Process Control Equipment

Abstract

To provide a process controller which can obtain a speed actual value outputted by a speed meter with no long time required for determination, no false detection and no erroneous determination.SOLUTION: A process controller comprises: filter means that inputs a speed actual measured value of a material which is arrested between continuously located rolling machines and is transported, and outputs a speed actual value; speed actual prediction means which outputs to the filter means with an upper limit value of the speed actual measured value on the basis of a speed target value of a downstream rolling machine and with a lower limit value of the speed actual measured value on the basis of a speed target value of an upstream rolling machine. The filter means outputs the upper limit value as the speed actual value when the speed actual measured value is larger than the upper limit value, and outputs the lower limit value as the speed actual value when the speed actual measured value is smaller than the lower limit value.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to a process control device having the capability of correcting an actual speed value of a speedometer that measures the speed of a material being conveyed. [Background technology]

[0002] In rolling facilities in steel plants, the thickness of rolled material is controlled by a control system including a drive system for driving the rolling mill and a process control device. The process control device is, for example, a programmable logic controller (hereinafter, referred to as a PLC).

[0003] In plate thickness control, a mass flow plate thickness control method is sometimes adopted in which the mass flow plate thickness is calculated using a plate thickness gauge that measures the material plate thickness and a speed meter that measures the material speed, and there is a need to improve plate thickness accuracy by increasing the measurement accuracy of the actual speed value.

[0004] An optical speedometer may be used as a speedometer, and Patent Document 1 describes a means for removing noise from the actual speed measurement value of the optical speedometer by correcting the speed measurement value based on time changes or a pre-specified index. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6614827 Summary of the Invention [Problem to be solved by the invention]

[0006] The above-mentioned conventional technology aims to solve the problem with the speedometer alone, and implements a function to correct the actual speed value measured by the speedometer. However, such technology has a problem that it is difficult to set the time and determine the index when determining an abnormality based on some index for time-dependent changes. In other words, if the judgment time is shortened, the accuracy cannot be improved unless the threshold value is very small, which leads to an increase in false detections / false judgments, and if the judgment time is extended, it becomes a delay element from measurement to judgment.

[0007] An object of an embodiment of the present invention is to provide a process control device that obtains an actual speed value output by a speedometer without requiring a long time for judgment or without erroneous detection or judgment. [Means for solving the problem]

[0008] A process control device according to an embodiment of the present invention receives an actual speed measurement value from a speedometer that measures and outputs an actual speed measurement value of a material being restrained and transported between a first rolling mill and a second rolling mill provided upstream of the first rolling mill, and outputs a first speed target value for the first rolling mill and a second speed target value for the second rolling mill, which are calculated based on the specifications of the material, to a first drive device that drives a first motor that drives the first rolling mill and a second drive device that drives a second motor that drives the second rolling mill, respectively. This process control device includes a filter means that receives the actual speed measurement value and outputs an actual speed value, and a speedometer that outputs a speed measurement value for the first speed target value. of the upper limit value of the actual speed measurement value, and the second speed target value ofand a speed result prediction means for outputting the actual speed result measurement value to the filter means as a lower limit value of the actual speed result measurement value. The filter means compares the input actual speed result measurement value with the upper limit value and the lower limit value, and outputs the actual speed result measurement value as the actual speed value when the actual speed result measurement value is equal to or greater than the lower limit value and equal to or less than the upper limit value, outputs the upper limit value as the actual speed value when the actual speed result measurement value is greater than the upper limit value, and outputs the lower limit value as the actual speed value when the actual speed result measurement value is smaller than the lower limit value. Effect of the Invention

[0009] In this embodiment, a process control device is realized that obtains an actual speed value output by a speedometer without taking a long time for judgment or without erroneous detection or judgment. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic block diagram illustrating a process control device according to a first embodiment. [Diagram 2] 4 is an example of a schematic timing chart for explaining the operation of the process control device of the first embodiment. [Diagram 3] FIG. 11 is a schematic block diagram illustrating a process control device according to a second embodiment. [Figure 4] 13 is an example of a schematic timing chart for explaining the operation of the process control device of the second embodiment. [Diagram 5] FIG. 11 is a schematic block diagram illustrating a process control device according to a third embodiment. [Figure 6] 13 is an example of a schematic timing chart for explaining the operation of the process control device of the third embodiment. [Figure 7] 13 is an example of a schematic timing chart for explaining the operation of the process control device according to the fourth embodiment. [Figure 8] 13 is an example of a schematic timing chart for explaining the operation of the process control device of the fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as in reality. Even when the same part is shown, the dimensions and ratios of each part may be different depending on the drawing. In this specification and each drawing, elements similar to those described above with reference to the previous drawings are given the same reference numerals and detailed description thereof will be omitted as appropriate.

[0012] (First embodiment) FIG. 1 is a schematic block diagram illustrating a process control device according to the present embodiment. FIG. 1 shows a process control device (represented as PLC in FIG. 1 and in FIGS. 3 and 5 described later) 9, as well as a process control system 10 including the process control device 9, and also shows rolling equipment and a driving system for the rolling mills controlled by the process control system 10. In this example, the rolling equipment includes a downstream rolling mill 3 and an upstream rolling mill 4, and the material 1 is conveyed while being rolled from the upstream rolling mill 4 to the downstream rolling mill 3 as shown by the arrow in FIG. 1. The driving system for the rolling mill includes motors 5 and 6 and drive devices 7 and 8. The drive device 7 is connected to the process control device 9 and drives the motor 5 based on a command from the process control device 9. The motor 5 drives the downstream rolling mill 3. The drive device 8 is connected to the process control device 9 and drives the motor 6 based on a command from the process control device 9. The motor 6 drives the upstream rolling mill 4.

[0013] In the example of Fig. 1, two rolling mills are shown, but two or more rolling mills are sufficient, and three or more rolling mills may be used. In other words, a rolling mill may be provided further upstream of the upstream rolling mill 4, or further downstream of the downstream rolling mill 3. A motor and a drive device are provided for each rolling mill.

[0014] A speedometer 2 is provided between the two rolling mills 3, 4. The speedometer 2 is provided so as to be able to measure the conveying speed of the material 1 conveyed between the rolling mills 3, 4 while being restrained by the rolling mills 3, 4. For example, the speedometer 2 is provided above or to the side of the material 1. The speedometer 2 is, for example, a laser speedometer that utilizes the laser Doppler effect. The output of the speedometer 2 is connected to a process control device 9.

[0015] The process control device 9 generates a speed pattern for each of the drive devices 7, 8 based on production management information and other information related to material specifications such as the quality of the material and rolling dimensions, which are stored in a host computer such as a process computer connected to the process control system 10. The process control device 9 supplies the generated speed pattern to each of the drive devices 7, 8.

[0016] Drive devices 7 and 8 drive the motors 5 and 6, respectively, so that the speeds of the rolling mills 3 and 4 follow the generated speed patterns.

[0017] When performing mass flow thickness control, in addition to the speedometer 2, the process control device 9 is provided with a speedometer at the exit side of the downstream rolling mill 3 and a speedometer at the entry side of the upstream rolling mill 4. Also, a thickness gauge for measuring the thickness of the material 1 is provided at the entry side of each of the rolling mills 3 and 4. The process control device 9 also inputs data measured by these measuring instruments, and uses a mass flow gauge (not shown) or the like to control the reduction amount of the rolling mills so that the thickness at the exit side of each of the rolling mills 3 and 4 becomes a target value.

[0018] The material 1 conveyed between two or more rolling mills arranged in succession is conveyed at a speed slower than that of the rolling mill 3 arranged downstream and faster than that of the rolling mill 4 arranged upstream due to the characteristics of the rolling process. In other words, the actual speed measurement value of the material 1 is limited so that the value of the speed pattern for the downstream rolling mill 3 is the upper limit value, and the value of the speed pattern for the upstream rolling mill 4 is limited so that the lower limit value is the value of the speed pattern for the upstream rolling mill 4. The process control device 9 of this embodiment inputs the actual speed measurement value of the material 1 acquired by the speed meter 2, and outputs an actual speed value limited to a range from the value of the speed pattern for the downstream rolling mill 3 to the value of the speed pattern for the upstream rolling mill 4. The actual speed value is used as an actual value of the speed of the material on the outlet side of the upstream rolling mill 4, for example, in the case of mass flow plate thickness control. In addition, it may be used as data on the conveying speed for tracking the material 1, etc.

[0019] The configuration of the process control device 9 of this embodiment will be described. The process control device 9 of this embodiment includes a speed record prediction calculation device (speed record prediction means) 11 and a delay-free low-pass filter (filter means) 12. The process control device 9 is, for example, a PLC, and as described above, generates a speed pattern for each of the rolling mills 3 and 4 based on information acquired from a higher-level computer or the like, and supplies the generated speed patterns to the drive devices 7 and 8, respectively. The speed patterns for each of the rolling mills 3 and 4 are not limited to those generated by the process control device 9, and may be data generated and output by another external computer device or the like.

[0020] The speed result prediction calculation device 11 acquires a speed pattern for the downstream rolling mill 3 and a speed pattern for the upstream rolling mill 4. In the following description, the speed pattern for the downstream rolling mill 3 may be simply referred to as the downstream speed pattern, and the speed pattern for the upstream rolling mill 4 may be simply referred to as the upstream speed pattern. The speed result prediction calculation device 11 outputs the downstream speed pattern as an upper limit value V1 and the upstream speed pattern as a lower limit value V2 to the delay-free low-pass filter 12.

[0021] The non-delay low-pass filter 12 sets the upstream speed pattern as the upper limit value V1 of the speed actual value Vb and sets the downstream speed pattern as the lower limit value V2 of the speed actual value Vb.

[0022] The non-delay low-pass filter 12 inputs the speed actual measurement value Va of the material 1 obtained from the speedometer 2 and outputs the speed actual value Vb so that the speed actual measurement value Va is within the range from the lower limit value V2 to the upper limit value V1.

[0023] Specifically, when V2 ≤ Va ≤ V1, the non-delay low-pass filter 12 outputs the speed actual measurement value Va as the speed actual value Vb as it is.

[0024] When Va < V2, the non-delay low-pass filter 12 outputs the lower limit value V2 as the speed actual value Vb.

[0025] When V1 < Va, the non-delay low-pass filter 12 outputs the upper limit value V1 as the speed actual value Vb.

[0026] FIG. 1 shows a process control system 10, and the process control system 10 includes the process control device 9 of the present embodiment. The process control system 10 includes, in addition to the process control device 9, an HMI terminal, an operation panel for manual operation by an operator, etc. Further, the process control system 10 may include an engineering computer or the like that performs debugging of the program of the process control device 9 which is a PLC.

[0027] As described above, the process control device 9 is a PLC, and may be a virtual PLC in which the functions of a PLC are implemented as software in a computer device or the like. These PLCs etc. are not limited to being realized by hardware when realizing the functions of the speed actual prediction arithmetic device and the non-delay low-pass filter, and a part or all of these functions may be realized and implemented by software. The software includes one or more programs, and the functions of the above-described respective components are realized by one or more steps constituting the program.

[0028] The operation of the process control device 9 of this embodiment will be described. FIG. 2 is a schematic timing chart illustrating an example of the operation of the process control device of the present embodiment.

[0029] A more specific description will be given with reference to FIG. FIG. 2 shows the time variation of the actual speed measurement value Va acquired by the speedometer 2, as well as the time variation of the upper speed limit value V1, the lower speed limit value V2, and the actual speed value Vb. 2 and in Fig. 4, 6 to 8 described later, the actual speed measurement value Va is indicated by a thin dashed line, the upper limit value V1 and the lower limit value V2 are indicated by a thick solid line, and the actual speed value Vb is indicated by a thick dashed line. In addition, the constant speed period of the speed pattern is sufficiently longer than the acceleration period and the deceleration period, and is therefore indicated by an ellipsis in the figures.

[0030] 2, the period up to time t1 is a constant speed period of the speed pattern. The actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and the no-delay low-pass filter 12 outputs the actual speed measurement value Va as the actual speed value Vb.

[0031] The period from time t1 to time t4 is an acceleration period of the speed pattern. In the period from time t2 to time t3, the actual speed measurement value Va exceeds the upper limit value V1. In the period from time t2 to time t3, the no-delay low-pass filter 12 outputs the upper limit value V1 as the actual speed value Vb.

[0032] The period from time t4 to time t7 is a constant speed period of the speed pattern. In the period from time t4 to time t5, the actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and the no-delay low-pass filter 12 outputs the actual speed measurement value Va as the actual speed value Vb.

[0033] Between time t5 and time t6, the actual speed measurement value Va exceeds the upper limit value V1 and then falls below the lower limit value V2. The no-delay low-pass filter 12 outputs the upper limit value V1 as the actual speed value Vb during the period in which the actual speed measurement value Va exceeds the upper limit value V1, and outputs the lower limit value V2 as the actual speed measurement value Vb during the period in which the actual speed measurement value Va falls below the lower limit value V2.

[0034] The period from time t7 to time t8 is a deceleration period of the speed pattern. In this example, the value of the actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and the no-delay low-pass filter 12 outputs the actual speed measurement value Va as the actual speed value Vb.

[0035] The period from time t8 to time t11 is a constant speed period of the speed pattern. From time t8 to time t9, the value of the actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and the no-delay low-pass filter 12 outputs the actual speed measurement value Va as the actual speed value Vb. From time t9 to time t10, the actual speed measurement value Va exceeds the upper limit value V1 for multiple periods and falls below the lower limit value V2 for multiple periods. The no-delay low-pass filter 12 outputs the upper limit value V1 as the actual speed value Vb during the period when the actual speed measurement value Va exceeds the upper limit value V1, and outputs the lower limit value V2 as the actual speed value Vb during the period when the actual speed measurement value Va falls below the lower limit value V2.

[0036] In this manner, in the process control device 9 of this embodiment, the delay-free low-pass filter 12 limits the actual speed measurement value Va to the upper limit value V1 and lower limit value V2 acquired from the actual speed prediction calculation device 11 and outputs the result as the actual speed value Vb.

[0037] The effects of the process control device 9 of this embodiment will be described. The process control device 9 of this embodiment includes a speed actual value prediction calculation device 11 and a delay-free low-pass filter 12. The speed actual value prediction calculation device 11 sets the downstream side speed pattern and the upstream side speed pattern as the upper limit value V1 and the lower limit value V2 for the speed actual value Vb. The upper limit value V1 and the lower limit value V2 are generated by the process control device 9 itself or acquired from a higher-level computer or the like, so that they can be set without requiring complex calculations. The upper limit value V1 and the lower limit value V2 are also the target speeds of the rolling mills 3 and 4, so that they can be expected to have sufficient accuracy as limit values. The delay-free low-pass filter 12 compares the input speed actual value measurement value Va with the upper limit value V1 and the lower limit value V2, and outputs the speed actual value Vb according to a preset judgment criterion. Therefore, the speed actual value Vb can be output without taking a long time to judge whether or not there is an abnormality in the speed actual value measurement value Va, and without the risk of erroneous detection or erroneous judgment.

[0038] In rolling plants such as continuous cold rolling facilities, there are many cases where steam or various gases surround the material to be rolled, or where water covers the material. When the light beam for measurement is blocked by steam or the like, an optical speedometer such as a laser speedometer undergoes abrupt fluctuations, and in severe cases, may cause a loss of measured values. In the process control device 9 of this embodiment, upper and lower limit values ​​are set for the actual speed measurement value Va, so that if it is determined whether the actual speed measurement value Va due to abrupt fluctuation touches the infinity side or the zero side, the upper limit value V1 or the lower limit value V2 can be output, and there is no risk of a loss of measured values.

[0039] In this way, the process control device 9 of this embodiment can utilize conditions that cannot be handled by a speedometer alone in order to solve problems in the entire control system of the rolling equipment. The conditions are logically obtained from the rolling control conditions, so that in principle, a long judgment time is not required. Therefore, the process control device 9 can obtain the actual speed value Vb more accurately and quickly, making it possible to build a more accurate rolling control system.

[0040] In the rolling technology, there is a tendency that more accurate plate thickness control is required, and the mass flow plate thickness control technology is often used. By using the process control device 9 of the present embodiment for mass flow plate thickness control, it is possible to obtain accurate speed actual values ​​without delay, which has the advantage of enabling more accurate plate thickness control.

[0041] Second Embodiment In the process control device of this embodiment, a rolling mill model is introduced to determine the upper and lower limit values, making it possible to obtain a more accurate actual speed value. The same components as those in the other embodiments described above are given the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0042] FIG. 3 is a schematic block diagram illustrating a process control device according to the present embodiment. As in FIG. 1, in addition to the process control device 209, FIG. 3 also shows a process control system 210 and rolling equipment, etc., but since these have the same configuration as in the other embodiments described above, detailed explanations of these will be omitted. As shown in FIG. 3, the process control device 209 of this embodiment includes a speed result prediction calculation device 211, a no-delay low-pass filter 12, and a model calculator 213.

[0043] The model calculator 213 has a rolling model created for each rolling mill. The model calculator 213 calculates a backward rate r for the rolling mill 3 using a rolling model of the downstream rolling mill 3 and has the calculated backward rate r as a parameter. The model calculator 213 calculates a forward rate f for the rolling mill 4 using a rolling model of the upstream rolling mill 4 and has the calculated forward rate f as a parameter. The model calculator 213 outputs the calculated forward rate f and backward rate r to the speed actual result prediction calculation device 211.

[0044] The speed result prediction calculation device 211 calculates a speed target value for each of the rolling mills 3 and 4 using the forward rate f and the reverse rate r calculated by the model calculator 213. The speed result prediction calculation device 211 outputs the calculated speed target values ​​as an upper limit value V1' and a lower limit value V2' for the no-delay low-pass filter 12.

[0045] When the speed target value is calculated for each of the rolling mills 3 and 4 using the forward rate f and the backward rate r, the two speed target values ​​may become the same value. For that case, an adjustment parameter α is set in advance in the speed performance prediction calculation device 211. The adjustment parameter α is a parameter that gives a range to the speed target value calculated by the model calculator. The adjustment parameter α is set to an appropriate value in a range greater than 0 and less than 1. In the speed performance prediction calculation device 211, when the calculated speed target value Vcal is set to the lower limit value V2', the upper limit value V1' is set to (1+α)×V2'. The setting of the upper limit value V1' and the lower limit value V2' by the adjustment parameter α is not limited to the above, and the upper limit value V1' may be set to (1+α)×Vcal and the lower limit value V2' may be set to (1-α)×Vcal, with the calculated speed target value as the center. The adjustment parameter α, the upper limit value V1', and the lower limit value V2' are set to appropriate values ​​by experiments, simulations, etc.

[0046] The speed result prediction calculation device 211 outputs the calculated upper limit value V 1 ′ and lower limit value V 2 ′ to the no-delay low-pass filter 12 .

[0047] The no-delay low-pass filter 12 sets the upper limit value V1' and the lower limit value V2' outputted by the speed result prediction calculation device 211, as in the case of the other embodiments described above.

[0048] When V2’ ≤ Va ≤ V1’, the non-delay low-pass filter 12 outputs the speed actual measurement value Va as the speed actual value Vb without delay. When Va < V2’, the non-delay low-pass filter 12 outputs the lower limit value V2’ as the speed actual value Vb. When V1’ < Va, the non-delay low-pass filter 12 outputs the upper limit value V1’ as the speed actual value Vb.

[0049] The operation of the process control device 209 of this embodiment will be described. FIG. 4 is an example of a schematic timing chart for explaining the operation of the process control device of this embodiment. As shown in FIG. 4, the width from the lower limit value V2’ to the upper limit value V1’ set in the non-delay low-pass filter 12 can be made narrower than the width from the lower limit value V2 to the upper limit value V1 in the case of the first embodiment.

[0050] The period until time t21 is the constant speed period of the speed pattern. In this example, the speed actual measurement value Va is within the range from the lower limit value V2’ to the upper limit value V1’, and the non-delay low-pass filter 12 outputs the speed actual measurement value Va as the speed actual value Vb.

[0051] The period from time t21 to time t22 is the acceleration period of the speed pattern. In this example, the speed actual measurement value Va is within the range from the lower limit value V2’ to the upper limit value V1’, and the non-delay low-pass filter 12 outputs the speed actual measurement value Va as the speed actual value Vb.

[0052] The period from time t22 to time t23 is the constant speed period of the speed pattern. The speed actual measurement value Va exceeds the upper limit value V1’ for a period. During this period, the non-delay low-pass filter 12 outputs the upper limit value V1’ as the speed actual value Vb. After the period in which the speed actual measurement value Va exceeds the upper limit value V1’, there is a period in which the speed actual measurement value Va is below the lower limit value V2’. During this period, the non-delay low-pass filter 12 outputs the lower limit value V2’ as the speed actual value Vb.

[0053] The period from time t23 to time t24 is a deceleration period of the speed pattern. In this example, the actual speed measurement value Va is within the range from the lower limit value V2' to the upper limit value V1', so the no-delay low-pass filter 12 outputs the actual speed measurement value Va as the actual speed value Vb.

[0054] The period from time t24 to time t25 is a constant speed period of the speed pattern. During this period, there are multiple periods during which the actual speed measurement value Va exceeds the upper limit value V1' and falls below the lower limit value V2'. During the period during which the actual speed measurement value Va exceeds the upper limit value V1', the non-delay low-pass filter 12 outputs the upper limit value V1' as the actual speed value Vb. During the period during which the actual speed measurement value Va falls below the lower limit value V2', the non-delay low-pass filter 12 outputs the lower limit value V2' as the actual speed value Vb.

[0055] In this manner, the process control device 209 of the present embodiment can suppress fluctuations in the actual speed measurement value Va and output a more accurate actual speed value Vb without requiring a long determination time.

[0056] The effects of the process control device 209 of this embodiment will be described. The process control device 209 of this embodiment includes a model calculator 213. Therefore, the speed result prediction calculation device 211 can more accurately calculate the speed target value using the advance rate f and the reverse rate r calculated by the model calculator 213, and can calculate the upper limit value V1' and the lower limit value V2' for the speed result value Vb based on the speed target value. In this case, the width from the lower limit value V2' to the upper limit value V1' can be narrower than the width from the lower limit value V2 to the upper limit value V1 according to the speed pattern calculated based on the material information and the like held by the upper computer and the like. Therefore, the speed result value Vb can be output more accurately in response to fluctuations in the speed result measurement value Va and noise superposition.

[0057] (Third embodiment) FIG. 5 is a schematic block diagram illustrating a process control device according to the present embodiment. In this embodiment, the configuration of the delay-free low-pass filter 312 is different from that of the first embodiment described above, but other points are the same as those of the first embodiment. The same components are denoted by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate. 5, the reference numerals of a process control device 409 of a fourth embodiment and a process control device 509 of a fifth embodiment, which will be described later, are also shown in parentheses. In these process control devices 409, 509, the configuration of the delay-free low-pass filters 412, 512 is different from that in the first embodiment, and different reference numerals are shown in parentheses. In addition, the process control systems 410, 510 also include different process control devices 409, 509, and therefore different reference numerals are shown in parentheses. As shown in FIG. 5, the process control device 309 of this embodiment includes the speed result prediction calculation device 11 and a no-delay low-pass filter 312.

[0058] The no-delay low-pass filter 312 sets the upper limit value V1 and the lower limit value V2 output by the speed result prediction calculation device 11, as in the case of the above-mentioned first embodiment. The no-delay low-pass filter 312 operates at a preset cycle. The preset cycle may be set based on the operating frequency (clock frequency) of the calculation device for operating the process control device 409, or may be set based on the network transmission cycle set in the process control device 409.

[0059] The no-delay low-pass filter 312 acquires a speed actual measurement value Va for each period and determines whether the speed actual measurement value Va is within the range from the lower limit value V2 to the upper limit value V1. If the acquired speed actual measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, the no-delay low-pass filter 312 outputs the acquired speed actual measurement value Va as a speed actual value Vb.

[0060] If the acquired speed actual measurement value Va is not within the range from the lower limit value V2 to the upper limit value V1, the no-delay low-pass filter 312 outputs the speed actual measurement value Va acquired in the period immediately preceding the current period as the speed actual value Vb.

[0061] FIG. 6 is a schematic timing chart illustrating an example of the operation of the process control device of the present embodiment. As shown in FIG. 6, during the constant speed period of the speed pattern up to time t31, the actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and the no-delay low-pass filter 312 outputs the actual speed measurement value Va as the actual speed value Vb.

[0062] The period from time t31 to time t34 is an acceleration period of the speed pattern. At time t32 within this period, the no-delay low-pass filter 312 determines that the actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and outputs the actual speed measurement value Va as the actual speed measurement value Vbi.

[0063] After time t32 has passed, the no-delay low-pass filter 312 determines that the actual speed measurement value Va has exceeded the upper limit value V1. The no-delay low-pass filter 312 outputs the actual speed value Vbi at time t32 immediately before the current actual speed value as the current actual speed value Vbi+1. Note that in this embodiment, during an acceleration period or deceleration period as in this example, by applying the immediately preceding actual speed value to the current actual speed value, it is possible that the actual speed value will not fall within the range from the lower limit value V2 to the upper limit value V1.

[0064] The period from time t34 to time t38 is a constant speed period of the speed pattern. At time t35 within the period from time t34 to time t38, the no-delay low-pass filter 312 determines that the actual speed measurement value Va is within the range from the lower limit value V2 to the upper limit value V1, and outputs the actual speed measurement value Va as the actual speed value Vbj.

[0065] The no-delay low-pass filter 312 determines that the actual speed value Va exceeds the upper limit value V1 after time t35. The no-delay low-pass filter 312 outputs the actual speed value Vbj at the immediately preceding time t35 as the actual speed value Vbj+1 at the current time t36.

[0066] The no-delay low-pass filter 312 determines that the actual speed measurement value Va falls below the lower limit value V2 during the period from time t36 to time t37. The no-delay low-pass filter 312 outputs the actual speed value Vbj+1 at the immediately preceding time t36 as the actual speed value Vbj+2 at the current time t37.

[0067] In this manner, the process control device 309 of this embodiment can input an actual speed measurement value and output an appropriate actual speed value to be used as a control parameter.

[0068] The effects of the process control device 309 of this embodiment will be described. In the process control device 309 of this embodiment, the no-delay low-pass filter 312 monitors and sequentially judges whether the actual speed measurement value is within the range from the lower limit value V2 to the upper limit value V1. When the no-delay low-pass filter 312 judges that the actual speed measurement value is not within the range from the lower limit value V2 to the upper limit value V1, it outputs the previously output actual speed value as the current actual speed value. Therefore, the previous actual speed value is a value in the range from the lower limit value V2 to the upper limit value V1, and applying this value as the current actual speed value makes it possible to obtain an actual speed value closer to the true value than applying the upper limit value V1 or the lower limit value V2.

[0069] When used to obtain actual speed values ​​for mass flow plate thickness control, more accurate actual speed values ​​can be obtained without response delay, making it possible to achieve more accurate plate thickness control.

[0070] (Fourth embodiment) In this embodiment, the configuration of the delay-free low-pass filter 412 differs from that of the first and third embodiments described above. Other points are the same as those of the other embodiments, and the same components as those of the other embodiments are denoted by the same reference numerals and detailed descriptions thereof are omitted as appropriate. As shown in FIG. 5, the process control device 409 of this embodiment includes the speed result prediction calculation device 11 and a no-delay low-pass filter 412.

[0071] In the process control device 409 of this embodiment, the no-delay low-pass filter 412 operates at a preset cycle, similar to the third embodiment described above. When the acquired actual speed measurement value Va is not within the range from the lower limit value V2 to the upper limit value V1, the no-delay low-pass filter 412 outputs the immediately preceding actual speed value as the current actual speed value, similar to the third embodiment. Here, in the process control device 409 of this embodiment, the no-delay low-pass filter 412 monitors the actual speed value. When the current actual speed value is set as the immediately preceding actual speed value, the no-delay low-pass filter 412 outputs the upper limit value V1 or the lower limit value V2 instead of the immediately preceding actual speed value when it is determined that the actual speed value exceeds the upper limit value V1 or falls below the lower limit value V2.

[0072] A specific example of the operation will be described below. FIG. 7 is a schematic timing chart illustrating an example of the operation of the process control device of the present embodiment. As shown in FIG. 7, the period from time t31 to time t34 is an acceleration period of the speed pattern, and at time t32 within this acceleration period, the no-delay low-pass filter 412 outputs the actual speed measurement value Va as the actual speed value Vbi, in the same manner as described in relation to FIG. 6.

[0073] After time t32, the no-delay low-pass filter 412 determines that the actual speed measurement value Va has exceeded the upper limit value V1. The no-delay low-pass filter 412 determines whether the previous actual speed value Vbi is within the range from the lower limit value V2 to the upper limit value V1. In this example, the no-delay low-pass filter 412 determines that the actual speed value Vbi at the previous time t32 has fallen below the lower limit value V2 at the immediately following time t43. The no-delay low-pass filter 412 outputs the lower limit value V2 as the actual speed value Vbi+1' at the current time t43, instead of the actual speed value Vbj at the previous time t32.

[0074] The period from time t34 to time t37 is a constant speed period of the speed pattern. In the constant speed period of the speed pattern, when the actual speed measurement value Va is not within the range from the lower limit value V2 to the upper limit value V1, the no-delay low-pass filter 412 outputs the previous actual speed value as the current actual speed value, since the previous actual speed value will always be within the range from the lower limit value V2 to the upper limit value V1 even if it is set as the current actual speed value.

[0075] During an acceleration period of the speed pattern, if the immediately preceding actual speed value is used as the current actual speed value, the current actual speed value may fall below the lower limit value but will not exceed the upper limit value. Also, during a deceleration period of the speed pattern, if the immediately preceding actual speed value is used as the current actual speed value, the current actual speed value may exceed the upper limit value but will not fall below the lower limit value. The no-delay low-pass filter 412 monitors and determines whether the current actual speed value is larger than the upper or lower limit value depending on whether the speed pattern is in an acceleration period or a deceleration period.

[0076] In this manner, the process control device 409 of the present embodiment can input the actual speed measurement value and output an appropriate actual speed value.

[0077] The effects of the process control device 409 of this embodiment will be described. In the process control device 409 of this embodiment, the delay-free low-pass filter 412 judges whether or not the immediately preceding actual speed value falls within the range from the lower limit value V2 to the upper limit value V1 when applied to the current actual speed value during the acceleration period or deceleration period of the speed pattern. When the immediately preceding actual speed value exceeds the upper limit value V1 when applied to the current actual speed value, the delay-free low-pass filter 412 applies the upper limit value V1 instead of this value as the current actual speed value and outputs it. When the immediately preceding actual speed value falls below the lower limit value V2 when applied to the current actual speed value, the delay-free low-pass filter 412 applies the lower limit value V2 instead of this value as the current actual speed value and outputs it. Therefore, even during the acceleration period or deceleration period of the speed pattern, it is possible to apply an actual speed value within the range from the lower limit value V2 to the upper limit value V1.

[0078] Fifth embodiment As shown in FIG. 5, the process control device 509 of this embodiment includes the speed result prediction calculation device 11 and a no-delay low-pass filter 512. In this embodiment, the configuration of the delay-free low-pass filter 512 differs from that of the first, third, and fourth embodiments described above. Other points are the same as those of the other embodiments, and the same components as those of the other embodiments are denoted by the same reference numerals and detailed descriptions thereof are omitted as appropriate.

[0079] In the process control device 509 of this embodiment, the no-delay low-pass filter 512 outputs an actual speed value closer to the true value during the acceleration period and deceleration period of the speed pattern. The no-delay low-pass filter 512 monitors the actual speed value. When the no-delay low-pass filter 512 determines that the current actual speed value, assuming that the previous actual speed value, exceeds the upper limit value V1 or falls below the lower limit value V2, it calculates the current actual speed value using the acceleration rate during the acceleration period or the deceleration rate during the deceleration period.

[0080] The acceleration rate and deceleration rate may be the time change rate in the acceleration period and deceleration period of the upper limit value V1, or may be the time change rate in the acceleration period and deceleration period of the lower limit value V2. In a normal case, the acceleration rate in the acceleration period and the deceleration rate in the deceleration period of the upper limit value V1 are equal to the acceleration rate in the acceleration period and the deceleration rate in the deceleration period of the lower limit value V2, respectively. When these are different, for example, the acceleration rate applied by the no-delay low-pass filter 512 may be the arithmetic average of the acceleration rate of the upper limit value V1 and the acceleration rate of the lower limit value V2, and the deceleration rate may be the simple average of the deceleration rate of the upper limit value V1 and the deceleration rate of the lower limit value V2. An appropriate calculation method is derived using experiments, simulations, etc., and set in advance.

[0081] A specific example of the operation will be described below. FIG. 8 is an example of a schematic timing chart for explaining the operation of the process control device of the present embodiment. As shown in FIG. 8, at time t32 within the acceleration period of the speed pattern from time t31 to time t34, the no-delay low-pass filter 512 outputs the actual speed measurement value Va as the actual speed value Vbi, in the same manner as described in relation to FIG. 6.

[0082] After time t32 has elapsed, the no-delay low-pass filter 512 determines that the actual speed value Va has exceeded the upper limit value V1. The no-delay low-pass filter 312 applies the acceleration rate k for the acceleration period from time t31 to time t34 to the actual speed value Vbi output at time t32, to calculate and output the actual speed value Vbi+1'' at time t53. The acceleration rate k is, for example, as described above, the time rate of change of the upper limit value V1 for the acceleration period from time t31 to time t34.

[0083] In this way, the process control device 509 of this embodiment can calculate and output the actual speed value without any response delay, and with a time change rate that nearly matches the acceleration rate or deceleration rate of the speed pattern, even during the acceleration or deceleration period of the speed pattern.

[0084] The effects of the process control device 509 of this embodiment will be described. In the process control device 509 of this embodiment, the no-delay low-pass filter 512 monitors and sequentially judges whether the actual speed measurement value is within the range from the lower limit V2 to the upper limit V1. When the no-delay low-pass filter 512 judges that the actual speed measurement value is not within the range from the lower limit V2 to the upper limit V1 during the acceleration period or deceleration period of the speed pattern, it calculates and outputs the current actual speed value using the previous actual speed value and acceleration rate and deceleration rate. Therefore, even during the acceleration period or deceleration period of the speed pattern, the current actual speed value can be calculated at a time change rate that is approximately equal to the acceleration rate or deceleration rate, making it possible to realize more accurate speed control.

[0085] In the third to fifth embodiments described above, it goes without saying that the upper and lower limit values ​​may be calculated using the forward rate f and reverse rate r by model calculation in the second embodiment.

[0086] According to the embodiment described above, it is possible to realize a process control device that obtains an actual speed value output by a speedometer without lengthening the determination time or without erroneous detection or determination.

[0087] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. In addition, the above-mentioned embodiments can be implemented in combination with each other. [Explanation of symbols]

[0088] 1 Material, 2 Speedometer, 3, 4 Rolling mill, 5, 6 Motor, 7, 8 Drive device, 9, 209, 309, 409, 509 Process control device, 10, 210, 310, 410, 510 Process control system, 11, 211 Speed ​​performance prediction calculation device, 12, 312, 412, 512 Delay-free low-pass filter, 13 Model computer

Claims

1. A process control device that receives an actual speed measurement value from a speedometer that measures and outputs an actual speed measurement value of a material being restrained and transported between a first rolling mill and a second rolling mill provided upstream of the first rolling mill, and outputs a first target speed value for the first rolling mill and a second target speed value for the second rolling mill, the first target speed value and the second target speed value, which are calculated based on specifications of the material, to a first drive device that drives a first motor that drives the first rolling mill and a second drive device that drives a second motor that drives the second rolling mill, a filter means for inputting the speed performance measurement value and outputting a speed performance value; a speed result prediction means for predicting the first speed target value as an upper limit value of the speed result measurement value and for outputting the second speed target value as a lower limit value of the speed result measurement value to the filter means; Equipped with The filter means comprises: The input speed performance measurement value is compared with the upper limit value and the lower limit value, When the actual speed measurement value is equal to or greater than the lower limit value and equal to or less than the upper limit value, the actual speed measurement value is output as the actual speed value; When the actual speed measurement value is greater than the upper limit value, the upper limit value is output as the actual speed value; When the actual speed measurement value is smaller than the lower limit value, the process control device outputs the lower limit value as the actual speed value.

2. A process control device that receives an actual speed measurement value from a speedometer that measures and outputs an actual speed measurement value of a material being restrained and transported between a first rolling mill and a second rolling mill provided upstream of the first rolling mill, and outputs a first target speed value for the first rolling mill and a second target speed value for the second rolling mill, the first target speed value and the second target speed value, which are calculated based on specifications of the material, to a first drive device that drives a first motor that drives the first rolling mill and a second drive device that drives a second motor that drives the second rolling mill, a filter means for inputting the speed performance measurement value and outputting a speed performance value; a model calculation means for calculating a backward rate of the first rolling mill based on a first rolling model for the first rolling mill and for calculating a forward rate of the second rolling mill based on a second rolling model for the second rolling mill; a speed result prediction means for calculating the first speed target value for the first drive device and the second speed target value for the second drive device based on the reverse rate and the forward rate calculated by the model calculation means; Equipped with The speed performance prediction means a tuning parameter that is set to a value greater than 0 and less than 1; When the first speed target value and the second speed target value are different values, the first speed target value is set as an upper limit value of the speed actual measurement value, and the second speed target value is set as a lower limit value of the speed actual measurement value, and the set values ​​are output to the filter means; When the first speed target value and the second speed target value are the same value, when the adjustment parameter is α and the calculated first speed target value and second speed target value are Vcal, (1+α)×Vcal is set as an upper limit value of the actual speed measurement value, and Vcal or (1−α)×Vcal is output to the filter means as a lower limit value of the actual speed measurement value, The filter means comprises: The input speed performance measurement value is compared with the upper limit value and the lower limit value, When the actual speed measurement value is equal to or greater than the lower limit value and equal to or less than the upper limit value, the actual speed measurement value is output as the actual speed value; When the actual speed measurement value is greater than the upper limit value, the upper limit value is output as the actual speed value; When the actual speed measurement value is smaller than the lower limit value, the process control device outputs the lower limit value as the actual speed value.

3. A process control device that receives an actual speed measurement value from a speedometer that measures and outputs an actual speed measurement value of a material being restrained and transported between a first rolling mill and a second rolling mill provided upstream of the first rolling mill, and outputs a first target speed value for the first rolling mill and a second target speed value for the second rolling mill, the first target speed value and the second target speed value, which are calculated based on specifications of the material, to a first drive device that drives a first motor that drives the first rolling mill and a second drive device that drives a second motor that drives the second rolling mill, a filter means for inputting the speed performance measurement value and outputting a speed performance value; a speed result prediction means for predicting the first speed target value as an upper limit value of the speed result measurement value and for outputting the second speed target value as a lower limit value of the speed result measurement value to the filter means; Equipped with The filter means comprises: obtaining the actual speed measurement from the speedometer for each period; When the actual speed measurement value is greater than the upper limit value or smaller than the lower limit value, the process control device outputs the actual speed measurement value obtained in the immediately preceding cycle as the actual speed value.

4. A process control device that receives an actual speed measurement value from a speedometer that measures and outputs an actual speed measurement value of a material being restrained and transported between a first rolling mill and a second rolling mill provided upstream of the first rolling mill, and outputs a first target speed value for the first rolling mill and a second target speed value for the second rolling mill, the first target speed value and the second target speed value, which are calculated based on specifications of the material, to a first drive device that drives a first motor that drives the first rolling mill and a second drive device that drives a second motor that drives the second rolling mill, a filter means for inputting the speed performance measurement value and outputting a speed performance value; a model calculation means for calculating a backward rate of the first rolling mill based on a first rolling model for the first rolling mill and for calculating a forward rate of the second rolling mill based on a second rolling model for the second rolling mill; a speed result prediction means for calculating the first speed target value for the first drive device and the second speed target value for the second drive device based on the reverse rate and the forward rate calculated by the model calculation means; Equipped with The speed performance prediction means a tuning parameter that is set to a value greater than 0 and less than 1; When the first speed target value and the second speed target value are different values, the first speed target value is set as an upper limit value of the speed actual measurement value, and the second speed target value is set as a lower limit value of the speed actual measurement value, and the set values ​​are output to the filter means; When the first speed target value and the second speed target value are the same value, when the adjustment parameter is α and the calculated first speed target value and second speed target value are Vcal, (1+α)×Vcal is set as an upper limit value of the actual speed measurement value, and Vcal or (1−α)×Vcal is output to the filter means as a lower limit value of the actual speed measurement value, The filter means comprises: obtaining the actual speed measurement from the speedometer for each period; When the actual speed measurement value is greater than the upper limit value or smaller than the lower limit value, the process control device outputs the actual speed measurement value obtained in the immediately preceding cycle as the actual speed value.

5. The filter means comprises: In the case of an acceleration period of the first speed target value and the second speed target value, when the speed actual measurement value acquired in the immediately preceding period is set as the speed actual value, if the speed actual value is smaller than the lower limit value, output the lower limit value as the speed actual value of the current period; 5. The process control device according to claim 3, wherein in the case of a deceleration period of the first speed target value and the second speed target value, when the actual speed value is set to the actual speed measurement value acquired in the immediately previous cycle, if the actual speed value is greater than the upper limit value, the upper limit value is output as the actual speed value of the current cycle.

6. The filter means comprises: in the case of an acceleration period of the first speed target value and the second speed target value, when the actual speed value is smaller than the lower limit value when the actual speed measurement value obtained in the immediately preceding period is the actual speed value, calculate and output an actual speed value of the current period based on a preset acceleration rate and the actual speed value of the immediately preceding period; 5. The process control device according to claim 3, wherein, in the case of a deceleration period of the first speed target value and the second speed target value, when the actual speed value is greater than the upper limit value when the actual speed measurement value acquired in an immediately preceding cycle is used as the actual speed value, the process control device calculates and outputs the actual speed value of the current cycle based on a preset deceleration rate and the actual speed value of the immediately preceding cycle.

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