Scheduling optimization method for cold-rolled strip steel width trimming process

Abstract

The invention relates to the technical field of automatic control of cold-rolled strip steel production, and particularly discloses an optimized scheduling method for a cold-rolled strip steel width trimming procedure, which comprises the following steps: first-level decision: performing acid rolling inlet width overrun treatment, and dynamically triggering recoiling and pre-trimming; in the second-level decision, acid rolling and finished product trimming collaborative optimization are carried out, the basic trimming amount delta is calculated, and trimming control of a finished product unit and an acid rolling unit is executed according to the priority; the third-level decision comprises the following steps: dynamically selecting a rewinding position, and dynamically selecting an optimal trimming position in a rewinding process; in the fourth-level decision, boundary exception processing is carried out, when the third-level decision fails, a minimum trimming combination Sa = A1, Sp = B1 or entry direct trimming Sre = W0-Wt is tried, and otherwise, an error is reported; according to the method, multiple procedures are coordinated, and through a four-stage progressive model, acid rolling, finished product obtaining and rewinding trimming are coordinated, so that the width deviation is reduced, and the width hit rate is increased; trimming procedures are intelligently distributed, and the recoiling and trimming probability is reduced; automatic decision making is more efficient than manual decision making.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic control of cold-rolled strip production, and particularly relates to an optimized scheduling method for a cold-rolled strip width trimming process. BACKGROUND

[0002] In cold-rolled strip production, width control is a key link to ensure product quality. The traditional production process has the following technical problems: difficulty in coordinating multiple processes: the strip needs to go through multiple processes such as pickling, continuous annealing, galvanizing, and rewinding, and the trimming range and width constraints of each process are different. Necking effect is complex: the pickling unit and the finished product unit (continuous annealing and galvanizing) have width necking according to the steel grade, and the width transmission process is nonlinear. Low efficiency of manual decision-making: the operator relies on experience to set the trimming process and the trimming amount, and the production scheduling efficiency is low. Large cost loss of rewinding trimming: the unoptimized trimming of the finished product unit leads to trimming in the rewinding process, increasing the process cost.

[0003] The existing patent CN112893479B proposes single-unit trimming optimization for the pickling unit, but does not solve the problem of multi-process coordination; CN114985478A proposes trimming of hot-rolled defects to optimize the width target value of each process, but does not involve trimming scheduling optimization for each process, and cannot achieve global trimming coordination. It is only for offline redesign of target values after defects occur, and the application scenario is single, ensuring defect trimming, without involving coordination between processes. Therefore, there is an urgent need to design an optimized scheduling method for the cold-rolled strip width trimming process to solve the problems of difficulty in coordinating multiple trimming processes, low efficiency of manual decision-making, and large trimming loss or inability to schedule production in existing cold-rolled strip production. SUMMARY

[0004] To solve the problems in the prior art, the present application provides an optimized scheduling method for a cold-rolled strip width trimming process, which is particularly suitable for a cold-rolled production line composed of a pickling unit, a finished product unit (such as a galvanizing unit and a continuous annealing unit), and a rewinding unit. This method establishes a width transmission model and an intelligent decision-making algorithm to achieve global optimization of the trimming process, improve the accuracy of width control and production efficiency, automatically optimize the trimming of the finished product process, reduce the probability of rewinding trimming, reduce losses, quickly make optimal decisions, and support real-time production scheduling.

[0005] The technical solution adopted by the present application to solve its technical problems is as follows: an optimized scheduling method for a cold-rolled strip width trimming process, comprising the following steps:

[0006] S1, first-level decision-making: acid pickling inlet width out-of-limit processing, dynamically triggering rewinding pre-trimming;

[0007] S2, second-level decision-making: pickling and finished product trimming coordination optimization, calculating the basic trimming amount δ, and performing trimming control of the finished product unit and the pickling unit according to the priority;

[0008] S3, third level decision: dynamic selection of re-coiling position, dynamic selection of re-coiling process optimal cutting position;

[0009] S4, fourth level decision: boundary exception handling, when the third level decision fails, try the minimum cutting edge combination S a = A1, S p = B1 or direct cutting edge at the entrance S pre = W0-W t , otherwise, error.

[0010] Specifically, the acid pickling entrance width overrun processing in step S1 sets the input acid pickling incoming width W0, the maximum allowed width W max_in of the acid pickling entrance, the cutting edge capability range [C1, C2] of the re-coiling unit;

[0011] If W0> W max_in , calculate the re-coiling pre-cutting amount S pre = max(C1, W0-W max_in ), check S pre ≤ C2, output the acid pickling entrance basic width W base = W0-S pre ; otherwise, output W base = W0.

[0012] Specifically, the acid pickling and finished product cutting edge collaborative optimization in step S2 is that the system inputs the acid pickling entrance basic width W base , the target width W t , the acid pickling necking amount a, the finished product necking amount b, the acid pickling cutting edge range [A1 A2], and the finished product cutting edge range [B1, B2].

[0013] Specifically, the calculation of the basic cutting edge amount δ = (W base -a-b)-W t is performed according to the priority:

[0014] If δ∈[B1,B2], the finished product unit is single cut, and the cutting edge amount = δ;

[0015] If δ∈[A1 A2], the acid pickling unit is single cut, and the cutting edge amount = δ;

[0016] If δ∈[A1+B1,A2+B2], the finished product cutting edge amount S p = min(δ, B2) is allocated, and the acid pickling cutting edge amount S a = δ-S p ;

[0017] If δ<0, error; if δ is out of the above interval, go to the third level decision.

[0018] Specifically, in the second level decision, when δ∈[A1 A2] and , the finished product unit edge cutting is preferentially selected.

[0019] Specifically, the dynamic selection of the rewinding position in the step S3 is to calculate the finished product outlet width W out = W base -a-b;

[0020] Rewinding after finished product priority: if W out ≤ W max_out , the rewinding cutting amount S rec = W out -W t is calculated, and S rec ∈[C1,C2] is checked.

[0021] Secondly, rewinding after pickling: if the rewinding after finished product fails, the pickling outlet width W p_out = W base -a is calculated, the theoretical rewinding cutting amount S rec_mid = W p_out -(W t +b) is calculated, and S rec_mid ∈[C1,C2] and W p_out -S rec_mid ≤ W max_mid are checked.

[0022] If both fail, the fourth level decision is converted.

[0023] Specifically, in the step S4, the minimum cutting edge combination is to set the pickling cutting amount S a =A1, the finished product cutting amount S p =B1, and the theoretical rewinding cutting amount S rec_mid =(W base -a-S a -b)-W t is calculated, and S rec_mid ∈[C1,C2] is checked.

[0024] Direct cutting at the inlet: if the minimum cutting edge combination fails, S pre =W0-W t is calculated, and S pre ∈[C1,C2] is checked.

[0025] If there is still no solution, “no feasible scheduling” is output.

[0026] Specifically, in the fourth level decision, the direct cutting at the inlet needs to satisfy S pre ≤C2 and W0-S pre ≤W max_in .

[0027] The present application has the following beneficial effects:

[0028] The optimization scheduling method for the width trimming process of the cold-rolled strip steel designed by the present application has the following advantages: multi-process coordination: through a four-stage progressive model, the pickling, finished product, and heavy roll trimming are coordinated to reduce the width deviation and improve the width hit rate; loss reduction: intelligent allocation of the trimming process (preferably the finished product unit trimming) reduces the probability of heavy roll trimming and avoids the additional trimming cost caused by the non-optimized upstream in the traditional process; efficiency improvement: automatic decision-making is more efficient than manual decision-making. Through the method, the problems of trimming coordination difficulty and low manual efficiency are effectively solved, and real-time production scheduling is realized, which is suitable for cold-rolled strip steel production lines. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be further described clearly and completely. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0030] The present application provides an optimization scheduling method and system for the width trimming process of a cold-rolled strip steel, which is characterized by constructing a "four-stage progressive decision-making model". The first stage handles the width overrun at the pickling inlet and dynamically triggers the heavy roll pre-trimming. The second stage optimizes the combination of pickling and finished product unit trimming. The third stage introduces the heavy roll process to dynamically select the optimal trimming position. The fourth stage handles abnormal or boundary conditions and flexibly adjusts the trimming of each process. The decision-making process mainly relies on formula calculation and condition checking to ensure efficient real-time decision-making.

[0031] Step 1: First-stage decision: handling of width overrun at pickling inlet.

[0032] Input: pickling incoming width W0, maximum allowable width at pickling inlet W max_in = 1900, heavy roll unit trimming capacity range [C1, C2], C1 minimum trimming amount, C2 maximum trimming amount.

[0033] If W0 > W max_in , calculate the minimum trimming requirement S min = W0-W max_in , and calculate the heavy roll pre-trimming amount S pre = max(C1, W0-W max_in ).

[0034] Determine the pickling raw material heavy roll pre-trimming amount S pre = max(C1, S min ), and the pickling raw material heavy roll pre-trimming amount = the larger value between the minimum trimming amount of the heavy roll or the minimum trimming requirement.

[0035] Check S pre ≤ C2. If not, report an error "inlet trimming overrun" or go to the fourth-stage decision.

[0036] Output the pickling entry base width W base = W0-S pre ; the pickling entry base width is the difference between the raw material width and the recoiling pre-cut edge width.

[0037] Otherwise output W base = W0.

[0038] Step 2: Second-level decision: pickling and finished product edge cutting coordination optimization.

[0039] System input: pickling entry base width W base , target width W t , pickling necking amount a (related to steel grade), finished product necking amount b (related to steel grade), pickling edge cutting range [A1 A2], finished product edge cutting range [B1, B2].

[0040] Calculate the base edge amount δ = (W base -a-b)-W t , the base edge amount = pickling entry base width-pickling unit necking amount-finished product unit necking amount-target width.

[0041] Priority decision:

[0042] If δ ∈ [B1, B2], the finished product unit is cut alone, and the cutting amount = δ.

[0043] If δ ∈ [A1 A2], the pickling unit is cut alone, and the cutting amount = δ; if , the finished product unit cutting alone is preferentially selected.

[0044] If δ ∈ [A1+B1, A2+B2], combined edge cutting is needed, the finished product unit cutting width is preferentially determined, and the remaining cutting width is in the pickling unit cutting. Distribution strategy: the finished product cutting amount S p = min(δ, B2), the pickling cutting amount S a = δ-S p ; verify S a ∈ [A1, A2]. The finished product unit cutting amount takes the smaller value of the cutting amount and the upper limit of the finished product unit cutting, and the pickling unit cutting amount is the difference between the cutting amount and the finished product unit cutting amount.

[0045] If δ < 0, an error message “target width cannot be reached” is reported.

[0046] If δ exceeds the above interval (δ < A1 or δ > A2+B2 or outside the interval), go to the third-level decision.

[0047] Step 3: Third-level decision: dynamic selection of recoiling position.

[0048] Trigger condition: second stage decision fails.

[0049] Finished product post-recoiling priority: calculate finished product exit width W out = W base -a-b; finished product mill exit width = pickling entry base width - pickling mill necking amount - finished product mill necking amount.

[0050] Finished product post-recoiling priority: if W out ≤ W max_out (W max_out = 1850), then calculate recoiling trimming amount S rec = W out -W t , recoiling trimming amount = finished product mill exit width - target width.

[0051] Check S rec ∈ [C1, C2]; verify whether the recoiling trimming amount is between the minimum and maximum recoiling trimming amounts, if yes, then adopt; otherwise, turn to pickling post-recoiling or fourth stage.

[0052] Second pickling post-recoiling: if finished product post-recoiling fails, then calculate pickling exit width W p_out = W base -a, pickling mill exit width = pickling entry base width - pickling mill necking amount.

[0053] Calculate theoretical finished product mill entry required width W req = W t +b, theoretical finished product mill entry required width = target width + finished product mill necking amount.

[0054] Set theoretical recoiling trimming amount S rec_mid = W p_out -W req , that is, S rec_mid = W p_out -(W t +b), theoretical recoiling trimming amount = pickling mill exit width - theoretical finished product mill entry required width.

[0055] Check S rec_mid ∈ [C1, C2] and W p_out -S rec_mid ≤ W max_mid (W max_mid = 1880); if yes, then adopt.

[0056] If both fail, turn to fourth stage decision.

[0057] Step 4: fourth stage decision: boundary exception handling.

[0058] Trigger condition: third stage decision fails.

[0059] Set the skinning amount S of the pickling mill a = A1, the skinning amount S of the finished product p = B1, the minimum skinning amount of the pickling mill is A1, and the minimum skinning amount of the finished product unit is B1.

[0060] Calculate the width W of the pickling mill outlet p_out = W base -a-S a , the width of the pickling mill outlet = the basic width of the pickling mill inlet - the necking amount of the pickling mill unit - the minimum skinning amount of the pickling mill.

[0061] Calculate the theoretical skinning amount S of the recoiling rec_mid = (W p_out -b), that is, S rec_mid = (W base -a-S a -b)-W t , the theoretical skinning amount of the recoiling = the width of the pickling mill outlet - the necking amount of the finished product unit - the target width.

[0062] Check S rec_mid ∈ [C1, C2]; if yes, adopt; otherwise, turn to the direct skinning at the inlet.

[0063] Pre-recoiling skinning at the inlet of the pickling mill:

[0064] S pre = W0-W t , the pre-skinning amount of the raw material recoiling of the pickling mill = the width of the pickling mill inlet - the target width.

[0065] Check S pre ∈ [C1, C2], verify whether the pre-skinning amount of the raw material recoiling of the pickling mill is between the minimum and maximum skinning amounts of the recoiling.

[0066] If yes, adopt; otherwise, output "No feasible scheduling, manual intervention is required".

[0067] If there is still no solution, output "No feasible scheduling".

[0068] Embodiment 1: Conventional skinning scenario.

[0069] Input parameters: the width W0 of the incoming material of the pickling mill = 1876 mm, and the target width W t = 1829 mm.

[0070] The necking amount a of the pickling mill = 5 mm, the necking amount b of the finished product = 4 mm, the skinning range of the pickling mill = [22, 80] mm, and the skinning range of the finished product = [16, 80] mm.

[0071] Scheduling process:

[0072] Step 1: W0=1876≤1900mm, base width=1876mm.

[0073] Step 2: base trimming amount=(1876-5-4)-1829=38mm.

[0074] 38mm is in the product trimming range [16,80]→ adopt product single trimming.

[0075] Output scheme: no trimming in pickling and rolling, product trimming amount 38mm.

[0076] Example 2: rewinding intervention scenario.

[0077] Input parameters: W0=1872mm, W t =1848mm, a=5mm, b=4mm, pickling and rolling trimming range [22,80]mm, product trimming range [16,80]mm, rewinding trimming range [8,80]mm.

[0078] Scheduling process:

[0079] Step 1: base width=1872mm.

[0080] Step 2: base trimming amount=15mm<minimum single process trimming amount (16mm)→failure.

[0081] Step 3: product post-rewinding: product outlet width=1863>1850mm→skip.

[0082] Pickling and rolling post-rewinding: pickling and rolling outlet width=1867mm, theoretical product unit inlet required width=1848+4=1852mm, rewinding trimming amount=1867-1852=15mm∈[8,80]→adopt.

[0083] Output scheme: no trimming in pickling and rolling, no trimming in product, pickling and rolling post-rewinding trimming amount 15mm.

[0084] The present application is not limited to the above-mentioned embodiments, and anyone should know that structural changes made under the inspiration of the present application, any technical solution with the same or similar to the present application, falls within the protection scope of the present application.

[0085] The technical, shape, structure parts not described in detail in the present application are all known technologies.

Claims

1. A method for optimizing scheduling of a cold-rolled strip width trimming process, characterized in that, Comprising the following steps: S1, first level decision: acid pickling inlet width overrun processing, dynamic trigger re-rolling pre-edging; S2, second level decision: acid pickling and finished product edge optimization, calculate the basic edge amount δ, and execute the edge control of the finished product unit and the acid pickling unit according to the priority; S3, third level decision: dynamic selection of re-rolling position, dynamic selection of optimal edge position in re-rolling process; S4, fourth level decision: boundary exception handling, when the third level decision fails, try the minimum cutting combination S a = A1, S p = B1 or entry direct cutting S pre = W0 - W t , otherwise error.

2. The method of optimizing scheduling of cold rolled strip width trimming process as claimed in claim 1 wherein, The acid pickling entry width overrun processing in the step S1 sets an input acid pickling entry width W0, an acid pickling entry maximum allowable width W max_in , a range of the slitter-winder unit edge cutting capacity [C1, C2]; If W0> W max_in , then calculate the recoiling pre-cutting amount S pre = max(C1, W0-W max_in ), check S pre ≤ C2, output the pickling entrance basic width W base = W0-S pre ; otherwise output W base = W0.

3. The method of optimizing scheduling of cold rolled strip width trimming operations according to claim 2, wherein, The skin pass in the step S2 is optimized in coordination with the finished product skinning to be system input skin pass inlet base width W base , target width W t , skin pass necking amount a, finished product necking amount b, skin pass skinning range [A1, A2], finished product skinning range [B1, B2].

4. The method of optimizing scheduling of cold rolled strip width trimming operations of claim 3, wherein, The calculation of the basis trim amount δ = (W base -a-b)-W t , with priority: If δ∈[B1, B2], the finished product unit is single-edged, and the edge amount is δ; If δ∈[A1, A2], the acid pickling unit is single-edged, and the edge amount is δ; If δ ∈ [A1+B1, A2+B2], then the amount of cut-off S is allocated to the finished product p = min(δ, B2), the amount of cut-off S in pickling a = δ - S p ; If δ<0, an error is reported; if δ is out of the above interval, the third level decision is transferred.

5. The method of optimizing scheduling of cold rolled strip width trimming operations of claim 4, wherein, In the second level decision, when δ∈[A1 A2] and the single-edge finished unit is preferentially selected.

6. The method of optimizing scheduling of cold rolled strip width trimming process as claimed in claim 4 wherein, The dynamic selection of the re-winding position in step S3 is calculated as the finished product exit width W out = W base -a-b; Priority after-product re-winding: if W out ≤ W max_out , then calculate the re-winding cutting edge amount S rec = W out -W t , check S rec ∈ [C1, C2]; Second option: re-coiling after pickling: if re-coiling after finishing fails, calculate the pickling exit width W p_out = W base -a, theoretical re-coiling trimming amount S rec_mid = W p_out -(W t +b), check S rec_mid ∈ [C1, C2] and W p_out -S rec_mid ≤ W max_mid ; If both fail, the fourth level decision is transferred.

7. The method of optimizing scheduling of cold rolled strip width trimming operations of claim 6, wherein, The minimum trimming combination in the step S4 is to set the pickling trimming amount S a = A1, the finished product trimming amount S p = B1, the calculated theoretical re-rolling trimming amount S rec_mid = (W base -a-S a -b)-W t , the check S rec_mid ∈ [C1, C2]; Inlet direct trim: if the minimum trim combination fails, then calculate S pre = W0- W t , check S pre ∈ [C1, C2]; If there is still no solution, output "no feasible scheduling".

8. The method of optimizing scheduling of cold rolled strip width trimming operations of claim 7, wherein, In the fourth level decision, the entry direct trim needs to satisfy S pre ≤ C2and W0- S pre ≤ W max_in .