A method, storage medium, and program product for controlling the flow rate and thickness of a cold rolling mill.

Abstract

This invention proposes a high-precision method for controlling the thickness per second of a cold continuous rolling mill. First, the inlet and outlet flow rate difference is integrated to correct the strip inlet speed, and the strip outlet thickness difference is pre-calculated using the flow rate equation. Next, the speed difference between the inlet tension roll and the first stand is compensated, and the pre-calculated thickness difference is corrected using a monitored thickness difference. Finally, an adaptive PI controller is used to calculate the flow rate thickness control quantity. This method compensates for errors in the inlet and outlet flow rates, the speed difference between the inlet tension roll and the first stand, and uses a monitored thickness difference correction, thereby obtaining a high-precision outlet thickness difference value. The use of adaptive proportional and integral parameters that follow the speed and adjust the response time of the regulating mechanism to adapt to different operating conditions ensures good control performance throughout the rolling process, significantly improving the overall accuracy of the flow rate AGC.

Description

Technical Field

[0001] This invention relates to the field of steel rolling control technology, specifically to a high-precision method for controlling the flow rate and thickness of a cold continuous rolling mill, as well as a storage medium and program product. Background Technology

[0002] The thickness control system of a cold rolling mill generally includes three types of thickness control (Automatic Gauge Control): feedforward, flow rate per second (AGC), and monitoring. Flow rate AGC and monitoring AGC are both feedback control methods. Flow rate AGC is based on the constant flow rate per second in the deformation zone. This law means that the mass flow of metal before and after the stand is constant. Since the strip width is basically the same before and after the stand, the strip speed and thickness maintain a strict proportional relationship before and after the stand, i.e.:

[0003]

[0004] In the formula -Strip inlet speed; -Strip exit speed; - Strip entry thickness; - Strip exit thickness.

[0005] Because the use of laser velocimeters can obtain the inlet and outlet speeds of the deformation zone with high precision, and with the addition of a pre-mounted thickness gauge, the strip outlet thickness can be calculated without lag and then feedback control can be performed. Thus, the use of second-flow AGC can significantly improve the performance of thickness control.

[0006] Because the outlet thickness gauge is some distance from the mill roll gap, its measurement of the outlet thickness is delayed, making it unsuitable for direct feedback control. Monitored AGC typically uses the average measured outlet thickness for control, employing an integral controller to compensate for long-term trends in the outlet thickness difference. The monitored thickness difference can be used to correct the pre-calculated outlet thickness for the flow rate per second, further improving the accuracy of the flow rate per second outlet thickness difference.

[0007] Currently, the practical industrial method for second-flow AGC generally calculates the roll gap adjustment amount through a proportional-integral (PI) controller. As is well known, the selection of proportional-integral parameters has a great impact on the control performance of the PI controller, and the operating conditions are constantly changing during the rolling process, making it difficult to maintain good control performance using fixed proportional-integral parameters. Summary of the Invention

[0008] In view of the technical defects and drawbacks existing in the prior art, embodiments of the present invention provide a method, storage medium, and program for controlling the flow rate and thickness of a cold continuous rolling mill, which overcomes or at least partially solves the above problems. The specific solution is as follows:

[0009] As a first aspect of the present invention, a method for controlling the thickness per second of a cold continuous rolling mill is provided, comprising the following steps:

[0010] S1. The flow rate per second at the inlet thickness gauge is synchronously transmitted to the outlet thickness gauge, the difference between the inlet and outlet flow rates is integrated to correct the strip inlet speed, and the strip outlet thickness difference at the roll gap is pre-calculated using the flow rate per second equation.

[0011] S2. Compensate for the speed difference between the inlet tension roller and the first frame, and use the monitoring of the outlet thickness difference to correct the pre-calculated strip outlet thickness difference, and obtain the total outlet thickness difference per second of flow rate;

[0012] S3. The parameters of the proportional-integral (PI) controller are adaptively adjusted based on the outlet speed and the response time of the regulating mechanism, and the thickness control amount of the flow rate per second is calculated using the PI controller with adaptive parameters based on the total outlet thickness difference of the flow rate per second.

[0013] This invention significantly improves thickness control accuracy through multi-step coordination of synchronous transmission of flow rate per second, integral correction of inlet and outlet flow rate difference, speed difference compensation, thickness difference monitoring correction, and adaptive PI control; it solves the problem of performance degradation of traditional fixed PI parameters under varying operating conditions by adjusting PI parameters in real time based on outlet speed and mechanism response time; and it provides a reliable basis for subsequent compensation and correction by pre-calculating the roll gap outlet thickness difference through the flow rate per second equation.

[0014] Furthermore, the step S1 of synchronously transmitting the flow rate per second at the inlet thickness gauge to the outlet thickness gauge includes:

[0015] The actual value H of the strip inlet thickness measured by the inlet thickness gauge is transmitted using the first synchronous transmission model TPM1. en,act Multiply by the actual inlet velocity V en,act The obtained inlet flow rate is delayed and transmitted to the mill roll gap; then, it is transmitted via the second synchronous transmission model TPM2 with the actual strip exit speed V. ex,act Using this as a reference, the inlet flow rate per second at the mill roll gap is synchronously transmitted to the outlet thickness gauge to obtain the inlet flow rate M synchronously transmitted to the outlet thickness gauge. en,Exthg The synchronous transmission model precisely delays the input velocity when it changes.

[0016] This invention employs a dual synchronous transmission model (TPM1+TPM2), which can still accurately transmit the inlet flow rate per second to the outlet thickness gauge with a delay when the inlet velocity changes, eliminating the synchronization error of the traditional fixed delay model and improving the reliability of the inlet flow rate per second data.

[0017] Furthermore, the integral inlet and outlet flow rate difference in S1 to correct the strip inlet velocity includes:

[0018] The actual value of the strip exit velocity V is processed using a first-order hysteresis element PT11.ex,act To compensate for measurement delay, multiply by the exit thickness setting h. ex,sp Obtain the outgoing flow rate per second; compare the outgoing flow rate per second with the synchronously transmitted incoming flow rate per second M. en,Exthg The inlet and outlet flow rate difference is obtained by comparison; the inlet velocity correction factor is obtained by integrating the inlet and outlet flow rate difference, and the actual value of the strip inlet velocity V is corrected accordingly. en,act To correct the inlet velocity V en,Md The specific formula is as follows:

[0019]

[0020] Where INT stands for integrator, and the discrete integrator algorithm is as follows:

[0021]

[0022] in, and The integrator outputs for the current and previous time steps are T, respectively. A T is the PLC sampling time. N Let I(k) be the integration time parameter, and I(k) be the integrator input value; the PT11 discrete algorithm is as follows;

[0023]

[0024] In the formula, and These are the output values ​​of the current time step and the previous time step of the PT11 stage, respectively; The time constant of the PT11 stage; This is the input value for the PT11 stage.

[0025] This invention uses PT1 filtering to process the outlet velocity and integrates the outlet flow rate difference per second to correct the actual inlet velocity value, thus solving the flow rate deviation caused by measurement delay and improving the accuracy of pre-calculated thickness difference. The discrete integration algorithm combined with the hysteresis element effectively suppresses noise interference, ensures the stability of the correction factor, and enhances anti-interference capability.

[0026] Furthermore, the pre-calculation of the strip exit thickness difference at the roll gap using the flow rate equation in S1 includes:

[0027] Using the corrected inlet velocity V en,Md The inlet thickness difference ΔH is handled by two first-order hysteresis circuits PT12 and PT13. en =H en,act- H en,sp Based on the speed signal and the flow rate equation, the strip thickness difference Δh at the roll gap is pre-calculated. gap,P The specific formula is as follows:

[0028]

[0029] In the formula, This represents the strip thickness difference at the roll gap exit, where... Used to compensate for the measurement delay of the inlet thickness gauge. Used to compensate for the delay in inlet velocity measurement Set the entry thickness value for the strip steel.

[0030] This invention is achieved through (Entrance thickness gauge delay) The combined processing of (entry speed delay) and TPM1 (entry thickness difference synchronization) accurately compensates for the measurement delay in each stage, improves the accuracy of the pre-calculation of the thickness difference at the roll gap exit, and enhances the adaptability of the model by dividing the entry thickness difference by the set value to make it dimensionless.

[0031] Furthermore, the compensation for the speed difference between the inlet tension roller and the first frame in S2 includes:

[0032] When the automatic thickness control AGC for the first rack is activated, the speed difference compensation ΔV is calculated. C The formula is:

[0033]

[0034] In the formula, and These are the actual speed values ​​of the first frame and the inlet tension roller, respectively. and These are the speed settings for the first frame and the inlet tension roller, respectively.

[0035] This invention addresses the difference in transmission response between the inlet tension roller and the first frame by calculating the speed difference compensation amount ΔVc, thereby avoiding false thickness difference signals caused by deviations between the speed setpoint and the actual value, and improving the stability of thickness difference control.

[0036] Furthermore, the correction of the pre-calculated strip exit thickness difference using the monitored exit thickness difference in S2 includes:

[0037] The adaptive gain G is calculated based on the exit speed, exit thickness difference, and acceleration / deceleration state. C :

[0038]

[0039] In the formula, This is the adaptive gain value for the thickness difference at the outlet; This is the export speed factor, which decreases as the export speed increases; This is the export thickness difference factor, which increases as the export thickness difference increases; This is the acceleration / deceleration factor; it takes a larger value when the vehicle is accelerating or decelerating, and 1.0 when the speed is steady.

[0040] The thickness difference Δh measured by the thickness gauge at the exit ex Multiply by G C The monitored thickness difference is obtained, and the average value Δh is obtained by averaging it over the monitored length using the Dynamic Averaging (MAV) module. Mon ;

[0041]

[0042] Combined and ΔV C Calculate the total outlet thickness difference Δh for the flow rate per second. Mfc ;

[0043] .

[0044] This invention dynamically optimizes the monitoring thickness difference weight by using the outlet speed factor Vc (speed ↑ → gain ↓), outlet thickness difference factor Hc (thickness difference ↑ → gain ↑), and acceleration / deceleration factor Ac (gain ↑ during acceleration / deceleration) to avoid over-adjustment or under-adjustment. The MAV module calculates the average over the monitoring length to effectively filter out high-frequency noise and extract trend-based thickness difference compensation values. By combining the pre-calculated thickness difference, speed difference compensation, and monitoring thickness difference, a high-precision total outlet thickness difference per second of flow rate is obtained.

[0045] Furthermore, the parameters of the PI controller in S3, which are adaptively adjusted based on the outlet speed and the response time of the regulating mechanism, include:

[0046] The proportional coefficient K is calculated based on the export speed and the response time of the regulating mechanism. P,Mfc :

[0047]

[0048] In the formula, The flow rate control length is per second, set according to the actual site conditions, V ex,act This represents the actual strip exit speed. To adjust the response time of the mechanism;

[0049] The integral time parameter T is calculated based on the export speed and the response time of the regulating mechanism. I,Mfc ;

[0050] .

[0051] Furthermore, the PI controller using adaptive parameters in S3 calculates the flow rate thickness control quantity based on the total outlet thickness difference of the flow rate per second, including:

[0052] The proportional-integral controller is used to calculate the inlet tension roller speed adjustment ΔV based on the total outlet thickness difference per second flow rate. 0,MFC and the first frame roll gap adjustment amount ΔS1,MFC The formula is:

[0053]

[0054]

[0055] Where, Δh Mfc The total outlet thickness difference per second is h. ex,sp G sets the export thickness value. V and G S These are the speed adjustment gain and the roll gap adjustment gain, respectively, V 0,s p is the setpoint for the inlet tension roller speed, PI represents a proportional-integral controller, and C S C is the mill stiffness coefficient. M The strip's plasticity coefficient is used; the discrete PI controller algorithm is as follows:

[0056]

[0057] In the formula, and These are the output values ​​of the PI controller at the current time and the previous time, respectively; and These represent the difference in total outlet thickness per second between the current time and the previous time, respectively, T. A This refers to the PLC sampling time.

[0058] The calculated inlet tension roller speed adjustment is sent to the inlet tension roller drive controller, and the first frame roll gap adjustment is sent to the first frame hydraulic pressing controller. By executing the control of the second flow rate AGC, this optimized second flow rate thickness control method can be realized.

[0059] Using the methods described above, the thickness difference at the exit of the first stand is further corrected, and the parameters of the PI controller can adaptively change with the operating conditions, thus ensuring that the flow rate AGC maintains good control performance throughout the rolling process. The flow rate control method on other stands is similar.

[0060] As a second aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a computer, causes the computer to perform the cold rolling mill second flow rate thickness control method as described above.

[0061] As a third aspect of the present invention, a computer program product is provided, comprising computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code, wherein when the computer-readable code is run in a processor of an electronic device, the processor in the electronic device executes the cold rolling mill second flow rate thickness control method as described above.

[0062] The beneficial effects of this invention are as follows:

[0063] 1. This invention takes into account the error of the inlet and outlet flow rate per second and the speed difference between the inlet tension roller and the frame, and uses the monitoring thickness difference to finely correct the pre-calculated outlet thickness difference of the flow rate per second, thereby obtaining a high-precision outlet thickness difference value.

[0064] 2. This invention uses an adaptive parameter PI controller to calculate the speed and roll gap adjustment, which can achieve good control effect under various working conditions and improve the overall accuracy of the flow rate thickness control. Attached Figure Description

[0065] Figure 1 A schematic flowchart of a method for controlling the flow rate and thickness of a cold continuous rolling mill, provided in an embodiment of the present invention;

[0066] Figure 2 This is a schematic diagram of a thickness control system and its main detection instruments for a five-stand cold rolling mill, provided as an embodiment of the present invention. Detailed Implementation

[0067] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0068] To enable those skilled in the art to better understand the technical solutions of the present invention, exemplary embodiments of the present invention are described below in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to aid understanding. These should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description.

[0069] Where there is no conflict, the various embodiments of the present invention and the features thereof may be combined with each other.

[0070] As used herein, the term “and / or” includes any and all combinations of one or more related enumerated entries.

[0071] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when the terms “comprising” and / or “made of” are used in this specification, the presence of the stated feature, integral, step, operation, element, and / or component is specified, but the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof is not excluded. Terms such as “connected” or “linked” are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect.

[0072] Unless otherwise specified, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art and the invention, and will not be interpreted as having an idealized or overly formal meaning unless expressly so defined herein.

[0073] In the technical solution of this invention, the collection, storage, use, processing, transmission, provision, and disclosure of user personal information all comply with relevant laws and regulations and do not violate public order and good morals. The use of user data in this technical solution follows relevant national laws and regulations (e.g., the "Information Security Technology - Personal Information Security Specification"). For example: appropriate measures are taken for personal information access control; restrictions are imposed on the display of personal information; the purpose of using personal information does not exceed the scope of direct or reasonable association; and explicit identity targeting is eliminated when using personal information to avoid precisely locating a specific individual.

[0074] To address at least one of the technical problems existing in the aforementioned related technologies, the present invention provides a high-precision method for controlling the flow rate and thickness of a cold continuous rolling mill. Figure 1 This is a flowchart illustrating a preferred embodiment of a method for controlling the flow rate and thickness of a cold continuous rolling mill, as provided in this invention.

[0075] In this embodiment, the method includes the following steps:

[0076] Step S1: The flow rate per second at the inlet thickness gauge is synchronously transmitted to the outlet thickness gauge, the difference between the inlet and outlet flow rates is integrated to correct the strip inlet speed, and the strip outlet thickness difference at the roll gap is pre-calculated using the flow rate per second equation.

[0077] Step S2: Compensate for the speed difference between the inlet tension roller and the first frame, and use the monitored outlet thickness difference to correct the strip outlet thickness difference pre-calculated in S1, so as to obtain the total outlet thickness difference per second of flow rate.

[0078] Step S3: Based on the outlet speed and the response time of the regulating mechanism, the parameters of the proportional-integral (PI) controller are adaptively adjusted, and the PI controller with adaptive parameters is used to calculate the AGC thickness control amount of the flow rate per second based on the total outlet thickness difference of the flow rate per second.

[0079] This invention significantly improves thickness control accuracy through multi-step coordination of synchronous transmission of flow rate per second, integral correction of inlet and outlet flow rate difference, speed difference compensation, thickness difference monitoring correction, and adaptive PI control; it solves the problem of performance degradation of traditional fixed PI parameters under varying operating conditions by adjusting PI parameters in real time based on outlet speed and mechanism response time; and it provides a reliable basis for subsequent compensation and correction by pre-calculating the roll gap outlet thickness difference through the flow rate per second equation.

[0080] In some embodiments, step S1 specifically includes:

[0081] S101, synchronously transmits the flow rate per second at the inlet thickness gauge to the outlet thickness gauge, including;

[0082] The inlet flow rate is obtained by multiplying the strip inlet thickness measured at the first stand inlet thickness gauge by the actual inlet speed. This flow rate is then transmitted to the mill roll gap via a delay using the first synchronous transmission model, TPM1. Since the delay time varies with changes in the strip inlet speed, a synchronous transmission model is used to perform the delay function. This model can accurately transmit the tracked strip inlet flow rate from the inlet thickness gauge to the mill roll gap even with arbitrary changes in the inlet speed. The flow rate is then synchronously transmitted to the outlet thickness gauge via the second synchronous transmission model, TPM2, with the synchronous transmission speed being the strip outlet speed. The inlet flow rate transmitted synchronously to the outlet thickness gauge is then calculated as follows:

[0083]

[0084] In the formula, To synchronously transmit the inlet flow rate per second to the outlet thickness gauge, This is the actual value of the strip entry thickness measured by the entry thickness gauge. This represents the actual value of the strip inlet velocity.

[0085] S102, Integrating the inlet and outlet flow rate difference to correct the strip inlet velocity, including;

[0086] The first-order hysteresis loop PT11 is used to process the exit velocity to compensate for the exit velocity measurement delay. Multiplying this by the exit thickness setpoint yields the exit flow rate per second. This flow rate is compared with the inlet flow rate per second synchronously transmitted to the exit thickness gauge to obtain the inlet-outlet flow rate difference. Integrating this difference yields the inlet velocity correction factor, used to correct the strip's inlet velocity.

[0087]

[0088] In the formula, This is the corrected strip inlet velocity. This represents the actual strip exit speed. Set the thickness of the strip at the exit. Representing an integrator, the discrete integrator algorithm is as follows:

[0089]

[0090] In the formula, and These are the integrator output values ​​for the current time step and the previous time step, respectively. The sampling time of the PLC controller. For the integration time parameter, in this embodiment, =4ms The integrator input value at time k is the inlet / outlet flow rate difference per second.

[0091] PT1 is a first-order lag element. The algorithm for a discrete first-order lag element is as follows:

[0092]

[0093] In the formula, and These are the output values ​​of the current time step and the previous time step of the PT1 stage, respectively; The time constant of the PT1 stage is, in this embodiment, ; This is the input value for the PT1 stage, which is the actual value of the strip exit speed at the current moment.

[0094] S103. Pre-calculate the strip thickness difference at the roll gap using the flow rate equation, including:

[0095] Using the modified inlet velocity and two first-order hysteresis loops, the modified inlet flow rate per second is obtained. Then, the strip exit thickness difference at the roll gap is pre-calculated based on the flow rate per second equation. That is:

[0096]

[0097] In the formula, This represents the difference in strip thickness at the roll gap exit. and For the second and third PT1 stages, among which Used to compensate for the measurement delay of the inlet thickness gauge. In this embodiment, it is used to compensate for the delay in inlet velocity measurement. , . The inlet thickness difference, i.e. , Set the entry thickness value for the strip steel.

[0098] In some embodiments, step S2 specifically includes:

[0099] S201, compensating for the speed difference between the inlet tension roller and the first frame, including;

[0100] In the thickness control scheme of the cold continuous rolling mill, the inlet tension roll is treated as the No. 0 stand without reduction. The exit thickness is adjusted by regulating the transmission speed of the inlet tension roll and the first stand. Considering the significant difference in dynamic performance between the inlet tension roll and the first stand's transmission control, compensation for the speed difference between the inlet tension roll and the first stand is required when the second-flow AGC of the first stand is activated. However, no speed difference compensation is needed when the second-flow AGC of other stands is activated.

[0101] The algorithm for speed difference compensation is as follows:

[0102]

[0103] In the formula, and These are the actual speed values ​​of the first frame and the inlet tension roller, respectively. and These are the speed settings for the first frame and the inlet tension roller, respectively.

[0104] S202, calculates adaptive gain based on exit speed, exit thickness difference, and acceleration / deceleration conditions;

[0105] The gain value is adaptively calculated based on the exit speed, exit thickness difference, and acceleration / deceleration conditions.

[0106]

[0107] In the formula, This is the adaptive gain value for the thickness difference at the outlet. This is the export speed factor, which decreases as the export speed increases. This is the export thickness difference factor, which increases as the export thickness difference increases. This is the acceleration / deceleration factor, which takes a larger value when in an acceleration / deceleration state and 1.0 when maintaining a steady speed. In this embodiment, It takes values ​​in the range of 0.7 to 1.0. Values ​​are taken within the range of 0.8 to 1.0, during acceleration and deceleration. When the speed is steady .

[0108] S203, use the dynamic averaging module to obtain the average value of the monitoring thickness difference over the monitoring distance to obtain the monitoring thickness difference compensation value;

[0109] The thickness difference measured by the exit thickness gauge is multiplied by the adaptive gain to obtain the monitored thickness difference. The monitoring length is set to the distance from the roll gap of the stand to the exit thickness gauge. To accurately calculate the average value of the monitored thickness difference over the specified length even when the strip exit speed varies arbitrarily, a dynamic averaging module (see Chinese Patent CN201110274939.3) is used to obtain the monitored thickness difference compensation value. That is:

[0110]

[0111] In the formula, To monitor the thickness difference compensation value, It is the export thickness difference (i.e., the actual export thickness minus the actual export thickness). This indicates the dynamic averaging module, which is used to dynamically calculate the average value of the monitored thickness difference over the monitored length.

[0112] S204, calculate the total outlet thickness difference of the flow rate per second;

[0113] The final total outlet thickness difference for the flow rate per second is obtained by adding the pre-calculated outlet thickness difference, the monitored thickness difference compensation value, and the velocity difference compensation amount.

[0114]

[0115] In some embodiments, step S3 specifically includes:

[0116] S301, calculate the proportional coefficient based on the export speed and the response time of the regulating mechanism;

[0117] In a PI controller, the proportional element primarily functions to quickly eliminate interference. Increasing the proportional parameter enhances system stability and smooths the change in the controlled variable, but also increases the residual error. Conversely, decreasing the proportional parameter degrades system stability, strengthens the oscillation trend of the controlled variable, and in severe cases, can cause strip breakage and mechanical equipment damage in the rolling mill. Considering the influence of exit speed and the response time of the regulating mechanism, the algorithm for adaptively adjusting the proportional coefficient is as follows:

[0118]

[0119] In the formula, The length is controlled by the flow rate per second. To adjust the mechanism's response time, in this embodiment, the setting is based on the site conditions. , .

[0120] S302, calculate the integral time parameter based on the outlet speed and the response time of the regulating mechanism;

[0121] In a PI controller, the integrator mainly plays the role of eliminating residuals. The selection of its integral time parameter is very important. If it is too small, the oscillation of the control system will increase, and in severe cases, it will become unstable. If it is too large, the residuals will take a long time to be eliminated, which will directly affect the yield of the product.

[0122] Taking into account the effects of outlet velocity and the response time of the regulating mechanism, the integral time parameter of the second flow controller is:

[0123]

[0124] S303 uses an adaptive parameter PI controller to calculate the flow rate and thickness control quantity per second.

[0125] A proportional-integral controller is used to calculate the inlet tension roller speed adjustment based on the total outlet thickness difference per second flow rate. Simultaneously, to avoid tension fluctuations caused by speed adjustment, the first frame roller gap adjustment is also calculated to eliminate the influence of thickness control on the inter-frame tension. That is:

[0126]

[0127] In the formula, and These are the speed adjustment amount of the inlet tension roller and the roll gap adjustment amount of the first frame, respectively. and These are the speed adjustment gain and the roll gap adjustment gain, respectively. In this embodiment, they are set as follows: , PI stands for Proportional-Integral Controller. Set the inlet tension roller speed. This is the mill stiffness coefficient, obtained through testing during mill commissioning. This represents the plasticity coefficient of the strip steel.

[0128] The discrete PI controller algorithm is as follows:

[0129]

[0130] In the formula, and These are the output values ​​of the PI controller at the current time and the previous time, respectively; and These represent the difference in total outlet flow rate per second between the current time and the previous time, respectively.

[0131] The calculated inlet tension roller speed adjustment is sent to the inlet tension roller drive controller, and the first frame roll gap adjustment is sent to the first frame hydraulic pressing controller. By executing the control of the second flow rate AGC, this optimized second flow rate thickness control method can be realized.

[0132] Using the methods described above, the thickness difference at the exit of the first stand is further corrected, and the parameters of the PI controller can adaptively change with the operating conditions, thus ensuring that the flow rate AGC maintains good control performance throughout the rolling process. The flow rate control method on other stands is similar.

[0133] The second-flow-per-second thickness control method for cold continuous rolling mills proposed in this embodiment first uses a synchronous transmission model to synchronously transmit the inlet second-flow rate to the outlet thickness gauge. The difference between the inlet and outlet second-flow rates is obtained by comparing the inlet and outlet second-flow rates. The inlet speed of the strip is corrected by integrating the second-flow rate difference. Then, the exit thickness difference of the strip is pre-calculated using the second-flow rate equation. Next, the speed difference between the inlet tension roll and the first stand is compensated, and the pre-calculated thickness difference is further corrected using monitored thickness difference. Finally, an adaptive PI controller is used to calculate the second-flow-per-second thickness control quantity, where the proportional coefficient and integral time parameters can be adaptively adjusted according to the exit speed and the response time of the regulating mechanism. Through the above steps, this high-precision second-flow-per-second thickness control method is finally achieved. This method compensates for errors in the inlet and outlet second-flow rates, the speed difference between the inlet tension roll and the first stand, and corrects the pre-calculated exit thickness difference using monitored thickness difference, thus obtaining a high-precision exit thickness difference value. Finally, adaptive proportional-integral parameters are used to adapt to different working conditions, ensuring that the second-flow-per-second AGC maintains good control performance throughout the rolling process, significantly improving the overall accuracy of thickness control.

[0134] refer to Figure 2 The diagram shown is a schematic of a thickness control system and its main detection instruments for a five-stand cold rolling mill according to an embodiment of the present invention. It includes a first stand 1, a second stand 2, a third stand 3, a fourth stand 4, a fifth stand 5, an upper support roll 6, an upper intermediate roll 7, an upper work roll 8, a lower work roll 9, a lower intermediate roll 10, a lower support roll 11, an inlet tension roll 12, an outlet coiler 13, a hydraulic cylinder 14, a first stand inlet thickness gauge 15, a first stand inlet laser velocimeter 16, a first stand outlet thickness gauge 17, a first stand outlet laser velocimeter 18, a fifth stand outlet thickness gauge 19, and a PLC controller 20.

[0135] The first frame 1 is equipped with an inlet thickness gauge 15 and an outlet thickness gauge 17, respectively, to measure the thickness of the strip at the inlet and outlet of the first frame 1. It is also equipped with an inlet laser velocimeter 16 and an outlet laser velocimeter 18, respectively, to measure the speed of the strip at the inlet and outlet of the first frame 1. Thus, according to the flow rate equation, the outlet thickness of the strip can be pre-calculated based on the inlet strip thickness and the inlet-outlet speed ratio. All thickness control functions are implemented through programming in the PLC controller 20.

[0136] This invention also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of any of the cold rolling mill second-flow-thickness control methods described in the above embodiments. The computer-readable storage medium can be volatile or non-volatile.

[0137] This invention also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code. When the computer-readable code is run in the processor of an electronic device, the processor in the electronic device executes the above-described cold rolling mill flow rate and thickness control method.

[0138] Those skilled in the art will understand that all or some of the steps, systems, and apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software can be distributed on a computer-readable storage medium, which may include computer storage media (or non-transitory media) and communication media (or transient media).

[0139] As is known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information, such as computer-readable program instructions, data structures, program modules, or other data. Computer storage media includes, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), static random access memory (SRAM), flash memory or other memory technologies, portable compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, it is known to those skilled in the art that communication media typically contain computer-readable program instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0140] The computer-readable program instructions described herein can be downloaded from computer-readable storage media to various computing / processing devices, or downloaded via a network, such as the Internet, local area network, wide area network, and / or wireless network, to an external computer or external storage device. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards them to the computer-readable storage media in the respective computing / processing device.

[0141] The computer program instructions used to perform the operations of this invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, etc., and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, electronic circuitry, such as programmable logic circuitry, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), is personalized by utilizing state information from the computer-readable program instructions. This electronic circuitry can execute the computer-readable program instructions to implement various aspects of the invention.

[0142] The computer program product described herein can be implemented specifically through hardware, software, or a combination thereof. In one alternative embodiment, the computer program product is specifically embodied in a computer storage medium; in another alternative embodiment, the computer program product is specifically embodied in a software product, such as a software development kit (SDK), etc.

[0143] Various aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer-readable program instructions.

[0144] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when executed by the processor of the computer or other programmable data processing apparatus, they create means for implementing the functions / actions specified in one or more blocks of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other device to operate in a particular manner; thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing aspects of the functions / actions specified in one or more blocks of the flowchart and / or block diagram.

[0145] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0146] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0147] Example embodiments have been disclosed herein, and while specific terminology has been used, it is for illustrative purposes only and should be construed as such, and is not intended to be limiting. In some instances, it will be apparent to those skilled in the art that features, characteristics, and / or elements described in conjunction with particular embodiments may be used alone, or in combination with features, characteristics, and / or elements described in conjunction with other embodiments, unless otherwise expressly indicated. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the scope of the invention as set forth in the appended claims.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for controlling the thickness per second of a cold continuous rolling mill, characterized in that, Includes the following steps: S1. The flow rate per second at the inlet thickness gauge is synchronously transmitted to the outlet thickness gauge, the difference between the inlet and outlet flow rates is integrated to correct the strip inlet speed, and the strip outlet thickness difference at the roll gap is pre-calculated using the flow rate per second equation. S2. Compensate for the speed difference between the inlet tension roller and the first frame, and use the monitoring of the outlet thickness difference to correct the pre-calculated strip outlet thickness difference, and obtain the total outlet thickness difference per second of flow rate; S3. The parameters of the proportional-integral (PI) controller are adaptively adjusted based on the outlet speed and the response time of the regulating mechanism, and the thickness control amount of the flow rate per second is calculated using the PI controller with adaptive parameters based on the total outlet thickness difference of the flow rate per second. Specifically, S1 involves synchronously transmitting the flow rate per second from the inlet thickness gauge to the outlet thickness gauge, which includes: The actual value H of the strip inlet thickness measured by the inlet thickness gauge is transmitted using the first synchronous transmission model TPM1. en,act Multiply by the actual inlet velocity V en,act The obtained inlet flow rate is delayed and transmitted to the mill roll gap; then, it is transmitted via the second synchronous transmission model TPM2 with the actual strip exit speed V. ex,act Using this as a reference, the inlet flow rate per second at the mill roll gap is synchronously transmitted to the outlet thickness gauge to obtain the inlet flow rate M synchronously transmitted to the outlet thickness gauge. en,Exthg ; Wherein, the integral inlet and outlet flow rate difference in S1 to correct the strip inlet velocity includes: The actual value of the strip exit velocity V is processed using a first-order hysteresis element PT11. ex,act To compensate for measurement delay, multiply by the exit thickness setting h. ex,sp Obtain the outgoing flow rate per second; compare the outgoing flow rate per second with the synchronously transmitted incoming flow rate per second M. en,Exthg The inlet and outlet flow rate difference is obtained by comparison; the inlet velocity correction factor is obtained by integrating the inlet and outlet flow rate difference, and the actual value of the strip inlet velocity V is corrected accordingly. en,act To correct the inlet velocity V en,Md The specific formula is as follows: ； Where INT stands for integrator, and the discrete integrator algorithm is as follows: ； in, and The integrator outputs for the current and previous time steps are T, respectively. A T is the PLC sampling time. N I(k) is the integration time parameter, and I(k) is the integrator input value. The PT11 discrete algorithm is as follows: ； In the formula, and These are the output values ​​of the current time step and the previous time step of the PT11 stage, respectively; The time constant of the PT11 stage; This is the input value for the PT11 stage; Among them, the pre-calculation of the strip exit thickness difference at the roll gap using the flow rate equation in S1 includes: Using the corrected inlet velocity V en,Md The inlet thickness difference ΔH is handled by two first-order hysteresis circuits PT12 and PT13. en =H en,act -H en,sp Based on the speed signal and the flow rate equation, the strip thickness difference Δh at the roll gap is pre-calculated. gap,P The specific formula is as follows: ； In the formula, This represents the strip thickness difference at the roll gap exit, where... Used to compensate for the measurement delay of the inlet thickness gauge. Used to compensate for the delay in inlet velocity measurement Set the entry thickness value for the strip steel; Wherein, the compensation for the speed difference between the inlet tension roller and the first frame in S2 includes: When the automatic thickness control AGC for the first rack is activated, the speed difference compensation ΔV is calculated. C The formula is: ； In the formula, and These are the actual speed values ​​of the first frame and the inlet tension roller, respectively. and These are the speed settings for the first frame and the inlet tension roller, respectively; Specifically, S2 includes correcting the pre-calculated strip exit thickness difference using monitoring exit thickness difference: The adaptive gain G is calculated based on the exit speed, exit thickness difference, and acceleration / deceleration state. C : ； In the formula, This is the adaptive gain value for the thickness difference at the outlet; Export speed factor; Export thickness difference factor; For acceleration / deceleration factors; The thickness difference Δh measured by the thickness gauge at the export site ex Multiply by G C The monitored thickness difference is obtained, and the average value Δh is obtained by averaging it over the monitored length using the Dynamic Averaging (MAV) module. Mon ; ； Combined and ΔV C Calculate the total outlet thickness difference Δh for the flow rate per second. Mfc ; ； The parameters of the adaptive PI controller based on the outlet speed and the response time of the regulating mechanism in S3 include: The proportional coefficient K is calculated based on the export speed and the response time of the regulating mechanism. P,Mfc : ； In the formula, For flow control length per second, V ex,act This represents the actual strip exit speed. To adjust the response time of the mechanism; The integral time parameter T is calculated based on the export speed and the response time of the regulating mechanism. I,Mfc ; ； Specifically, the PI controller using adaptive parameters in S3 calculates the thickness control quantity for the flow rate per second based on the total outlet thickness difference of the flow rate per second, including: The proportional-integral controller is used to calculate the inlet tension roller speed adjustment ΔV based on the total outlet thickness difference per second flow rate. 0,MFC and the first frame roll gap adjustment amount ΔS 1,MFC The formula is: ； ； Where, Δh Mfc The total outlet thickness difference per second is h. ex,sp G is the set value for the export thickness. V and G S These are the speed adjustment gain and the roll gap adjustment gain, respectively, V 0,s p is the setpoint for the inlet tension roller speed, PI represents a proportional-integral controller, and C S C is the mill stiffness coefficient. M The strip's plasticity coefficient is used; the discrete PI controller algorithm is as follows: ； In the formula, and These are the output values ​​of the PI controller at the current time and the previous time, respectively; and These represent the difference in total outlet thickness per second between the current time and the previous time, respectively, T. A This refers to the PLC sampling time.

2. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a computer, causes the computer to perform the cold continuous rolling mill second flow rate thickness control method as described in claim 1.

3. A computer program product, characterized in that, Includes computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code, wherein when the computer-readable code is run in a processor of an electronic device, the processor in the electronic device executes the cold continuous rolling mill second flow rate thickness control method as described in claim 1.

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