An accuracy evaluation method for the work roll bending equipment of a hot rolling mill

Abstract

The present invention provides a method for evaluating the accuracy of the bending roll equipment of a hot rolling mill, belonging to the field of accuracy control of bending rolls for hot rolled strip steel. The method includes: determining the response time of the bending roll equipment on both sides of the rolling mill; determining the deviation of the steady-state value of the bending roll force on both sides of the rolling mill; determining the accompanying accuracy of the bending roll force; determining the rise time of the bending roll force on both sides of the rolling mill; determining the steady-state error of the bending roll force on both sides of the rolling mill; using a four-level scoring system to score the above five indicators respectively, namely, the response time of the bending roll equipment on both sides of the rolling mill, the deviation of the steady-state value of the bending roll force on both sides of the rolling mill, the accompanying accuracy of the bending roll force, the rise time of the bending roll force on both sides of the rolling mill, and the steady-state error of the bending roll force on both sides of the rolling mill, and determining the comprehensive score of the operating accuracy of the bending rolls of the rolling mill according to the scoring results of each indicator obtained. By using the present invention, the operating accuracy and effect of the bending rolls of the rolling mill can be judged in real time.

Description

Technical Field

[0001] The present invention relates to the field of precision control of bending rolls for hot-rolled strip steel, and particularly to a method for evaluating the precision of bending roll equipment of a hot-rolling mill. Background Art

[0002] During the production process of hot-rolled strip steel, bending rolls can improve the shape of the strip steel during production, and are an important part of ensuring product quality and process quantification. Real-time monitoring of bending roll control parameters and operation curves, for the operation status of the bending rolls during the production of each coil of strip steel, to promptly discover problems and make adjustments. Bending roll position control belongs to automatic position control, which automatically adjusts the position of the controlled object to the specified target value within a given time and within the allowed accuracy range.

[0003] The patent (CN111346926A, a method for controlling the bending roll force of a temper mill) proposes to adjust the bending roll force by using the feedforward adjustment amount of the rolling force, so that the bending roll force in the Nth scanning period matches the rolling force, to adjust the bending roll amount of the rolling roll, and further compensate for the deformation amount of the rolling roll, thereby avoiding the problems of middle waves, edge waves, and edge fold marks in the rolled strip steel caused by the deformation of the rolling roll. The patent (CN112439794A, a method for predicting the hot-rolling bending roll force based on LSTM) proposes a network model with an updated mechanism, which improves the predicted value of the bending roll force and makes the network more stable. The patent (CN110340151B, a method and system for determining and controlling the bending roll force during roll change of a rolling mill) proposes in the technical field of rolling mill roll change maintenance, obtaining the roll weight of the roll to be replaced of the target rolling mill, the friction force of the roll change track, and the weight of the bearing block of the roll to be replaced; based on the roll weight, the friction force of the roll change track, and the weight of the bearing block of the roll to be replaced, determining the theoretical minimum bending roll force required to lift the roll to be replaced; applying the theoretical minimum bending roll force to the roll to be replaced, and cumulatively applying a bending roll force with a preset bending roll force gradient value on the basis of the theoretical minimum bending roll force until the roll change track in the stand where the roll to be replaced is located and the track of the roll change vehicle are horizontal, to determine the target bending roll force; solving the technical problem that the bending roll force in the existing roll change method is too large, resulting in frequent oil leakage of the hydraulic cylinder of the stand.

[0004] The above-mentioned existing technologies are introduced from aspects such as the process design and control system of the bending roll, and the control and prediction of the bending roll are proposed. However, none of the above-mentioned solutions involve the online quantitative evaluation of the running accuracy of the bending roll and the real-time warning of the running of the bending roll. Summary of the Invention

[0005] The embodiments of the present invention provide a method for evaluating the precision of bending roll equipment of a hot-rolling mill, which can judge the running precision and effect of the bending rolls of the rolling mill in real time. The technical solution is as follows:

[0006] The embodiments of the present invention provide a method for evaluating the precision of bending roll equipment of a hot-rolling mill, including:

[0007] Determine the response time of the work roll bending equipment on both sides of the rolling mill;

[0008] Determine the deviation of the steady-state value of the work roll bending force on both sides of the rolling mill;

[0009] Determine the accompanying accuracy of the work roll bending force;

[0010] Determine the rise time of the work roll bending force on both sides of the rolling mill;

[0011] Determine the steady-state error of the work roll bending force on both sides of the rolling mill;

[0012] Adopt a four-level scoring system to score the five indicators of the response time of the work roll bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the work roll bending force on both sides of the rolling mill, the accompanying accuracy of the work roll bending force, the rise time of the work roll bending force on both sides of the rolling mill, and the steady-state error of the work roll bending force on both sides of the rolling mill respectively. According to the scoring results of each indicator obtained, determine the comprehensive score of the operation accuracy of the work roll bending of the rolling mill.

[0013] Further, before determining the response time of the work roll bending equipment on both sides of the rolling mill, the method further includes:

[0014] Real-time collect the set and measured data of the work roll bending;

[0015] Automatically start the calculation of the evaluation of the work roll bending accuracy according to the trigger event.

[0016] Further, the collected set data of the work roll bending includes: the given data of the work roll bending force, and the given data of the work roll bending force is the given curve of the work roll bending force; the collected measured data of the work roll bending includes: the signal of the rolling mill biting the steel and the measured data of the work roll bending force, and the measured data of the work roll bending force is the feedback curve of the work roll bending force.

[0017] Further, the trigger event includes: the event of each stand throwing off the steel.

[0018] Further, the determination of the response time of the work roll bending equipment on both sides of the rolling mill includes:

[0019] Determine the starting and ending times [t s , t e of the steel biting for each coil of steel, where t s is the moment when the steel biting signal appears at the current stand, and t e is the moment when the steel throwing signal appears at the current stand;

[0020] Select the moment t s , t e corresponding to the maximum work roll bending force within the starting and ending times [t max , and make a difference between it and t s to obtain the response time t of the work roll bending equipment on both sides of the rolling mill:

[0021] t = t max - t s .

[0022] Further, the determination of the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill includes:

[0023] Determine the starting and ending times of steel biting [t s , t e , where t s is the moment when the steel-biting signal appears at the current stand, and t e is the moment when the steel-throwing signal appears at the current stand;

[0024] Within the starting and ending times of steel biting [t s , t e , calculate the signal points (x m , y m ) where the roll-bending forces on both sides first reach the steady state. Among them, x m represents the length information when the roll-bending forces on both sides reach the steady state, and y m represents the specific values of the roll-bending forces on both sides when entering the steady state. Both sides include the operating side and the drive side. Define the moment of reaching the steady state as the minimum time when the feedback signals on both sides enter the allowable error band and no longer exceed this error band;

[0025] Adopt the formula to calculate the means of N sample points after the signals on the operating side and the drive side reach the steady state respectively where y i represents the measured data of the steady-state roll-bending forces on the operating side and the drive side. i = {OS, DS}, and OS and DS represent the operating side and the drive side respectively. The difference △y is the calculation result of the deviation of the steady-state values of the roll-bending forces on both sides, expressed as:

[0026]

[0027] Compare the calculation result of the deviation of the steady-state values of the roll-bending forces on both sides with the normal range [thd min , thd max in real time and make a judgment. When the calculation result exceeds the normal range, give an alarm in time to remind the on-site personnel to check and adjust the working state of the roll-bending of the rolling mill. Among them, thd min and thd max are the minimum and maximum values of the normal range of the deviation calculation result respectively.

[0028] Further, the determination of the accompanying accuracy of the roll-bending force includes:

[0029] Obtain the same starting and ending times [t s , t eThe measured rolling force value corresponding to the rolling force feedback signal within and the measured roll bending force value corresponding to the roll bending force feedback signal are used to obtain the correlation coefficient between the two by applying the correlation coefficient formula to get the roll bending force accompanying accuracy value, where the correlation coefficient formula is expressed as:

[0030]

[0031] where ρ represents the roll bending force accompanying accuracy value; f(n) represents the measured rolling force value; f w (n) represents the roll bending force data of the rolling mill, that is, the sum of the measured roll bending force values on both sides; cov(f(n), f w (n)) represents the covariance of the measured rolling force and the roll bending force data; var(f(n)), var(f w (n)) respectively represent the variances of the measured rolling force and the roll bending force data.

[0032] Furthermore, the determination of the rise time of the roll bending forces on both sides of the rolling mill includes:

[0033] Determine the interval [t s , t e for biting steel, where t s is the moment when the biting steel signal appears at the current stand, and t e is the moment when the throwing steel signal appears at the current stand;

[0034] Obtain the given roll bending force data, the roll bending force feedback curves on the operator side and the drive side of the rolling mill within the biting steel start and end time [t s , t e ;

[0035] Determine that the rise time numerical interval is: (k 2 - k 1 ) × 0.1 + k 1 ~ (k 2 - k 1 ) × 0.9 + k 1 , where the base value is the actual value k s corresponding to the biting steel signal moment t 1 , and the end value is the set value k 2 ;

[0036] Calculate the time [t 2 , t 1 when the actual value reaches (k 1 ~ (k 2 - k 1 ) × 0.9 + k 1 , then the rise time t 1 , t 2 is such that the rise time t r = t 2 - t1 。

[0037] Further, the determination of the steady-state error of the roll-bending force on both sides of the rolling mill includes:

[0038] Determine the starting and ending times [t s , t e of steel biting, where t s is the moment when the steel-biting signal appears at the current stand, and t e is the moment when the steel-throwing signal appears at the current stand;

[0039] Obtain the given data of the roll-bending force, and the feedback curves of the roll-bending force on the operator side and the drive side of the rolling mill within the starting and ending times [t s , t e of steel biting;

[0040] Determine the steady-state range as: K - C to K + C, where K is the given curve data and C is the error;

[0041] Determine the steady-state time: Put all the points where the feedback curve intersects with K - C and K + C into the same one-dimensional matrix, and then put the start and end times of the sliding window into it. Sort the values in the matrix, and calculate the two points with the largest distance between adjacent ones in order. The corresponding moments are t 3 , t 4 , and the obtained [t 3 , t 4 is the steady-state duration;

[0042] Calculate the average value of the given values and the average value of the feedback values within the time of [t 3 , t 4 , and the absolute value of their difference is the steady-state deviation.

[0043] Further, using a four-level scoring system, score the following five indicators respectively: the response time of the roll-bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill, the accompanying accuracy of the roll-bending force, the rise time of the roll-bending force on both sides of the rolling mill, and the steady-state error of the roll-bending force on both sides of the rolling mill. According to the obtained scoring results of each indicator, the comprehensive scoring of the operation accuracy of the roll-bending of the rolling mill includes:

[0044] Using a four-level scoring system, score the following five indicators respectively: the response time of the roll-bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill, the accompanying accuracy of the roll-bending force, the rise time of the roll-bending force on both sides of the rolling mill, and the steady-state error of the roll-bending force on both sides of the rolling mill. Add up the scoring results of each obtained indicator to get the comprehensive scoring of the operation accuracy of the roll-bending of the rolling mill; where the four-level scoring system is:

[0045]

[0046] Among them, s kIndicates the score of the k-th index of the roll bending, Thd k1 ~Thd k3 Indicates the thresholds at all levels, w 1 ~w 4 Indicates the index k Score within different threshold ranges; Comprehensive score s for the operating accuracy of the roll bending of the rolling mill WRB Is expressed as:

[0047] s WRB =∑s k

[0048] In real time, the comprehensive score s for the operating accuracy of the roll bending of the rolling mill WRB Is compared with the normal range [Score min , Score max , and a determination is made. When s WRB Exceeds the normal range, an alarm is given in a timely manner to remind the on-site personnel to check and adjust the working state of the roll bending. Among them, Score min , Score max Are respectively the minimum and maximum values of the normal range of the comprehensive accuracy score.

[0049] The beneficial effects brought by the technical solution provided by the embodiment of the present invention at least include:

[0050] In the embodiment of the present invention, first, the roll bending accuracy evaluation content is decomposed into several specific indicators that are easy to quantify and collect data; then, a four-level scoring system is adopted to score the 5 indicators of the response time of the roll bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll bending force on both sides of the rolling mill, the accompanying accuracy of the roll bending force, the rise time of the roll bending force on both sides of the rolling mill, and the steady-state error of the roll bending force on both sides of the rolling mill respectively. According to the scoring results of each index obtained, the operating accuracy and effect of the roll bending of the rolling mill are judged in real time, which can help to eliminate roll bending equipment and production faults in a timely manner at the production site and improve the working state of the roll bending in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0052] Figure 1 Is a schematic flow chart of the method for evaluating the accuracy of the roll bending equipment of the hot rolling mill provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0053] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in detail with reference to the accompanying drawings.

[0054] As Figure 1 shown, an accuracy evaluation method for the roll-bending equipment of a hot rolling mill provided by an embodiment of the present invention includes:

[0055] S101. Determine the response time of the roll-bending equipment on both sides of the rolling mill, which specifically may include the following steps:

[0056] A1. Determine the starting and ending times [t s , t e of steel biting for each coil, where t s is the moment when the steel biting signal appears at the current stand, and t e is the moment when the steel throwing signal appears at the current stand;

[0057] A2. Select the moment t s , t e corresponding to the maximum roll-bending force within the starting and ending times [t max , and calculate the difference between it and t s to obtain the response time t of the roll-bending equipment on both sides of the rolling mill:

[0058] t = t max - t s .

[0059] In this embodiment, the accuracy of the response time t of the roll-bending equipment on both sides of the rolling mill is calculated in real time, and the calculation results are displayed in a timely manner to provide a basis for on-site personnel to verify and adjust the roll bending.

[0060] In this embodiment, before determining the response time (S101) of the roll-bending equipment on both sides of the rolling mill, the method further includes the following steps:

[0061] First, collect the roll-bending setting and measured data in real time;

[0062] In this embodiment, the collected roll-bending setting data includes: the given roll-bending force data, and the given roll-bending force data is a given roll-bending force curve; the collected roll-bending measured data includes: the steel biting signal of the stand and the measured roll-bending force data, and the measured roll-bending force data is a roll-bending force feedback curve.

[0063] Next, automatically start the roll-bending accuracy evaluation calculation according to the trigger event, that is: execute S101 - S106.

[0064] In this embodiment, the trigger event includes: the steel throwing event of each stand.

[0065] S102. Determine the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill, which specifically may include the following steps:

[0066] B1. Determine the starting and ending times of steel biting [t s , t e , where t s is the moment when the steel biting signal appears at the current stand, and t e is the moment when the steel discharging signal appears at the current stand;

[0067] B2. Calculate the signal points (x s , y e ) at which the bending roll forces on both sides first reach a steady state within the steel biting starting and ending time [t m , y m ). Among them, x m represents the length information at which the bending roll forces on both sides reach a steady state, and y m represents the specific values of the bending roll forces on both sides when entering the steady state. Both sides include the operating side and the drive side. Define the moment of reaching the steady state as the minimum time when the feedback signals on both sides enter the allowable error band and no longer exceed this error band;

[0068] B3. Use the formula to calculate the mean values of N sample points after the signals on the operating side and the drive side reach a steady state respectively Among them, y i represents the measured data of the bending roll forces at the steady state on the operating side and the drive side. i = {OS, DS}, where OS and DS represent the operating side and the drive side respectively. The difference △y is the calculation result of the deviation of the steady state values of the bending roll forces on both sides, which is expressed as:

[0069]

[0070] B4. Compare the calculation result of the deviation of the steady state values of the bending roll forces on both sides with the normal range [thd min , thd max in real time and make a judgment. When the calculation result exceeds the normal range, give an alarm in time to remind the on-site personnel to check and adjust the working state of the rolling mill bending rolls. Among them, thd min and thd max are the minimum and maximum values of the normal range of the deviation calculation result respectively.

[0071] S103. Determine the accompanying accuracy of the bending roll force;

[0072] In this embodiment, obtain the measured rolling force values corresponding to the rolling force feedback signals and the measured bending roll force values corresponding to the bending roll force feedback signals within the same starting and ending time [t s , t e . Apply the correlation coefficient formula to obtain the correlation coefficient between the two to get the accompanying accuracy value of the bending roll force. Among them, the correlation coefficient formula is expressed as:

[0073]

[0074] Among them, ρ represents the accompanying accuracy value of the roll bending force; f(n) represents the measured value of the rolling force; f w (n) represents the roll bending force data of the rolling mill, that is, the sum of the measured values of the roll bending forces on both sides; cov(f(n), f w (n)) represents the covariance of the measured rolling force and the roll bending force data; var(f(n)), var(f w (n)) represent the variances of the measured rolling force and the roll bending force data respectively.

[0075] In this embodiment, the accompanying accuracy value ρ of the roll bending force can also be output in real time and this value can be displayed in time to provide the on-site personnel with the basis for verifying and adjusting the roll bending force.

[0076] S104. Determine the rising time of the roll bending forces on both sides of the rolling mill, which can specifically include the following steps:

[0077] C1. Determine the interval [t s , t e for biting the steel, where t s is the moment when the steel biting signal appears on the current stand, and t e is the moment when the steel throwing signal appears on the current stand;

[0078] C2. Obtain the given roll bending force data, and the feedback curves of the roll bending forces on the operator side and the drive side of the rolling mill within the time interval [t s , t e for biting the steel;

[0079] C3. Determine that the numerical interval of the rising time is: (k 2 - k 1 ) × 0.1 + k 1 ~(k 2 - k 1 ) × 0.9 + k 1 , where the basic value is the actual value k s corresponding to the moment t 1 of the steel biting signal, and the end value is the set value k 2 ;

[0080] C4. Calculate the time [t 2 , t 1 when the actual value reaches (k 1 - k 2 ) × 0.1 + k 1 ~(k 1 ) × 0.9 + k 1 , t 2 , then the rising time t r = t 2 - t 1 .

[0081] In this embodiment, the rising time of the roll bending force on both sides of the rolling mill is calculated accurately in real time, and the calculation results are displayed in time to provide a basis for on-site personnel to check and adjust the roll bending force.

[0082] S105. Determine the steady-state error of the roll bending force on both sides of the rolling mill, which may specifically include the following steps:

[0083] D1. Determine the starting and ending times of steel biting [t s , t e , where t s is the moment when the steel biting signal appears in the current stand, and t e is the moment when the steel throwing signal appears in the current stand;

[0084] D2. Obtain the given data of the roll bending force and the feedback curves of the roll bending forces on the operator side and the drive side of the rolling mill within the starting and ending times of steel biting [t s , t e ;

[0085] D3. Determine the steady-state range as: K - C to K + C, where K is the given curve data and C is the error;

[0086] D4. Determine the steady-state time: Put all the points where the feedback curve intersects with K - C and K + C into the same one-dimensional matrix, and then put the start and end times of the sliding window into it. Sort the values in the matrix, and calculate the two points with the largest distance between adjacent two points in order. The corresponding moments are t 3 , t 4 , and the obtained [t 3 , t 4 is the steady-state duration;

[0087] D5. Calculate the average value of the given value and the average value of the feedback value within the time of [t 3 , t 4 , and the absolute value of their difference is the steady-state deviation.

[0088] In this embodiment, the steady-state error of the roll bending force on both sides of the rolling mill is calculated accurately in real time, and the calculation results are displayed in time to provide a basis for on-site personnel to check and adjust the roll bending force.

[0089] S106. Adopt a four-level scoring system to score the five indicators of the response time of the roll bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll bending force on both sides of the rolling mill, the accompanying accuracy of the roll bending force, the rising time of the roll bending force on both sides of the rolling mill, and the steady-state error of the roll bending force on both sides of the rolling mill respectively. According to the obtained scoring results of each indicator, determine the comprehensive score of the operation accuracy of the roll bending of the rolling mill, which may specifically include the following steps:

[0090] E1. Using a four - level scoring system, score the following five indicators respectively: the response time of the roll - bending equipment on both sides of the rolling mill, the deviation of the steady - state value of the roll - bending force on both sides of the rolling mill, the accompanying accuracy of the roll - bending force, the rise time of the roll - bending force on both sides of the rolling mill, and the steady - state error of the roll - bending force on both sides of the rolling mill. Add up the scores of each indicator obtained to get the comprehensive score of the operation accuracy of the roll - bending of the rolling mill. Among them, the four - level scoring system is as follows:

[0091]

[0092] Among them, s k represents the score of the k - th indicator of roll - bending, Thd k1 ~Thd k3 represents the thresholds of each level, w 1 ~w 4 represents the scores of the indicator index k in different threshold ranges; the comprehensive score s WRB of the operation accuracy of the roll - bending of the rolling mill is expressed as:

[0093] s WRB =∑s k

[0094] E2. Compare the comprehensive score s wRB of the operation accuracy of the roll - bending of the rolling mill with the normal range [Score min , Score max in real - time and make a judgment. When s WRB exceeds the normal range, give an alarm in time to remind the on - site personnel to check and adjust the working state of the roll - bending, where Score min and Score max are the minimum and maximum values of the normal range of the comprehensive accuracy score respectively.

[0095] To better understand the present invention, it is described with specific examples. Apply the method for evaluating the accuracy of the roll - bending equipment of the hot - rolling mill provided in the embodiments of the present invention to a 5000 - mm medium - thick plate hot - rolling production line. In the rolling area, a four - high rolling mill is used to roll the slab.

[0096] The accuracy evaluation rules of the roll - bending equipment of this production line are shown in Table 1 (specifically, the accuracy evaluation rules of the roll - bending equipment of different production lines are determined according to the actual situation). In particular, the calculated value needs to be processed by taking the absolute value first and then scored. In Table 1, OS represents the operator side of the rolling mill, and DS represents the drive side of the rolling mill.

[0097] Table 1 Accuracy Evaluation Rules Table of Roll - Bending Equipment of a 5000 - mm Medium - Thick Plate Hot - Rolling Production Line

[0098] Evaluation Index Unit Calculated Value Weight Calculated Value Weight Calculated Value Weight Calculated Value Weight OS Response Time s [0，1] 10 (1，1.5] 8 (1.5，1.8] 5 (1.8，+∞) 0 OS Rise Time s [0，0.5] 10 (0.5，0.8] 8 (0.8，1.0] 5 (1.0，+∞) 0 OS Steady-State Time s [0，1] 10 (1，2] 8 (2，3] 5 (3，+∞) 0 OS Steady-State Deviation kN [0，5] 10 (5，10] 8 (10，15] 5 (15，+∞) 0 DS Response Time s [0，1] 10 (1，1.5] 8 (1.5，1.8] 5 (1.8，+∞) 0 DS Rise Time s [0，0.5] 10 (0.5，0.8] 8 (0.8，1.0] 5 (1.0，+∞) 0 DS Steady-State Time s [0，1] 10 (1，2] 8 (2，3] 5 (3，+∞) 0 DS Steady-State Deviation kN [0，5] 10 (5，10] 8 (10，15] 5 (15，+∞) 0 Deviation on Both Sides kN [0，5] 10 (5，10] 8 (10，15] 5 (15，+∞) 0 Accompanying Precision ％ [100，98] 10 (98，95] 8 (95，90] 5 (90，0] 0

[0099] According to the evaluation rules in Table 1, the present invention evaluates the accuracy of the bending roll equipment for the first 6 passes in a certain rolling process of this production line. The results are shown in Table 2. From Table 2, the calculation results of each index, the scoring situation, the weight occupied, and the comprehensive scores of each stand of the bending roll equipment for each pass can be quickly queried. For this case, during the rolling process of the 3rd pass, the OS response time of the bending roll equipment is 1.6 seconds, getting 5 points; the OS rise time is 0.66 seconds, getting 8 points; the OS steady-state time is 0.83 seconds, getting 10 points; the OS steady-state deviation is 0.0985 kN, getting 10 points; the DS response time is 1.04 seconds, getting 8 points; the DS rise time is 0.49 seconds, getting 10 points; the DS steady-state time is 5.78 seconds, deducting 10 points; the DS steady-state deviation is 0.0365 kN, getting 10 points; the deviation of the bending roll forces on both sides is 0.363 kN, getting 10 points; the accompanying accuracy of the bending roll force and the rolling force is 99.17%, getting 10 points; the total score is 81 points. From Table 2, it can clearly show the evaluation results of the bending roll equipment for each pass in the rolling process for process and equipment personnel, facilitating on-site personnel to locate and verify the equipment status.

[0100] Table 2 Evaluation Results of the Accuracy of the Bending Roll Equipment for a 5000mm Medium and Heavy Plate Hot Rolling Production Line

[0101]

[0102] The method for evaluating the accuracy of the bending roll equipment of the hot rolling mill described in the embodiment of the present invention first decomposes the bending roll accuracy evaluation content into several specific indexes that are easy to quantify and collect data. Then, using a four-level scoring system, the 5 indexes of the response time of the bending roll equipment on both sides of the rolling mill, the deviation of the steady-state value of the bending roll forces on both sides of the rolling mill, the accompanying accuracy of the bending roll force, the rise time of the bending roll forces on both sides of the rolling mill, and the steady-state error of the bending roll forces on both sides of the rolling mill are scored respectively. According to the scoring results of each index obtained, the running accuracy and effect of the bending roll of the rolling mill can be judged in real time, which can help to eliminate the bending roll equipment and production faults in time at the production site and improve the working state of the bending roll in time.

[0103] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill, characterized in that, it includes: Determine the response time of the roll-bending equipment on both sides of the rolling mill; Determine the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill; Determine the accompanying accuracy of the roll-bending force; Determine the rise time of the roll-bending force on both sides of the rolling mill; Determine the steady-state error of the roll-bending force on both sides of the rolling mill; Adopt a four-level scoring system to score the five indicators of the response time of the roll-bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill, the accompanying accuracy of the roll-bending force, the rise time of the roll-bending force on both sides of the rolling mill, and the steady-state error of the roll-bending force on both sides of the rolling mill respectively. According to the scoring results of each indicator obtained, determine the comprehensive scoring of the operating accuracy of the roll-bending of the rolling mill; Among them, the determination of the steady-state error of the roll-bending force on both sides of the rolling mill includes: Determine the starting and ending times of steel biting [t s , t e , where t s is the moment when the steel biting signal appears at the current stand, and t e is the moment when the steel throwing signal appears at the current stand; Obtain the bending roll force given data within the biting start and end time [t s , t e , and the bending roll force feedback curves on the operator side and the drive side of the rolling mill; Determine the steady-state range as: K - C to K + C, where K is the given curve data and C is the error; Determine the steady-state time: Put all the points where the feedback curve intersects with K-C and K+C into the same one-dimensional matrix, and then put the start and end times of the sliding window into it. Sort the values in the matrix, and calculate the two points with the largest distance between adjacent ones in order. The corresponding times are t 3 and t 4 . The obtained [t 3 and t 4 is the steady-state duration; Calculate the average value of the given value and the average value of the feedback value within the time of [t 3 , t 4 . The absolute value of their difference is the steady-state deviation.

2. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 1, characterized in that, Before determining the response time of the roll-bending equipment on both sides of the rolling mill, the method further includes: Real-time collect the set and measured data of roll-bending; Automatically start the calculation of roll-bending accuracy evaluation according to the trigger event.

3. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 2, characterized in that, The collected set data of roll-bending includes: the given data of roll-bending force, and the given data of roll-bending force is the given curve of roll-bending force; the collected measured data of roll-bending includes: the signal of the rolling mill biting steel and the measured data of roll-bending force, and the measured data of roll-bending force is the feedback curve of roll-bending force.

4. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 2, characterized in that, The trigger event includes: the event of each stand throwing steel.

5. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 1, characterized in that, The determination of the response time of the roll-bending equipment on both sides of the rolling mill includes: Determine the starting and ending times [t s , t e for the steel biting of each coil, where t s is the moment when the steel biting signal appears at the current stand, and t e is the moment when the steel throwing signal appears at the current stand; Select the time t when the rolling starts and ends s , t e corresponding to the maximum roll bending force at the moment t max , and take the difference between it and t s to obtain the response time t of the roll bending equipment on both sides of the rolling mill: t = t max -t s 。 6. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 1, characterized in that, The determination of the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill includes: Determine the start and end times of steel biting [t s , t e , where t s is the moment when the steel biting signal appears in the current stand, and t e is the moment when the steel throwing signal appears in the current stand; Calculate the signal points (x s , y e ) where the bending roll forces on both sides first reach a steady state within the biting start and end times [t m , t m . Among them, x m represents the length information when the bending roll forces on both sides reach a steady state, and y m represents the specific values of the bending roll forces on both sides when entering the steady state. The two sides include the operating side and the drive side. Define the moment of reaching the steady state as the minimum time when the feedback signals on both sides enter the allowed error band and no longer exceed this error band; Using the formula Calculate the mean values of N sample points after the operation side signal and the drive side signal reach the steady state respectively where y i represents the measured data of the steady state bending roll forces on the operation side and the drive side. i = {OS, DS}, where OS and DS represent the operation side and the drive side respectively. The difference △y is the calculation result of the deviation of the steady state values of the bending roll forces on both sides, which is expressed as: Calculate the deviation of the steady-state value of the bending roll forces on both sides in real time and compare it with the normal range [thd min ,thd max for determination. When the calculation result exceeds the normal range, an alarm is given in a timely manner to remind the on-site personnel to check and adjust the working state of the mill's bending rolls. Among them, thd min and thd max are the minimum and maximum values of the normal range of the deviation calculation result, respectively.

7. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 1, characterized in that, The determination of the accompanying accuracy of the roll-bending force includes: Obtain the measured rolling force value corresponding to the rolling force feedback signal and the measured roll bending force value corresponding to the roll bending force feedback signal within the same start and end time [t s , t e , and use the correlation coefficient formula to obtain the correlation coefficient between the two to obtain the roll bending force accompanying accuracy value. Among them, the correlation coefficient formula is expressed as: Among them, ρ represents the accompanying precision value of the bending roll force; f(n) represents the measured value of the rolling force; f w (n) represents the bending roll force data of the rolling mill, that is, the sum of the measured values of the bending roll forces on both sides; cov(f(n), f w (n)) represents the covariance of the measured rolling force and the bending roll force data; var(f(n)) and var(f w (n)) respectively represent the variances of the measured rolling force and the bending roll force data.

8. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 1, characterized in that, The determination of the rise time of the roll-bending force on both sides of the rolling mill includes: Determine the starting and ending intervals of steel biting [t s , t e , where t s is the moment when the steel biting signal appears at the current stand, and t e is the moment when the steel throwing signal appears at the current stand; Obtain the bending roll force given data within the biting start and end times [t s , t e , and the bending roll force feedback curves on the operator side and the drive side of the rolling mill; Determine that the rising time value range is: (k 2 -k 1 ) × 0.1 + k 1 ~(k 2 -k 1 ) × 0.9 + k 1 , where the base value is the actual value k s corresponding to the steel biting signal moment t 1 , and the end value is the set value k 2 ; Calculate the time [t 1 , t 2 ] when the actual value reaches (k 2 - k 1 )×0.1 + k 1 to (k 2 - k 1 )×0.9 + k 1 . Then the rise time t r = t 2 - t 1 .​​​​​​​​​​​​​​​​​​​​​​ 9. The method for evaluating the accuracy of the roll-bending equipment of a hot rolling mill according to claim 1, characterized in that, The adoption of the four-level scoring system to score the five indicators of the response time of the roll-bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill, the accompanying accuracy of the roll-bending force, the rise time of the roll-bending force on both sides of the rolling mill, and the steady-state error of the roll-bending force on both sides of the rolling mill respectively. According to the scoring results of each indicator obtained, the determination of the comprehensive scoring of the operating accuracy of the roll-bending of the rolling mill includes: Using a four-level scoring system, the response time of the roll-bending equipment on both sides of the rolling mill, the deviation of the steady-state value of the roll-bending force on both sides of the rolling mill, the accompanying accuracy of the roll-bending force, the rise time of the roll-bending force on both sides of the rolling mill, and the steady-state error of the roll-bending force on both sides of the rolling mill, which are determined, are scored respectively. The scores of each index obtained are added together to obtain the comprehensive score of the running accuracy of the roll-bending of the rolling mill. Among them, the four-level scoring system is as follows: Among them, s k represents the score of the k-th index of the roll bending, Thd k1 ~Thd k3 represents the thresholds at all levels, w 1 ~w 4 represents the scores of the index k within different threshold ranges; the comprehensive score s WRB of the operating accuracy of the mill roll bending is expressed as: s WRB = ∑s k Comprehensively score s in real time for the operating accuracy of the mill bending rolls WRB Compare it with the normal range [Score min , Score max and make a judgment. When s WRB exceeds the normal range, an alarm is given in time to remind the on-site personnel to check and adjust the working state of the bending rolls. Among them, Score min , Score max are the minimum and maximum values of the normal range of the comprehensive accuracy score respectively.

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