JP3073612B2 - Board removal method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet removing method, and more particularly, to a material sheet removing method for optimally combining a plurality of orders from a plurality of slabs of metal or the like.

[0002]

2. Description of the Related Art Conventionally, in preparing a planing plan by allocating a plurality of orders to a plurality of slabs, a plan creator tries a combination of the slabs and a plurality of orders based on given information of the slabs. She was trying to make mistakes and took a plank.

[0003]

However, the above-mentioned conventional board-cutting method in which a person obtains a combination by trial and error and prepares a board-cutting plan has the following problems. (1) The number of combinations of slabs and orders is enormous because the amount of information used for the planing is extremely large, but the number of combinations required by hand is limited. (2) In addition, there are many constraints on stripping, and it takes time to find a combination that satisfies this condition from the combinations obtained above. (3) Further, it is difficult to evaluate the optimality of the final board removal. An object of the present invention is to improve a board removing method in order to solve such problems in the conventional technology, and to provide a board removing method capable of creating an optimal board removing plan in a short time that can be practically used. It is assumed that.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a method of applying a plate to each of a plurality of plates, which is applied to one or more orders. By rearranging the order of application of the order to the above by the simulated annealing method, creating a planing plan for each combination, and applying an evaluation function based on predetermined conditions for the planing for each planing plan. It is configured as a board removal method that determines an optimal board removal plan. The predetermined conditions include such conditions as minimizing the area of the discarded portion of the plate material, productivity, the delivery date of the order, and using the old plate material as soon as possible.

[0005]

According to the present invention, in order to allocate one or more orders to each of a plurality of plate materials and create a plate-cutting plan, the order in which the plate materials are used and the order in which the order is allocated to the plate materials are simulated.・ Sheet plan is prepared for each combination by rearranging by the annealing method. Then, an optimal planing plan is determined for each planing plan by applying an evaluation function based on predetermined conditions for the planing. That is, a combination of the order of use of the plate materials and the order of application of the order can be quickly obtained, and a combination that satisfies the above condition can be easily found from the combination. For this reason, the yield and the like can be improved, and the time for creating a combination can be reduced. Furthermore, it is possible to objectively evaluate the optimality of the final board removal. As a result, it is possible to obtain a board removing method that can create an optimal board removing plan in a short time that can withstand actual use.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. The following embodiment is an example embodying the present invention and is not intended to limit the technical scope of the present invention. FIG. 1 is a flowchart (a) showing a procedure for creating a board removal plan by the board removal method according to one embodiment of the present invention;
(B), FIG. 2 is a table showing the specifications of the slab and the order and the contents of their combination, and FIG. 3 is a plan view of the planing method according to the present embodiment. The sheet removing problem in the present embodiment means that a plurality of orders 0 are assigned to a plurality of slabs S (corresponding to a sheet material).
Is a problem that is optimally applied. Here, “optimal” means that the area of the discarded portion of the slab S is minimized when creating the planing plan, and that conditions such as productivity, the delivery date of order 0, and the use of the old slab S as soon as possible are the most important. Means to satisfy. This stripping problem has the following features. (1) The shape of the slab S in order 0 is the same (rectangular), but has attributes of length × thickness × width × steel type, and there are quite many types. (2) A plurality of steel slabs S can be allocated to one order 0. (3) The size of the material is variable because the slab S is rolled to make the material, instead of allocating order 0 from a material of a fixed size. (4) There is a restriction on the order of the order 0 within the same material (for example, an order having a width larger than the first order cannot be taken). (5) Only the order 0 of the same thickness can be obtained from the same material. (6) Materials that can be ordered 0 by turning over (2) above are limited by steel type. To solve such a problem, the order 0 is allocated to the slab S (the slab S
And the order 0) are determined, and the arrangement of the order 0 in the slab S is determined. In particular, the problem has a large solution space due to the reasons (1) to (3). It can be said that there is. For this reason, in this embodiment, a simulated annealing method (Simulated Annealing Algorithm), which is a powerful method for solving a large-scale combinatorial optimal problem,
(Hereinafter abbreviated as SA). That is, the optimal solution is obtained while performing a so-called transition that changes the solution candidate of the problem viewed on the metal to be annealed by SA. When applied to an actual problem, the number of slabs S is about 200 and the number of orders 0 is about 96
It is impractical in terms of calculation time to find the optimal solution using all data at the same time as 0, which is very large. Therefore,
In order to narrow the solution space, the data was grouped based on a certain criterion, and SA was applied to each group.

Hereinafter, a procedure for preparing a board removal plan by the board removal method according to the present embodiment will be described in the order of steps S1, S2,... With reference to FIGS. FIG.
As shown in (a), in this embodiment, first, data of a slab S and an order 0 are input (S1), and grouped (S1).
2). As a grouping method, for example, the following two methods are applied. The method of grouping order 0 with common steel types that can be used. The method of further grouping the groups classified by the grouping by the above method into the board-cutting group. If the search space is too narrow, the optimal solution may be missed. Conversely, the above method is less likely to miss the optimal solution, but requires more computation time than the above method. Initially set as group number i = 1 (S
3) Then, the group i is optimized by the SA (S
4). Hereinafter, the content of step S4 will be described more specifically with reference to FIG. In SA, the initial temperature T0 is set (S11). The initial temperature T0 is a temperature T which is a kind of parameter for performing convergence calculation by SA.
Must be set to a value sufficient to change the solution candidate of the problem viewed from the metal to be annealed, that is, to cause a transition. Next, in SA, the solution candidate of the problem is represented by a code x composed of a fixed-length character string. Here, the code x is composed of a first half code indicating the order of use of the slab S and a second half code indicating the order of application of the order 0. For example, FIG.
As shown in (b), the number of slabs S is 6, and the number of orders 0 is 7
In the case of, the solution candidate is represented by the following 13-digit code. The combination of the slab S corresponding to the code x and the order 0 is as shown in FIG. Neighborhood Sx of this code x
A so-called transition candidate x ', which is a new code, is randomly selected and generated from among (a code group that differs from the code x only in the order in which the slab S is used or the order in which the order 0 is applied) (S1).
2). The algorithm for creating this transition candidate x 'is, for example, 2
The order in which the two slabs S are used or the order in which the order 0 is applied is randomly changed.

In the order of use of the slab S represented by the code x and the transition candidate x 'thus created, and the order of application of the order 0, the constraint on the thickness and the type of steel, and the maximum width of the leading plate are considered. A combination of slab S and order 0 that satisfies the constraint is determined. At this time, the length of the material is determined by the size of the first order.
And the combination of order 0 and. Then, a planing plan as shown in FIG. 3 is created for these combinations. In FIG. 3, a maximum of two sheets are taken in the width direction of the slab S, and whether or not to take two sheets is determined by the width of the order 0. The following evaluation function E1 is determined in order to evaluate the optimality of such a planing plan (S13). E1 = Σ (Cai + Cbi + Ai * Cci) (1) where E1: the sum of the evaluation functions Ca: the loss amount of the waste within the block Cb: the loss time required for the setup required for cutting Cc: the waste amount of the waste outside the block Loss A: 30 / age of slab (elapsed days after manufacturing slab S) Here, the block represents the length in which orders of the same width are placed successively. It is predetermined. FIG. 3 shows an example of the relationship between blocks, Ca and Cc, and Cb. Further, the coefficient A plays a role of a weight for the discarded portion Cc outside the block, and when the discarded portion Cc outside the block has the same area, the coefficient A and the evaluation function E1 are smaller when the old slab S is used. It turns out that it becomes. Then, the evaluation function E1 before and after the transition, which is the rearrangement of the code between the code x and the transition candidate x '.
Is calculated (S14). It is determined whether to accept or reject the transition candidate x 'based on the change Δ of the evaluation function E1 (S15). That is, when the transition candidate x 'is generated, the current state x is changed to x' with the probability P (Δ). This is referred to as "accepting a transition candidate" or "performing a transition." Conversely, the current candidate is discarded with the probability 1-P (Δ). This is called "rejecting transition candidates". Here, P (Δ) is represented by the following equation. P (Δ) = 1, ifΔ ≦ 0 (2a) P (Δ) = exp (−Δ / T), ifΔ> 0 (2b) If the transition candidate x ′ is not accepted, Sx is returned again. And randomly selecting x 'from. In the step of individually accepting with the probability P (Δ), a uniform random number r in the section (0, 1) is used. That is, r is P
If it is smaller than (Δ), the transition candidate x ′ is accepted, and if it is larger, it is rejected. As can be seen from the above equation (2b), when the evaluation function E1 is deteriorated (Δ>
It is a feature of the SA that the transition candidate x 'is accepted with a certain probability even in the case of 0). For this reason, it is possible to escape from the minimum solution. Such a transition is repeated until the equilibrium condition at the temperature T is achieved (S16). Then, when the equilibrium is achieved (until the termination condition is satisfied (S17)), the temperature T is updated (S18), and the steps S12 to S12 are performed.
Repeat 18. In this way, when the temperature T is gradually lowered and the termination condition is satisfied, the evaluation function E1 is minimized, and an optimal planing plan is obtained.

In the above algorithm, the setting method of the initial temperature T0, the determination condition of the equilibrium condition at each temperature, the updating method of the temperature T, and the determination of the termination condition are, for example, Kirkpatrick, Hu
A known annealing schedule such as ang is used. Optimization of group i by such SA (S4)
After the end, the code x "indicating the optimum planing plan result in the group i is output together with the evaluation function E1" (S
5). i = i + 1 is set (S6). Step S4 and above
S6 is repeated for all groups (S7). As described above, an optimal board removal plan can be determined by transiting the code x representing the order of use of the slabs S and the order of apportionment of the order 0 for the metal to be annealed for all groups. That is, a combination of the order of use of the slabs S and the order of application of the order 0 can be quickly obtained, and a combination satisfying the condition can be easily found from this combination. For this reason, the yield etc. are improved,
Combination creation time can be reduced. Furthermore, it is possible to objectively evaluate the optimality of the final board removal. As a result, it is possible to obtain a planing method capable of creating an optimum planing plan within a practical time range. In the above-described embodiment, the present invention is applied to the plate cutting of the slab S. However, in actual use, the present invention can be similarly applied to the plate cutting of a material obtained by rolling the slab S. Note that the evaluation function E used in the above embodiment was used.
In place of 1, an evaluation function E2, E3, E4 represented by the following equation, for example, may be used depending on the situation. (1)
When it is necessary to consider the delivery date of order 0 E2 = (1 + NP / TNO) ｃ (Cai + Cbi + Ai * Cci) (3) where, NP: the number of orders (must order) that are not manufactured and whose delivery date is approaching (must order) (Must order can be set by delivery date.) TNO: Total number of orders in group (2) When it is not necessary to use old slab S, E3 = Σ (Cai + Cbi + Cci) ... (4) (3) Delivery date and yield To adjust the balance with E4 = Σ (Cai + Cbi + Cci + NP) (5) Further, the first to third expressions in the above equations (1), (3), (4) and (5)
Weights Wa, Wb, and Wc are assigned to Ca, Cb, and Cc of the third term, respectively.
May be multiplied.

[0010]

Since the sheet removing method according to the present invention is configured as described above, the code representing the order of use of the slabs and the order of application of the slabs to the metal to be annealed is changed. An optimal planing plan can be determined. That is, a combination of the order of use of the slabs and the order of application of the order can be quickly obtained, and a combination satisfying the conditions can be easily found from the combination. For this reason, the yield and the like can be improved, and the time for creating a combination can be reduced. Furthermore, it is possible to objectively evaluate the optimality of the final board removal. As a result, it is possible to obtain a board removing method that can create an optimal board removing plan in a short time that can withstand practical use.

[Brief description of the drawings]

FIG. 1 is a flowchart (a) showing a procedure for creating a board removal plan by a board removal method according to an embodiment of the present invention;
(B).

FIG. 2 is a table showing specifications of a slab and an order and contents of a combination thereof.

FIG. 3 is a plan view of the board removing method according to the board removing method of the embodiment.

[Explanation of symbols]

 S: slab (corresponding to plate material) 0: order x, x ', x "... code (or transition candidate) E1, E1', E1" ... evaluation function SA: simulated annealing method

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kazuo Nose 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Kobe Steel, Ltd. Kobe Research Institute (72) Inventor Shigeru Sakai Kanazawa, Kakogawa-shi, Hyogo No. 1 in Kobe Steel, Ltd.Kakogawa Works (72) Inventor Sasaki Main Budget No. 1, Kanazawa-cho, Kakogawa, Hyogo Prefecture Kobe Steel, Ltd. Company Kobe Steel Works Kakogawa Works (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 37/00

Claims (1)

(57) [Claims] 1. A method for allocating one or more orders to each of a plurality of plate materials to prepare a plate-cutting plan, the order in which the plate materials are used and the order in which the orders are applied to the plate materials are determined by a simulated annealing method. A planing method in which a planing plan is created for each combination by rearrangement, and an optimal planing plan is determined for each planing plan by applying an evaluation function based on predetermined conditions for the planing.