Speed control method for continuous processing line, manufacturing method of strip-shaped product, and speed control device for continuous processing line
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- JFE STEEL CORP
- Filing Date
- 2025-02-25
- Publication Date
- 2026-05-22
Smart Images
Figure 00000011_0000 
Figure 00000011_0001
Abstract
Description
[Technical Field]
[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. [Background technology]
[0002] Patent Document 1 discloses a technique for controlling the speed of the 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 stored material, constraints on the amount of stored material and the speed of the material to be processed, and an evaluation function on the speed. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-126333 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-155249 Summary of the Invention [Problem to be solved by the invention]
[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 the 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, so when the next material to be processed requires handling work such as cutting or welding, it is difficult to operate while ensuring a storage volume of materials that takes into account that time (handling time). Therefore, in the past, managing the storage volume of materials to be processed had to be dependent on manual operation 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. [Means for solving the problem]
[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. [Effects of the Invention]
[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. [Brief explanation of the drawings]
[0016] [Figure 1] 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. [Figure 2] 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. DETAILED DESCRIPTION OF THE 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 also 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 discharging 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, discharging 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 to be treated S, 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 to be treated S can continue to be supplied to the central treatment facility even if the supply of material to be treated S from the inlet treatment facility is stopped during the period in which the material to be treated S is being treated at the inlet treatment facility. The length of the material to be treated S stored in the storage facility (looper remaining length) is set according to the processing time of the inlet treatment facility. Note that, although Figure 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, there is provided a second bridle roll 6 (hereinafter also referred to as "2BR") that adjusts the speed of the material S to be processed before rolling. In addition, on the downstream side (exit side) of the plurality of rolling mills 3, there is provided a third bridle roll 7 (hereinafter also referred to as "3BR") that adjusts the speed of the material S to be processed after rolling.
[0023] The outlet processing facility is a facility for processing the material S to be processed that is supplied from the central processing facility, 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. Then, the control device 8 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 treatment facility and the storage facility. The above constraints include at least constraints regarding the length, speed, and operating conditions of the material S to be treated in the central treatment facility. The above evaluation function is configured to include at least the speed of the material S to be treated in the central treatment facility and the storage amount of the material S to be treated 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 manipulates or automatically controls the speed of the material S based on the calculated command value.
[0029] (Model) The model used in the optimization problem is an equation of state that indicates the flow of the material S to be treated in the continuous treatment line, as shown in the following equation (1).
[0030]
number
[0031] In the above equation (1), k is the discretized time, T sindicates the control period (the length from time k to time k+1), and d indicates the reduction ratio (thickness of the workpiece S after rolling / thickness before rolling).
[0032] In addition, in the above formula (1), x i is the length [m] of the material S to be treated at the i-th location (section) of the continuous treatment line, and specifically indicates the following: x1: Length of material S to be treated from payoff reel 1 to the entrance of looper 2 x2: Amount of material S stored in the looper 2 + Length of material S from the exit side of the looper 2 to the entrance side of the rolling mill 3 x3: Length of the material S after rolling by the rolling mill 3 x4: Length of the material S to be processed from the exit side of the rolling mill 3 to the tension reel 4
[0033] The length x1 also includes the length of the material S that has not yet been paid out from the payoff reel 1. The length x4 also includes the length of the material S that has been wound up 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: v1: Speed of material S to be treated from payoff reel 1 to the entrance of looper 2 v2: 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 v3: Speed of the material S after rolling in the rolling mill 3 v4: Speed of the material S to be processed from the exit side of the rolling mill 3 to the tension reel 4
[0035] The speed v1 is the same as the speed of the first bridle roll 5. The speed v2 is the same as the speed of the second bridle roll 6. The speed v3 is the same as the speed of the third bridle roll 7. The speed v4 is the same as the winding speed of the tension reel 4. The speeds v1 and v2 are set independently because the looper 2 is sandwiched between them. The speeds v3 and v4 are the same value.
[0036] Furthermore, although the material S to be processed does not remain in the central processing facility (rolling mill 3), its length changes due to rolling. Therefore, although speed v2 is the same value as speed v3 multiplied by reduction ratio d (v2 = v3 × d), for the sake of convenience in modeling, variables are set separately for speed v2 and speed v3.
[0037] Furthermore, the speeds v1, v2, v3, and v4 are set for the material S passing through the observation points in each section of the continuous processing line. Furthermore, the length x2 corresponds to the length of the model that represents the change in the amount of material S stored in the looper 2 over time.
[0038] (constraints) Next, the constraints will be explained. 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 in speed between the 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 material S to be treated on payoff reel 1 (=Σx1) [m] l_lin: Amount of material S stored in looper 2 (remaining length of looper) (=Σx2) [m]
[0040] The length of the material S to be treated within the equipment such as the looper 2 is the total length of the material S to be treated in these pieces of equipment with respect to the material S present in the continuous treatment line.
[0041] Based on the above variables, the constraints on the length of the material S can be expressed, for example, as follows: Note that 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 constraints on the speed of the material S can be expressed, for example, as follows: 0≦v1≦730: Velocity v1 is within the range of up to 730 [m / sec] 0≦v2≦320: Velocity v2 is within the range of 0 to 320 [m / sec] 0≦v3≦320 ÷ reduction ratio: Speed v3 is within the range of 0 to 320 ÷ reduction ratio [m / sec]
[0043] Furthermore, constraints on the acceleration / deceleration rate of the material S to be treated can be expressed, for example, as follows: Note that dv1 below is the acceleration / deceleration rate of the material S to be treated from the payoff reel 1 to the entry side of the looper 2. Also, dv2 below 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. -20≦dv1≦20: Acceleration / deceleration rate dv1 is within the range of -20 to 20 -10≦dv2≦10: Acceleration / deceleration rate dv2 is within the range of -10 to 10
[0044] Furthermore, the constraint on the operating conditions of the material S is the processing time (handling time) for handling work such as cutting and welding of the material S in the inlet processing equipment. This handling time indicates, for example, the period during which the speed v1 (the speed of the first bridle roll 5) becomes 0.
[0045] (Evaluation function) Next, the evaluation function will be explained. 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) takes into account the speed and storage amount of the material S to be treated and is composed of the first term on the right-hand side (storage amount evaluation term) that evaluates the target deviation of the storage amount of the material S to be treated stored in the storage facility, and the second term on the right-hand side (treatment efficiency evaluation term) that evaluates the treatment efficiency of the material S to be treated discharged from the storage facility.
[0046] During the period when the material S to be treated is stored in the storage facility, the speed v2 of the material S to be treated discharged from the storage facility slows down, resulting in a decrease in the processing efficiency of the material S to be treated. On the other hand, during the period when the material S to be treated that has been stored in the storage facility is being discharged, the speed v2 on the outlet side of the storage facility can be increased, resulting in an improvement in the processing efficiency of the material S to be treated. As such, the storage volume evaluation term and the processing efficiency evaluation term of the evaluation function are in a contradictory relationship, and therefore an adjustment term (weight α) is provided in the following equation (2) to adjust the priority of the two.
[0047]
number
[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 the 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), v2 is the 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, and 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 value obtained by subtracting a constant C (target looper remaining length) from the looper remaining length is minimized by multiplying the speed v2 by a weight and subtracting it.
[0050] That is, in the first term on the right side of the above equation (2), if the supply of treated material S from the inlet-side treatment facility is stopped (a constraint on the operating conditions of the treated material S) during the period in which the treated material S is being treated in the inlet-side treatment facility and the storage volume decreases, the difference with constant C increases, and the value of evaluation function J increases. Constant C is a parameter that represents the size of the target storage volume. The first term on the right side is provided to solve an optimization problem to obtain a speed pattern (speeds v1, v2) that returns the looper remaining length inventory to the target after treatment of the treated material S in the inlet-side treatment facility is completed. Furthermore, in the second term on the right side of the above equation (2), the evaluation function J decreases as speed v2 increases, and the treated material S is transported more quickly. Therefore, the second term on the right side is provided to solve an optimization problem to obtain a speed pattern that improves processing efficiency while maintaining a predetermined storage volume.
[0051] In the continuous processing line, when the material S can be discharged, the speed v1 is set to the maximum speed and the material is discharged. Similarly, when the material S can be wound up, the speed v4 is set to the maximum speed and the material is wound up. Furthermore, in the central processing facility (rolling mill 3), once the speed v2 and the reduction ratio d are determined, the speed v3 is also determined. Therefore, in the above equation (2), only the speed v2 is evaluated, and the speeds v1, v3, and v4 are not taken into consideration.
[0052] It is advisable to set the constant C, which is a parameter that represents the size of the target storage volume, in accordance with the processing time (handling time) of handling work such as cutting and welding of the material S to be processed 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 to be processed in the entire continuous processing line.
[0053] The evaluation period (from the current time k=0 to the future time k=K-1) should be set longer than the handling time. This is because solving the optimization problem makes it possible to reflect the suspension of the supply of the material S from the inlet treatment facility during the handling period and obtain an optimal speed pattern 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 the above equation (2) 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 of manufacturing belt-shaped products) 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, the method for manufacturing a strip-shaped product uses the above-described speed control method for a continuous processing line to manufacture a strip-shaped product (e.g., a coil) while controlling the speed of the material S to be processed in the continuous processing line. This allows the strip-shaped product to be manufactured while optimizing the speed of the material S 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 to be processed, 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 to be processed based on the calculated command values, it is possible to perform optimal speed control of the continuous processing line.
[0058] (Example) 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] (a) of Figure 2 shows speed v1, which is the speed of the first bridle roll 5 (1BR speed). (b) of Figure 2 shows speed v2, which is the speed of the second bridle roll 6 (2BR speed). (c) of Figure 2 shows the amount of material S stored in the looper 2 (looper remaining length). (d) of Figure 2 shows the ON / OFF 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 looper length), and parameter K = 250 [seconds] representing the future time of the evaluation period. As a constraint on the operating conditions, assuming work such as cutting and welding at the inlet processing equipment, the period (handling time) during which payoff from payoff reel 1 is set to 0 (speed v1 is set to 0) is set to 35 to 185 [seconds] (see Figure 2 (d)). Here, parameter K is set to be longer than the handling time.
[0061] The speeds shown in Figure 2 (a) and (b) are the optimum speeds v1 and v2 for 250 seconds from the current time, calculated at the current time k = 0. Both speeds fluctuate from their initial values and reach their upper limits. Also, both speeds decelerate in accordance with the constraints and satisfy those constraints. Also, as shown in Figure 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 Figure 2(d), 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 its lower limit.
[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 the 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, so handling time is easy to predict.
[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, if a large number of defects occur at multiple locations on the material S, this will be the biggest 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 handling time 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 to evaluate the remaining looper length and processing efficiency (speed). Therefore, as shown in part A of (b) of Figure 2, the increase in speed v2 starts before the signal indicating handling work such as cutting, welding, drilling, etc. in the inlet processing equipment changes from ON to OFF (see (d) of Figure 2). This makes it possible to optimize the timing for increasing speed v2 from a low speed state.
[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 Figure 2 (a) and (b), and after a specified time has elapsed, optimization calculations are performed again to determine the next speed manipulated variable and perform speed control. This procedure is repeated, and the expected control effect can be achieved.
[0068] On the other hand, if work at the inlet processing equipment or the outlet processing equipment (tension reel 4) is not completed as scheduled, or if the transport of the material S at the inlet processing equipment or the outlet processing equipment is stopped due to an unexpected problem, the calculated speed control variable will not be optimal. In this case, each time the optimization problem is solved at the control period (a fixed time) or when a predetermined event occurs, the initial values of the variables in equation (2) above (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, an appropriate speed control variable 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 from now, and then perform optimization calculations corresponding to the next 250 seconds 10 seconds later.
[0070] Furthermore, optimization calculations may be performed for each preset event, rather than at regular intervals. Events may include events related to the speed or length of the material S being processed within the continuous processing line. Examples of events include operations at the inlet or outlet processing equipment, the start or end of the small steps that make up those operations, and the welding point of the material S passing a predetermined point within 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. [Explanation of symbols]
[0074] 1 Payoff Reel 2 Looper 3. Rolling mill 4 tension reels 5. First Bridle Roll (1BR) 6. Second Bridle Roll (2BR) 7. Third Bridle Roll (3BR) 8 Control Device S Treated material
Claims
1. In a continuous processing line having processing equipment for continuously processing strip-shaped materials to be processed and storage equipment for storing the materials to be processed, The aforementioned processing equipment includes an inlet processing facility and a central processing facility. The storage facility is located between the inlet processing facility and the central processing facility. The control device A model representing the time change in the length of each material to be treated in the processing equipment and the storage equipment, Constraints regarding the length, speed, and operating conditions of the material to be processed in the processing equipment, An evaluation function comprising the speed of the material to be processed in the processing equipment and the amount of the material to be processed stored in the storage equipment, An optimization problem consisting of the following: The processing time of the material to be processed in the aforementioned input processing equipment is used as a constraint condition relating to the operating conditions. The evaluation period in the evaluation function is set to be longer than the processing time, corresponding to the processing time. By solving the problem at regular intervals or each predetermined event, the command value for controlling the speed of the material being processed, which is included in the evaluation function, is calculated. The speed of the material to be processed is controlled based on the calculated command value. A method for controlling the speed of a continuous processing line.
2. The method for controlling the speed of a continuous processing line according to claim 1, wherein the evaluation function comprises a storage volume evaluation term that evaluates the target deviation of the amount of material to be processed stored in the storage facility, a processing efficiency evaluation term that evaluates the processing efficiency of the material to be processed 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. The method for controlling the speed of a continuous processing line according to claim 1, wherein each time the optimization problem is solved, the values of the variables used in the evaluation function at the start of the evaluation period of the evaluation function are adjusted to the actual values.
4. The control device Based on information regarding the location and number of defects in the material to be processed in a process prior to the continuous processing line, the processing time of the material to be processed in the input processing equipment is predicted. A method for controlling the speed of a continuous processing line according to claim 1.
5. The method for controlling the speed of a continuous processing line according to claim 2, wherein the parameter corresponding to the target amount of storage in the evaluation function is set in accordance with the processing time.
6. A method for manufacturing strip products, which involves controlling the speed of a material to be processed in a continuous processing line using the speed control method for a continuous processing line described in any one of claims 1 to 5, while manufacturing strip products.
7. In a continuous processing line having processing equipment for continuously processing strip-shaped materials to be processed and storage equipment for storing the materials to be processed, The aforementioned processing equipment includes an inlet processing facility and a central processing facility. The storage facility is located between the inlet processing facility and the central processing facility. A model representing the time change in the length of each material to be treated in the processing equipment and the storage equipment, Constraints regarding the length, speed, and operating conditions of the material to be processed in the processing equipment, An evaluation function comprising the speed of the material to be processed in the processing equipment and the amount of the material to be processed stored in the storage equipment, An optimization problem consisting of the following: The processing time of the material to be processed in the aforementioned input processing equipment is used as a constraint condition relating to the operating conditions. The evaluation period in the evaluation function is set to be longer than the processing time, corresponding to the processing time. By solving the problem at regular intervals or each predetermined event, the command value for controlling the speed of the material being processed, which is included in the evaluation function, is calculated. The device includes a control device that operates the speed of the material to be processed based on the calculated command value. Speed control device for a continuous processing line.