Digital hot continuous rolling loop evaluation method
By dividing the hot continuous rolling looper control cycle into steady-state, looper start-up, and looper drop-down stages, constructing evaluation parameters and performing digital scoring, the subjective and unpredictable problems of looper control evaluation in existing technologies are solved, realizing objective evaluation and continuous optimization of looper control, and reducing the occurrence of production accidents.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INNER MONGOLIA BAOTOU STEEL UNION
- Filing Date
- 2026-01-12
- Publication Date
- 2026-05-15
AI Technical Summary
In the existing technology, the evaluation of looper control in hot strip mill finishing units relies on human experience, which has problems such as strong subjectivity, lack of foresight, difficulty in optimization and technical accumulation. It is impossible to form a unified and objective evaluation system, resulting in frequent production and quality accidents.
The looper control cycle is divided into three stages: steady state, loop start-up, and loop drop-off. Corresponding evaluation parameters are constructed, and by setting reasonable and optimal ranges, a scoring function is used for digital evaluation to form a comprehensive score, thereby achieving objective assessment and trend early warning of looper control.
It achieves objective and precise control of the loop control, reduces the probability of loss of control and production accidents, improves production efficiency and product quality, forms a closed-loop process for sustainable optimization, and frees up a lot of troubleshooting time.
Smart Images
Figure CN122048115A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of industrial automation control technology, and in particular to a digital hot continuous rolling looper evaluation method. Background Technology
[0002] Loop control in hot strip mill finishing units is a key technology for ensuring stable rolling processes and maintaining constant strip thickness and tension. The quality of loop control directly affects product quality, production efficiency, and equipment safety. Currently, the evaluation of loop control effectiveness mainly relies on the experience of operators and engineers, making post-event qualitative judgments by observing fluctuations in the loop height (angle) curve and whether incidents such as "excessive looping," "tension loss," or "steel pulling" occur.
[0003] This qualitative evaluation method, which relies on human experience, has obvious drawbacks:
[0004] 1. Highly subjective: Due to differences in individual perception, different operators have different judgment standards, making it impossible to form a unified and objective evaluation system.
[0005] 2. Lack of foresight: Problems can only be detected after they occur or worsen, and it is impossible to provide early warnings through quantitative trends to reduce the occurrence of production and quality accidents.
[0006] 3. Difficult to optimize: Due to the lack of quantitative data support, it is difficult to accurately pinpoint the specific problems of the control system (such as whether the PID parameters are appropriate, whether the mechanical and hydraulic conditions are deteriorating, etc.), resulting in blind and inefficient optimization work, and requiring a lot of time for trial-and-error troubleshooting after problems occur.
[0007] 4. Difficulty in accumulating technical expertise: Excellent operational and control experience cannot be accumulated and passed on through data. Supervisors can only describe it qualitatively, with different standards for each person, making it difficult to quantify. It can only be accumulated through on-site experience.
[0008] Currently, there is an urgent need in this field for a method that can standardize, digitize, and periodically evaluate the effectiveness of looper control in order to achieve precise control, trend warning, and continuous optimization of the looper status. Summary of the Invention
[0009] To address the aforementioned problems, the purpose of this invention is to provide a digital hot continuous rolling looper evaluation method.
[0010] A digital hot rolling looper evaluation method includes:
[0011] Step 1: Divide the complete control cycle of the looper into a steady-state control stage, a looper start-up control stage, and a looper drop-off control stage;
[0012] Step 2: Construct evaluation parameters based on the working parameters during the steady-state control stage, the start-up control stage, and the unloading control stage;
[0013] Step 3: Set a reasonable range and an optimal range for each evaluation parameter. Map each evaluation parameter to a single score using a preset scoring function.
[0014] Step 4: Obtain the live-fit quality control standard based on all individual scores.
[0015] Preferably, the evaluation parameters for the steady-state control stage include:
[0016] Steady-state angle deviation: the difference between the actual steady-state angle and the set angle; Unit tension deviation: the relative deviation rate between the actual unit tension and the set value; Steady-state pressure fluctuation amplitude: the fluctuation amplitude of the sleeve hydraulic cylinder pressure during the steady-state period.
[0017] Preferably, the evaluation parameters for the start-up control stage include:
[0018] Loop start time: The time required from issuing the loop start signal to entering the loop feedback control stage;
[0019] Looping angle: The deviation between the looper angle when looping is completed and feedback control is entered and the steady-state setpoint;
[0020] Number of loop oscillations during loop opening: How many waves and how many oscillations exist in the loop angle curve before it reaches stability during the loop opening process;
[0021] Peak lifting pressure: The maximum pressure of the looper hydraulic cylinder during the lifting process;
[0022] Incremental starting pressure: The difference between the peak starting pressure and the steady-state pressure;
[0023] Uncontrolled start-up time: During the start-up process, the loop angle fails to reach the set total time due to improper control.
[0024] Preferably, the evaluation parameters for the unloading control stage include:
[0025] Looping time: The time the looper maintains a low position before the tail of the strip leaves the previous frame;
[0026] Steel throwing angle: The actual angle of the loop at the start of the slip loop placement;
[0027] Steel throwing pressure: The pressure of the looper hydraulic cylinder before the unsleeving begins;
[0028] Steel throwing pressure increment: the difference between the steel throwing pressure and the steady-state pressure;
[0029] Invalid time: The time during which the looper angle does not respond or responds slowly after the looper command is issued;
[0030] OFF time: The time from when the looper command is issued until the looper has completely returned to the mechanical zero position;
[0031] Steel throwing point delay: The time delay between the actual steel throwing time at the tail of the strip and the theoretical steel throwing time;
[0032] Loss of control during slip looping: The time during which the slip loop experiences abnormal shaking or loss of tension during the slip looping process.
[0033] Preferably, 100 points are obtained when the evaluation parameter P_i is within the optimal range [a_i, b_i].
[0034] When the evaluation parameter P_i is within a reasonable range [A_i, B_i] but outside the optimal range, the score decreases linearly from 100 to 60.
[0035] When the evaluation parameter P_i exceeds the reasonable range [A_i, B_i], a score of 0 is obtained.
[0036] Preferably, step 4 includes:
[0037] Weights are assigned to the evaluation parameters for each stage, and the scores for the steady-state stage, the initial stage, and the final stage are obtained by weighted summation.
[0038] The score for the successful trap is obtained by weighted summing of the scores in the steady-state phase, the initial trap phase, and the final trap phase; the formula for calculating the successful trap score is as follows:
[0039] S_F1 = K_steady * S_steady + K_start * S_start + K_finish * S_finish
[0040] Where S_F1 is the score of the first loop, K_steady is the steady-state stage weight coefficient, S_steady is the steady-state stage score, K_start is the starting stage weight coefficient, S_start is the starting stage score, K_finish is the ending stage weight coefficient, S_finish is the ending stage score, and K_steady + K_start + K_finish = 1.
[0041] The weighted sum of all the loop scores is used to obtain the overall loop control score.
[0042] This invention relates to a digital hot continuous rolling looper evaluation method. Compared with the prior art, this invention decomposes, standardizes and scores the key parameters of the entire looper control process to form a comprehensive digital evaluation. By utilizing its periodic trends, it achieves objective evaluation, precise control, fault early warning and continuous optimization of the looper control effect, ultimately reducing the probability of looper runaway and production accidents.
[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0045] Figure 1 The present invention provides a flowchart of a digital hot continuous rolling looper evaluation method. Detailed Implementation
[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0048] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0049] Please see Figure 1 A digital hot continuous rolling looper evaluation method, comprising:
[0050] Step 1: Divide the complete control cycle of the looper into a steady-state control stage, a looper start-up control stage, and a looper drop-off control stage;
[0051] Step 2: Construct evaluation parameters based on the working parameters during the steady-state control stage, the start-up control stage, and the unloading control stage;
[0052] Step 3: Set a reasonable range and an optimal range for each evaluation parameter. Map each evaluation parameter to a single score using a preset scoring function.
[0053] Step 4: Obtain the live-fit quality control standard based on all individual scores.
[0054] The method for evaluating the looper of the present invention will be further described below with reference to specific embodiments:
[0055] I. Defining the Evaluation Stage and Evaluation Parameters
[0056] The complete control cycle of a single looper is divided into three core stages: steady-state control stage, looper start-up control stage, and looper drop-off (steel ejection) control stage. Specific digital evaluation methods and parameters are defined for each stage.
[0057] 1. Steady-state control phase
[0058] Steady-state angle deviation: The difference between the actual steady-state angle and the set angle.
[0059] Unit tension deviation: The relative deviation rate between the actual unit tension and the set value.
[0060] Steady-state pressure fluctuation amplitude: The fluctuation amplitude of the pressure in the looper hydraulic cylinder during the steady-state period.
[0061] 2. Start-up control stage
[0062] Loop start time: The time required from issuing the loop start signal to entering the loop feedback control stage.
[0063] Looping angle: The deviation between the looping angle when the looping is completed and feedback control is entered and the steady-state setpoint.
[0064] Number of loop oscillations during loop opening: How many waves and how many oscillations exist in the loop angle curve before it reaches stability during the loop opening process.
[0065] Peak lifting pressure: The maximum pressure of the looper hydraulic cylinder during the lifting process.
[0066] Start-up pressure increment: the difference between the peak start-up pressure and the steady-state pressure.
[0067] Uncontrolled start-up time: During the start-up process, the loop angle fails to reach the set total time due to improper control.
[0068] 3. Looping Control Stage
[0069] Looping time: The time the looper maintains its low position before the tail of the strip leaves the previous frame.
[0070] Steel throwing angle: The actual angle of the loop at the start of the slip loop placement.
[0071] Steel throwing pressure: The pressure of the looper hydraulic cylinder before the unsleeving begins.
[0072] Steel throwing pressure increment: the difference between the steel throwing pressure and the steady-state pressure.
[0073] Invalid time: The time during which the looper angle does not respond or responds slowly after the looper command is issued.
[0074] OFF time: The time from when the looper command is issued until the looper has completely returned to the mechanical zero position.
[0075] Steel throwing point delay: The time delay between the actual steel throwing time at the tail of the strip and the theoretical steel throwing time.
[0076] Loss of control during slip looping: The time during which the slip loop experiences abnormal shaking or loss of tension during the slip looping process.
[0077] II. Parameter Standardization and One-Way Scoring
[0078] For each evaluation parameter P_i, a reasonable range [A_i, B_i] and an optimal range [a_i, b_i] are defined. Each parameter is mapped to a single score S_i (out of 100) using a predefined scoring function F(P_i).
[0079] Scoring rules:
[0080] A perfect score (100 points) is achieved when P_i is within the optimal range [a_i, b_i].
[0081] When P_i is within a reasonable range [A_i, B_i] but outside the optimal range, the score decreases linearly from full marks to passing marks (60 points).
[0082] 0 points are awarded when P_i exceeds the reasonable range [A_i, B_i].
[0083] For parameters such as "number of oscillations" and "runaway time", which are better the smaller they are, the optimal range is set to [0, a_i].
[0084] III. Calculation Stage Score and Overall Score
[0085] Assign weights to each stage and each parameter, and calculate stage score, rack score, and overall score.
[0086] Stage Score:
[0087] Steady-state score S_steady = Σ(W_i_steady * S_i_steady)
[0088] The score for the initial setup phase is S_start = Σ(W_i_start * S_i_start).
[0089] The score for the trapping stage is S_finish = Σ(W_i_finish * S_i_finish), where W_i is the weight of each parameter in the corresponding stage, and ΣW_i = 1.
[0090] Rack score and overall score:
[0091] S_F1 = K_steady * S_steady + K_start * S_start + K_finish * S_finish
[0092] S_total=K_F1*S_F1+K_F2*S_F2+K_F3*S_F3+K_F4*S_F4+K_F5*S_F5+K_F6*S_F6
[0093] In this paper, K_steady, K_start, and K_finish are the weight coefficients for the three stages, and K_steady + K_start + K_finish = 1. Considering that the initial setup stage is most prone to accidents and has the greatest impact on production stability, the weight of K_start is the highest, followed by K_finish and K_steady. K_F1 to K_F6 are the weight coefficients for the six loopers, and K_F1 + K_F2 + K_F3 + K_F4 + K_F5 + K_F6 = 1. Considering that downstream racks have a greater impact on product quality and production stability, this method sets the weight of the F6 rack looper to the highest, decreasing from downstream to upstream.
[0094] IV. Periodic Evaluation and Trend Analysis
[0095] The above steps are performed for each rolling unit to obtain a comprehensive score S_total. The comprehensive scores of the looper are recorded and stored according to the time series (weekly) and rolling series (similar steel grades and specifications) to form a numerical trend chart.
[0096] By analyzing this trend chart, we can achieve the following:
[0097] Control: Set a score threshold, and automatically alarm when the score falls below the threshold to remind engineers to intervene.
[0098] Optimization: When the trend continues to decline, it indicates that the performance of the looper control is deteriorating. By combining the parameters with low scores, we can accurately guide equipment maintenance (such as checking the hydraulic cylinder sealing and mechanical frame wear) or control system optimization (such as adjusting PID parameters).
[0099] Comparison: Conduct horizontal comparisons of the looper operation effects between different racks and between different work groups to promote overall improvement.
[0100] Implementation example:
[0101] Application of digital looper evaluation in a steel plant's 2250mm hot rolling line:
[0102] After the digital hot continuous rolling looper evaluation system was launched, weekly scores were given to the looper control system, with statistics compiled by specification group. This standardized evaluation method continuously guided equipment and automation personnel to perform precise maintenance. Based on trend charts and low-scoring reports, engineers discovered that the scores for "looper start-up pressure increment" and "steady-state pressure fluctuation" were consistently declining. Based on this, a preliminary judgment was made that the looper hydraulic system might be experiencing slow response or internal leakage. Repair was immediately arranged, and the hydraulic cylinders and servo valves were inspected, revealing slight wear on the valve cores. After replacement, the looper score rebounded to above 85 points during subsequent rolling, effectively preventing a potential steel pile-up accident caused by looper malfunction.
[0103] Within a three-month period, the number of head crushing incidents was reduced by 16, and the number of tail crushing incidents by 33, preventing five major production accidents such as steel pile-up. Thickness fluctuation was reduced by 30μm, and the width narrowing rate was reduced by 52%.
[0104] This embodiment demonstrates that the method of the present invention effectively improves production line output and quality. It provides effective and clear guidance, saves a significant amount of troubleshooting time, and achieves preventative control effects.
[0105] Compared with the prior art, the present invention has the following significant advantages:
[0106] 1. Objectivity and impartiality: Subjective experience and judgment are transformed into objective data, establishing a unified and flexible quality control standard. Furthermore, digital assessment enables third-party supervision, reducing problems arising from fluctuations in personnel quality and capabilities.
[0107] 2. Precise diagnosis: By analyzing the low scores of each stage and parameter, the root cause of the control problem can be quickly located, making the optimization work more targeted.
[0108] 3. Proactive Maintenance: By monitoring scoring trends, signs of performance degradation can be detected before the looper completely loses control and causes an accident, transforming reactive repairs into proactive prevention. Continuous Optimization Loop: A digital closed-loop optimization process of "evaluation -> diagnosis -> optimization -> re-evaluation" has been established, enabling continuous improvement in the looper control level.
[0109] 4. Knowledge Accumulation: The control experience of outstanding engineers is solidified in the parameter range and weights of the evaluation model, forming a replicable and inheritable corporate knowledge asset.
[0110] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A digital hot continuous rolling looper evaluation method, characterized in that, include: Step 1: Divide the complete control cycle of the looper into a steady-state control stage, a looper start-up control stage, and a looper drop-off control stage; Step 2: Construct evaluation parameters based on the working parameters during the steady-state control stage, the start-up control stage, and the unloading control stage; Step 3: Set a reasonable range and an optimal range for each evaluation parameter. Map each evaluation parameter to a single score using a preset scoring function. Step 4: Obtain the live-fit quality control standard based on all individual scores.
2. The digital hot continuous rolling looper evaluation method according to claim 1, characterized in that, The evaluation parameters for the steady-state control phase include: Steady-state angle deviation: the difference between the actual steady-state angle and the set angle; Unit tension deviation: the relative deviation rate between the actual unit tension and the set value; Steady-state pressure fluctuation amplitude: the fluctuation amplitude of the sleeve hydraulic cylinder pressure during the steady-state period.
3. The digital hot continuous rolling looper evaluation method according to claim 1, characterized in that, The evaluation parameters for the start-up control phase include: Loop start time: The time required from issuing the loop start signal to entering the loop feedback control stage; Looping angle: The deviation between the looper angle when looping is completed and feedback control is entered and the steady-state setpoint; Number of loop oscillations during loop opening: How many waves and how many oscillations exist in the loop angle curve before it reaches stability during the loop opening process; Peak lifting pressure: The maximum pressure of the looper hydraulic cylinder during the lifting process; Incremental starting pressure: The difference between the peak starting pressure and the steady-state pressure; Uncontrolled start-up time: During the start-up process, the loop angle fails to reach the set total time due to improper control.
4. The digital hot continuous rolling looper evaluation method according to claim 1, characterized in that, The evaluation parameters for the unloading control stage include: Looping time: The time the looper maintains a low position before the tail of the strip leaves the previous frame; Steel throwing angle: The actual angle of the loop at the start of the slip loop placement; Steel throwing pressure: The pressure of the looper hydraulic cylinder before the unsleeving begins; Steel throwing pressure increment: the difference between the steel throwing pressure and the steady-state pressure; Invalid time: The time during which the looper angle does not respond or responds slowly after the looper command is issued; OFF time: The time from when the looper command is issued until the looper has completely returned to the mechanical zero position; Steel throwing point delay: The time delay between the actual steel throwing time at the tail of the strip and the theoretical steel throwing time; Loss of control during slip looping: The time during which the slip loop experiences abnormal shaking or loss of tension during the slip looping process.
5. A digital hot continuous rolling looper evaluation method according to any one of claims 2-4, characterized in that, 100 points are awarded when the evaluation parameter P_i is within the optimal range [a_i, b_i]. When the evaluation parameter P_i is within a reasonable range [A_i, B_i] but outside the optimal range, the score decreases linearly from 100 to 60. When the evaluation parameter P_i exceeds the reasonable range [A_i, B_i], a score of 0 is obtained.
6. The digital hot continuous rolling looper evaluation method according to claim 5, characterized in that, Step 4 includes: Weights are assigned to the evaluation parameters for each stage, and the scores for the steady-state stage, the initial stage, and the final stage are obtained by weighted summation. The score for the successful trap is obtained by weighted summing of the scores in the steady-state phase, the initial trap phase, and the final trap phase; the formula for calculating the successful trap score is as follows: S_F1 = K_steady * S_steady + K_start * S_start + K_finish * S_finish Where S_F1 is the score of the first loop, K_steady is the steady-state stage weight coefficient, S_steady is the steady-state stage score, K_start is the starting stage weight coefficient, S_start is the starting stage score, K_finish is the ending stage weight coefficient, S_finish is the ending stage score, and K_steady + K_start + K_finish = 1. The weighted sum of all the loop scores is used to obtain the overall loop control score.