Double reverse cascade rolling mill speed control method and system and storage medium
By employing a dual-reverse cascaded mill speed control method and looper adjustment technology, the problem of mill speed fluctuation in bar production was solved, achieving precise matching and stable control of rolled products, thereby improving yield and production safety.
Patent Information
- Application Number
- CN202511132468.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-13
- Publication Date
- 2025-11-18
AI Technical Summary
In bar production, the large number of rolling mills and high rolling speeds result in poor control over the fluctuations in the exit line speed, making it impossible to guarantee equal cutting. This leads to inconsistent material shapes on the rolling line, affecting yield and production safety.
A dual reverse cascaded mill speed control method is adopted, which sets the mill speed by the process pass elongation rate and adjusts the mill speed in reverse during the rolling process. The looper is used to adjust the tension control to achieve precise matching and stability of the mill speed.
It improves the speed control precision of the rolling process, reduces exit speed fluctuations, ensures the quality of rolled products and production safety, and increases yield and production efficiency.
Smart Images
Figure CN120961619A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of bar rolling production line, in particular to a double reverse cascade rolling mill speed control method, system and storage medium. BACKGROUND
[0002] In the production of bars, the billets are sequentially rolled through multiple rolling mills. However, due to the large number of rolling mills and loops, the rolling speed is fast, which causes the outlet line speed to fluctuate and the control to be poor. Taking a double high bar production line as an example, the front rolling mills are shared, and then the single billet is divided into two parts, which are rolled in each production line respectively. After rolling, they are cut by a high-speed flying shear into a length that can adapt to the length of the cooling bed. The segmented rolling pieces are braked by a tail clamping device and then sent to a step rack type cooling bed one by one by a rotating drum. They are naturally cooled while stepping on the cooling bed.
[0003] Currently, the billet division is adjusted manually, which cannot guarantee equal division, resulting in inconsistent rolling line profiles after bifurcation. The operator needs to repeatedly adjust the speed of each rolling mill to prevent steel piling or excessive tension, and the outlet speed of the two production lines often changes or is inconsistent. Moreover, the rolling speed of the production line is extremely high, and the speed fluctuation of the outlet rolling mill needs to be as small as possible to ensure the accuracy of the double-length shear and the control of the rolling piece on the cooling bed. Otherwise, it will lead to low yield and easily induce production accidents. SUMMARY
[0004] The purpose of the embodiments of the present application is to provide a double reverse cascade rolling mill speed control method, system and storage medium. The method is suitable for the rolling piece processing process with multiple loops, high-speed rolling and multiple production lines. It provides a rolling mill speed setting and adjustment scheme for the specific speed regulation mode of the rolling mill and the large line difference before and during rolling in a reverse cascade manner in the main line and the auxiliary line, so as to adapt to the speed requirements of the rolling mill in the entire rolling production process and to achieve a complete and efficient speed regulation strategy.
[0005] To achieve the above-mentioned purpose, the embodiments of the present application provide a double reverse cascade rolling mill speed control method. During production, the rolling piece passes through multiple rolling mills on the auxiliary line extending between the main line and the auxiliary line in the production direction. The rolling mill speed control method includes the following steps: based on the process pass elongation, the speed of the rolling mill is set, and the rolling mill is controlled to run at the speed; the speed matching between the rolling mills on the production line is monitored; and when the speed between the rolling mills is matched, the speed of the rolling mill to be adjusted is adjusted according to the piling and pulling relationship of the rolling piece, and the speed of the other rolling mills on the main line / auxiliary line where the rolling mill to be adjusted is located is adjusted in reverse; otherwise, the speed of the rolling mill is reset, and the above steps are repeated.
[0006] Optionally, the rolling mill speed setting method based on the process groove elongation rate comprises the following steps: determining the exit speed of the exit rolling mill of the production line and the material shape elongation rate of each rolling mill based on production requirements; converting the material shape elongation rate into the process groove elongation rate, and inversely recursively calculating the entry speed of each rolling mill based on the exit speed; and setting the entry speed of each rolling mill and setting the exit speed of each rolling mill as the entry speed of the next rolling mill according to the entry speed of each rolling mill.
[0007] Optionally, the rolling mill comprises a bifurcated rolling mill arranged at the intersection of the main line and the auxiliary line; the rolled piece is a double-high bar, and after being divided by the bifurcated rolling mill, one part enters the auxiliary line and the other part enters the remaining main line.
[0008] Optionally, the rolling mill speed control method further comprises: when the speeds of the bifurcated rolling mill and the exit rolling mills of the main line and the auxiliary line do not match, taking the bifurcated rolling mill as the rolling mill to be adjusted; and when the speed of the bifurcated rolling mill and the exit rolling mill of the auxiliary line do not match, taking the exit rolling mill of the auxiliary line as the rolling mill to be adjusted.
[0009] Optionally, when the speeds of the exit rolling mill of the main line and the exit rolling mill of the auxiliary line do not match, only adjusting the exit speed of the main line and / or the exit speed of the auxiliary line, and making the proportion of the exit speed of the auxiliary line to the exit speed of the main line a preset proportion.
[0010] Optionally, the rolling mill speed control method further comprises: monitoring the line difference between the two parts of the double-high bar after being divided; when the line difference is less than a preset line difference, taking the bifurcated rolling mill as the rolling mill to be adjusted; otherwise, taking the exit rolling mill of the auxiliary line as the rolling mill to be adjusted.
[0011] Optionally, the speed of the rolling mill is adjusted by adjusting the corresponding loop of the rolling mill, wherein the type and adjustment mode of the loop are determined according to the function of the rolling mill.
[0012] Optionally, the adjustment mode adjusts multiple variables with different preset adjustment values, and the variables include a proportional coefficient, an integral coefficient, an adjustment dead zone, a speed adjustment slope, and a maximum adjustment limit.
[0013] Optionally, the type and adjustment mode of the loop are determined according to the function of the rolling mill, and the type and adjustment mode of the loop corresponding to the bifurcated rolling mill are at least one of the following: the type of the loop is a large side loop, and the adjustment mode is a fast and slow mixed adjustment; the type of the loop corresponding to the last rolling mill in the pre-finishing rolling mill group is a large side loop, and the adjustment mode is a slow speed adjustment; and / or the type of the loop corresponding to the ordinary rolling mill is a vertical loop, and the adjustment mode is a fast adjustment.
[0014] Optionally, in the main line and the auxiliary line, the loop height setting value and the adjustment characteristic value of the loop corresponding to the last rolling mill in the pre-finishing rolling mill group are the same, and the adjustment dead zone value of the auxiliary line is greater than that of the main line; in the bifurcated rolling mill, the loop height setting value, the adjustment characteristic value, and the adjustment dead zone value of the loop connecting the rolling mill of the main line and the rolling mill of the auxiliary line are the same.
[0015] In a second aspect, the double reverse cascade rolling mill speed control system comprises a memory in which instructions are stored, and a processor which invokes the instructions in the memory to enable the system to implement the rolling mill speed control method.
[0016] In a third aspect, the computer readable storage medium stores instructions which, when executed by a processor, implement the rolling mill speed control method.
[0017] Through the above technical solution, the rolling mills in the main line and the auxiliary line are simultaneously pre-set with speed before rolling and adjusted with speed during rolling in a reverse cascade manner. During speed pre-setting, the speed of each rolling mill is recursively derived based on the process pass elongation and the pre-set outlet speed, fully considering the case that there are two speeds of a rolled piece in the same rolling mill driven by the same motor, highlighting the change of the pass of the rolling mill in which the rolled piece enters during rolling, and the result of speed setting is more accurate. During rolling, the outlet speed is kept unchanged, and the speed of each rolling mill is adjusted, controlling the fluctuation of the outlet and not affecting the production efficiency, i.e. subsequent production process, and the adjustment mode is flexible and practical.
[0018] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS
[0019] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation part to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:
[0020] Figure 1 is a basic flowchart of the double reverse cascade rolling mill speed control method of the present application;
[0021] Figure 2 is a basic flowchart of setting speed for rolling mills based on speed elongation;
[0022] Figure 3 is a basic structure diagram of the production line in the present embodiment. DETAILED DESCRIPTION
[0023] The specific implementation of the embodiments of the present application will be described in detail below in combination with the drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application.
[0024] It should be noted that the acquisition, transmission, storage, use, processing and the like of data in the technical solutions of the present application comply with the relevant provisions of laws and regulations. In the embodiments of the present application, some industry existing solutions such as software, components, models and the like may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility in the implementation of the technical solutions of the present application, but it does not mean that the applicant has or will necessarily use the solutions.
[0025] The double reverse cascade rolling mill speed control method described in the present application, in production, the rolled piece (i.e. blank) passes through a plurality of rolling mills arranged on the sub-line extending from the middle of the main line and the sub-line in the production direction, when the rolling mill completes rolling, the rolled piece is output after passing through the outlet rolling mill of the main line and the sub-line respectively, and then cut and cooled in the cooling bed. In normal production, the selection of the main line and the sub-line is selected by the operator on the HMI, and generally the branch close to the operator for easy observation and adjustment is the main line.
[0026] Please refer to Figure 1 The rolling mill speed control method comprises the following steps: setting the speed of the rolling mill based on the process pass elongation, controlling the rolling mill to run at the set speed; monitoring the speed matching between the rolling mills on the production line; and when the speed between the rolling mills is matched, adjusting the speed of the rolling mill to be adjusted according to the stacking and pulling relationship of the rolled piece, and inversely adjusting the speed of the other rolling mills on the main line / sub-line where the rolling mill to be adjusted is located, otherwise, resetting the speed of the rolling mill and repeating the above steps. If the speed setting relationship of the rolling mills is obviously unreasonable, the speed of each rolling mill needs to be recalculated and set according to the cascade of the speed; if the speed setting relationship is basically reasonable, but the speed between some rolling mills needs to be matched due to the adjustment of the pass and the like, at this time, the speed of each rolling mill does not need to be reset, but the speed of a part of the rolling mills is inversely adjusted. The present application adopts a control strategy to ensure that the speed of the outlet rolling mill is stable and unchanged, and in the rolling process, the adjustment capacity of the rolling mill speed regulator is fully utilized, the tension control between the rolling mills is realized through the looper, and the adjustment direction is all upstream adjustment in the reverse process production direction. In addition, the speed control system has different control processes due to the different modes of the main line and the sub-line, so as to adapt to the needs of process production and material type adjustment, and has a switching function.
[0027] In the present application, the speed of the rolling mill on the whole line is pre-set before starting rolling. The present application sets the speed of each rolling mill based on the process pass elongation, and precisely matches the process material type setting through the double reverse rolling mill cascade speed setting of the main line and the sub-line, to precisely pre-set the speed of the rolling mill. Please refer to Figure 2 , comprising the following steps:
[0028] Firstly, based on the production requirements, the exit speed of the exit rolling mill of the production line, and the material type elongation rate of each rolling mill are determined. The exit speed is the speed value set for the exit rolling mill (such as the last rolling mill used in the main line or the auxiliary line) of the production line according to the production requirements. The material type elongation rate is determined when designing each rolling mill according to the production requirements. Specifically, the rolling mill process specialty has a material type elongation rate parameter for each rolling mill when designing the pass. The physical meaning is to describe the ratio of the entry equivalent cross-sectional area of the rolled piece to the exit equivalent cross-sectional area after rolling. Due to the "calendering" effect of the rolling mill, the material type elongation rate μ is always greater than 1. The specific formula is shown in formula 1:
[0029] μ = A1 / A2 Formula 1
[0030] Wherein, μ is the material type elongation rate of the rolling mill, unitless; A1 is the equivalent cross-sectional area of the rolled piece at the inlet side of the rolling mill, unit is square meter (m 2 ); A2 is the equivalent cross-sectional area of the rolled piece at the outlet side of the rolling mill, unit is square meter (m 2 ).
[0031] Then, the material type elongation rate is converted into the process pass elongation rate, and the inlet speed of each rolling mill is recursively calculated in reverse from the exit speed.
[0032] According to the actual production requirements, due to the influence of tension, rolling mill loss and the like, it may not be possible to produce according to the value of the material type elongation rate in actual production. At the same time, there are different speeds at the inlet and outlet of a single rolling mill (except for the exit rolling mill), but there is only one motor driving the rolling mill, that is, there is only one motor speed. Therefore, in the speed regulation system of the rolling mill, the material type elongation rate cannot be directly used. The material type elongation rate is converted into the process pass elongation rate in the present application to reflect the change of the pass in the rolling process of a single rolling mill, and then indirectly reflect the tension relationship of the rolled piece. At the same time, considering that the outlet linear speed of the exit rolling mill of the main line is generally constant and the speed of the exit rolling mill is unique, the corresponding process pass elongation rate of the exit rolling mill is constant and equal to 1. The relationship between the material type elongation rate and the process pass elongation rate is established, and formula 2 composed of multiple formulas is obtained:
[0033] E dummy = 1
[0034] E n = μ n+1 Formula 2
[0035] E exit = 1
[0036] Wherein, E exit is the process pass elongation rate of the exit rolling mill (the last exit rolling mill used), unitless; E n is the process pass elongation rate of the n rolling mill, unitless; μn+1 E represents the elongation of the material profile at the (n+1)th mill, without dimensions. dummy The elongation of the process pass through the empty rolling mill (discarding unused parts).
[0037] Based on the principle of equal metal flow rate per second, meaning that the metal flow rate must remain consistent across all passes during continuous rolling to ensure the quality and dimensional stability of the rolled piece, Formula 3 applies to each rolling mill:
[0038] V1*A1=V2*A2 Formula 3
[0039] Where V1 is the entry velocity of the workpiece at the mill, in meters per second (m / s); A1 is the equivalent cross-sectional area of the workpiece at the mill entrance, in square meters (m²). 2 V2 is the exit speed of the rolling mill, in meters per second (m / s); A2 is the equivalent cross-sectional area of the rolling mill exit side, in square meters (m²). 2 ).
[0040] Combining equations 1 and 3, we obtain equation 4, and from equation 4, we obtain equation 5:
[0041] μ=V2 / V1 Formula 4
[0042] V1=V2 / μ Formula 5
[0043] Combining formulas 2 and 4, we obtain formula 6, which is the formula for the inlet speed of each rolling mill:
[0044] V1 n =V2 n / E n-1 Formula 6
[0045] Among them, V1 n V2 represents the inlet speed of the nth rolling mill currently in use on the production line, along the production line direction. n It represents the exit speed of the nth rolling mill currently in use on the production line, along the production line direction.
[0046] For two adjacent rolling mills, under ideal, tension-free conditions, the inlet velocity of the downstream rolling mill is the same as the outlet velocity of the upstream rolling mill:
[0047] V2 n =V1 n+1 Formula 7
[0048] Finally, according to the entry speed of each rolling mill, the entry speed of each rolling mill is set and the exit speed of each rolling mill is set as the entry speed of the next rolling mill. For two adjacent rolling mills, in the ideal case without tension, the entry speed of the downstream rolling mill is the exit speed of the upstream rolling mill, and so on until the first rolling mill on the production line. At the same time, the exit speed of the exit rolling mill is the same as the entry speed, so when the exit speed of the production line is determined, the speed of each rolling mill on the production line can be obtained by formula 6 and formula 7. Specifically, the entry speed of each rolling mill is calculated according to the exit speed and the process parameters, and the exit speed of the rolling mill is the entry speed of the next rolling mill.
[0049] In the production line, the arrangement and type of the rolling mills can be set as needed. For ease of description, the present application takes a double high bar production line as an example to further describe the subsequent control method. The rolling mills in the double high bar production line include a split rolling mill, which is arranged at the intersection of the main line and the auxiliary line. At this time, the rolled piece is a double high bar, which is divided by the split rolling mill, and one part enters the auxiliary line and the other part enters the remaining main line. Compared with the exit speed of about 18 m / s of conventional bar, the exit speed of the double high bar production line is as high as 45 m / s, which has great production capacity and quality advantages.
[0050] In this embodiment, please refer to Figure 3 The 12# rolling mill arranged in the main line is a split rolling mill, and the 1#-11# rolling mills before the 12# rolling mill are also main line rolling mills. The rolled piece is cut into two rolled pieces A and B by a shearing device after exiting the 12# rolling mill. The 13A#-19A# rolling mills are arranged in the second half of the main line, i.e. the A line, and the 13B#-19B# rolling mills are arranged in the auxiliary line, i.e. the B line. The qualified billet after heating is first rolled for 6 passes in the rough rolling mill group (1#-6# rolling mills), enters the intermediate rolling mill group (7#-12# rolling mills) after the first flying shear head (tail), and is rolled for 6 passes. After the split rolling mill, the rolled piece is sent to the double line (A line or B line) for rolling. After each line passes through the second flying shear head (tail), it enters the pre-precision rolling mill group (13A#-16A# rolling mills, 13B#-16B# rolling mills) and is rolled for 4 passes. Then, after passing through the third flying shear head (tail), it is sent to the finishing rolling mill group (17A#-19A# rolling mills, 17B#-19B# rolling mills) and is rolled for 2-6 passes. After rolling, the rolled pieces of the A line and the B line enter the respective shearing devices at high speed and are cut by the double-length shears, respectively. The cut rolled pieces enter the cooling bed at a certain speed and are cooled for a certain time. The exit speed of the exit stand 19A# rolling mill of the A line is the exit speed of the main line, and the exit speed of the exit stand 19B# rolling mill of the B line is the exit speed of the auxiliary line.
[0051] In the above embodiment, the bifurcated rolling mill serves as a "slitting stand" to split the rolled piece into two from a single piece. Since it is difficult to ensure absolutely even slitting control for the material shape, there is a different elongation between the bifurcated rolling mill and the downstream rolling mill between the A line and the B line. In accordance with the above formula 6 and formula 7, the production requires that the rolling For example, the speed of each rolling mill based on the process pass elongation setting and the corresponding material property elongation, process pass elongation are shown in Table 1.
[0052] In the above embodiment, the speed of the other rolling mills on the main line / secondary line where the rolling mill to be adjusted is adjusted in reverse, that is, when the speed of the main line 16A# rolling mill is adjusted, the speed of the downstream rolling mill of the 16A# stand remains unchanged, and only the upstream rolling mills 1#-12#, 13A#-15A# rolling mills change with the set speed. The speed adjustment of the secondary line rolling mill is also cascaded in the reverse (upstream) direction, but the speed adjustment is only cascaded to the first stand after the bifurcation, that is, to the 13# rolling mill, and is no longer conducted to the 12# rolling mill and the upstream rolling mills. In this embodiment, the reverse adjustment is performed in the same proportion. For example, after the speed setting of the 16B# rolling mill in the secondary line is changed from 10 to 20, the speed setting is doubled, at which time the speed of the 13B#-15B# rolling mills should also be doubled to ensure the consistency of the overall speed of the secondary line.
[0053] Table 1: Speed and elongation setting example
[0054]
[0055] The loop is located downstream of the corresponding rolling mill in the process direction. In order to reduce the size fluctuation of the rolled piece caused by the change of tension in the finishing mill, a number of loops are usually set in the pre-finishing and intermediate rolling mill group before the finishing mill to eliminate the interference of the dynamic speed change of each stand in the continuous rolling and to ensure the accuracy of the rolled piece. The "excess" rolled piece is formed between the adjacent rolling stands by adjusting the speed of the rolling stands through the automatic control system, and the "excess" rolled piece forms an arc-shaped loop under the assistance of the loop starting device and dynamically maintains the arc-shaped loop. This loop is called a loop. The loop is composed of a loop table, support rollers, guide grooves, loop starting rollers, and loop scanners, etc. The support rollers and the loop starting rollers play a guiding and supporting role for the rolled piece. The loop starting rollers and the turning guide plates are driven by air cylinders, and the loop starting roller air cylinder is controlled by double electromagnetic valves.
[0056] Looping can achieve tensionless rolling by changing the loop storage, that is, there is no tension between the stands during rolling. When the rolling stock between the adjacent stands is pulled, the loop size is reduced, which can act as a buffer to prevent tension between the stands and prevent the rolling stock from being broken and affecting the accuracy of the rolling stock size. On the other hand, it can absorb excess rolling stock to prevent the rolling stock from piling up and causing a piling accident between the stands. However, the loop size adjustment range and the loop storage are limited. When the loop size deviation is too large due to unreasonable speed matching between adjacent stands or other reasons, the automatic control system cannot adjust in time or cannot adjust, which may cause the rolling stock to pile up. According to the loop piling and pulling relationship, the speed of the corresponding rolling mill is adjusted by adjusting the loop of the rolling mill. When the speed of the rolling mill is adjusted by the loop, the loops are first classified, and different loops are matched with different types and speed adjustment modes to ensure accurate adjustment of the rolling mill. During continuous rolling, the speed or tension of the adjacent stands is adjusted to balance the metal flow rate and avoid the occurrence of piling or pulling.
[0057] The present application classifies the loops according to the rolling mill fine classification, and different loops are matched with different adjustment modes. The flexible and fine loop control method is beneficial to efficient and accurate rolling mill speed adjustment. The type and adjustment mode of the loop are determined according to the function of the rolling mill. The loop control is suitable for the scene of small rolling stock cross section and fast rolling speed, which can eliminate the interference of dynamic speed change of the continuous rolling stand, ensure the accuracy of the rolling stock, and includes the steps of loop starting, stable adjustment, loop closing, loop type analysis and loop controller output adjustment. The adjustment mode of the loop adjusts multiple variables with different preset adjustment values, including proportional coefficient, integral coefficient, adjustment dead zone, speed adjustment slope and maximum adjustment limit. The type and adjustment mode of the loop are determined according to the function of the rolling mill, including at least one of the following: the loop type corresponding to the diverging rolling mill is large side loop, and the adjustment mode is fast and slow mixed adjustment; the loop type corresponding to the last rolling mill in the pre-finishing rolling mill group is large side loop, and the adjustment mode is slow speed adjustment; and / or, the loop type corresponding to the ordinary rolling mill is vertical loop, and the adjustment mode is fast adjustment. The plane of the large side loop is parallel to the production line plane, and the loop height is high. The plane of the vertical loop is perpendicular to the production line plane. At present, only one type of loop appears on the unified production line, and there is basically no relationship between the loop type and the rolling mill. Through the performance matching of different loop adjusters, the rolling mill speed adjustment function of fast adjustment in a single rolling line and gradual matching between material types is realized.
[0058] Each type of loop involved in the speed adjustment of the rolling mill corresponds to different adjustment characteristics to achieve different process adjustment purposes. In the embodiment, the loops are set as shown in Table 2. The adjustment type F is a fast adjustment type, and the main structure is a short-stroke vertical loop device. The speed adjustment characteristic is fast, and the purpose is to quickly respond and adjust the speed matching relationship between the rolling mills to avoid the steel piling accident caused by loop feedback and adjustment lag. The adjustment type S is a slow adjustment type, and is specifically for the 5A loop and the 5B loop at the entrance of the finishing mill. The structure is a large side loop, and the loop reserve is large. The speed adjustment characteristic is slow, and is used to buffer the loop caused by the material type and speed change. The adjustment type S / F is a mixed adjustment type, and is specifically for the 1A loop and the 1B loop after the bifurcated mill stand. The structure is a large side loop, and the loop reserve is large. In normal adjustment, it is a slow adjustment, and is used to buffer the loop caused by the material type and speed change. When the loop height exceeds the dangerous value, the adjustment characteristic is changed to fast adjustment, and the speed of the upstream rolling mill is quickly adjusted to avoid the steel piling accident. The adjustment characteristic parameters of different types are shown in Table 3 (S / F characteristic is automatically selected S characteristic or F characteristic parameter).
[0059] Table 2: Loop setting example table
[0060]
[0061] Table 3: Loop adjustment characteristic parameter table
[0062] Adjustment type F S Proportional coefficient Kp 0.12 0.06 Integral coefficient Ki 0.1 0.12 Adjustment dead zone (mm) 3 50 Speed regulation slope (s) 0.4 1 Maximum adjustment limit % 1.5 6
[0063] The rolling mill speed control method further comprises: in the main line and the auxiliary line, the loop height set value and the adjustment characteristic value of the last rolling mill in the pre-finishing mill group corresponding to the loop are the same, and the adjustment dead zone value (i.e. the difference range between the loop height set value and the loop height feedback value) of the auxiliary line is greater than the adjustment dead zone value of the main line; in the bifurcated rolling mill, the loop height set value (i.e. the loop height set in advance and expected to be reached) of the loop connecting the rolling mill of the main line and the rolling mill of the auxiliary line, the adjustment characteristic value, and the adjustment dead zone value are the same. In addition, it should be noted that, in order to ensure the balance of the loop adjustment, the calibration height, the loop height set, and the like of the loops of the A line and the B line after the bifurcation are set to be the same, and the rolling mill transmission characteristics (such as the acceleration and deceleration slope) and the speed regulator parameters (such as the proportional parameter, the integral parameter, and the feedforward) corresponding to the loops are set to be the same, so as to ensure the synchronization of the adjustment and avoid the speed matching error caused by the inconsistent speed adjustment between the rolling mills.
[0064] Specifically, taking the 1A loop and the 1B loop after the bifurcated mill stand with the adjustment type S / F as an example, the control process is as follows:
[0065] The loop height set value, loop adjustment characteristics, and adjustment dead zone value of the 1A and 1B loops are set to the same value. The loop height feedback value (actual loop height value) is directly scanned by the loop scanner. Due to the actual tension and other factors, the actual loop height feedback value may not be equal to the loop height set value. When the loop is raised, if the loop height set value and the loop height feedback value are inconsistent (excluding the dead zone and other factors), a correction amount will be generated for the speed of the upstream rolling mill. When the difference between the loop height set value and the loop height feedback value is less than the adjustment dead zone value, it is considered that the current loop height set value is equal to the loop height feedback value, the current adjustment amount is locked, and the speed of the upstream rolling mill remains unchanged; when the difference is greater than the adjustment dead zone value, it is considered that the current loop height set value is equal to the loop height feedback value, and the speed of the upstream rolling mill is controlled by the output value of the loop adjuster. Specifically, when the loop height feedback value is less than the loop height set value, the loop controller controls the speed of the upstream rolling mill to increase; otherwise, the speed of the upstream rolling mill is reduced.
[0066] Since the 1A loop and the 1B loop are connected to the 13A rolling mill and the 13B rolling mill of the 12# rolling mill respectively, both loops have their own loop adjuster, which generates a respective speed correction amount for the 12# rolling mill. The output values of the 1A loop and the 1B loop adjusters are adjusted according to the different proportion factors of the main line and the secondary line, and are used as the speed adjustment amount of the bifurcated rolling mill, i.e., the 12# rolling mill. By default, when the material type at the 12# rolling mill is evenly divided, the speed correction amounts of the 1A loop and the 1B loop are multiplied by a coefficient of 0.5, and the sum is used as the speed correction amount of the 12# rolling mill. However, when the material type at the 12# rolling mill is unevenly divided, the speed correction amounts generated by the 1A loop and the 1B loop deviate greatly, which may cause a large speed error of the 12# rolling mill. In this case, the coefficient can be adjusted, such as from 0.5 to 0.3, to reduce the influence of the speed correction amount generated by the loop; or from 0.5 to 0.7, to increase the influence of the speed correction amount generated by the loop. For example, the output weight of the main line adjuster is 0.6, and the output weight of the secondary line is 0.4, which can be set by the operator according to the specific situation of the production line.
[0067] A dangerous loop height value is set. When the loop height feedback value of any of the 1A or 1B loops reaches the set dangerous loop height value, the system alarms, and all loop adjusters switch to fast adjustment characteristics parameters, rapidly reducing the speed of the 12# rolling mill to ensure that the steel is not stacked due to excessively high loop height. When the loop height is lower than the dangerous loop height value, the slow adjustment characteristics parameters are switched back after a delay.
[0068] Taking the 5A loop and the 5B loop at the inlet of the finishing mill of the adjustment type S as an example, the control process is as follows:
[0069] The sleeve height set value of 5A and 5B is set to the same value, and the adjustment dead zone value of the secondary line is set to 2-3 times that of the primary line. If the dead zone of the primary line is set to 50 mm, the dead zone of the secondary line is set to 100-150 mm. When the difference between the sleeve height set value and the feedback value is less than the adjustment dead zone value, the current sleeve height set value is considered to be equal to the sleeve height feedback value, the current adjustment amount is locked, and the upstream rolling mill speed remains unchanged; when the difference is greater than the adjustment dead zone value, the current sleeve height set value is considered to be equal to the sleeve height feedback value, and the upstream rolling mill speed is controlled by the sleeve adjustment output value.
[0070] A dangerous sleeve height value is set, which is greater than the sum of the sleeve height set value and the adjustment dead zone value of the secondary line. When the sleeve height feedback value of any of 5A or 5B is greater than the risk sleeve height value, the higher sleeve height feedback value of 5A and 5B is taken as the feedback of the sleeve adjustment, ensuring that the sleeve adjustment direction is consistent and the adjustment amount increases rapidly, thereby rapidly reducing the speed of the upstream rolling mill and avoiding the steel stacking accident caused by the high sleeve.
[0071] For the production line with the above structure, the rolling mill speed control method further comprises: when the speeds of the bifurcated rolling mill and the outlet rolling mills of the primary line and the secondary line do not match, taking the bifurcated rolling mill as the rolling mill to be adjusted, and adjusting the speeds of the bifurcated rolling mill and the previous rolling mills of the bifurcated rolling mill. The stacking and pulling relationship between the bifurcated rolling mill and the outlet rolling mills of the primary line and the secondary line is observed. Due to unreasonable speed setting, the speed between the bifurcated rolling mill and the outlet rolling mills of the double lines does not match, and at this time, the speed relationship between the two needs to be adjusted as a whole. When the speed of the bifurcated rolling mill and the outlet rolling mill of the secondary line does not match, the outlet rolling mill of the secondary line is taken as the rolling mill to be adjusted, that is, the speed of the outlet rolling mill of the secondary line and all the rolling mills in the reverse direction of the secondary line are adjusted. The stacking and pulling relationship between the bifurcated rolling mill and the outlet rolling mill of the secondary line is observed. Due to uneven cutting and inconsistent material type adjustment, the speed relationship between the bifurcated rolling mill and the outlet rolling mill of the secondary line is inconsistent, and at this time, the speed relationship between the bifurcated rolling mill and the outlet rolling mill of the secondary line is adjusted separately.
[0072] The outlet speed settings of the primary line and the secondary line allow a difference, which is adjusted by selecting the outlet rolling mill of the secondary line and adjusting the speed by the speed adjusting lever. Due to the cutting accuracy of the downstream double-length flying shear and the reliability of the upper cooling bed, it is recommended that the outlet speeds of the finishing mills of the primary line and the secondary line remain consistent, or the speed difference is as small as possible.
[0073] The exit speed of the main line generally does not change, but in some cases, the exit speed of the main line also needs to be adjusted artificially. One of the cases is that the exit speed of the main line does not match the exit speed of the exit mill of the secondary line, only the exit speed of the main line and / or the exit speed of the secondary line is adjusted, and the ratio of the exit speed of the secondary line to the exit speed of the main line is a preset ratio. In this embodiment, when the exit speed of the main line is adjusted, the exit speed of the secondary line is also adjusted in the same proportion. Since the line difference of the process material type (i.e., the difference in the material type of the rolled piece entering the A line and the B line) can generally be controlled to be below 1-3%, the exit speed ratio of the secondary line is limited to 97-103% of the speed of the main line, and the preset ratio can be adjusted by the operator as appropriate. The exit speed of the main line and the exit speed of the secondary line should be adjusted under the premise that the rolling line does not contain steel to avoid affecting the subsequent process.
[0074] Since the incoming materials of the A line and the B line are fed in respectively after being cut by the split mill, and the cutting of the mill is adjusted by the cutting mechanism of the mill, due to factors such as adjustment accuracy and equipment wear, it is impossible to ensure that the material types of the A line and the B line are absolutely consistent. Generally, the line difference (i.e., the difference in the material type of the rolled piece entering the A line and the B line) on site is generally controlled to be 1-3%. This leads to the fact that the speed of the secondary line is not consistent with the speed of the main line, and there is a speed difference of 1-3%. In view of the above situation, the mill speed control method further includes maintaining the line difference within a reasonable range through speed adjustment. Mainly, the mill speed control method further includes: monitoring the line difference of the two parts after the double high rod is split; when the line difference is less than a preset line difference, the split mill is adjusted as the to-be-adjusted mill; otherwise, the exit mill of the secondary line is adjusted as the to-be-adjusted mill. The speed control system has different control processes due to the difference between the main line and the secondary line mode to adapt to the needs of process production and material type adjustment, and has a switching function.
[0075] Specifically, for the case where the material type line difference is small, through the above loop adjustment control method, 1A and 1B, 5A and 5B two large measuring loops are used for buffering and adjustment, and when the loop storage is full and it is difficult to adjust and compensate, an alarm is issued. The split rack maintains the steel passing through the mill at a speed with a certain tension without adjusting the exit speed of the main line and the exit speed of the secondary line, so as to ensure the smooth progress of the subsequent double-shear cutting and cooling bed processes. For the case where the material type difference is large and the above adjustment method cannot adjust, the operator can manually adjust the exit line speed of the secondary line during the rolling interval, and inversely cascade the 13B# mill of the secondary line. Although the exit line speeds of the main line and the secondary line are different, they remain stable during the production process, so there is no adverse effect on the subsequent double-shear cutting and cooling bed processes.
[0076] The proposed dual-reverse cascaded mill speed control method enables precise matching of metal flow rates per second between each continuous rolling mill stand. Through a dual-reverse cascaded mill speed setting algorithm based on the process pass elongation rate, the preset speeds of each mill can be precisely matched, essentially ensuring the stacking relationship within the production line. During rolling, the dual-reverse speed regulation speed cascaded control method for the main and auxiliary lines achieves reverse cascaded speed regulation for shared stands, branch stands, and A / B lines, ensuring that the exit stand speeds of A / B lines remain constant, thus guaranteeing high stability for multiple-length shearing and cooling bed collection. Despite the large number of loopers, this invention classifies loopers according to the mill and employs different adjustment methods. By automatically adjusting the loopers and manually resetting them, the mill speed can be adjusted to adapt to speed fluctuations in A / B lines caused by material shape variations, achieving good speed matching across the entire mill line without affecting subsequent production processes. It also provides a method for adjusting the exit line speed for line difference to adapt to the speed requirements of the rolling mill throughout the rolling production process. The speed regulation strategy is complete, efficient and precise.
[0077] The dual reverse cascaded rolling mill speed control system of the present invention includes:
[0078] Memory, in which instructions are stored; and
[0079] The processor calls instructions from memory to enable the dual reverse-cascaded mill speed control system to implement the mill speed control method described above.
[0080] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured. By adjusting kernel parameters, based on the motor's load sensing characteristics, it can precisely control each working component under various operating conditions to prevent or promptly respond to blockages, achieving both high efficiency and strong practicality.
[0081] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.
[0082] The computer-readable storage medium of the present invention stores instructions that, when executed by a processor, implement the double reverse cascaded rolling mill speed control method.
[0083] Computer-readable media includes permanent and non-permanent, movable and non-movable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer-readable media does not include transitory media such as modulated data signals and carriers.
[0084] Those skilled in the art will appreciate that embodiments of the present application can be provided as methods, systems or computer program products. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage etc.) containing computer usable program code.
[0085] The present application is described with reference to the flowcharts and / or block diagrams according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the flow Figure 1 one or more flows and / or blocks Figure 1 an apparatus that implements the function specified in the flow or flows and / or block or blocks.
[0086] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including instruction apparatus, which implements the flow Figure 1 one or more flows and / or blocks Figure 1 an apparatus that implements the function specified in the flow or flows and / or block or blocks.
[0087] These computer program instructions can also be loaded into a computer or other programmable data processing devices, so that a series of operational steps are performed on the computer or other programmable devices, to generate computer-implemented processes, thus the instructions executed on the computer or other programmable devices provide processes for implementing the flowcharts Figure 1 one flowchart or multiple flowcharts and / or blocks Figure 1 one flowchart or multiple flowcharts and / or blocks
[0088] In one typical arrangement, the computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.
[0089] The memory can include non-persistent memory and / or volatile memory, such as random access memory (RAM) and / or cache memory, non-volatile memory, such as read-only memory (ROM), EPROM, and / or flash memory. The memory is an example of computer readable media.
[0090] It should also be noted that the terms "comprising," "including," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.
[0091] The above merely provides an example of the present application and is not intended to limit the present application. The present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the scope of claims of the present application.
Claims
1. A method of speed control of a tandem cold rolling mill with double reverse cascades, characterized in that, In production, a rolled piece passes through a plurality of rolling mills arranged on a main line and a sub-line extending from the middle of the main line in a production direction, and the rolling mill speed control method comprises the following steps: setting the speed of the rolling mills based on the process pass elongation, and controlling the rolling mills to run at the speed; monitoring the matching of the speed between the rolling mills on the production line; and when the speed between the rolling mills is matched, adjusting the speed of the to-be-adjusted rolling mill according to the stacking and pulling relationship of the rolled piece, and inversely adjusting the speed of other rolling mills on the main line / sub-line where the to-be-adjusted rolling mill is located; otherwise, resetting the speed of the rolling mills and repeating the above steps.
2. The mill speed control method according to claim 1, characterized in that, The step of setting the speed of the rolling mills based on the process pass elongation comprises the following steps: determining the exit speed of the exit rolling mill on the production line, and the material shape elongation of each rolling mill based on production requirements; converting the material shape elongation into the process pass elongation, and inversely recursively calculating the entry speed of each rolling mill from the exit speed; and setting the entry speed of each rolling mill according to the entry speed of each rolling mill, and setting the exit speed of each rolling mill as the entry speed of the next rolling mill.
3. The mill speed control method according to claim 1, characterized in that, The rolling mills comprise a bifurcated rolling mill arranged at the intersection of the main line and the sub-line; The rolled piece is a double high bar, after being divided by the bifurcated rolling mill, one part enters the sub-line, and the other part enters the remaining main line.
4. The mill speed control method according to claim 3, characterized in that The rolling mill speed control method further comprises: when the bifurcated rolling mill does not match the speed of the exit rolling mill of the main line and the sub-line at the same time, taking the bifurcated rolling mill as the to-be-adjusted rolling mill; when the bifurcated rolling mill does not match the speed of the exit rolling mill of the sub-line, taking the exit rolling mill of the sub-line as the to-be-adjusted rolling mill.
5. The mill speed control method according to claim 4, characterized in that, When the exit rolling mill of the main line and the exit rolling mill of the sub-line do not match the speed, only the exit speed of the main line and / or the exit speed of the sub-line is adjusted, and the proportion of the exit speed of the sub-line to the exit speed of the main line is a preset proportion.
6. The mill speed control method according to claim 3, characterized in that, The rolling mill speed control method further comprises: monitoring the line difference between the two parts of the double high bar after being divided; when the line difference is less than a preset line difference, taking the bifurcated rolling mill as the to-be-adjusted rolling mill for adjustment; otherwise, taking the exit rolling mill of the sub-line as the to-be-adjusted rolling mill for adjustment.
7. The mill speed control method according to claim 1 or 3, characterized in that, The speed of the rolling mill is adjusted by adjusting the corresponding loop of the rolling mill, wherein the type and adjustment mode of the loop are determined according to the function of the rolling mill.
8. The mill speed control method according to claim 7, characterized in that The adjustment mode adjusts a plurality of variables with different preset adjustment values, and the variables include a proportional coefficient, an integral coefficient, an adjustment dead zone, a speed regulation slope, and a maximum adjustment limit.
9. The mill speed control method according to claim 7, characterized in that, The type and adjustment mode of the loop are determined according to the function of the rolling mill, and at least one of the following is included: the type of the loop corresponding to the bifurcated rolling mill is a large side loop, and the adjustment mode is a fast and slow mixed adjustment; the type of the loop corresponding to the last rolling mill in the pre-finishing rolling mill group is a large side loop, and the adjustment mode is a slow speed adjustment; and / or the type of the loop corresponding to the ordinary rolling mill is a vertical loop, and the adjustment mode is a fast adjustment.
10. The mill speed control method according to claim 9, characterized in that, In the main line and the sub-line, the set value of the loop height and the adjustment characteristic value of the loop corresponding to the last rolling mill in the pre-finishing rolling mill group are the same, and the adjustment dead zone value of the sub-line is greater than the adjustment dead zone value of the main line; The loop height set value, the adjusting characteristic value and the adjusting dead zone value of the loop connecting the main line rolling mill and the auxiliary line rolling mill are the same.
11. A dual reverse cascade rolling mill speed control system characterized by, The system comprises: a memory having instructions stored therein; and a processor invoking the instructions in the memory to cause the system to implement the rolling mill speed control method according to any one of claims 1 to 10.
12. A computer-readable storage medium having stored thereon instructions, the instructions comprising, The instructions are executed by the processor to implement the rolling mill speed control method according to any one of claims 1 to 10.