JP2012071326A - Method for determining order of manufacturing steps of thick steel plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for determining an order of manufacturing steps of a thick steel plate, which can determine the order of the manufacturing steps of the thick steel plate while dynamically changing a constraint condition group even when constraint conditions conflict with each other.SOLUTION: The method for determining the order of the manufacturing steps of the thick steel plate, includes: a purchase information input step of inputting dimensions and setting temperatures of a purchase group; an initial solution creating step of creating an initial state of an order of the manufacturing steps; a solution improving step of updating the solution to obtain an optimum solution when reshuffling the resultant order in the initial solution creating step so that the order is made to be practical and an evaluation function is made to be improved; and a manufacturing step order output step of outputting the optimum solution.

Description

  The present invention relates to a method for determining a manufacturing order of thick steel plates, in which the manufacturing order is determined for thick steel plates.

  In a production line having a rolling mill on the upstream side and a finishing facility on the downstream side, the processing pitches on the upstream and downstream facilities are different. Therefore, the timing of material supply and processing may not match, and the efficiency of the production line may decrease. Therefore, a physical distribution simulation method for simulating actual movement of an article with a computer has been developed.

  For example, in Patent Document 1, when controlling the logistics of a production line including a refining process, a simulation is repeated to formulate a logistics plan that includes line down and line up for efficient operation of equipment. A technology entitled a line logistics control method is disclosed.

JP-A-11-285716

  However, in order to determine the manufacturing order of thick steel plates, in addition to rolling and finishing, the constraints of each of a series of equipment called heating furnaces must be considered at the same time, which is disclosed in Patent Document 1 described above. In such a technique, there are cases in which all of the constraint conditions of each cannot be satisfied (the manufacturing order cannot be uniquely determined).

  This is because the constraints of each set of equipment do not necessarily harmonize with each other. In such a case, the planner tries a flexible operation such as relaxing some of the constraints of the planning assumptions. It goes wrong and somehow decides the production order. There are problems such as prolonged planning time due to trial and error, and variations in correspondence among planners.

  The present invention has been made in view of such circumstances, and even when the constraints are not in harmony with each other, the manufacturing order of the thick steel plates can be determined while dynamically changing the constraints. An object of the present invention is to provide a method for determining the manufacturing order of thick steel plates.

  The above problems are solved by the following invention.

[1] A method for determining the manufacturing order of thick steel plates, which determines the manufacturing order of thick steel plates,
An order information input step for inputting the dimensions and set temperature of the order group,
An initial solution creation step for creating an initial state of the production sequence;
A solution improvement step for renewing the solution when the execution of the initial solution creation step result is changed and the evaluation function is improved, and obtaining the best solution;
And a manufacturing sequence output step for outputting the best solution.

[2] In the method for determining the order of production of thick steel plates according to [1] above,
In the solution improving step,
Determine the target and position to be reordered based on the evaluation function priority order,
A method for determining the order of manufacturing thick steel plates, wherein acceptability of a solution whose order has been changed is determined based on an evaluation function violation determination value.

[3] In the method for determining the production order of thick steel plates according to [1] or [2] above,
In the solution improving step,
A method for determining the order of manufacturing thick steel sheets, wherein a range of violation judgment values is expanded for a constraint condition in which a violation occurs when an acceptable solution cannot be obtained even after a predetermined number of improvements of the solution.

[4] In the method for determining the order of production of thick steel plates according to any one of [1] to [3],
A method for determining the manufacturing order of thick steel plates, characterized by narrowing the range of violation judgment values for constraints where the difference between the calculated value and the judgment value is large when the acceptance success rate is high as a result of performing the solution improvement a predetermined number of times .

[5] In the method for determining the production order of thick steel plates according to any one of [1] to [4],
For solutions that include violations by relaxing the judgment method and allowing multiple violations in succession instead of a single violation when an acceptable solution is not obtained even after a certain number of improvements. Is a provisional solution and is not subject to renewal of the solution.

  According to the present invention, when repeating an operation for changing the order so as to be improved from a higher priority for a plurality of evaluation function groups, the determination method based on the constraint violation determination value reflecting the success rate of the improvement operation Has been dynamically relaxed or tightened so that feasible solutions can be found under constraints that often interfere with each other.

It is a figure which shows an example of a series of equipment rows which manufacture a thick steel plate. It is a figure which shows the structural example of the system for implementing this invention. It is a figure which shows the example of the whole process sequence in this invention. It is a figure which shows the process sequence example in a solution change step. It is a figure which shows an example of the manufacture order of 17 order groups of a thick steel plate. It is a figure which shows the preset temperature of the same order group as FIG. It is a figure which shows the rolling width and rolling length of the same order group as FIG. It is a figure which shows the example which rearranged the order group 17 sheets of the same thick steel plate as FIG. 5 in descending order of rolling width. It is a figure which shows the preset temperature of the same order group as FIG. It is a figure which shows the rolling width and rolling length of the same order group as FIG. It is a figure which shows an example of the manufacture order of 17 order groups of the thick steel plate by a present Example. It is a figure which shows the preset temperature of the same order group as FIG. It is a figure which shows the rolling width and rolling length of the same order group as FIG.

  Drawing 1 is a figure showing an example of a series of equipment rows which manufacture a thick steel plate. In the figure, 1 represents a heating furnace, 2 represents a rolling mill, and 3 represents a cutting machine.

  The heating furnace 1 extracts the steel material after heating it to a set temperature and supplies it to the next rolling step. Normally, an upper limit value and a lower limit value are set for the set temperature described above for each steel material, and operation is controlled so that the temperature in the heating furnace falls within this range. In addition, in the case where the manufacturing temperature condition of the steel material to be ordered, which is called “temperature control strict material”, is strict, the upper limit value and the lower limit value are set to the same value, and strict temperature control is imposed.

  Since it takes time to change the set temperature of the heating furnace, in order to secure manufacturing efficiency, it is usually necessary to sandwich custom materials called “temperature binders” between temperature control strict materials with different set temperatures. Is called. Here, a restriction is set that at least one temperature binder is required between the two. In addition, custom materials that can be used as “temperature binders” must have different upper and lower temperature limits, and must not satisfy the conditions that the set temperatures of the strict materials for temperature control before and after are included in the upper and lower limits. Don't be.

  The rolling mill 2 rolls the heated and extracted steel material and processes it to the final product size (sheet thickness). The rolled steel material (large plate) is combined with one to a plurality of order materials, and is cut in the next process (shearing) to finish the dimensions of each order material. As a restriction in rolling, in the case of a thin steel plate, there is a relatively strong restriction that the rolling width is descending (from the largest to the smallest). However, in the case of a thick steel plate, although the rolling length is short and the above width restriction is relatively loose, there is a restriction prohibiting large width reversal.

  The cutting machine 3 cuts the rolled large plate in the width / longitudinal direction and finishes it into a custom-made material having a predetermined size. In the cutting in the longitudinal direction, when a material having a long cutting length continues, there is a risk that the material stays and the upstream rolling mill stops. For example, here, a rolling length of 38 m or more is defined as a long material, and if two long materials continue, there is a risk of equipment stoppage.

  FIG. 5 is a diagram showing an example of the manufacturing order of the order group of 17 thick steel plates. Strict temperature control by focusing on the set temperature, which is an important condition in the heating furnace, and sorting by descending order of the first priority / setting temperature lower limit, ascending order of the second priority / setting temperature upper limit, third priority / descending order of the rolling width A lot of timber is made. However, it is not a feasible solution because there is no temperature binder between strict materials with different temperatures.

FIG. 6 is a diagram showing set temperatures of the same order group as in FIG. Temperature-strict materials with the same upper limit and lower limit of the set temperature are indicated by a single black circle. Otherwise, the upper limit and the lower limit are connected by a solid line, and the upper limit is indicated by a black circle. Similarly, FIG. 7 is a diagram showing the rolling width and rolling length of the same order group as FIG. In FIG. 7, six long materials having a rolling length of 38 m or more are represented by diamonds. Next, paying attention to the important rolling width transition in the rolling mill, the same order group is arranged in descending order of the rolling width. Think about sorting. FIG. 8 is a diagram illustrating an example in which the order group of 17 thick steel plates in FIG. 5 is rearranged in descending order of the rolling width. FIGS. 9 and 10 show this similarly to FIGS. That is, FIG. 9 is a diagram showing the set temperature of the same order group as FIG. FIG. 10 is a diagram showing the rolling width and rolling length of the same order group as in FIG.

  Referring to FIG. 8, although the rolling width is an ideal arrangement order, long materials are concentrated (first three pieces in FIG. 10), and the temperature binder is not properly inserted (FIG. 9). (3rd, 4th, 5th, 6th, etc.), as in the previous example, it can be seen that it is not a feasible solution.

  As shown in the example above, in the rearrangement considered up to the third priority, and in the simple index alignment such as the order of the set temperature of the heating furnace and the order of the rolling width of the rolling mill, all the constraint groups that interfere with each other are satisfied. This is a feature of the problem of determining the manufacturing order of thick steel plates, and is also a point that cannot be solved by the prior art.

  FIG. 2 is a diagram illustrating a configuration example of a system for carrying out the present invention. In the figure, 4 represents a steel plate manufacturing order determination device, 5 represents a database, 6 represents a terminal, and 7 represents a physical distribution device.

  The steel plate manufacturing order determination device 4 exchanges information with the database 5 containing various data, the terminal 6, and the physical distribution equipment 7 that handles the steel plates, and determines the manufacturing order of the steel plates. This thick steel plate manufacturing order determination device 4 is a device that is the center of processing, and a specific device is configured by a computer.

  FIG. 3 is a diagram showing an example of the entire processing procedure in the present invention. First, when the start of processing is instructed, in the order information input step of Step 01, the order information is read from the database and the order information is input.

  Next, in the initial solution creation step in Step 02, an initial solution is created based on the order information. For example, if it is created on the basis of the rolling width descending order, the manufacturing order shown in FIG. 8 corresponds to the initial solution.

  Then, in the solution change step of Step 03, the solution of the manufacturing order is changed based on the evaluation function priority order and the constraint violation determination value, and the best solution is obtained. The situation of constraint violations is stored in a database and the best solution is reached while referring to them.

  Finally, in the manufacturing order output step of Step 04, the best solution is output to a terminal such as a display or a database, and the process is terminated.

  An example in which the present invention is applied to the same order group as in FIG. 5 will be described below. The entire processing procedure follows FIG.

  FIG. 4 is a diagram illustrating an example of a processing procedure in the solution change step. The processing procedure (Step 31 to Step 38) following the initial solution creation step in Step 02 is the processing procedure in the solution change step.

  First, Step 31 is an end determination process. The first time following Step 02 is passed without processing, but when returning from Step 35, Step 37, or Step 38, the processing ends after comparing the current number of solution update upper limit times or the solution update try upper limit number with the preset number. Determine if necessary.

  Next Step 32 is a violation judgment value correction process. The success rate is calculated using the solution update try count as the denominator and the solution update success count as the numerator. If the success rate is lower than the preset numerical value, the violation determination value is relaxed from the current value to widen the allowable range, and the value is changed to allow even a slight improvement. When the success rate is high with respect to another preset numerical value, the violation determination value is made stricter than the current value, the allowable range is narrowed, and the update is not allowed unless the improvement amount is large.

  Step 33 is a solution change process according to the evaluation function. In the evaluation function priority order file, 1) minimization of continuous parts of long materials, 2) minimization of the number of temperature-controlled strict material lots, and 3) minimization of rolling width reversal parts are set.

  From the initial solutions of FIGS. 8, 9, and 10, attention is paid to the continuous portion of the long material having the highest priority of the evaluation function. In FIG. 8, long materials are continuous in the first, second and third rows. The third row is 3800mm wide and 40.7m long.

  Choose a location that minimizes the increase in the number of strict temperature-controlled material lots. Since the material in the third row is a strict temperature control material of 1100 degrees, the destination is searched so as to be adjacent to the strict temperature control material of 1100 degrees, which does not require an increase in the number of lots. The 9th row 2200mm wide and 35.4m long material is 1100 degrees temperature-strict material, so the 3rd row material is moved immediately after this material.

  Step 34 is a change acceptance determination process. Compare the state after Step 33 with the state before the change, and evaluate the change numerically.

  Step 35 is the change acceptance determination itself. As a result of the above change, the number of continuous long materials has been reduced from three to two, and the increase in the number of temperature-controlled strict material lots has been suppressed, so the change is accepted.

  Step 36 is a best solution update determination process. In the whole process from initial solution creation to solution update, the solution with the best evaluation value is continuously updated. The evaluation value of the change result is compared with the evaluation value of the best solution so far.

  Step 37 is the best solution update determination itself. If the result of the change updates the best value so far, update of the solution is allowed.

  Step 38 is the best solution update process. The change result is overwritten on the current best solution, and the sequence returns to Step 31 to repeat the series of processing until the end determination is cleared.

  An example of the processing result of the present embodiment is shown in FIGS. FIG. 11 shows the result of processing the rolling width descending order of FIGS. 8, 9, and 10 described above as an initial solution, and FIG. 11 is a diagram showing an example of the manufacturing order of 17 ordered groups of thick steel plates according to this example. FIG. 12 is a diagram showing set temperatures of the same order group as in FIG. FIG. 13 is a diagram showing the rolling width and rolling length of the same order group as in FIG.

  In FIG. 10 of the initial solution, the first three continuous long materials were all treated independently (FIG. 13). In FIGS. 5 and 6 described above, there are three temperature control strict material lots, but the number is doubled to six to minimize the width reversal point. Still, in Fig. 9 where only the rolling width descending order is emphasized, there are 10 temperature controlled strict material lots, and in Fig. 12, each lot of 1100 ° C, 1150 ° C and 1200 ° C is divided into 2 lots. It can be said that there is no result.

  And as for rolling width descending order, looking at Fig. 13, it is divided into 2 groups of 9 sheets in the first half with a rolling width of 2200mm or more and 8 sheets in the latter half with less than 2200mm. Is realized.

  As described above, it can be seen that the feasible order of manufacturing the thick steel plates can be determined in consideration of a plurality of constraint groups that interfere with each other.

DESCRIPTION OF SYMBOLS 1 Heating furnace 2 Rolling machine 3 Cutting machine 4 Thick steel plate manufacturing order determination apparatus 5 Database 6 Terminal 7 Logistics equipment

Claims (5)

A method for determining a production order of thick steel plates for determining a production sequence of thick steel plates,
An order information input step for inputting the dimensions and set temperature of the order group,
An initial solution creation step for creating an initial state of the production sequence;
A solution improvement step for renewing the solution when the execution of the initial solution creation step result is changed and the evaluation function is improved, and obtaining the best solution;
And a manufacturing sequence output step for outputting the best solution. In the manufacturing order determination method of the thick steel plate according to claim 1,
In the solution improving step,
Determine the target and position to be reordered based on the evaluation function priority order,
A method for determining the order of manufacturing thick steel plates, wherein acceptability of a solution whose order has been changed is determined based on an evaluation function violation determination value. In the manufacturing order determination method of the thick steel plate of Claim 1 or 2,
In the solution improving step,
A method for determining the order of manufacturing thick steel sheets, wherein a range of violation judgment values is expanded for a constraint condition in which a violation occurs when an acceptable solution cannot be obtained even after a predetermined number of improvements of the solution. In the manufacturing order determination method of the thick steel plate of any one of Claim 1 thru | or 3,
A method for determining the manufacturing order of thick steel plates, characterized by narrowing the range of violation judgment values for constraints where the difference between the calculated value and the judgment value is large when the acceptance success rate is high as a result of performing the solution improvement a predetermined number of times . In the manufacturing order determination method of the thick steel plate of any one of Claims 1 thru | or 4,
For solutions that include violations by relaxing the judgment method and allowing multiple violations in succession instead of a single violation when an acceptable solution is not obtained even after a certain number of improvements. Is a provisional solution and is not subject to renewal of the solution.