Speed control method for continuous processing line, production method for belt-like product, and speed control device for continuous processing line

Abstract

According to the present invention, a speed control method for a continuous processing line involves an optimization problem that involves: a model that represents the change over time in the lengths of a material to be processed at processing equipment and retention equipment of a continuous processing line; constraint conditions for the length, speed, and working conditions of the material to be processed at the processing equipment; and an evaluation function that includes the speed of the material to be processed at the processing equipment and the retention amount of the material to be processed at the retention equipment. A control device solves the optimization problem at a regular time interval or every time a prescribed event occurs to calculate a command value for controlling the speed of the material to be processed as included in the evaluation function and manages the speed of the material to be processed on the basis of the calculated command value.

Description

Speed ​​control method for continuous processing line, manufacturing method of strip-shaped product, and speed control device for continuous processing line

[0001] The present invention relates to a speed control method for a continuous processing line, a method for manufacturing a strip-shaped product, and a speed control device for a continuous processing line.

[0002] Patent Document 1 discloses a technique for controlling the speed of material to be processed in a central processing unit based on the amount of material (e.g., a coil) stored in a looper. Patent Document 2 discloses a technique for calculating a command value for the speed of the material to be processed by solving an optimization problem consisting of a model showing the amount of material to be stored, constraints on the amount of material stored and the speed of the material to be processed, and an evaluation function related to the speed.

[0003] Japanese Patent Laid-Open No. 6-126333 Japanese Patent Laid-Open No. 2008-155249

[0004] In the method disclosed in Patent Document 1, only the speed of the material to be processed in the central processing unit is the subject of optimization, and it is difficult to control and automate the speed of the process on a continuous processing line.

[0005] In the method disclosed in Patent Document 2, the evaluation function for the optimization problem does not include a term related to the storage volume of materials to be processed. In other words, in the method disclosed in Patent Document 2, maximizing efficiency is prioritized. Therefore, when handling work such as cutting or welding is required for the next material to be processed, it is difficult to operate the line while ensuring a storage volume of materials that takes into account the handling time. Therefore, in the past, managing the storage volume of materials to be processed had to be manually managed by an operator, which was a major obstacle to automating a continuous processing line.

[0006] The present invention has been made in consideration of the above, and aims to provide a speed control method for a continuous processing line, a method for manufacturing a strip-shaped product, and a speed control device for a continuous processing line that can achieve efficiency leveling without relying on manual operation by theoretically determining the optimal command value for the speed of the material to be processed within a constraint range.

[0007] In order to solve the above-mentioned problems and achieve the object, the speed control method for a continuous processing line of the present invention is a method for controlling the speed of a continuous processing line having a processing facility for continuously processing a strip-shaped material to be processed and a storage facility for storing the material to be processed.In this method, a control device solves an optimization problem consisting of a model representing the change in length of each material to be processed over time in the processing facility and the storage facility, constraints on the length, speed and operating conditions of the material to be processed in the processing facility, and an evaluation function comprising the speed of the material to be processed in the processing facility and the amount of the material to be processed stored in the storage facility, at regular intervals or each time a predetermined event occurs, thereby calculating a command value for controlling the speed of the material to be processed, which is included in the evaluation function, and manipulating the speed of the material to be processed based on the calculated command value.

[0008] In addition, the speed control method for a continuous processing line according to the present invention is configured such that, in the above invention, the evaluation function includes a storage volume evaluation term that evaluates the target deviation of the storage volume of the processed material stored in the storage facility, a processing efficiency evaluation term that evaluates the processing efficiency of the processed material discharged from the storage facility, and an adjustment term that adjusts the priority of the storage volume evaluation term and the processing efficiency evaluation term.

[0009] Furthermore, in the speed control method for a continuous processing line according to the present invention, in the above invention, the values ​​of the variables used in the evaluation function at the start of an evaluation period of the evaluation function are adjusted to actual values ​​each time the optimization problem is solved.

[0010] Furthermore, the speed control method for a continuous processing line according to the present invention is such that, in the above invention, the processing equipment includes an inlet processing equipment and a central processing equipment, the storage equipment is arranged between the inlet processing equipment and the central processing equipment, and the control device predicts the processing time for the processed material in the inlet processing equipment based on information on the location and number of defects in the processed material in a process prior to the continuous processing line, and solves the optimization problem using the predicted processing time as a constraint on the operating conditions.

[0011] In addition, in the speed control method for a continuous processing line according to the present invention, a parameter in the evaluation function corresponding to the target storage amount is set in correspondence with the predicted processing time.

[0012] In the speed control method for a continuous processing line according to the present invention, an evaluation period in the evaluation function is set so as to correspond to the predicted processing time.

[0013] In order to solve the above-mentioned problems and achieve the objectives, the method for manufacturing a strip-shaped product of the present invention uses the above-mentioned method for controlling the speed of the continuous processing line to manufacture a strip-shaped product while controlling the speed of the material to be processed in the continuous processing line.

[0014] In order to solve the above-mentioned problems and achieve the object, the speed control device for a continuous processing line of the present invention is provided with a control device that, in a continuous processing line having processing equipment that continuously processes strip-shaped processed material and storage equipment that stores the processed material, calculates a command value included in the evaluation function to control the speed of the processed material, by solving an optimization problem consisting of a model that represents the change in length of each processed material in the processing equipment and the storage equipment, constraints related to the length, speed and operating conditions of the processed material in the processing equipment, and an evaluation function that includes the speed of the processed material in the processing equipment and the storage amount of the processed material in the storage equipment, at regular intervals or each time a predetermined event occurs, and operates the speed of the processed material based on the calculated command value.

[0015] According to the present invention, by theoretically determining the optimum command value for the speed of the material to be treated within the constraint range, it is possible to achieve equalization of efficiency without relying on manual operation by an operator.

[0016] Fig. 1 is a schematic diagram showing an example of the configuration of a continuous processing line to which a speed control device for a continuous processing line according to an embodiment of the present invention is applied. Fig. 2 is a graph showing an example of the speed of the material to be processed, the remaining length in the looper, and the handling time obtained by solving an optimization problem in an example of a speed control method for a continuous processing line according to an embodiment of the present invention.

[0017] A method for controlling the speed of a continuous processing line, a method for manufacturing a web-shaped product, and a speed control device for a continuous processing line according to embodiments of the present invention will be described with reference to the drawings.

[0018] (Continuous Processing Line) An example of the configuration of a continuous processing line to which a speed control device for a continuous processing line according to an embodiment is applied will be described with reference to Fig. 1. The continuous processing line is a line for continuously processing a material S to be processed, such as a strip-shaped steel plate (coil). The continuous processing line has equipment for storing the material to be processed on at least one of the inlet and outlet sides of the processing equipment, such as a steel plate cold rolling line, pickling line, annealing line, plating line, or coating line.

[0019] Specifically, the continuous processing line according to the embodiment includes an inlet processing facility, a storage facility, a central processing facility, and an outlet processing facility. In the following description, each facility installed in the continuous processing line is also referred to as a "section."

[0020] The entry-side processing equipment (entry-side section) includes a payoff reel 1 for paying out the material S to be treated, and a first bridle roll 5 for adjusting the speed (conveying speed) of the material S to be treated. In addition, in the entry-side processing equipment, equipment for cutting, welding, and notching the material S to be treated, for example, is provided between the payoff reel 1 and the first bridle roll 5 (hereinafter also referred to as "1BR"). During the period in which the material S to be treated is being treated, the payment of the material S from the payoff reel 1 is stopped, and the first bridle roll 5 is stopped (speed is 0).

[0021] The storage facility is a facility for storing the material S to be treated, and is composed of, for example, a looper 2. The storage facility is located between the inlet treatment facility and the central treatment facility. The storage facility is provided so that the material S to be treated can continue to be supplied to the central treatment facility even if the supply of material S from the inlet treatment facility is stopped during the period in which the material S to be treated is being treated at the inlet treatment facility. The length of the material S to be treated stored in the storage facility (looper remaining length) is set according to the processing time of the inlet treatment facility. Note that, although FIG. 1 shows an example in which the storage facility is provided upstream of the central treatment facility, the storage facility may also be provided downstream of the central treatment facility.

[0022] The central processing facility is a facility for continuously processing the material S to be processed that is supplied from the entry processing facility and the storage facility, and is composed of, for example, a plurality of rolling mills 3. On the upstream side (entrance side) of these plurality of rolling mills 3, second bridle rolls 6 (hereinafter also referred to as "2BR") that adjust the speed of the material S to be processed before rolling are provided. Also, on the downstream side (exit side) of the plurality of rolling mills 3, third bridle rolls 7 (hereinafter also referred to as "3BR") that adjust the speed of the material S to be processed after rolling are provided.

[0023] The outlet processing equipment is equipment for processing the material S to be processed supplied from the central processing equipment, and is composed of, for example, a tension reel 4 for winding up the material S to be processed.

[0024] A control device 8 is connected to the inlet processing equipment, storage equipment, central processing equipment, and outlet processing equipment. The control device 8 is realized by a general-purpose information processing device such as a personal computer or a workstation. The speed control device for the continuous processing line mainly comprises a processor such as a CPU (Central Processing Unit) and a memory (main storage unit) such as a RAM (Random Access Memory) or a ROM (Read Only Memory).

[0025] The control device 8 solves an optimization problem consisting of a predetermined model, predetermined constraint conditions, and a predetermined evaluation function at regular intervals or whenever a predetermined event occurs, to calculate a command value included in the predetermined evaluation function for controlling the speed of the workpiece S. The control device 8 then operates the speed of the workpiece S based on the calculated command value.

[0026] The above model includes at least a model representing the change over time in the length of each material S to be treated in the central processing facility and the storage facility. The above constraints include at least constraints on the length, speed, and operating conditions of the material S to be treated in the central processing facility. The above evaluation function includes at least the speed of the material S to be treated in the central processing facility and the amount of material S stored in the storage facility (hereinafter also referred to as "looper remaining length").

[0027] Furthermore, the control device 8 predicts the processing time (hereinafter also referred to as "handling time") of the material S in the inlet processing equipment based on information on the location and number of defects in the material S in processes preceding the continuous processing line.The control device 8 then solves the optimization problem using the predicted processing time as a constraint on the operating conditions.The processing performed by the control device 8 will be described in detail below.

[0028] (Speed ​​Control Method for Continuous Processing Line) In the speed control method for a continuous processing line according to the embodiment, the control device 8 formulates an optimization problem for determining the speed of the material S to be processed that will improve processing efficiency, etc. This optimization problem is made up of the model, constraints, and evaluation function described above. The control device 8 solves the formulated optimization problem at regular intervals or whenever a predetermined event occurs, thereby calculating a command value included in the evaluation function for controlling the speed of the material S to be processed, and operates or automatically controls the speed of the material S to be processed based on the calculated command value.

[0029] (Model) The model used in the optimization problem is a state equation that indicates the flow of the material S to be treated in the continuous treatment line, as shown in the following formula (1).

[0030]

[0031] In the above formula (1), k is the discretized time, T ｓ indicates the control period (the length from time k to time k+1), and d indicates the reduction ratio (thickness after rolling / thickness before rolling of the workpiece S).

[0032] In addition, in the above formula (1), x ｉ is the length [m] of the material S to be treated at the ith location (section) of the continuous treatment line, and specifically indicates the following: x １ : Length of material S to be treated from payoff reel 1 to the inlet side of looper 2 x ２ : Amount of material S stored in the looper 2 + Length of material S from the outlet side of the looper 2 to the inlet side of the rolling mill 3 x ３ x: length of the material S after rolling by the rolling mill 3 ４ : Length of the material S to be treated from the exit side of the rolling mill 3 to the tension reel 4

[0033] In addition, the length x １ The length x also includes the length of the material S that has not yet been paid out from the payoff reel 1. ４ also includes the length of the material S wound by the tension reel 4.

[0034] In addition, in the above formula (1), v ｉ is the speed [m / sec] of the material S to be processed at the i-th location (section) of the continuous processing line, and specifically indicates the following: １ : Speed ​​of the material S to be treated from the payoff reel 1 to the entrance of the looper 2 v ２ : Speed ​​of the material S to be processed from the exit side of the looper 2 to the entry side of the rolling mill 3 ３ : Speed ​​of the workpiece S after rolling by the rolling mill 3 v ４ : Speed ​​of the material S to be treated from the exit side of the rolling mill 3 to the tension reel 4

[0035] In addition, the speed v １ is the same as the speed of the first bridle roll 5. ２ is the same as the speed of the second bridle roll 6. ３ is the same as the speed of the third bridle roll 7. ４is the same as the winding speed of the tension reel 4. １ and velocity v ２ Since the looper 2 is sandwiched between them, the speed v ３ and velocity v ４ are the same value.

[0036] Furthermore, although the material S to be treated does not remain in the central processing facility (rolling mill 3), its length changes due to rolling. ２ is the velocity v ３ is the same value as multiplied by the rolling reduction ratio d (v ２ =v ３ × d), and for convenience of modeling, the velocity v ２ and velocity v ３ The variables are set to distinguish between the above.

[0037] Also, the velocity v １ , v ２ , v ３ , v ４ is set for the material S to be treated passing through the observation point in each section of the continuous treatment line. ２ corresponds to the length of the model that represents the change over time in the amount of material S stored in the looper 2.

[0038] (Constraints) Next, the constraints will be described. The constraints include a constraint on the length of the material S to be treated in each facility, a constraint on the speed of the material S to be treated in each facility, a constraint on the acceleration / deceleration rate of the material S to be treated in each facility (the difference between the speed at discretized time k+1 and time k), and a constraint on the operating conditions.

[0039] First, the following variables are defined for the length of the material S to be treated in each facility: l_por: Length of the material S in the payoff reel 1 (=Σx １ ) [m] l_lin: Amount of material S stored in the looper 2 (looper remaining length) (=Σx ２ ) [m]

[0040] The length of the material S to be treated within the equipment such as the looper 2 is the sum of the lengths of the material S to be treated in these pieces of equipment with respect to the material S present on the continuous treatment line.

[0041] Based on the above variables, the constraints on the length of the material S to be treated can be expressed as follows, for example. The upper and lower limits of the inequalities included in the constraints below are given by equipment constraints. 0≦l_por: The length of the material S to be treated on the payoff reel 1 is 0 m or more. 120≦l_lin≦750: The remaining length of the looper is within the range of 120 to 750 m.

[0042] Furthermore, the constraint on the speed of the material S can be expressed as follows, for example: 0≦v １ ≦730: Speed ​​v １ is within the range of 730 [m / sec] 0≦v ２ ≦320: Speed ​​v ２ is in the range of 0 to 320 [m / sec] 0≦v ３ ≦320÷Reduction ratio: Speed ​​v ３ is within the range of 0 to 320 / reduction ratio [m / sec]

[0043] The constraints on the acceleration / deceleration rate of the material S can be expressed as follows: １ is the acceleration / deceleration rate of the material S from the payoff reel 1 to the entrance side of the looper 2. ２ is the acceleration / deceleration rate of the material S to be treated from the exit side of the looper 2 to the entry side of the rolling mill 3. １ ≦20: Acceleration / deceleration rate dv １ is within the range of -20 to 20 -10≦dv ２ ≦10: Acceleration / deceleration rate dv ２ is in the range of -10 to 10

[0044] The constraint on the operating conditions of the material S is the processing time (handling time) for handling operations such as cutting and welding of the material S in the inlet processing equipment. This handling time is, for example, the speed v １ 10 shows the period during which the speed of the first bridle roll 5 becomes zero.

[0045] (Evaluation Function) Next, the evaluation function will be described. As the evaluation function, for example, the one shown in the following formula (2) is used. The evaluation function shown in the following formula (2) is composed of the first term on the right-hand side (storage volume evaluation term) that evaluates the target deviation of the storage volume of the material S stored in the storage facility, taking into account the speed and storage volume of the material S to be treated, and the second term on the right-hand side (treatment efficiency evaluation term) that evaluates the treatment efficiency of the material S discharged from the storage facility.

[0046] The period during which the material S to be treated is stored in the storage facility is determined by the speed v of the material S to be treated discharged from the storage facility. ２ On the other hand, during the period when the material S stored in the storage facility is discharged, the speed v ２ can be increased, thereby improving the treatment efficiency of the material S. Since the storage volume evaluation term and the treatment efficiency evaluation term of the evaluation function are in a contradictory relationship, the following formula (2) provides an adjustment term (weight α) for adjusting the degree of priority between them.

[0047]

[0048] In the above formula (2), k is the time discretized in units of the control cycle, the evaluation period is the period from the current time k=0 to a future time k=K-1 (K is a parameter representing the future time), and l_lin is the looper remaining length. In addition, the constant C is a parameter representing the size of the target storage amount (looper remaining length), α is a weight (adjustment term for the evaluation function), and v ２ is the speed of the material S to be treated from the exit side of the looper 2 to the entry side of the rolling mill 3, T ｓ is the control period (the length from time k to time k+1).

[0049] In the above formula (2), in order to keep the looper remaining length constant during the evaluation period, the speed v is calculated from the term obtained by subtracting a constant C (target looper remaining length) from the looper remaining length. ２ The subtraction of multiplied by the weight is minimized.

[0050] That is, in the first term on the right side of the above formula (2), if the supply of material S from the inlet processing facility is stopped (a constraint on the operating conditions of material S) during the period when material S is being processed in the inlet processing facility and the storage volume decreases, the difference with the constant C increases and the value of the evaluation function J becomes larger. The constant C is a parameter that represents the size of the target storage volume. Then, by solving the optimization problem, a speed pattern (speed v １ , v ２ ) is provided in the first term on the right side of the equation (2). ２ The larger the value of the evaluation function J, the smaller the evaluation function J, and the faster the transport of the material S. Therefore, the second term on the right-hand side is provided to solve the optimization problem and obtain a speed pattern that improves the processing efficiency while maintaining a predetermined storage volume.

[0051] In addition, in the continuous processing line, when the material to be processed S can be discharged, the speed v １ Similarly, when the material S can be wound up, the speed v ４ Furthermore, in the central processing facility (rolling mill 3), the speed v ２ When the reduction ratio d is determined, the speed v ３ Therefore, in the above equation (2), the velocity v ２ Only the speed v １ , v ３ , v ４ This does not take into consideration.

[0052] The constant C, which is a parameter representing the size of the target storage amount, should be set in accordance with the processing time (handling time) of handling work such as cutting and welding of the material S in the inlet processing equipment. This is to prevent a situation in which the material S stored in the storage equipment during the handling period runs out (i.e., the looper remaining length becomes zero), causing the supply of material S to the central processing equipment to stop, and resulting in a significant drop in the processing efficiency of the material S in the entire continuous processing line.

[0053] The evaluation period (from the current time k=0 to a future time k=K-1) should be set longer than the handling time. This is because solving the optimization problem makes it possible to obtain an optimal speed pattern that reflects the suspension of the supply of the material S from the inlet treatment facility during the handling period and that balances the storage volume and treatment efficiency of the storage facility for the material S before and after the handling period. Specifically, the evaluation period is preferably set to about 1.3 to 1.5 times the handling time.

[0054] The optimization problem is constructed from the model, constraints, and evaluation function described above. The faster the speed of each piece of equipment, the faster the transport of the material S to be treated and the higher the treatment efficiency, so the smaller the value of the evaluation function shown in equation (2) above.

[0055] Therefore, in the speed control method for a continuous processing line according to the embodiment, an optimization problem is solved to determine the speed of the material S to be processed in each piece of equipment that minimizes the evaluation function shown in equation (2) above under the above constraints (reducing the deviation between the looper remaining length and the constant C and maximizing the processing efficiency of the material S to be processed throughout the continuous processing line). In this way, theoretically, it is possible to determine the speed of the material S to be processed that optimizes the processing efficiency of the continuous processing line, and by controlling the speed accordingly, it is possible to achieve optimal processing efficiency within operational constraints.

[0056] (Method for manufacturing a strip-shaped product) The speed control method for a continuous processing line according to the embodiment can also be applied to a method for manufacturing a strip-shaped product. In this case, in the method for manufacturing a strip-shaped product, the speed of the material S to be processed in the continuous processing line is controlled using the speed control method for a continuous processing line described above to manufacture a strip-shaped product (e.g., a coil). This makes it possible to manufacture a strip-shaped product while optimizing the speed of the material S to be processed within operational constraints.

[0057] In the speed control method for a continuous processing line according to the embodiment, the above-described optimization problem is solved at regular intervals or whenever a predetermined event occurs, thereby calculating command values ​​for controlling the speed of the material S, which are included in the evaluation function shown in the above formula (2), from moment to moment. Then, by controlling the speed of the material S based on the calculated command values, it is possible to perform optimal speed control of the continuous processing line.

[0058] An example of the speed control method for a continuous processing line according to the embodiment will be described with reference to Fig. 2. Fig. 2 shows an example of the speed, remaining length in the looper, and handling time of the material S to be processed obtained by solving the optimization problem defined above.

[0059] FIG. 2(a) shows the velocity v １ and indicates the speed of the first bridle roll 5 (1BR speed). ２ and indicates the speed (2BR speed) of the second bridle roll 6. (c) in Fig. 2 indicates the amount of material S stored in the looper 2 (looper remaining length). (d) in Fig. 2 indicates the ON / OFF status of work in the inlet processing equipment, and the period when the work is ON is the handling time.

[0060] In this embodiment, in the above formula (2), the control period T ｓ = 1 [second], weight α = 150, constant C = 600 (parameter representing the remaining length of the looper), parameter K representing the future time of the evaluation period = 250 [seconds]. As a constraint on the operating conditions, work such as cutting and welding in the inlet processing equipment is assumed, and the payout from the payoff reel 1 is set to 0 (speed v １ The period (handling time) during which the parameter K is set to 0 was set to 35 to 185 seconds (see FIG. 2(d)). Here, the parameter K was set to be longer than the handling time.

[0061] The speeds shown in (a) and (b) of Figure 2 are the optimal speed v １ , v ２2(c) shows the results of calculation at the current time k=0. All speeds have changed from their initial values ​​and reached their upper limits. All speeds have also decelerated in accordance with the constraint conditions and satisfied those constraint conditions. Also, as shown in FIG. 2(c), it can be seen that the remaining looper length is within the constraint range (120≦l_lin≦750).

[0062] Furthermore, as shown in (d) of Figure 2, by utilizing defect information from the previous process to predict the handling time in the inlet processing equipment and setting an evaluation period for the optimization problem that is longer than the handling time, it is possible to predict the time when the work in the inlet processing equipment will be completed, and to prevent the speed (2BR speed) of the processed material S at the outlet side of the storage equipment from stopping, while using up the looper remaining length exactly to the lower limit of the looper remaining length.

[0063] For example, if the number of defects in the upstream process is zero, the operator does not visually inspect for defects, and the material is cut to a specified cutting length from the welding point in the inlet processing equipment and welded. In this case, there is no fluctuation in the work in the inlet processing equipment, making it easy to predict handling time.

[0064] On the other hand, if the number of defects is small and the defects are close to the welding point, the operator visually inspects the defects, and then the inlet processing equipment instructs the operator to cut the material to an additional cutting length to remove the defective portion, and the material is then cut to that cutting length and welded. In this case, the handling time can be predicted by taking into account the time required for the visual inspection and the time required to instruct the additional cutting length.

[0065] Furthermore, when a large number of defects occur at multiple locations on the material S, this becomes the largest cause of variations in work at the inlet processing equipment. In this case, the handling time can be predicted based on, for example, the average of the handling times achieved according to the number of defects.

[0066] In this embodiment, the evaluation period (from time k=0 to future time k=K-1) in the evaluation function of the above formula (2) is set longer than the handling time, and the remaining looper length and processing efficiency (speed) are evaluated. Therefore, as shown in part A of FIG. 2(b), the speed v ２ This causes the speed v ２ The timing of the speed increase can be optimized.

[0067] If the operation of the continuous processing line is proceeding as expected at the current time, speed control is performed according to the speeds (speed manipulated variables) shown in Figures 2(a) and 2(b), and after a specified time has elapsed, optimization calculation is performed again to determine the next speed manipulated variable and perform speed control. This procedure is repeated, thereby achieving the expected control effect.

[0068] On the other hand, if work at the entry-side processing equipment or the exit-side processing equipment (tension reel 4) is not completed as scheduled, or if the transport of the material S at the entry-side processing equipment or the exit-side processing equipment is stopped due to an unexpected problem, the calculated speed control variables will not be optimal. In this case, each time the optimization problem is solved at the control period (a fixed time) or upon the occurrence of a predetermined event, the initial values ​​of the variables in the above equation (2) (the values ​​of the variables at the start time k = 0 of the evaluation period) are adjusted to the actual values. This improves the accuracy of predicting the future length of the material S at the payoff reel 1, looper 2, and tension reel 4. Therefore, even if the operating state deviates from the expected operating state, appropriate speed control variables can be determined.

[0069] Furthermore, if it is difficult to perform optimization calculations for each control period from the viewpoint of calculation load, it is also possible to perform optimization calculations, for example, every 10 seconds, and perform speed operation corresponding to the first 10 seconds of the speed operation amount from the current time up to 250 seconds into the future, and then perform optimization calculations corresponding to the next 250 seconds 10 seconds later.

[0070] Furthermore, the optimization calculation may be performed for each predetermined event, rather than at regular intervals. The event may be an event related to the speed or length of the material S in the continuous processing line. Examples of events include the start / end of work in the entry processing equipment or exit processing equipment, the start / end of the small steps that make up those work, and the welding point of the material S passing a predetermined point in the continuous processing line. Further examples of events include the length of the material S in the payoff reel 1 or tension reel 4, or the remaining length of the looper exceeding (or falling below) a predetermined threshold.

[0071] In addition, in the optimization calculation of this embodiment, the length of the workpiece S in each facility is assigned as one variable, but the sum of the lengths of the workpiece S in each facility may also be used as a variable. In this case, the workpiece S in each facility can be distinguished by tracking the position of the weld.

[0072] According to the speed control method for a continuous processing line, the manufacturing method for a strip-shaped product, and the speed control device for a continuous processing line of the embodiments described above, by theoretically determining the optimal command value for the speed of the material to be processed S within the constraint range, it is possible to achieve efficiency leveling without relying on manual operation by an operator.

[0073] The speed control method for a continuous processing line, the method for manufacturing a web-shaped product, and the speed control device for a continuous processing line according to the present invention have been specifically described above using the detailed description and examples for carrying out the invention, but the scope of the present invention is not limited to these descriptions and should be broadly interpreted based on the claims. Furthermore, it goes without saying that various changes and modifications based on these descriptions are also included in the scope of the present invention.

[0074] REFERENCE SIGNS LIST 1 Payoff reel 2 Looper 3 Rolling mill (mill) 4 Tension reel 5 First bridle roll (1BR) 6 Second bridle roll (2BR) 7 Third bridle roll (3BR) 8 Control device S Treated material

Claims

1. A speed control method for a continuous processing line having processing equipment that continuously processes strip-shaped material to be processed and storage equipment that stores the material to be processed, wherein a control device solves an optimization problem consisting of: a model that represents the change in length of each material to be processed in the processing equipment and the storage equipment over time; constraints on the length, speed, and operating conditions of the material to be processed in the processing equipment; and an evaluation function that includes the speed of the material to be processed in the processing equipment and the storage amount of the material to be processed in the storage equipment, at regular intervals or each time a predetermined event occurs, thereby calculating a command value that controls the speed of the material to be processed, which is included in the evaluation function, and operating the speed of the material to be processed based on the calculated command value.

2. A speed control method for a continuous processing line as described in claim 1, wherein the evaluation function includes a storage volume evaluation term that evaluates the target deviation of the storage volume of the processed material stored in the storage facility, a processing efficiency evaluation term that evaluates the processing efficiency of the processed material discharged from the storage facility, and an adjustment term that adjusts the priority of the storage volume evaluation term and the processing efficiency evaluation term.

3. A speed control method for a continuous processing line according to claim 1 or claim 2, wherein the values ​​of the variables used in the evaluation function at the start of the evaluation period of the evaluation function are adjusted to actual values ​​each time the optimization problem is solved.

4. A speed control method for a continuous processing line as set forth in any one of claims 1 to 3, wherein the processing equipment includes an inlet processing equipment and a central processing equipment, the storage equipment is arranged between the inlet processing equipment and the central processing equipment, and the control device predicts the processing time for the processed material in the inlet processing equipment based on information on the location and number of defects in the processed material in a process preceding the continuous processing line, and solves the optimization problem using the predicted processing time as a constraint on the operating conditions.

5. A speed control method for a continuous processing line according to claim 4, wherein a parameter in said evaluation function corresponding to said target storage amount is set in correspondence with said predicted processing time.

6. The speed control method for a continuous processing line according to claim 4, wherein the evaluation period in said evaluation function is set so as to correspond to said predicted processing time.

7. A method for manufacturing a strip-shaped product, in which the speed of the material to be processed in a continuous processing line is controlled using the speed control method for a continuous processing line described in any one of claims 1 to 6, while manufacturing the strip-shaped product.

8. A speed control device for a continuous processing line having processing equipment for continuously processing strip-shaped material to be processed and storage equipment for storing the material to be processed, the device calculating a command value for controlling the speed of the material to be processed included in the evaluation function by solving an optimization problem consisting of: a model representing the change in length of each material to be processed in the processing equipment and the storage equipment; constraints on the length, speed and operating conditions of the material to be processed in the processing equipment; and an evaluation function including the speed of the material to be processed in the processing equipment and the storage amount of the material to be processed in the storage equipment at regular intervals or each time a predetermined event occurs; and the device is equipped with a control device for operating the speed of the material to be processed based on the calculated command value.

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