper amount, and the tension change caused by the change in the outlet speed of the rolled piece at the i frame and the change in the inlet speed of the i+1 frame; The increment of the tension is expressed by the model: Where: ; ; is the tension of the rolled piece; E is Young's modulus; L is the distance between the i and i+1 stands; θ is the loop angle; is the forward sliding distance of the strip on the i frame; is the rear sliding distance of the i+1 rack; L i is the sleeve amount between the i and i+1 frames; F2 is the influence coefficient of the angle on the sleeve amount; K 10 v is the influence coefficient of tension on strip speed; i is the rolling mill speed of stand i; v i+1 is the rolling mill speed of the i+1 stand; t is the time.

3. The hot rolling looper tension control method based on cyber-physical system according to claim 2 is characterized in that: The incremental model of the looper height in step 1 is established in the following steps: The equation for the rate of change of the angular velocity of the looper is: Where: F1 is the influence coefficient of angle on the moment of the looper, ; F3 is the influence coefficient of tension on the gravity moment of the strip steel, ; T is the output torque of the hydraulic cylinder; T t is the strip tension moment; T ω It is the sum of the weight moment of the strip and the weight moment of the looper; T B B is the bending moment of the strip; T is the viscosity coefficient of the looper; J is the moment of inertia of the looper; ω is the angular velocity of the looper, ; The equation model for the looper angle is: Where: θ is the looper angle; ω is the looper angular velocity; is the loop transmission ratio.

4. The hot rolling looper tension control method based on cyber-physical system according to claim 3 is characterized in that: The state space model of the looper tension control system described in step 1: ; ; ; ; Where: ; ; ; A is the system matrix, B is the input matrix, C is the output matrix, x is the state variable, y is the output variable, u is the input variable, and V is the rolling mill speed.

5. The hot rolling looper tension control method based on cyber-physical system according to claim 1 is characterized in that: Step 2 is as follows: First, according to the ILQ theory, the optimal and stable feedback control rate K is obtained; Then, using the mathematical relationship between the feedback control rate K and the constructed system, the feedback gain matrix K is derived F and K I ; Solve the feedback gain matrix K F and K I Able to obtain various gains.

6. The hot rolling looper tension control method based on cyber-physical system according to claim 1 is characterized in that: The parameters of the database in step 4 include: The rolling process parameters measured include: strip exit and entry speeds of each stand and rolling mill speed, strip tension, looper angle, geometric position relationship of looper device, strip weight, looper moment of inertia, and looper transmission ratio; Parameters to be calculated: Calculate the forward slip of the strip in stand i based on the strip exit and entry speeds and the mill speed , slide back Value, and the influence coefficient of strip tension on strip speed ; According to the geometric position relationship between the loop angle and the loop device, the influence coefficient F2 of the loop angle on the loop amount is calculated; According to the strip tension, strip gravity and looper angle, calculate the influence coefficient F1 of the looper height on the looper torque; According to the geometric position relationship of the strip steel weight, the looper device and the strip steel tension, the influence coefficient F3 of the strip steel tension on the strip steel weight moment is calculated; According to the geometric position relationship of the loop device, the forward slide As well as the desired response of the loop tension ILQ control system, calculate the tension loop tension integral gain ; According to the geometric position relationship of the loop device, the forward slide , calculate the tension feedback gain of the tension ring ; Calculate the angle loop loop speed feedback gain based on the loop loop's rotational inertia ; Calculate the angle loop angle integral gain based on the loop transmission ratio and the loop rotation inertia ; Calculate the angle loop angle feedback gain based on the looper transmission ratio, looper moment of inertia, and the desired response of the looper tension ILQ control system And the angle loop tension integral gain .

7. The hot rolling looper tension control method based on cyber-physical system according to claim 1 is characterized in that: The establishment process of the digital virtual body in step 5 is as follows: using the established database, taking the rolling process parameters and the calculated gain as input, taking the looper angle and tension as output, and taking 0.05s as a sampling interval, a hot rolling looper angle tension prediction model is constructed. The specific steps are as follows: Define the fitness function as follows: in, is the coefficient, n is the number of nodes, is the expected output value, is the predicted output value; Assume that the probability of the target individual being selected There are the following forms: in, is the front sliding distance of the rack i, , N is the population size; Calculate chromosomes using real crossover method and : in, is a random number between [0,1]; The mutation operation method is as follows: in, , and are the upper and lower critical value scores of the gene, respectively; is a random coefficient between [0,1]; x is the current iteration number; is the maximum number of evolutions.

8. An electronic device, characterized in that: The electronic device comprises a processor and a memory, wherein the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory, so that the electronic device executes the method according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed, the method according to any one of claims 1 to 7 is performed.

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