Mechanical manufacturing feed automatic control system and method

Abstract

The application provides a mechanical manufacturing feed automatic control system and method, and belongs to the technical field of automatic control. Real-time process parameters of a rolling slab to be entered into a finishing mill stand are acquired. Multiple rolling force change trends of the rolling slab along the length direction are determined according to the real-time process parameters. Multiple rolling mill stiffness coefficients of the finishing mill set are determined. The first roll gap compensation sequence caused by the rolling force change is obtained by feeding forward mapping of the roll gap effective profile change and the thickness change based on all the rolling mill stiffness coefficients and all the rolling force change trends. The second roll gap compensation sequence is determined according to the actual thickness value and the target thickness value. The dynamic adjustment instruction of the working roll gap of the finishing mill set is determined according to the first roll gap compensation sequence and the second roll gap compensation sequence, and the rolling plate thickness is controlled based on the dynamic adjustment instruction. The scheme of the application can control the rolling plate thickness under the conditions of rolling force fluctuation and process parameter change at different positions of the rolling plate.

Description

Technical Field

[0001] This application relates to the field of automatic control technology, and more specifically, to an automatic control system and method for feeding materials in mechanical manufacturing. Background Technology

[0002] Mechanical manufacturing is a process that integrates design, processing, and assembly technologies to transform raw materials into mechanical products. In the production of hot-rolled strip steel, precise, continuous, and adaptive control of the geometric dimensions, position, and speed of the metal billet entering the deformation zone of the rolls is crucial to ensuring the stability of the rolling process and the uniformity of product quality. The core objective of the automatic feeding control system is to ultimately produce qualified products with high dimensional accuracy and uniform performance through real-time monitoring and dynamic adjustment of process parameters.

[0003] Existing hot strip mill finishing control technology mainly relies on thickness detection signals from the last stand exit of the finishing mill for feedback control. However, during the high-speed stable rolling stage, factors such as the temperature difference between the head and tail of the incoming slab and the resulting fluctuations in rolling force can lead to inconsistent thickness along the entire length of the finished strip, such as excessive width or narrowing at the head and tail. This feedback control is lagging and cannot fully compensate for rapid dynamic disturbances, thereby reducing metal yield and increasing the cost and difficulty of subsequent edge trimming. Therefore, how to control the thickness of the rolled strip under the conditions of rolling force fluctuations and changes in operating parameters at different positions of the rolled plate has become a challenge for the industry. Summary of the Invention

[0004] This application provides an automatic control system and method for feeding materials in mechanical manufacturing, which can control the thickness of the rolled plate under conditions of rolling force fluctuations and changes in working parameters at different positions of the rolled plate.

[0005] In a first aspect, this application provides a method for controlling the plate thickness of a hot strip mill finishing unit, used in an automatic feeding control system for mechanical manufacturing to control the plate thickness, wherein a target thickness value at the exit of the finishing mill is preset, and the method includes the following steps: Obtain the real-time process parameters of the slab to be entered the finishing mill stand; The trends of multiple rolling forces along the length of the slab during the finishing rolling process are determined based on the real-time process parameters. Multiple mill stiffness coefficients are determined during the rolling process of the finishing mill. Based on all mill stiffness coefficients and all rolling force variation trends, feedforward mapping is performed on the effective profile and thickness changes of the roll gap caused by rolling force fluctuations, thereby obtaining the first roll gap compensation sequence caused by rolling force changes during the rolling process. Monitor the actual thickness of the rolled plate at the exit of the last stand of the finishing mill during the rolling process, and determine the second roll gap compensation sequence based on the actual thickness and the target thickness. The dynamic adjustment command for the working roll gap of the finishing mill is determined based on the first roll gap compensation sequence and the second roll gap compensation sequence, and then the plate thickness is controlled based on the dynamic adjustment command.

[0006] In some embodiments, determining the variation trend of multiple rolling forces along the length direction of the slab during finishing rolling based on the real-time process parameters specifically includes: The rolled slab is divided into multiple slicing units along its length, and one slicing unit is selected as the selected slicing unit. The real-time process parameters are combined with a preset rolling force mathematical model to determine the rolling force variation along the length direction of the selected slice unit during the finishing rolling process; Continue to determine the rolling force variation of the remaining slicing units; All changes in rolling force are taken as the trend of rolling force change along the length of the slab during the finishing rolling process.

[0007] In some embodiments, determining multiple mill stiffness coefficients of the finishing mill during the rolling process specifically includes: Obtain the preset wear model; Offline pressing method is used to obtain the foundation stiffness coefficient of each stand of the finishing mill. Multiple mill stiffness coefficients for the finishing mill during the rolling process were determined using all the basic stiffness coefficients and the wear model.

[0008] In some embodiments, a feedforward mapping is performed on the effective profile and thickness changes of the roll gap caused by rolling force fluctuations based on all mill stiffness coefficients and all rolling force variation trends, thereby obtaining the first roll gap compensation sequence caused by rolling force changes during the rolling process. Specifically, this includes: Select one of the slab cutting units as the selected cutting unit; Based on the rolling force change and the corresponding mill stiffness coefficient of the selected slice unit from all rolling force change trends, determine the elastic deformation of the roll system of the selected slice unit under rolling force fluctuations. The elastic deformation of the roller system is mapped to the thickness change at the outlet of the selected slicing unit; Based on the thickness change, feedforward control is performed to offset the thickness change, and the first roll gap compensation amount of the selected slicing unit is obtained. Continue to determine the first roll gap compensation amount for the remaining slicing units; The set of all first roll gap compensation amounts is taken as the sequence of first roll gap compensation amounts caused by the change in rolling force during the rolling process.

[0009] In some embodiments, determining the second roll gap compensation sequence based on the actual thickness value and the target thickness value specifically includes: The actual thickness value and the target thickness value are compared to obtain the thickness deviation of the rolled slab at the current moment; Feedback control is performed on the thickness deviation to obtain the second roll gap compensation amount of the slab during the rolling process; The actual thickness of the rolled plate at the exit of the last stand of the finishing mill is continuously monitored during the rolling process, and the second roll gap compensation amount is obtained at each sampling time during the monitoring process. Arrange all the second roll gap compensation amounts in the order of sampling time to obtain the second roll gap compensation amount sequence.

[0010] In some embodiments, determining the dynamic adjustment command for the work roll gap of the finishing mill based on the first roll gap compensation sequence and the second roll gap compensation sequence specifically includes: Align the first roll gap compensation sequence and the second roll gap compensation sequence according to the length direction of the rolled slab. Multiple composite compensation amounts for the finishing mill are determined based on the aligned first roll gap compensation amount sequence and the second roll gap compensation amount sequence. All composite compensation values ​​are converted into dynamic adjustment commands for the working roll gap of the finishing mill.

[0011] In some embodiments, controlling the thickness of the rolled plate based on the dynamic adjustment command specifically includes: The dynamic adjustment command is sent to the hydraulic control system of each stand of the finishing mill; The hydraulic control system of each stand of the finishing mill controls the opening of the work roll gap by dynamically adjusting the servo valve driven by the servo valve to regulate the hydraulic cylinder pressure, thereby controlling the thickness of the rolled plate at the exit.

[0012] In some embodiments, the real-time process parameters of the slab to be entered into the finishing mill stand are obtained through the data acquisition module of the automatic feeding control system for mechanical manufacturing.

[0013] In some embodiments, the actual thickness of the rolled plate at the exit of the last stand of the finishing mill is monitored by a thickness gauge during the rolling process.

[0014] Secondly, this application provides an automatic feeding control system for mechanical manufacturing, which includes a plate thickness control unit for a hot continuous rolling mill, the plate thickness control unit comprising: The acquisition module is used to acquire the real-time process parameters of the slab to be entered into the finishing mill stand; The processing module is used to determine the changing trends of multiple rolling forces along the length direction of the slab during the finishing rolling process based on the real-time process parameters. The processing module is also used to determine multiple mill stiffness coefficients of the finishing mill during the rolling process, and to perform feedforward mapping on the effective profile change and thickness change of the roll gap caused by the rolling force fluctuation based on all mill stiffness coefficients and all rolling force change trends, thereby obtaining the first roll gap compensation amount sequence caused by the rolling force change during the rolling process. The processing module is also used to monitor the actual thickness value of the rolled plate at the exit of the last stand of the finishing mill during the rolling process, and to determine the second roll gap compensation sequence based on the actual thickness value and the target thickness value. The execution module is used to determine the dynamic adjustment command of the working roll gap of the finishing mill based on the first roll gap compensation sequence and the second roll gap compensation sequence, and then control the plate thickness based on the dynamic adjustment command.

[0015] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects: In the process of controlling the thickness of rolled slab in a hot strip mill finishing mill, this application first acquires the real-time process parameters of the slab to be entered the finishing mill stand; based on the real-time process parameters, it determines the multiple rolling force variation trends along the length of the slab during the finishing rolling process; since existing technologies rely only on a single thickness feedback at the last stand exit, they cannot predict the rolling force fluctuations over the entire length of the slab; this application, by discretizing the slab into multiple slice units and predicting the rolling force variation trend of each unit, achieves for the first time a quantitative description of the non-uniform incoming material condition, providing spatially continuous and positionally accurate disturbance distribution data for feedforward compensation, overcoming the deficiency of traditional methods in being unable to distinguish differences between different sections; secondly, based on all mill stiffness coefficients and all rolling force variation trends, it further analyzes the effective profile changes and thickness changes of the roll gap caused by rolling force fluctuations. By performing feedforward mapping, a first roll gap compensation sequence caused by changes in rolling force during the rolling process is obtained; a second roll gap compensation sequence is determined based on the actual thickness value and the target thickness value; a dynamic adjustment command for the working roll gap of the finishing mill is determined based on the first roll gap compensation sequence and the second roll gap compensation sequence, and then the plate thickness is controlled based on the dynamic adjustment command. Because existing technologies use pure feedback control, adjustments can only be made after thickness deviations occur, resulting in inherent lag and insufficient response to rapid disturbances during high-speed rolling. This application, by serializing and fusing the first compensation amount obtained from feedforward mapping with the second compensation amount obtained from feedback, forms a feedforward-feedback composite control. This can suppress the main disturbances of rolling force fluctuations in advance and eliminate model errors and residual deviations online, significantly improving the overall thickness control accuracy and response speed. The above scheme can control the plate thickness under conditions of rolling force fluctuations and changes in operating parameters at different positions of the plate. Attached Figure Description

[0016] Figure 1This is an exemplary flowchart of a hot strip mill plate thickness control method according to some embodiments of this application; Figure 2 This is an exemplary flowchart illustrating the determination of the rolling force variation trend according to some embodiments of this application; Figure 3 These are engineering implementation examples illustrating the determination of dynamic adjustment commands to control the thickness of rolled plates according to some embodiments of this application; Figure 4 This is a schematic diagram of the structure of the plate thickness control unit according to some embodiments of this application; Figure 5 This is a schematic diagram of the structure of a computer device for implementing a method for controlling the plate thickness of a hot strip mill, according to some embodiments of this application. Detailed Implementation

[0017] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0018] refer to Figure 1 The figure is an exemplary flowchart of a hot strip mill finishing mill plate thickness control method according to some embodiments of this application. The hot strip mill finishing mill plate thickness control method mainly includes the following steps: In step 101, the real-time process parameters of the slab to be entered into the finishing mill stand are obtained.

[0019] In specific implementation, the real-time process parameters of the slab to be entered into the finishing mill stand can be obtained in the following way: the data acquisition module of the automatic feeding control system of the mechanical manufacturing obtains the temperature data, thickness and width parameters, steel grade characteristic parameters, position parameters and speed parameters of the slab as it is about to enter the intermediate slab located at the entrance of the finishing mill. The temperature data can be continuously measured by an infrared thermometer installed on the roller table at the entrance of the finishing mill. The steel grade characteristic parameters (such as yield strength, deformation resistance, etc.) can be retrieved from the pre-stored steel grade database according to the identification information of the slab. All the above-mentioned parameters are used as the real-time process parameters of the slab to be entered into the finishing mill stand. Other methods can also be used in other embodiments, which are not limited here.

[0020] In step 102, the changing trends of multiple rolling forces along the length direction of the slab during the finishing rolling process are determined based on the real-time process parameters.

[0021] In some embodiments, reference Figure 2As shown, this figure is an exemplary flowchart for determining the rolling force variation trend in some embodiments of this application. In this embodiment, determining the multiple rolling force variation trends along the length direction of the slab during the finishing rolling process based on the real-time process parameters can be achieved by the following steps: First, in step 1021, the rolled slab is divided into multiple slicing units along its length, and one slicing unit is selected as the selected slicing unit. Secondly, in step 1022, the real-time process parameters are combined with a preset rolling force mathematical model to determine the rolling force variation of the selected slice unit along the length direction during the finishing rolling process; Then, in step 1023, the rolling force variation of the remaining slicing units is further determined; Finally, in step 1024, all rolling force changes are taken as the rolling force change trend of the slab along the length direction during the finishing rolling process.

[0022] In specific implementation, the slab can be divided into multiple slicing units along its length by means of the strip tracking module of the automatic feeding control system for mechanical manufacturing, which can be used to discretize the slab into multiple slicing units along its length. Each slicing unit corresponds to a control cycle (usually 100-500 mm). Other methods can also be used in other embodiments, which are not limited here.

[0023] In specific implementation, the determination of the rolling force variation along the length direction of a selected slice unit during the finishing rolling process, by combining the real-time process parameters with a preset rolling force mathematical model, can be achieved in the following way: The temperature data, steel grade characteristic parameters, and thickness parameters of the selected slice unit from the real-time process parameters are input into the preset rolling force mathematical model. The predicted rolling force of the selected slice unit is then calculated using the formula of the rolling force mathematical model. This predicted rolling force is used as the rolling force variation along the length direction of the selected slice unit during the finishing rolling process. Here, the rolling force variation refers to the continuously distributed rolling force along the length direction caused by the different process parameters of the selected slice unit, used to characterize the natural fluctuation trend of the rolling force along the length of the slab when no control intervention is applied. The rolling force mathematical model can use the Sims formula based on hot rolling theory or its improved version to calculate the predicted rolling force based on the real-time process parameters of the slab. The core expression of this model is: Where P is the predicted rolling force, Here, is the compressive stress state coefficient, and k is the deformation resistance of the rolled slab, which is obtained by looking up tables or regression based on the steel grade characteristics, temperature, and strain rate. For the front and rear tensile stress, The flattening radius of the roll. 'b' represents the reduction amount, and 'b' represents the width of the rolled plate. In specific implementation, the real-time process parameters such as the temperature, thickness, width, steel grade identification, and forward slip coefficient of the selected slice unit are substituted into the above model to calculate the predicted rolling force value of the slice unit during the finishing rolling process, thereby obtaining the rolling force variation trend along the length direction. Other methods can also be used in other embodiments, which are not limited here.

[0024] It should be noted that the rolling force variation trend in this application refers to the parameter value of the rolling force of each slice unit according to its variation trend in the slab length direction. This parameter is used to quantitatively characterize the full-length rolling force disturbance distribution of the slab to be rolled due to the unevenness of its own process parameters in the automatic control system of mechanical feeding. This facilitates the subsequent determination of the effective profile change and thickness change of the roll gap caused by the rolling force fluctuation. In this process, the continuous physical quantity is discretized into a digital sequence through the slicing method, that is, a continuous slab is mapped into a rolling force data sequence that can be processed by a program. This realizes the leap from analog control to digital predictive control, which is convenient for subsequent high-precision feedforward compensation.

[0025] In step 103, multiple mill stiffness coefficients of the finishing mill are determined during the rolling process. Based on all mill stiffness coefficients and all rolling force change trends, feedforward mapping is performed on the effective profile change and thickness change of the roll gap caused by rolling force fluctuations, thereby obtaining the first roll gap compensation sequence caused by the rolling force change during the rolling process.

[0026] In some embodiments, determining multiple mill stiffness coefficients of the finishing mill during the rolling process can be achieved by the following steps: Obtain the preset wear model; Offline pressing method is used to obtain the foundation stiffness coefficient of each stand of the finishing mill. Multiple mill stiffness coefficients for the finishing mill during the rolling process were determined using all the basic stiffness coefficients and the wear model.

[0027] It should be noted that the wear model in this application is used to describe the attenuation of the mill stiffness coefficient due to the cumulative rolling tonnage during the working rolling process of each stand in the finishing mill; this model can adopt an exponential empirical formula: Where M(t) is the mill stiffness coefficient at the current moment, The basic stiffness coefficient is obtained by the offline pressing method, T is the cumulative rolling tonnage of the current stand, and α is the attenuation coefficient related to the stand type, roll material and cooling conditions, with a value range of 0.001 to 0.005. In actual implementation, the system reads the cumulative steel tonnage of each stand from the manufacturing execution system or process database, and substitutes the basic stiffness coefficient, attenuation coefficient and cumulative tonnage into the above model to calculate the actual mill stiffness coefficient of each stand at the current moment.

[0028] In specific implementation, the offline pressing method for each stand of the finishing mill to obtain the foundation stiffness coefficient of each stand can be achieved in the following way: First, under no-load conditions, the work rolls of each stand of the finishing mill are pressed against each other with different pressures, and the pressing screw positions and hydraulic cylinder pressure data of each stand of the finishing mill are recorded under different pressures. Then, all the pressing screw positions and hydraulic cylinder pressure data are linearly regressed to obtain the static foundation stiffness coefficient of each stand of the finishing mill. Other methods can also be used in other embodiments, which are not limited here.

[0029] In specific implementation, determining the multiple mill stiffness coefficients of the finishing mill unit during the rolling process using all the basic stiffness coefficients and the wear model can be achieved in the following way: For each stand of the finishing mill unit, an independent wear model is introduced. The basic stiffness coefficients of each stand and the cumulative rolling tonnage of each stand are input into the wear model as known parameters. The stiffness attenuation of each stand is calculated based on the wear model. Finally, the difference between each basic stiffness coefficient and the corresponding stiffness attenuation is taken as the mill stiffness coefficient of the stand of each finishing mill unit. The cumulative rolling tonnage of each stand can be obtained from the automatic feeding system of the mechanical manufacturing plant. Other methods can also be used in other embodiments, which are not limited here.

[0030] It should be noted that the mill stiffness coefficient in this application is a parameter value characterizing the ability of each stand of the finishing mill to resist elastic deformation during the rolling stage. It is used to describe the dynamic stiffness of each stand of the finishing mill in the actual mechanical state during operation, that is, the relationship between the increase in rolling force and the increase in elastic deformation. This facilitates the compensation for rolling force fluctuations in subsequent feedforward control. In particular, during the rolling stage of the hot strip mill, the rolling force fluctuation of the incoming slab leads to inconsistencies in the overall length and width of the finished strip, thereby reducing the metal yield. Therefore, for the strip shape problem caused by rolling force fluctuations, the slab is controlled by partitioning. The mill stiffness is no longer regarded as a constant value, but an independent, time-varying parameter model is established for each execution stand in the multi-stand system. This allows for differentiated feedforward compensation on each stand and ensures the stability of strip shape control at the system level. Secondly, a preset wear model can be established by performing statistical regression analysis on a large amount of historical production data of rolled strip.

[0031] In some embodiments, the effective profile and thickness changes of the roll gap caused by rolling force fluctuations are fed forward based on all mill stiffness coefficients and all rolling force variation trends, thereby obtaining the first roll gap compensation sequence caused by rolling force changes during the rolling process. This can be achieved through the following steps: Select one of the slab cutting units as the selected cutting unit; Based on the rolling force change and the corresponding mill stiffness coefficient of the selected slice unit from all rolling force change trends, determine the elastic deformation of the roll system of the selected slice unit under rolling force fluctuations. The elastic deformation of the roller system is mapped to the thickness change at the outlet of the selected slicing unit; Based on the thickness change, feedforward control is performed to offset the thickness change, and the first roll gap compensation amount of the selected slicing unit is obtained. Continue to determine the first roll gap compensation amount for the remaining slicing units; The set of all first roll gap compensation amounts is taken as the sequence of first roll gap compensation amounts caused by the change in rolling force during the rolling process.

[0032] In specific implementation, the elastic deformation of the roll system of the selected slice unit under rolling force fluctuation can be determined by the following method based on the rolling force change corresponding to the selected slice unit and the corresponding mill stiffness coefficient among all rolling force change trends: obtain the preset rolling force of the mill stand corresponding to the selected slice unit, and take the difference between the rolling force change of the selected slice unit and the preset rolling force as the rolling force deviation of the selected slice unit among all rolling force change trends. Then, substitute the above rolling force deviation and the mill stiffness coefficient of the stand of the finishing mill corresponding to the selected slice unit into the bounce equation to calculate the elastic deformation of the roll system caused by rolling force fluctuation of the selected slice unit. Other methods can also be used in other embodiments, which are not limited here.

[0033] It should be noted that the elastic deformation of the roll system in this application refers to the total deformation of the roll system of the finishing mill under the action of rolling force deviation. As a key intermediate variable connecting rolling force fluctuation and thickness change, this elastic deformation of the roll system transforms the thickness disturbance that cannot be directly measured into a calculable physical quantity, thereby quantifying the harmful deformation of the roll system caused by rolling force fluctuation, and providing a reliable quantitative basis for subsequent feedforward compensation.

[0034] In specific implementation, mapping the elastic deformation of the roll system to the thickness change at the exit of the selected strip unit can be achieved in the following way: the obtained elastic deformation of the roll system is directly used as the thickness change at the exit of the selected strip unit; where the thickness change describes the change in thickness of the slab caused by rolling force fluctuations during the rolling stage; the elastic deformation of the roll system is calculated based on the bounce equation in rolling theory combined with rolling force and mill stiffness coefficient, so that the elastic deformation of the roll system characterizes the elastic deformation of the entire roll system under the action of rolling force for the selected strip unit. This deformation will cause an equal change in the unloaded roll gap, which is directly reflected in the thickness of the exit strip. Therefore, the elastic deformation of the roll system is numerically equal to the thickness change at the exit that needs to be compensated; other methods can also be used in other embodiments, which are not limited here.

[0035] In specific implementation, the first roll gap compensation amount for the selected slicing unit is obtained by feedforward control based on the thickness change to offset the thickness change. This can be achieved as follows: if the exit thickness change of the selected slicing unit obtained through feedforward mapping is Δh, the first roll gap compensation amount is S1. In order to eliminate the thickness deviation caused by rolling force fluctuations before it actually occurs, the control system can, based on the linear relationship between the roll gap adjustment amount and the exit thickness change amount in the rolling bounce principle, take the opposite of Δh and directly use it as the roll gap adjustment amount corresponding to the slicing unit, i.e., the first roll gap compensation amount S1. =–Δh; Then, the first roll gap compensation amount is multiplied by the preset hydraulic cylinder displacement conversion coefficient to convert it into the control current increment or voltage increment of the hydraulic servo valve, and an advance time offset related to the rolling speed is added, where the offset is equal to the transmission time of the slicing unit from the measurement point to the roll gap of the stand, thereby generating a single-cycle feedforward control signal with timestamp and amplitude; this signal is superimposed on the set value of the hydraulic cylinder position controller before or when the corresponding slicing unit is about to enter the finishing mill stand, driving the servo valve to adjust the displacement of the hydraulic cylinder piston, so that the working roll gap decreases or increases by a value equal to S1 in advance, thereby accurately offsetting the expected thickness change caused by the rolling force fluctuation; where the preset hydraulic cylinder displacement conversion coefficient is usually 0.01 to 0.1 The specific value (mm / mA) depends on the servo valve flow rate, cylinder diameter, and oil source pressure. The purpose of feedforward control is to eliminate the disturbance caused by the thickness variation of the rolled sheet before it affects the final strip output. Therefore, it is necessary to inject a control quantity into the mill roll gap that is equal in magnitude but opposite in direction to the disturbance effect. That is, the thickness variation is taken as the inverse number as the first roll gap compensation quantity of the selected slicing unit. Other methods can be used to achieve this in other embodiments, which are not limited here.

[0036] It should be noted that the feedforward mapping in this application refers to a mathematical transformation relationship in which the elastic deformation of the roll system caused by rolling force fluctuations is converted into the exit thickness change through the bounce equation based on the predetermined mill stiffness coefficient and the predicted rolling force change trend along the length of the slab, and further calculated into the compensation amount for adjusting the working roll gap in advance. The feedforward mapping directly calculates the compensation value to be applied to the roll gap in advance based on the changes in process parameters on the inlet side, thereby achieving feedforward suppression of rolling force disturbances. The entire mapping process can generate the corresponding roll gap adjustment command in advance before the rolling force fluctuations affect the exit thickness, thereby achieving pre-compensation for thickness deviation.

[0037] It should be noted that the first roll gap compensation sequence in this application refers to a set sequence formed by arranging the first roll gap compensation amounts of all slice units in the order of their corresponding slab length direction positions. This first roll gap compensation sequence serves as the final output of the feedforward control calculation, providing a complete compensation data basis for the subsequent generation of hydraulic system control commands. Specifically, the slab is divided into multiple slice units, and the continuous slab is discretized into independent control units. This allows for the generation of precise compensation amounts for each slice unit to address the slab shape issues caused by fluctuations in the parameters of the incoming material and the rolling force during the high-speed and stable rolling stage of the hot strip mill. This achieves a shift from traditional global average control to local precise compensation. This discretization method based on slice units enables the control system to accurately track temperature unevenness and rolling force fluctuations along the slab length direction, thereby achieving precise compensation and control of the strip thickness consistency throughout its entire length.

[0038] In step 104, the actual thickness value of the rolled plate at the exit of the last stand of the finishing mill is monitored during the rolling process, and the second roll gap compensation sequence is determined based on the actual thickness value and the target thickness value.

[0039] In specific implementation, the actual thickness value of the rolled plate at the exit of the last stand of the finishing mill during the rolling process can be achieved by the following method: continuously measuring the thickness value of the rolled plate at the exit of the last stand of the finishing mill during the rolling process using a thickness gauge (such as an X-ray thickness gauge) installed at the exit of the last stand of the finishing mill to obtain the actual thickness value of the rolled plate at the exit of the last stand of the finishing mill; other methods can also be used in other embodiments, which are not limited here.

[0040] In some embodiments, determining the second roll gap compensation sequence based on the actual thickness value and the target thickness value can be achieved using the following steps: The actual thickness value and the target thickness value are compared to obtain the thickness deviation of the rolled slab at the current moment; Feedback control is performed on the thickness deviation to obtain the second roll gap compensation amount of the slab during the rolling process; The actual thickness of the rolled plate at the exit of the last stand of the finishing mill is continuously monitored during the rolling process, and the second roll gap compensation amount is obtained at each sampling time during the monitoring process. Arrange all the second roll gap compensation amounts in the order of sampling time to obtain the second roll gap compensation amount sequence.

[0041] In specific implementation, comparing the actual thickness value and the target thickness value to obtain the thickness deviation of the slab at the current moment can be achieved in the following way: the difference between the actual thickness value and the target thickness value is used as the thickness deviation of the slab at the current moment during the rolling process; feedback control is performed on the thickness deviation to obtain the second roll gap compensation amount of the slab during the rolling process, which can be achieved in the following way: the second roll gap compensation amount is input into the feedback control algorithm (e.g., PID algorithm) to calculate the second roll gap compensation amount of the slab at the current moment during the rolling process; other methods can also be used in other embodiments, which are not limited here.

[0042] It should be noted that the second roll gap compensation sequence in this application is a compensation sequence formed by arranging the roll gap adjustment amounts at each moment in chronological order based on the deviation between the measured value and the target value of the thickness at the exit of the finishing mill, calculated by the feedback control algorithm. This sequence is used to eliminate residual thickness deviations and random disturbances caused by rolling force fluctuations that cannot be fully compensated by the feedforward control. The second roll gap compensation sequence complements the feedforward control of the slice method mentioned above, constructing a complete feedforward-feedback composite control system. Real-time feedback enhances the anti-interference capability of the control system, effectively solving the problem of insufficient thickness control accuracy caused by unmodeled disturbances and model mismatch in the high-speed stable rolling stage of the hot strip finishing mill, and improving the thickness uniformity of the strip along its entire length.

[0043] In step 105, the dynamic adjustment command of the working roll gap of the finishing mill is determined according to the first roll gap compensation sequence and the second roll gap compensation sequence, and then the plate thickness is controlled based on the dynamic adjustment command.

[0044] In some embodiments, determining the dynamic adjustment command for the work roll gap of the finishing mill based on the first roll gap compensation sequence and the second roll gap compensation sequence can be achieved by the following steps: Align the first roll gap compensation sequence and the second roll gap compensation sequence according to the length direction of the rolled slab. Multiple composite compensation amounts for the finishing mill are determined based on the aligned first roll gap compensation amount sequence and the second roll gap compensation amount sequence. All composite compensation values ​​are converted into dynamic adjustment commands for the working roll gap of the finishing mill.

[0045] In specific implementation, aligning the first roll gap compensation sequence and the second roll gap compensation sequence along the length direction of the rolled slab can be achieved in the following way: taking each slice unit as a reference, aligning the first roll gap compensation amount and the second roll gap compensation amount corresponding to the same slice unit position using an interpolation algorithm; determining multiple composite compensation amounts of the finishing mill based on the aligned first roll gap compensation sequence and second roll gap compensation sequence can be achieved in the following way: vectorically superimposing the first roll gap compensation amount and the second roll gap compensation amount at each slice unit position, and using the superimposed result as the corresponding slice unit. The composite compensation amount is used to obtain multiple composite compensation amounts for the finishing mill. Converting all composite compensation amounts into dynamic adjustment commands for the working roll gap of the finishing mill can be achieved in the following way: converting all composite compensation amounts into hydraulic cylinder displacement amounts using a displacement conversion coefficient, adding system response delay compensation, and then setting the command output speed to be synchronized with the rolling speed (set to 20ms / command in this application), finally obtaining a timestamped command sequence, which is then used as the dynamic adjustment command for the working roll gap of the finishing mill. Other methods can also be used in other embodiments, which are not limited here.

[0046] It should be noted that the composite compensation amount in this application refers to the comprehensive compensation value obtained by vector superposition of the first roll gap compensation amount and the second roll gap compensation amount according to a set weight at the same slice unit position; data alignment refers to the data processing process of unifying the first roll gap compensation amount sequence and the second roll gap compensation amount sequence obtained based on different sampling periods and control periods into the same time-position coordinate system through an interpolation algorithm; the dynamic adjustment command of the roll gap refers to the set of digital control signals containing time series and displacement amount generated by fusing feedforward and feedback compensation amounts. This dynamic adjustment command converts the calculated compensation amount into a precise action command that the hydraulic system can execute, thereby connecting the continuous The system connects the control system and the actuator to achieve precise programmed control of the roll gap of the finishing mill. Typically, the weights for both the first and second roll gap compensation amounts are set to 1. If overshoot or oscillation occurs during actual rolling, the on-site engineer can fine-tune the weights based on the standard deviation of the measured fluctuation in the finishing mill's exit thickness. For example, when feedback compensation causes overshoot, the feedback weight is lowered to 0.9; when drastic fluctuations in incoming material parameters increase the feedforward prediction error, the feedforward weight is lowered to 0.8–0.95. The specific weight values ​​are determined through offline simulation or online step tests, with a typical range of 0.8–1.2.

[0047] In some embodiments, controlling the thickness of the rolled plate based on the dynamic adjustment command can be achieved by the following steps: The dynamic adjustment command is sent to the hydraulic control system of each stand of the finishing mill; The hydraulic control system of each stand of the finishing mill controls the opening of the work roll gap by dynamically adjusting the servo valve driven by the servo valve to regulate the hydraulic cylinder pressure, thereby controlling the thickness of the rolled plate at the exit.

[0048] It should be noted that the reference Figure 3 As shown, this figure is an engineering implementation example of dynamically adjusting the control of the plate thickness using commands in some embodiments of this application. The hydraulic control system of each stand of the finishing mill receives dynamic adjustment commands from the process computer. These commands are sent as setpoints to the comparison unit of the servo controller, where they are compared with the actual position feedback values ​​of the hydraulic cylinders from the displacement sensors to generate a deviation signal. After calculation by the feedback control regulator, a control current is output to drive the opening of the servo valve, adjusting the flow rate and direction of the oil entering the hydraulic cylinder, thereby precisely controlling the piston displacement of the hydraulic cylinder. Finally, the work rolls are moved through the roller system, adjusting the work roll gap opening to control the plate thickness.

[0049] In another aspect, in some embodiments, this application provides an automatic feeding control system for mechanical manufacturing, which includes a plate thickness control unit for a hot continuous rolling mill. (Refer to...) Figure 4 The figure is a schematic diagram of the structure of a plate thickness control unit according to some embodiments of this application. The plate thickness control unit includes an acquisition module, a processing module, and an execution module, which are described below: The acquisition module in this application is mainly used to acquire the real-time process parameters of the slab to be entered into the finishing mill stand; The processing module in this application is used to determine the changing trends of multiple rolling forces along the length direction of the slab during the finishing rolling process based on the real-time process parameters. It should be noted that the processing module in this application is also used to determine multiple mill stiffness coefficients of the finishing mill during the rolling process, and to perform feedforward mapping on the effective profile change and thickness change of the roll gap caused by the rolling force fluctuation based on all mill stiffness coefficients and all rolling force change trends, thereby obtaining the first roll gap compensation amount sequence caused by the rolling force change during the rolling process. In addition, it should be noted that the processing module in this application is also used to monitor the actual thickness value of the rolled plate at the exit of the last stand of the finishing mill during the rolling process, and to determine the second roll gap compensation sequence based on the actual thickness value and the target thickness value. The execution module in this application is mainly used to determine the dynamic adjustment command of the working roll gap of the finishing mill based on the first roll gap compensation amount sequence and the second roll gap compensation amount sequence, and then control the plate thickness based on the dynamic adjustment command.

[0050] In addition, this application also provides a computer device, which includes a memory and a processor. The memory stores code, and the processor is configured to acquire the code and execute the above-described hot strip mill plate thickness control method.

[0051] In some embodiments, reference Figure 5 The figure is a schematic diagram of the structure of a computer device for implementing a hot strip mill finishing unit's plate thickness control method according to some embodiments of this application. The hot strip mill finishing unit's plate thickness control method in the above embodiments can be achieved through... Figure 5 The computer device shown is used to implement this, and the computer device includes at least one processor, a communication bus, a memory, and at least one communication interface.

[0052] A processor can be a general-purpose central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0053] A communication bus can be used to transmit information between the aforementioned components.

[0054] The memory can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, universal optical discs, Blu-ray discs, etc.), magnetic disks or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to these. The memory can exist independently and be connected to the processor via a communication bus. The memory can also be integrated with the processor.

[0055] The memory stores program code for executing the scheme of this application, and its execution is controlled by a processor. The processor executes the program code stored in the memory. The program code may include one or more software modules. The method used in the above embodiments can be implemented by a processor and one or more software modules in the program code in the memory.

[0056] A communication interface is a device that uses any transceiver or similar device to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0057] In a specific implementation, as one example, a computer device may include multiple processors, each of which may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. Here, a processor may refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0058] The aforementioned computer device can be a general-purpose computer device or a special-purpose computer device. In specific implementations, the computer device can be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. This application does not limit the type of computer device.

[0059] In addition, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for controlling the plate thickness of a hot strip mill finishing unit.

[0060] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0061] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method of controlling the thickness of a rolled plate in a hot continuous rolling finishing mill train, for controlling the thickness of the rolled plate by a mechanical manufacturing feed automatic control system, wherein, The method of pre-setting a target thickness value at the exit of a finishing mill is characterized by comprising the following steps: Obtain the real-time process parameters of the slab to be entered the finishing mill stand; The trends of multiple rolling forces along the length of the slab during the finishing rolling process are determined based on the real-time process parameters. Multiple mill stiffness coefficients are determined during the rolling process of the finishing mill. Based on all mill stiffness coefficients and all rolling force variation trends, feedforward mapping is performed on the effective profile and thickness changes of the roll gap caused by rolling force fluctuations, thereby obtaining the first roll gap compensation sequence caused by rolling force changes during the rolling process. Monitor the actual thickness of the rolled plate at the exit of the last stand of the finishing mill during the rolling process, and determine the second roll gap compensation sequence based on the actual thickness and the target thickness. The dynamic adjustment command for the working roll gap of the finishing mill is determined based on the first roll gap compensation sequence and the second roll gap compensation sequence, and then the plate thickness is controlled based on the dynamic adjustment command.

2. The method of claim 1, wherein, The specific trends of multiple rolling force changes along the length direction of the slab during the finishing rolling process, determined based on the real-time process parameters, include: The rolled slab is divided into multiple slicing units along its length, and one slicing unit is selected as the selected slicing unit. The real-time process parameters are combined with a preset rolling force mathematical model to determine the rolling force variation along the length direction of the selected slice unit during the finishing rolling process; Continue to determine the rolling force variation of the remaining slicing units; All changes in rolling force are taken as the trend of rolling force change along the length of the slab during the finishing rolling process.

3. The method of claim 1, wherein, Determining the multiple mill stiffness coefficients of the finishing mill during the rolling process specifically includes: Obtain the preset wear model; Offline pressing method is used to obtain the foundation stiffness coefficient of each stand of the finishing mill. Multiple mill stiffness coefficients for the finishing mill during the rolling process were determined using all the basic stiffness coefficients and the wear model.

4. The method as described in claim 1, characterized in that, Based on all mill stiffness coefficients and all rolling force variation trends, a feedforward mapping is performed on the effective profile and thickness changes of the roll gap caused by rolling force fluctuations. This yields the sequence of first roll gap compensation amounts caused by rolling force variations during the rolling process, specifically including: Select one of the slab cutting units as the selected cutting unit; Based on the rolling force change and the corresponding mill stiffness coefficient of the selected slice unit from all rolling force change trends, determine the elastic deformation of the roll system of the selected slice unit under rolling force fluctuations. The elastic deformation of the roller system is mapped to the thickness change at the outlet of the selected slicing unit; Based on the thickness change, feedforward control is performed to offset the thickness change, and the first roll gap compensation amount of the selected slicing unit is obtained. Continue to determine the first roll gap compensation amount for the remaining slicing units; The set of all first roll gap compensation amounts is taken as the sequence of first roll gap compensation amounts caused by the change in rolling force during the rolling process.

5. The method of claim 1, wherein, Determining the second roll gap compensation sequence based on the actual thickness value and the target thickness value specifically includes: The actual thickness value and the target thickness value are compared to obtain the thickness deviation of the rolled slab at the current moment; Feedback control is performed on the thickness deviation to obtain the second roll gap compensation amount of the slab during the rolling process; The actual thickness of the rolled plate at the exit of the last stand of the finishing mill is continuously monitored during the rolling process, and the second roll gap compensation amount is obtained at each sampling time during the monitoring process. Arrange all the second roll gap compensation amounts in the order of sampling time to obtain the second roll gap compensation amount sequence.

6. The method of claim 1, wherein, The dynamic adjustment instructions for the work roll gap of the finishing mill, determined based on the first roll gap compensation sequence and the second roll gap compensation sequence, specifically include: Align the first roll gap compensation sequence and the second roll gap compensation sequence according to the length direction of the rolled slab. Multiple composite compensation amounts for the finishing mill are determined based on the aligned first roll gap compensation amount sequence and the second roll gap compensation amount sequence. All composite compensation values ​​are converted into dynamic adjustment commands for the working roll gap of the finishing mill.

7. The method of claim 1, wherein, Controlling the thickness of the rolled plate based on the aforementioned dynamic adjustment command specifically includes: The dynamic adjustment command is sent to the hydraulic control system of each stand of the finishing mill; The hydraulic control system of each stand of the finishing mill controls the opening of the work roll gap by dynamically adjusting the servo valve driven by the servo valve to regulate the hydraulic cylinder pressure, thereby controlling the thickness of the rolled plate at the exit.

8. The method of claim 1, wherein, The real-time process parameters of the slab to be rolled into the finishing mill stand are obtained through the data acquisition module of the automatic feeding control system for mechanical manufacturing.

9. The method of claim 1, wherein, The actual thickness of the rolled plate at the exit of the last stand of the finishing mill is monitored using a thickness gauge during the rolling process.

10. A mechanical manufacturing feed automatic control system including a plate thickness control unit of a hot continuous rolling finishing rolling mill train, characterized by, The plate thickness control unit includes: The acquisition module is used to acquire the real-time process parameters of the slab to be entered into the finishing mill stand; The processing module is used to determine the changing trends of multiple rolling forces along the length direction of the slab during the finishing rolling process based on the real-time process parameters. The processing module is also used to determine multiple mill stiffness coefficients of the finishing mill during the rolling process, and to perform feedforward mapping on the effective profile change and thickness change of the roll gap caused by the rolling force fluctuation based on all mill stiffness coefficients and all rolling force change trends, thereby obtaining the first roll gap compensation amount sequence caused by the rolling force change during the rolling process. The processing module is also used to monitor the actual thickness value of the rolled plate at the exit of the last stand of the finishing mill during the rolling process, and to determine the second roll gap compensation sequence based on the actual thickness value and the target thickness value. The execution module is used to determine the dynamic adjustment command of the working roll gap of the finishing mill based on the first roll gap compensation sequence and the second roll gap compensation sequence, and then control the plate thickness based on the dynamic adjustment command.

Images