A method and system for rolling mill slip automatic determination and protection

Abstract

This invention discloses a method and system for automatic detection and protection against slippage in rolling mills, belonging to the field of automated rolling technology. The method includes: analyzing historical curves of slippage process data acquisition; selecting the speed factor and rolling force factor that best reflect different slippage types through comparison; identifying slippage using a specific algorithm for the fluctuation changes of the speed factor and rolling force factor; converting the specific algorithm for the speed factor and rolling force factor into a PLC timing control program; and, based on the PLC timing control anti-slippage detection and judgment, activating the automatic speed reduction function of the rolling mill to prevent slippage when it occurs. This invention automatically executes anti-slippage measures based on real-time detection and judgment results, mitigating or eliminating rolling mill slippage faults, thereby reducing downtime and improving rolling rhythm and production capacity.

Description

Technical Field

[0001] This invention belongs to the field of automated rolling technology, and more specifically, relates to a method and system for real-time identification, judgment and suppression of mill slippage, which is mainly used for automatic judgment and protection of slippage faults in the roughing R2 mill of hot rolling production line. Background Technology

[0002] Due to the influence of steel grades and rolling processes, roughing mills (R2 mills) are prone to producing iron oxide scale due to large reductions, incomplete descaling, and significant temperature drops. This leads to a decrease in the friction coefficient between the billet and the rolls, making slippage more likely. This can cause minor issues like tracking errors and scrapped steel, or even serious equipment failures, significantly impacting production flow. Furthermore, the need to increase production line capacity necessitates reducing the number of passes and increasing speed, which objectively exacerbates slippage. Therefore, mitigating or eliminating mill slippage is crucial for improving rolling rhythm, reducing downtime, and increasing production capacity. Figure 1 The image shows the dramatic fluctuations in mill speed and current during the slippage process.

[0003] Existing anti-slip measures for rolling mills mainly focus on the process, meaning that operators adjust parameters such as reduction amount, rolling speed, descaling strategy, and heating temperature for each pass after discovering slippage. These are all reactive measures, lacking real-time detection and protection methods, and also lacking a unified standard for judging slippage. Summary of the Invention

[0004] In response to the above-mentioned defects or improvement needs of existing technologies, this invention proposes a method and system for automatic detection and protection of rolling mill slippage. Based on real-time detection and judgment results, it automatically executes anti-slippage measures to mitigate or eliminate rolling mill slippage faults, thereby reducing downtime and improving rolling rhythm and production capacity.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for automatic detection and protection against slippage in a rolling mill is provided, comprising:

[0006] Analyze the historical curves of the slippage process data to identify the characteristic patterns of the slippage curves, and then determine the manifestation of slippage characteristics.

[0007] Based on the characteristics of slippage, the speed factor and rolling force factor that best reflect different types of slippage were selected through comparison.

[0008] Slippage is identified using a specific algorithm that detects fluctuations in the speed factor and rolling force factor.

[0009] The specific algorithm for the fluctuation of speed factor and rolling force factor is converted into a PLC timing control program;

[0010] Based on the anti-slip detection and judgment of PLC timing control, anti-slip is achieved by activating the automatic speed reduction function of the rolling mill when slippage occurs.

[0011] In some alternative implementations, slippage is identified through specific algorithms based on changes in the velocity factor fluctuation, including:

[0012] ① In the primary PLC, the actual speed of the upper and lower working rolls of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Ta, after m periods, i.e. mTa time intervals, m actual speed values ​​of the upper and lower rolls will be obtained respectively. This set of values ​​is stored in the primary PLC.

[0013] ② For the upper roll, the actual speed is Vt_act, and the set speed is Vt_ref. Let Kt = Vt_act / Vt_ref. Within the mTa interval, there will be m Kt values, where the maximum value is Kt_max and the minimum value is Kt_min. Let Rt = Kt_max - Kt_min. During the period when the mill has steel, the Rt value is continuously compared. When the Rt value exceeds the first preset threshold, it is judged that the mill is slipping. Here, Rt > the first preset threshold is the key judgment parameter for slippage of the upper roll speed.

[0014] ③ For the lower roll, the actual speed is Vb_act, and the set speed is Vb_ref. Let Kb = Vb_act / Vb_ref. Within the mTa interval, there will be m Kb values, where the maximum value is Kb_max and the minimum value is Kb_min. Let Rb = Kb_max - Kb_min. During the period when the mill has steel, the Rb value is continuously compared. When the Rb value exceeds the first preset threshold, it is judged that the mill is slipping. Rb > the first preset threshold is the key judgment parameter for the lower roll speed slipping.

[0015] ④ If either the upper or lower roller Rt value is greater than the first preset threshold, it is determined to be speed slippage.

[0016] In some alternative implementations, slippage is identified through specific algorithms based on variations in the rolling force factor, including:

[0017] ① In the primary PLC, the rolling force on the drive side and the operating side of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Tb, after n periods, i.e. nTb time intervals, n actual rolling force values ​​on the drive side and the operating side will be obtained respectively, and these values ​​will be stored in the primary PLC. After another n periods, i.e. nTb time intervals, another n actual rolling force values ​​on the drive side and the operating side will be obtained, and these values ​​will also be stored in the primary PLC. That is, the PLC always stores two sets of rolling force values ​​for adjacent time intervals.

[0018] ② For the drive side, the actual rolling force is Fds. In the first nTb interval period, there will be n Fds values, with the maximum value recorded as Fds_max1; in the second nTb interval period, there will also be n Fds values, with the maximum value recorded as Fds_max2; let Rd = Fds_max1 - Fds_max2, and continuously compare the Rd values ​​during the steel-bearing period of the rolling mill. When the Rd value exceeds the second preset threshold, it is judged that the rolling force of the rolling mill is slipping, where Rd > the second preset threshold is the key judgment parameter for the slipping of the rolling force of the rolling mill.

[0019] ③ For the operating side, the actual rolling force is Fos. In the first nTb interval period, there will be n Fos values, with the maximum value recorded as Fos_max1; in the second nTb interval period, there will also be n Fos values, with the maximum value recorded as Fos_max2; let Ro = Fos_max1 - Fos_max2, and continuously compare the Ro values ​​during the steel-bearing period of the rolling mill. When the Ro value exceeds the second preset threshold, it is judged that the rolling force of the rolling mill is slipping, where Ro > the second preset threshold is the key judgment parameter for the rolling force slipping of the rolling mill.

[0020] ④ If any Rd or Ro value on the transmission side or the operating side is greater than the second preset threshold, it is determined that the rolling force is slipping.

[0021] In some alternative implementations, anti-slip measures during the rolling stage include:

[0022] If slippage is detected during the rolling process, the mill will immediately initiate automatic speed reduction to suppress slippage. For non-final pass speeds, the main speed ramp is used for positioning control to ensure the steel ejection position, and the automatic speed reduction target value is equal to the fixed steel ejection speed. For the final pass speed ejection, there are two scenarios: when the final pass speed ejection equals the theoretical rolling speed, the main speed ramp is used for speed control, and the automatic speed reduction target value is equal to the fixed steel ejection speed; when the final pass speed ejection reaches 90% of the maximum rolling speed, and the main speed ramp is used for positioning control, the automatic speed reduction function first switches the main speed ramp to speed control, and then executes the target speed equal to the fixed steel ejection speed. Initiating automatic mill speed reduction is a key measure to suppress slippage.

[0023] According to another aspect of the present invention, a system for automatic detection and protection against slippage in a rolling mill is provided, comprising:

[0024] The feature selection module is used to analyze the historical curves of the slippage process data collection, find the characteristic patterns of the slippage curves, and then determine the form of slippage characteristics.

[0025] The type determination module is used to select the speed factor and rolling force factor that best reflect different slippage types based on the slippage characteristics.

[0026] The identification module is used to identify slippage through a specific algorithm that detects fluctuations in the speed factor and rolling force factor.

[0027] The PLC control module is used to convert specific algorithms for the fluctuation changes of speed factor and rolling force factor into PLC timing control programs;

[0028] The slippage suppression module is used to prevent slippage by activating the automatic speed reduction function of the rolling mill when slippage occurs, based on the anti-slippage detection and judgment of PLC timing control.

[0029] In some alternative implementations, slippage is identified through specific algorithms based on changes in the velocity factor fluctuation, including:

[0030] ① In the primary PLC, the actual speed of the upper and lower working rolls of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Ta, after m periods, i.e. mTa time intervals, m actual speed values ​​of the upper and lower rolls will be obtained respectively. This set of values ​​is stored in the primary PLC.

[0031] ② For the upper roll, the actual speed is Vt_act, and the set speed is Vt_ref. Let Kt = Vt_act / Vt_ref. Within the mTa interval, there will be m Kt values, where the maximum value is Kt_max and the minimum value is Kt_min. Let Rt = Kt_max - Kt_min. During the period when the mill has steel, the Rt value is continuously compared. When the Rt value exceeds the first preset threshold, it is judged that the mill is slipping. Here, Rt > the first preset threshold is the key judgment parameter for slippage of the upper roll speed.

[0032] ③ For the lower roll, the actual speed is Vb_act, and the set speed is Vb_ref. Let Kb = Vb_act / Vb_ref. Within the mTa interval, there will be m Kb values, where the maximum value is Kb_max and the minimum value is Kb_min. Let Rb = Kb_max - Kb_min. During the period when the mill has steel, the Rb value is continuously compared. When the Rb value exceeds the first preset threshold, it is judged that the mill is slipping. Rb > the first preset threshold is the key judgment parameter for the lower roll speed slipping.

[0033] ④ If either the upper or lower roller Rt value is greater than the first preset threshold, it is determined to be speed slippage.

[0034] In some alternative implementations, slippage is identified through specific algorithms based on variations in the rolling force factor, including:

[0035] ① In the primary PLC, the rolling force on the drive side and the operating side of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Tb, after n periods, i.e. nTb time intervals, n actual rolling force values ​​on the drive side and the operating side will be obtained respectively, and these values ​​will be stored in the primary PLC. After another n periods, i.e. nTb time intervals, another n actual rolling force values ​​on the drive side and the operating side will be obtained, and these values ​​will also be stored in the primary PLC. That is, the PLC always stores two sets of rolling force values ​​for adjacent time intervals.

[0036] ② For the drive side, the actual rolling force is Fds. During the first nTb interval period, there will be n Fds values, with the maximum value denoted as Fds_max1; during the second nTb interval period, there will also be... During the steelmaking period, the Rd value is continuously compared. When the Rd value exceeds the second preset threshold, it is determined that the rolling force of the rolling mill is slipping. Rd > the second preset threshold is the key judgment parameter for the rolling force slipping of the rolling mill.

[0037] ③ For the operating side, the actual rolling force is Fos. In the first nTb interval period, there will be n Fos values, with the maximum value recorded as Fos_max1; in the second nTb interval period, there will also be n Fos values, with the maximum value recorded as Fos_max2; let Ro = Fos_max1 - Fos_max2, and continuously compare the Ro values ​​during the steel-bearing period of the rolling mill. When the Ro value exceeds the second preset threshold, it is judged that the rolling force of the rolling mill is slipping, where Ro > the second preset threshold is the key judgment parameter for the rolling force slipping of the rolling mill.

[0038] ④ If any Rd or Ro value on the transmission side or the operating side is greater than the second preset threshold, it is determined that the rolling force is slipping.

[0039] In some alternative implementations, anti-slip measures during the rolling stage include:

[0040] If slippage is detected during the rolling process, the mill will immediately initiate automatic speed reduction to suppress slippage. For non-final pass speeds, the main speed ramp is used for positioning control to ensure the steel ejection position, and the automatic speed reduction target value is equal to the fixed steel ejection speed. For the final pass speed ejection, there are two scenarios: when the final pass speed ejection equals the theoretical rolling speed, the main speed ramp is used for speed control, and the automatic speed reduction target value is equal to the fixed steel ejection speed; when the final pass speed ejection reaches 90% of the maximum rolling speed, and the main speed ramp is used for positioning control, the automatic speed reduction function first switches the main speed ramp to speed control, and then executes the target speed equal to the fixed steel ejection speed. Initiating automatic mill speed reduction is a key measure to suppress slippage.

[0041] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0042] 1) Based on two different types of slippage phenomena, two algorithms, "speed" and "rolling force", are used to achieve dual protection against slippage in the rolling mill, eliminating more than 90% of rolling mill slippage.

[0043] 2) The problem of storing the sampling period is solved by cleverly using PLC timing control, saving debugging time.

[0044] 3) The anti-slipping measure is to increase the sliding friction coefficient by automatically reducing the speed of the rolling mill, so that the rolling mill can be restored from the slipping state to the normal state without stopping the machine for process adjustment, which is in line with the actual situation on site.

[0045] 4) The entire process is completed automatically by PLC, without the need for manual monitoring and intervention, ensuring standardization and real-time performance. Attached Figure Description

[0046] Figure 1 This is a schematic diagram illustrating the drastic fluctuations in mill speed and current during slippage, provided by an embodiment of the present invention.

[0047] Figure 2 This is a flowchart illustrating a method for automatic detection and protection of slippage in a rolling mill, provided by an embodiment of the present invention.

[0048] Figure 3 This invention provides a method for identifying speed slippage by applying a specific algorithm to the frequency and amplitude of the high-frequency oscillation curve of the rolling mill speed.

[0049] Figure 4 This invention provides a method for identifying pressure slippage by employing a specific algorithm on the fluctuations of the rolling force curves on both sides of the rolling mill.

[0050] Figure 5 This invention provides a PLC timing control method for periodic signal sampling.

[0051] Figure 6 This is the actual anti-slip effect after the speed slip function is activated according to an embodiment of the present invention;

[0052] Figure 7 This is the actual anti-slip effect after the rolling force slippage function is put into operation according to an embodiment of the present invention;

[0053] Figure 8 This is a schematic diagram of a system for automatic detection and protection of slippage in a rolling mill, provided by an embodiment of the present invention. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0055] Example 1

[0056] like Figure 2 The diagram shown is a flowchart illustrating a method for automatic detection and protection against slippage in a rolling mill, provided by an embodiment of the present invention. Based on the detection result, anti-slippage measures are automatically executed. Figure 2 The method shown includes the following steps:

[0057] S1: Analyze the historical curves of the slippage process data collection to find the characteristic patterns of the slippage curves, and then determine the form of slippage characteristics;

[0058] In step S1, it is necessary to analyze a large number of historical slippage curves to identify the characteristic patterns of the slippage curves, and then determine the two forms of slippage characteristics: ① drastic fluctuations in speed and current. ② abnormal decrease in rolling force on both sides of the rolling mill during the rolling process.

[0059] S2: Based on the characteristics of slippage, the speed factor and rolling force factor that best reflect different types of slippage are selected through comparison;

[0060] In step S2, by analyzing the slippage history curves, based on the two similar characteristics of all slippage curves, and according to the slippage type, the two factors that best reflect different slippage types, "speed" and "rolling force", are selected by comparison, and slippage is identified by developing a suitable algorithm.

[0061] S3: Slippage is identified through a specific algorithm that detects fluctuations in the speed factor and rolling force factor;

[0062] In step S3, process data acquisition algorithms based on the "speed slippage" factor and the "rolling force slippage" factor are developed, and algorithm formulas are formed. The slippage algorithm formulas for the "speed factor" and the "rolling force factor" are developed based on single-cycle curves. The algorithm formulas need to be tested against a large number of historical curves to verify the effectiveness and accuracy of the algorithm. Then, based on the verification results, the parameters such as the cycle and threshold value in the algorithm formulas are optimized and tuned.

[0063] ① Development of a slippage algorithm for the "speed factor". This algorithm is used to prevent mill vibration-related faults caused by slippage. Slippage is identified by applying a specific algorithm to the frequency and amplitude of the mill speed curve. The algorithm principle is as follows: the speeds of the upper and lower rolls of the mill are periodically sampled. If the difference between the maximum and minimum values ​​of the ratio of the actual speed to the set speed within several adjacent cycles is greater than a speed threshold, slippage is identified. The sampling period and speed threshold need to be optimized and tuned by combining multiple historical speed curves, such as... Figure 3 As shown, Figure 3 The R2 rolling mill experienced severe fluctuations in the speed of the lower roll due to slippage. The slippage result determined by the speed anti-slippage formula was highly consistent with the slippage process. The specific implementation process is as follows. In this embodiment of the invention, m is set to 8 and the first preset threshold is set to 0.04. However, it is understood that m and the first preset threshold in this invention can also be other values, which can be determined according to the actual situation.

[0064] ① In the primary PLC, the actual speed of the upper and lower working rolls of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Ta, after 8 periods, i.e. 8Ta time intervals, 8 actual speed values ​​of the upper and lower rolls will be obtained respectively. This set of values ​​is stored in the primary PLC.

[0065] ② For the upper roll, the actual speed is Vt_act, and the set speed is Vt_ref. Let Kt = Vt_act / Vt_ref. Within the 8Ta interval, there will be 8 Kt values, with the maximum value being Kt_max and the minimum value being Kt_min. Let Rt = Kt_max - Kt_min. During the steel-carrying period of the mill, the Rt value is continuously compared. When the Rt value exceeds 0.04, it is judged that the mill is slipping. Rt > 0.04 is the key judgment parameter for slippage of the upper roll speed.

[0066] ③ For the lower roll, the actual speed is Vb_act, and the set speed is Vb_ref. Let Kb = Vb_act / Vb_ref. Within the 8Ta interval, there will be 8 Kb values, with the maximum value being Kb_max and the minimum value being Kb_min. Let Rb = Kb_max - Kb_min. During the period when the mill has steel, the Rb value is continuously compared. When the Rb value exceeds 0.04, it is judged that the mill is slipping. Rb > 0.04 is the key judgment parameter for the lower roll speed slipping.

[0067] ④ If either the upper or lower roller Rt value is greater than 0.04, it is determined to be speed slippage.

[0068] ② Development of a slippage algorithm for the "rolling force factor". This algorithm is used to prevent mill tracking faults caused by slippage. Slippage is identified by applying a specific algorithm to the actual rolling force curves detected on the mill drive side and working side. The algorithm principle is as follows: The rolling force on both sides of the mill is periodically sampled. If the difference between the two maximum values ​​of the actual rolling force on one side in two adjacent time periods is greater than a rolling force threshold value, slippage is identified. The sampling period and rolling force threshold value need to be optimized and tuned in conjunction with multiple historical rolling force curves, such as... Figure 4 As shown, Figure 4 During the rolling process, the R2 mill experiences a sharp drop in pressure on both sides due to slippage. An anti-slippage formula based on rolling force is applied to issue a slippage alarm at the first sign of an abnormal drop in rolling force. The specific implementation process is as follows, where, in this embodiment of the invention, n is set to 5, and the second preset threshold is 1.0e. 6 This is an explanation, but it is understood that n and the second preset threshold in this invention can also be other values, which can be determined according to the actual situation:

[0069] ① In the primary PLC, the rolling force on the drive side and the operating side of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Tb, after 5 periods, i.e. 5Tb time intervals, 5 actual rolling force values ​​on the drive side and the operating side will be obtained respectively, and these values ​​will be stored in the primary PLC. After another 5 periods, i.e. 5Tb time intervals, another 5 actual rolling force values ​​on the drive side and the operating side will be obtained, and these values ​​will also be stored in the primary PLC. That is, the PLC always stores two sets of rolling force values ​​for adjacent time intervals.

[0070] ② For the drive side, the actual rolling force is Fds. In the first 5Tb interval period, there will be 5 Fds values, with the maximum value recorded as Fds_max1; in the second 5Tb interval period, there will also be 5 Fds values, with the maximum value recorded as Fds_max2; let Rd = Fds_max1 - Fds_max2, and continuously compare the Rd values ​​during the steel-bearing period of the rolling mill. When the Rd value exceeds 1.0e... 6 This indicates slippage in the rolling mill force, where Rd > 1.0e. 6 Key parameters for judging rolling force slippage in rolling mills;

[0071] ③ For the operating side, the actual rolling force is Fos. In the first 5Tb interval period, there will be 5 Fos values, with the maximum value recorded as Fos_max1; in the second 5Tb interval period, there will also be 5 Fos values, with the maximum value recorded as Fos_max2; let Ro = Fos_max1 - Fos_max2, and continuously compare the Ro values ​​during the steel-bearing period of the mill. When the Ro value exceeds 1.0e... 6 This indicates slippage in the rolling mill's rolling force, where Ro > 1.0e. 6Key parameters for judging rolling force slippage in rolling mills;

[0072] ④ Any Rd or Ro value on the transmission side and the operating side is greater than 1.0e 6 This indicates that the rolling force is slipping.

[0073] S4: Transform the specific algorithm for the fluctuation of speed factor and rolling force factor into PLC timing control;

[0074] In step S4, the optimized and tuned PDA algorithm formulas for "speed" and "rolling force" are converted into a PLC program. The key to converting the algorithm formulas into a PLC program is the processing of periodic sampling of speed and rolling force. Since the PLC scans periodically, processing values ​​from several adjacent periods requires establishing a buffer function block in the PLC program. Therefore, the program can only be modified offline, and the PLC must be reset and the program written back when the machine can be stopped, which is inconvenient for program debugging and parameter tuning. This invention considers using PLC timing control to solve this problem, cleverly utilizing PLC timing control to complete periodic signal sampling, enabling online program debugging and modification, which can significantly shorten debugging time. Figure 5 As shown, taking speed sampling as an example, the buffer function block has a loop time T1 = 10ms, and samples the values ​​from adjacent 80ms intervals. Rolling force sampling is similar. Because these buffer function blocks can be inserted and modified online, debugging time is greatly reduced.

[0075] S5: Based on the anti-slip detection and judgment of PLC timing control, anti-slip is achieved by activating the automatic speed reduction function of the rolling mill when slippage occurs.

[0076] In step S5, based on the PLC program's anti-slip detection and judgment function, a PLC program to suppress anti-slip is developed. This is achieved by activating the automatic speed reduction function of the rolling mill. After multiple simulated rolling verifications, the final target speed for speed reduction is selected to be equal to the steel ejection speed.

[0077] During the rolling process, automatic speed reduction of the rolling mill is mainly used to suppress slippage. The main speed ramp for non-final passes is controlled by positioning, requiring the steel ejection position to be guaranteed. The target value of the automatic speed reduction is equal to a fixed steel ejection speed (e.g., 1.8 m / s). The steel ejection speed for the final pass falls into two categories:

[0078] When the steel-throwing speed in the final pass is equal to the theoretical rolling speed, the main ramp wave is speed-controlled, and the automatic speed reduction target value is equal to the fixed steel-throwing speed (e.g., 1.8 m / s).

[0079] When the steel throwing speed in the final pass reaches 90% of the maximum rolling speed, and the main speed ramp is in positioning control, the automatic speed reduction function first changes the main speed ramp to speed control, and then executes the target speed equal to the fixed steel throwing speed (e.g., 1.8 m / s).

[0080] like Figure 6 As shown, Figure 6 During the second pass of the R2 rolling mill, the anti-slip function detected signs of slippage and immediately reduced the mill speed from 3.0 m / s to 1.8 m / s, thus eliminating the slippage.

[0081] like Figure 7 As shown, Figure 7 During the R2 rolling process, a sharp drop in pressure occurred on both sides due to slippage. The pressure anti-slippage function promptly made a judgment and automatically reduced the speed of the rolling mill. After about 0.94 seconds, the rolling force returned to normal and the slippage disappeared.

[0082] In this embodiment of the invention, after the anti-slip function was implemented, the results were continuously tracked. The anti-slip function was verified in actual field conditions and achieved good results. Figure 6 and Figure 7 As shown in the statistics, after nearly a year of functional deployment, the average number of times slippage was identified and suppressed per month exceeded 10, and the time spent eliminating faults caused by slippage was 590 minutes per year.

[0083] Example 2

[0084] like Figure 8 The diagram shown is a structural schematic of a system for automatic detection and protection of slippage in a rolling mill, provided by an embodiment of the present invention, comprising:

[0085] The feature selection module 801 is used to analyze the historical curves of the slippage process data acquisition, find the characteristic patterns of the slippage curves, and then determine the form of slippage characteristics.

[0086] The type determination module 802 is used to select the speed factor and rolling force factor that best reflect different slippage types based on the slippage characteristic manifestations.

[0087] The identification module 803 is used to identify slippage through a specific algorithm that detects fluctuations in the speed factor and rolling force factor.

[0088] PLC control module 804 is used to convert a specific algorithm for the fluctuation of speed factor and rolling force factor into a PLC timing control program;

[0089] The slippage suppression module 805 is used to prevent slippage by activating the automatic speed reduction function of the rolling mill when slippage occurs, based on the slippage detection and judgment of PLC timing control.

[0090] In this embodiment of the invention, slippage is identified through a specific algorithm based on the fluctuation of the speed factor. Specifically, in this embodiment, m is described as being 8 and the first preset threshold as 0.04. However, it is understood that m and the first preset threshold in this invention can also be other values, which can be determined according to actual circumstances.

[0091] ① In the primary PLC, the actual speed of the upper and lower working rolls of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Ta, after 8 periods, i.e. 8Ta time intervals, 8 actual speed values ​​of the upper and lower rolls will be obtained respectively. This set of values ​​is stored in the primary PLC.

[0092] ② For the upper roll, the actual speed is Vt_act, and the set speed is Vt_ref. Let Kt = Vt_act / Vt_ref. Within the 8Ta interval, there will be 8 Kt values, with the maximum value being Kt_max and the minimum value being Kt_min. Let Rt = Kt_max - Kt_min. During the steel-carrying period of the mill, the Rt value is continuously compared. When the Rt value exceeds 0.04, it is judged that the mill is slipping. Rt > 0.04 is the key judgment parameter for slippage of the upper roll speed.

[0093] ③ For the lower roll, the actual speed is Vb_act, and the set speed is Vb_ref. Let Kb = Vb_act / Vb_ref. Within the 8Ta interval, there will be 8 Kb values, with the maximum value being Kb_max and the minimum value being Kb_min. Let Rb = Kb_max - Kb_min. During the period when the mill has steel, the Rb value is continuously compared. When the Rb value exceeds 0.04, it is judged that the mill is slipping. Rb > 0.04 is the key judgment parameter for the lower roll speed slipping.

[0094] ④ If either the upper or lower roller Rt value is greater than 0.04, it is determined to be speed slippage.

[0095] In this embodiment of the invention, slippage is identified through a specific algorithm based on the fluctuation of the rolling force factor, including, in this embodiment of the invention, n is set to 5, and the second preset threshold is 1.0e. 6 This is an explanation, but it is understood that n and the second preset threshold in this invention can also be other values, which can be determined according to the actual situation:

[0096] ① In the primary PLC, the rolling force on the drive side and the operating side of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Tb, after 5 periods, i.e. 5Tb time intervals, 5 actual rolling force values ​​on the drive side and the operating side will be obtained respectively, and these values ​​will be stored in the primary PLC. After another 5 periods, i.e. 5Tb time intervals, another 5 actual rolling force values ​​on the drive side and the operating side will be obtained, and these values ​​will also be stored in the primary PLC. That is, the PLC always stores two sets of rolling force values ​​for adjacent time intervals.

[0097] ② For the drive side, the actual rolling force is Fds. In the first 5Tb interval period, there will be 5 Fds values, with the maximum value recorded as Fds_max1; in the second 5Tb interval period, there will also be 5 Fds values, with the maximum value recorded as Fds_max2; let Rd = Fds_max1 - Fds_max2, and continuously compare the Rd values ​​during the steel-bearing period of the rolling mill. When the Rd value exceeds 1.0e... 6 This indicates slippage in the rolling mill force, where Rd > 1.0e. 6 Key parameters for judging rolling force slippage in rolling mills;

[0098] ③ For the operating side, the actual rolling force is Fos. In the first 5Tb interval period, there will be 5 Fos values, with the maximum value recorded as Fos_max1; in the second 5Tb interval period, there will also be 5 Fos values, with the maximum value recorded as Fos_max2; let Ro = Fos_max1 - Fos_max2, and continuously compare the Ro values ​​during the steel-bearing period of the mill. When the Ro value exceeds 1.0e... 6 This indicates slippage in the rolling mill's rolling force, where Ro > 1.0e. 6 Key parameters for judging rolling force slippage in rolling mills;

[0099] ④ Any Rd or Ro value on the transmission side and the operating side is greater than 1.0e 6 This indicates that the rolling force is slipping.

[0100] In this embodiment of the invention, the anti-slip measures during the rolling stage include:

[0101] During the rolling process, if slippage is detected, the mill automatically reduces its speed to suppress it. For non-final pass speeds, the main speed ramp is used for positioning control to ensure the steel ejection position is maintained, and the automatic speed reduction target value equals a fixed ejection speed. For the final pass speed ejection, there are two scenarios: when the final pass speed ejection equals the theoretical rolling speed, the main speed ramp is used for speed control, and the automatic speed reduction target value equals a fixed ejection speed; when the final pass speed ejection reaches 90% of the maximum rolling speed, and the main speed ramp is used for positioning control, the automatic speed reduction function first switches the main speed ramp to speed control, and then executes the target speed equal to the fixed ejection speed. Initiating automatic mill speed reduction is a key measure to suppress slippage.

[0102] This invention detects slippage in real time by monitoring speed and pressure fluctuations during the rolling process, and eliminates slippage in its early stages through the automatic speed reduction function of the rolling mill. The entire process is completed automatically by the PLC system without manual intervention, achieving standardized slippage judgment with a success rate of over 90%, significantly reducing slippage failure time and meeting the requirements of continuous production lines.

[0103] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0104] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for automatic detection and protection against slippage in rolling mills, characterized in that, include: Analyze the historical curves of the slippage process data to identify the characteristic patterns of the slippage curves, and then determine the manifestation of slippage characteristics. Based on the characteristics of slippage, the speed factor and rolling force factor that best reflect different types of slippage were selected through comparison. Slippage is identified using a specific algorithm that detects fluctuations in the speed factor and rolling force factor. The specific algorithm for the fluctuation of speed factor and rolling force factor is converted into a PLC timing control program; Based on the anti-slip detection and judgment of PLC timing control, anti-slip is achieved by activating the automatic speed reduction function of the rolling mill when slippage occurs; Slippage is identified through a specific algorithm that detects fluctuations in the velocity factor, including: ① In the primary PLC, the actual speed of the upper and lower working rolls of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Ta, after m periods, i.e. mTa time intervals, m actual speed values ​​of the upper and lower rolls will be obtained respectively. This set of values ​​is stored in the primary PLC. ② For the upper roller, the actual speed is Vt_act, the set speed is Vt_ref, and let Kt = Vt_act / Vt_ref. Within the mTa interval, there will be m Kt values, where the maximum value is Kt_max and the minimum value is... Kt_min; Let Rt=Kt_max-Kt_min, continuously compare the Rt value during the steel-carrying period of the rolling mill, and judge the rolling mill slippage when the Rt value exceeds the first preset threshold, where Rt>the first preset threshold is the key judgment parameter for slippage of the upper roll speed of the rolling mill. ③ For the lower roll, the actual speed is Vb_act, and the set speed is Vb_ref. Let Kb = Vb_act / Vb_ref. During the mTa interval, there will be m Kb values, where the maximum value is Kb_max and the minimum value is Kb_min. Let Rb = Kb_max - Kb_min. During the period when the mill has steel, the Rb value is continuously compared. When the Rb value exceeds the first preset threshold, it is judged that the mill is slipping. Rb > the first preset threshold is the key judgment parameter for the lower roll speed slipping. ④ If either the upper or lower roller Rt value is greater than the first preset threshold, it is determined to be speed slippage.

2. The method according to claim 1, characterized in that, Slippage is identified through a specific algorithm that detects fluctuations in the rolling force factor, including: ① In the primary PLC, the rolling force on the drive side and the operating side of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Tb, after n periods, i.e. nTb time intervals, n actual rolling force values ​​on the drive side and the operating side will be obtained respectively, and these values ​​will be stored in the primary PLC. After another n periods, i.e. nTb time intervals, another n actual rolling force values ​​on the drive side and the operating side will be obtained, and these values ​​will also be stored in the primary PLC. That is, the PLC always stores two sets of rolling force values ​​for adjacent time intervals. ② For the drive side, the actual rolling force is Fds. In the first nTb interval period, there will be n Fds values, with the maximum value recorded as Fds_max1; in the second nTb interval period, there will also be n Fds values, with the maximum value recorded as Fds_max2; let Rd = Fds_max1 - Fds_max2, and continuously compare the Rd values ​​during the steel-bearing period of the rolling mill. When the Rd value exceeds the second preset threshold, it is judged that the rolling force of the rolling mill is slipping, where Rd > the second preset threshold is the key judgment parameter for the slipping of the rolling force of the rolling mill. ③ For the operating side, the actual rolling force is Fos. In the first nTb interval period, there will be n Fos values, of which the maximum value is recorded as Fos_max1; in the second nTb interval period, there will also be n Fos values, of which the maximum value is recorded as Fos_max2; let Ro = Fos_max1 - Fos_max2, and continuously compare the Ro values ​​during the period when the mill has steel. When the Ro value exceeds the second preset threshold, it is judged that the mill rolling force is slipping, where Ro > the second preset threshold is the key judgment parameter for mill rolling force slipping; ④ If any Rd or Ro value on the transmission side or the operating side is greater than the second preset threshold, it is determined that the rolling force is slipping.

3. The method according to claim 1 or 2, characterized in that, Anti-slip measures during the rolling stage include: If slippage is detected during the rolling process, the mill will immediately initiate automatic speed reduction to suppress slippage. For non-final pass speeds, the main speed ramp is used for positioning control to ensure the steel ejection position, and the automatic speed reduction target value is equal to the fixed steel ejection speed. For the final pass speed ejection, there are two scenarios: when the final pass speed ejection equals the theoretical rolling speed, the main speed ramp is used for speed control, and the automatic speed reduction target value is equal to the fixed steel ejection speed; when the final pass speed ejection reaches 90% of the maximum rolling speed, and the main speed ramp is used for positioning control, the automatic speed reduction function first switches the main speed ramp to speed control, and then executes the target speed equal to the fixed steel ejection speed. Initiating automatic mill speed reduction is a key measure to suppress slippage.

4. A system for automatic detection and protection against slippage in rolling mills, characterized in that, include: The feature selection module is used to analyze the historical curves of the slippage process data collection, find the characteristic patterns of the slippage curves, and then determine the form of slippage characteristics. The type determination module is used to select the speed factor and rolling force factor that best reflect different slippage types based on the slippage characteristics. The identification module is used to identify slippage through a specific algorithm that detects fluctuations in the speed factor and rolling force factor. The PLC control module is used to convert specific algorithms for the fluctuation changes of speed factor and rolling force factor into PLC timing control programs; The slippage suppression module is used to prevent slippage by activating the automatic speed reduction function of the rolling mill when slippage occurs, based on the anti-slippage detection and judgment of PLC timing control. Slippage is identified through a specific algorithm that detects fluctuations in the velocity factor, including: ① In the primary PLC, the actual speed of the upper and lower working rolls of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Ta, after m periods, i.e. mTa time intervals, m actual speed values ​​of the upper and lower rolls will be obtained respectively. This set of values ​​is stored in the primary PLC. ② For the upper roller, the actual speed is Vt_act, the set speed is Vt_ref, and let Kt = Vt_act / Vt_ref. Within the mTa interval, there will be m Kt values, where the maximum value is Kt_max and the minimum value is Kt_min. Let Rt = Kt_max - Kt_min. During the period when the mill has steel, the Rt value is continuously compared. When the Rt value exceeds the first preset threshold, it is judged that the mill is slipping. Rt > the first preset threshold is the key judgment parameter for slipping of the upper roll speed of the mill. ③ For the lower roll, the actual speed is Vb_act, and the set speed is Vb_ref. Let Kb = Vb_act / Vb_ref. During the mTa interval, there will be m Kb values, where the maximum value is Kb_max and the minimum value is Kb_min. Let Rb = Kb_max - Kb_min. During the period when the mill has steel, the Rb value is continuously compared. When the Rb value exceeds the first preset threshold, it is judged that the mill is slipping. Rb > the first preset threshold is the key judgment parameter for the lower roll speed slipping. ④ If either the upper or lower roller Rt value is greater than the first preset threshold, it is determined to be speed slippage.

5. The system according to claim 4, characterized in that, Slippage is identified through a specific algorithm that detects fluctuations in the rolling force factor, including: ① In the primary PLC, the rolling force on the drive side and the operating side of the rolling mill is continuously sampled periodically. Assuming the PLC sampling period is Tb, after n periods, i.e. nTb time intervals, n actual rolling force values ​​on the drive side and the operating side will be obtained respectively, and these values ​​will be stored in the primary PLC. After another n periods, i.e. nTb time intervals, another n actual rolling force values ​​on the drive side and the operating side will be obtained, and these values ​​will also be stored in the primary PLC. That is, the PLC always stores two sets of rolling force values ​​for adjacent time intervals. ② For the drive side, the actual rolling force is Fds. In the first nTb interval period, there will be n Fds values, with the maximum value recorded as Fds_max1; in the second nTb interval period, there will also be n Fds values, with the maximum value recorded as Fds_max2; let Rd = Fds_max1 - Fds_max2, and continuously compare the Rd values ​​during the steel-bearing period of the rolling mill. When the Rd value exceeds the second preset threshold, it is judged that the rolling force of the rolling mill is slipping, where Rd > the second preset threshold is the key judgment parameter for the slipping of the rolling force of the rolling mill. ③ For the operating side, the actual rolling force is Fos. In the first nTb interval period, there will be n Fos values, of which the maximum value is recorded as Fos_max1; in the second nTb interval period, there will also be n Fos values, of which the maximum value is recorded as Fos_max2; let Ro = Fos_max1 - Fos_max2, and continuously compare the Ro values ​​during the period when the mill has steel. When the Ro value exceeds the second preset threshold, it is judged that the mill rolling force is slipping, where Ro > the second preset threshold is the key judgment parameter for mill rolling force slipping; ④ If any Rd or Ro value on the transmission side or the operating side is greater than the second preset threshold, it is determined that the rolling force is slipping.

6. The system according to claim 4 or 5, characterized in that, Anti-slip measures during the rolling stage include: If slippage is detected during the rolling process, the mill will immediately initiate automatic speed reduction to suppress slippage. For non-final pass speeds, the main speed ramp is used for positioning control to ensure the steel ejection position, and the automatic speed reduction target value is equal to the fixed steel ejection speed. For the final pass speed ejection, there are two scenarios: when the final pass speed ejection equals the theoretical rolling speed, the main speed ramp is used for speed control, and the automatic speed reduction target value is equal to the fixed steel ejection speed; when the final pass speed ejection reaches 90% of the maximum rolling speed, and the main speed ramp is used for positioning control, the automatic speed reduction function first switches the main speed ramp to speed control, and then executes the target speed equal to the fixed steel ejection speed. Initiating automatic mill speed reduction is a key measure to suppress slippage.

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