JP7786607B2 - Rolling equipment overload prevention support system - Google Patents

Description

This disclosure relates to a rolling equipment overload avoidance support system for assisting in avoiding overload operation of rolling equipment.

For example, in a hot rolling plant, a large number of steel plates (coils) are rolled each day by operating rolling equipment such as roughing mills and finishing mills. Rolling equipment has limits such as a reduction limit set as protection circuits to prevent exceeding capacity during operation. If the rolling equipment is forced to stop due to a limit being reached, a significant amount of time is required to restore operation, including processing the coils being rolled, and this time becomes downtime.

To shorten downtime, when rolling equipment operation is close to reaching its limit, an alarm or other means is used to notify the operator, allowing the operator to take manual action (manual intervention). At the same time, the control staff, who receive the report from the operation staff, analyze and consider the situation at the time of the near-excess, and the equipment staff adjusts the rolling conditions and control methods based on the results of this analysis. Thus, in the past, after an overload operation such as exceeding or near-excessing rolling equipment capacity occurred, the rolling equipment could not be restored from overload operation unless the operators, equipment staff, and control staff worked together.

In addition, to prevent downtime from occurring, Patent Document 1 below discloses a method for preventing overload on the drive system of rolling equipment. This method estimates TAF (the ratio of maximum torque at rolling bite to steady-state torque during rolling) from the rolling speed set based on the rolling schedule, and calculates the maximum torque (peak torque) at rolling bite from the estimated TAF and the steady-state torque determined from the rolling conditions. Overload on the drive system, such as the spindle, is prevented by correcting the set value of the rolling speed so that the calculated maximum torque is below the allowable torque.

Japanese Patent Publication No. 11-10214

Incidentally, overload operation of rolling equipment is caused not only by the rolling schedule but also by the operational track record of the rolling equipment. However, in Patent Document 1, it cannot be said that the operational track record of the rolling equipment is effectively utilized, and there is room for improvement.

This disclosure has been made to solve the problems described above. The purpose of this disclosure is to provide a rolling equipment overload avoidance support system that can effectively utilize the operating history of rolling equipment to avoid overload operation of rolling equipment.

A first aspect of the present disclosure relates to an overload avoidance support system for rolling equipment installed in a rolling plant for supporting the avoidance of overload operation of rolling equipment. The overload avoidance support system includes a recording means, a data aggregating device, a determination device, and a guidance device. The recording means records multiple pieces of past operation data in a database, including product information on previously manufactured steel plates, steel plate time unit information including the thickness and temperature of the steel plate in rolling time units, rolling equipment time unit information including the rolling load of the rolling equipment, steel plate length unit information and rolling equipment length unit information obtained by converting the steel plate time unit information and rolling equipment time unit information into length units in the rolling direction, and limit violations, alarms, and countermeasures that occurred during rolling. The data aggregating device aggregates the multiple pieces of past operation data recorded in the database by product information. The determination device determines, from the multiple pieces of past operation data aggregated by the data aggregating device, past operation data of other steel plates that is similar to the past operation data of the target steel plate to be rolled as similar past operation data. The guidance device displays guidance on a display unit, including limit violations, alarms, and countermeasures that occurred during rolling and are contained in the similar past operation data, prior to rolling the target steel plate. The judgment device has a similarity score calculation unit and a comprehensive judgment unit. The similarity score calculation unit calculates a first similarity score indicating the similarity between multiple digital data included in the past operation data of the target steel plate and multiple digital data included in the past operation data of other steel plates, and a second similarity score indicating the similarity between multiple analog data included in the past operation data of the target steel plate and multiple analog data included in the past operation data of other steel plates. The comprehensive judgment unit calculates a comprehensive similarity score by adding the first similarity score and the second similarity score calculated by the similarity score calculation unit, and judges the data as similar past operation data if the comprehensive similarity score is equal to or greater than a reference value. The similarity score calculation unit plots the multiple analog data of the target steel plate and the multiple analog data of the other steel plates to determine their centers of gravity, and calculates the second similarity score based on the distance between the determined centers of gravity.

The second aspect has the following features in addition to those of the first aspect. The recording means includes a first recording device, a second recording device, a third recording device, a fourth recording device, and a fifth recording device. The first recording device records steel plate time unit information, rolling equipment time unit information, and time unit information of manual operation by a rolling plant operator in a time axis performance database in association with product information. The conversion device converts the steel plate time unit information, rolling equipment time unit information, and manual operation time unit information into length unit information, respectively. The second recording device records each piece of information converted by the conversion device in a product unit database in association with product information. The third recording device records the rolling plant's rolling plan, rolling equipment limit violations, alarm occurrence records, and response methods in the product unit database. The fourth recording device records rolling equipment mechanical system maintenance information in a machine unit database in association with product information. The fifth recording device records electrical system maintenance information of the rolling equipment in the electrical unit database in association with the product information.

The third aspect has the following characteristics in addition to the first aspect: the comprehensive determination unit calculates a comprehensive similarity score by adding values obtained by multiplying the first similarity score and the second similarity score by different weighting coefficients.

In the first aspect, multiple pieces of past operational data recorded in a database are aggregated for each steel plate product information, and from the aggregated multiple pieces of past operational data, past operational data for other steel plates similar to the past operational data for the target steel plate to be rolled is determined as similar past operational data. Prior to rolling the target steel plate, limit violations, alarms, and guidance including countermeasures contained in the similar past operational data are displayed on the display unit, thereby helping to avoid overload operation of the rolling equipment. In this way, according to the first aspect, it is possible to effectively utilize the operating history of the rolling equipment to avoid overload operation of the rolling equipment.

According to the second aspect, past operating data can be stored using the first to fifth recording devices, a time-axis performance database, a product unit database, a machine unit database, and an electrical unit database.

According to the third aspect, similar past operational data that is similar to the past operational data of the target steel plate can be determined using an index called a similarity score.

According to the fourth aspect, even when the past operational data contains a relatively large amount of analog data, the second similarity score can be easily calculated using the distance between the centers of gravity.

According to the fifth aspect, by using a weighting coefficient, it is possible to set the weighting of the first similarity score and the second similarity score relative to the overall similarity score.

FIG. 1 is a diagram illustrating an example of a rolling plant. 1 is a block diagram showing an overload avoidance support system for rolling equipment according to an embodiment; 3 is a diagram showing an example of calculation of a similarity score of digital data by the similarity score calculation unit shown in FIG. 2 . FIG. 3 is a diagram showing an example of calculation of a similarity score of analog data by the similarity score calculation unit shown in FIG. 2 . FIG. FIG. 1 is a diagram illustrating an example of a hardware configuration of a rolling equipment overload avoidance support system.

The following describes, with reference to the drawings, a rolling equipment overload avoidance support system for supporting the avoidance of overload operation of rolling equipment installed in a hot rolling plant (hereinafter referred to as "rolling plant"). Note that elements that are common to each figure are given the same reference numerals, and duplicate explanations will be omitted.

[Rolling plant]
Fig. 1 is a diagram showing an example of a rolling plant 1. The rolling plant 1 is equipped with, as main rolling equipment, a heating furnace 2, a roughing mill 3, a crop shear 4, a finishing mill 5, a cooling device 6, and a winder 7. The rolling plant 1 is also equipped with a conveying table (not shown) for conveying steel sheets Pr between the rolling equipment. These rolling equipment are driven by an electrical system including electric motors and actuators.

The heating furnace 2 is configured to heat the steel plate (slab) Pr to a predetermined temperature (e.g., 1200°C) before rolling. The roughing mill 3 has at least one rolling stand (usually one to three) and rolls the steel plate (slab) Pr heated in the heating furnace 2 in multiple passes in the forward direction (from upstream to downstream of the rolling line) and the reverse direction (from downstream to upstream of the rolling line). The crop shear 4 uses upper and lower blades to cut off any shape defects present at the leading or trailing end of the steel plate Pr based on the shape measured by the shape detector 81 (described below). The finishing mill 5 is a tandem rolling mill equipped with, for example, seven rolling stands F1-F7 arranged in the rolling direction of the steel plate Pr. Each rolling stand F1-F7 has two upper and lower work rolls 51, two upper and lower backup rolls 52, and an electric motor 53 for roll rotation. The backup rolls 52 are provided with a screw down device 54, which is configured to be able to adjust the gap between the upper and lower work rolls 51. The rolling load of each rolling stand F1 to F7 is measured by a rolling load sensor 55. The cooling device 6 cools the steel sheet Pr by injecting water onto the steel sheet Pr using a cooling bank. The cooled steel sheet Pr is wound by a winder 7 into a coil.

Various sensors serving as measuring instruments are installed at key points in the rolling plant 1. Key points in the rolling plant 1 include, for example, the outlet side of the heating furnace 2, the outlet side of the roughing mill 3, the outlet side of the finishing mill 5, and the inlet side of the winder 7. Various sensors may also be installed between rolling stands F1 to F7 of the finishing mill 5. The various sensors include a shape detector 81 capable of measuring the shape of the steel sheet Pr at the outlet side of the roughing mill 3, a thermometer 82 that measures the surface temperature of the steel sheet Pr at the inlet side of the finishing mill 5, a speed detector 83 that measures the speed Va of the steel sheet Pr at the outlet side of the finishing mill 5, a thickness/width meter 84 that measures the thickness and width of the steel sheet Pr at the outlet side of the finishing mill 5, a thermometer 85 that measures the surface temperature of the steel sheet Pr at the inlet side of the winder 7, and the rolling load sensor 55. The various sensors sequentially measure the state of the steel sheet Pr and the state of each rolling facility.

The rolling plant 1 is operated by a control system using computers with a hierarchical structure. The computers include a level 1 process control computer 11 and a level 2 host computer 12, which are connected to each other via a network. The process control computer 11 and host computer 12 are connected via the network to a rolling equipment overload avoidance support system 20, described below. The process control computer 11 has a control controller such as a PLC (programmable logic controller). An interface screen 13, which serves as an operation screen on which manual operations are performed by an operator of the rolling plant 1, is connected to the process control computer 11 via the network. The interface screen 13 also serves as a display unit on which guidance, described below, is displayed. When a rolling plan is input into the host computer 12 by a rolling plan designer, the rolling plan is sent from the host computer 12 to the process control computer 11. In addition to the rolling plan, slab information such as the thickness, width, length, and steel type of the slab, which is the material to be rolled before rolling, and coil target information such as the target thickness, target width, and target temperature of the coil, which is the material to be rolled after rolling, are input from the host computer 12 to the process control computer 11. The process control computer 11 receives input from the host computer 12 and executes setting calculations and control of the control targets in a series of rolling processes.

[Rolling equipment overload avoidance support device]
2 is a block diagram showing an overload avoidance support system 20 for rolling equipment according to an embodiment. The overload avoidance support system 20 comprises five recording devices (registration devices) 21 to 25 as recording means, and a conversion device 26. Note that the recording devices 21 to 25 can also be integrated into a single recording device.

The first recording device 21 records product information including the size and steel type of steel plates Pr manufactured in the past, as well as steel plate time unit information, rolling equipment time unit information, and manual operation time unit information input from the process control computer 11, in a time-axis performance database (DB) 31. The steel plate time unit information includes, for example, the thickness, width, temperature, and waveforms of the steel plate Pr for each rolling time unit during rolling. The rolling equipment time unit information is information during rolling by the rolling equipment installed in the rolling plant 1. The rolling equipment time unit information includes, for example, measurement data such as the rolling load, speed, temperature, rolling torque, and motor current of the roughing rolling mill 3, the rolling load, speed, and temperature of the finishing rolling mill 5, and the speed, torque, and temperature of the cooling device 6, and further includes the maximum value, root mean square (RMS), limit exceedance time, etc. of these. The time unit information on the manual operation related to the limit violation is information on the manual operation such as button operation or lever operation performed on the operation screen 13 by the operator of the rolling plant 1 .

The time unit information recorded in the time axis performance database 31 is also input from the process control computer 11 to the conversion device 26. The conversion device 26 converts the steel plate time unit information, rolling equipment time unit information, and manual operation time unit information into information on the length unit in the rolling direction of the steel plate Pr (hereinafter referred to as "steel plate length unit information," "rolling equipment length unit information," and "manual operation length unit information"), respectively. Since well-known methods can be used to convert from time units to length units, a detailed explanation will be omitted here.

The second recording device 22 records the steel plate length unit information, rolling equipment length unit information, and manual operation length unit information converted by the conversion device 26 in association with the product information of the steel plate Pr in the product unit database 32.

The third recording device 23 records the rolling plan of the rolling plant 1 input from the host computer 12 and the error occurrence records of the rolling equipment in the product unit database 32 in association with the product information of the steel plate Pr. The rolling plan includes information on the product size, steel type, rolling schedule, plate threading time, and the slabs used. The error occurrence records of the rolling equipment include the limit violation of the screw down device 54 that occurred during the rolling of the steel plate Pr, the type and location of the alarm that occurred during the rolling, and the response (operation) method.

The fourth recording device 24 records the rolling equipment's mechanical maintenance information in the machine unit database 33 in association with the product information of the steel plate Pr. The mechanical maintenance information includes the date, time, and content of maintenance, adjustments, and other care.

The fifth recording device 25 records electrical system maintenance information for the rolling equipment in the electrical unit database 34 in association with the product information for the steel plate Pr. The electrical system maintenance information includes the date, time, and details of maintenance, repairs, calibration, adjustments, etc.

In this way, recording devices 21 to 25 record multiple past operating data in databases 31, 32, 33, and 34.

The overload avoidance support system 20 further includes a data aggregation device 27, a judgment device 28, and a guidance device 29.

The data aggregation device 27 aggregates measurement data recorded in databases 31, 32, 33, and 34, as well as multiple past operational data including limit violations, alarms, and countermeasures, for each product information of steel plate Pr.

The determination device 28 determines, from among the multiple past operation data aggregated by the data aggregation device 27, past operation data of other steel plates Pr that is similar to the past operation data of the target steel plate Pr to be rolled, as similar past operation data. If the similar past operation data contains a limit violation, it can be determined that a limit violation may occur when rolling the target steel plate Pr, and if the similar past operation data contains an alarm, it can be determined that an alarm may occur when rolling the target steel plate Pr.

The judgment device 28 has a similarity score calculation unit 281 and a comprehensive judgment unit 282. The similarity score calculation unit 281 calculates a first similarity score indicating the degree of similarity between multiple digital data included in the past operation data of the target steel plate Pr and multiple digital data included in the past operation data of other steel plates, and a second similarity score indicating the degree of similarity between multiple analog data included in the past operation data of the target steel plate Pr and multiple analog data included in the past operation data of other steel plates Pr. In other words, the similarity score calculation unit 281 calculates the first similarity score and the second similarity score as indices for determining whether the past operation data being compared are similar.

Figure 3 is a diagram showing an example of calculation of a similarity score for digital data by the similarity score calculation unit 281. Figure 3 shows an example of comparing digital data "ABC-a" contained in the past operation data of the target steel plate Pr with digital data "ABC-a", "ABC-b", and "DEF-a" contained in the past operation data of three types of steel plate Pr. If the digital data are a perfect match, the first similarity score is calculated as "3". If the digital data are similar (prefix match), the first similarity score is calculated as "1". In this case, the similarity criteria can be set appropriately depending on the type of digital data. Furthermore, if the digital data are not a match, the first similarity score is calculated as "0".

Figure 4 shows an example of the calculation of similarity scores for analog data by the similarity score calculation unit 281. Figure 4 shows an example of comparing analog data (triangles) included in the past operation data of a target steel plate Pr with analog data (diamonds, stars, circles, and squares) included in the past operation data of four types of steel plates Pr. In this case, various types of analog data are plotted, and the centers of gravity Cg of the plotted analog data are determined for each. The horizontal axis of the plotted graph represents, for example, time and the length of the steel plate Pr, and the vertical axis represents, for example, sensor measurements (analog data) such as rolling load, speed, and temperature. In the figure, the centers of gravity Cg are indicated by black dots. The distance D between the determined centers of gravity Cg (hereinafter referred to as the "center-of-gravity distance") is calculated, and the second similarity score is calculated based on the length of the determined center-of-gravity distance D. This allows the second similarity score to be easily calculated using the center-of-gravity distance D, even when the past operation data contains a relatively large amount of analog data. In this example, the second similarity score is calculated in four stages based on the distance D between the centers of gravity, but the number of stages is not limited to four, and can be set according to the variation in the distance D between the centers of gravity.

The overall determination unit 282 calculates an overall similarity score by adding the first similarity score and the second similarity score calculated by the similarity score calculation unit 281, and determines the data as similar past operation data if the overall similarity score is equal to or greater than a reference value (reference point). Here, the overall similarity score may be calculated by adding a value obtained by multiplying the first similarity score by a first weighting coefficient and a value obtained by multiplying the second similarity score by a second weighting coefficient, as shown in the following formula (1). By using the first weighting coefficient and the second weighting coefficient, it is possible to set the weighting of the first similarity score and the second similarity score with respect to the overall similarity score.
Total similarity score = first similarity score × first weighting coefficient
+ second similarity score × second weighting coefficient (1)

In the above formula (1), for the sake of simplicity, one first similarity score and one second similarity score are added together, but multiple first similarity scores or multiple second similarity scores may be added together. In that case, different first weighting coefficients and second weighting coefficients may be multiplied.

The guidance device 29 has a guidance creation unit 291 and a guidance output unit 292. The guidance creation unit 291 creates guidance including limit violations, alarms, and countermeasures contained in the similar past operation data. The guidance can also include occurrence trends, including the frequency of limit violations. The guidance output unit 292 outputs the guidance created by the guidance creation unit 291 and displays the output guidance on the display unit 13. This allows guidance including limit violations, alarms, and countermeasures contained in the similar past operation data to be displayed on the display unit 13 prior to rolling the target steel plate Pr. The operator (operator of the rolling plant 1) who receives the displayed guidance can be alerted to the limit violation.

Figure 5 is a diagram showing an example of the hardware configuration of the overload avoidance support system 20. The above-mentioned functions of the overload avoidance support system 20 can be realized by the processing circuit shown in Figure 5. This processing circuit 20 may be dedicated hardware 20a. This processing circuit may include a processor 20b and a memory 20c. This processing circuit may be partially formed as dedicated hardware 20a and further include a processor 20b and a memory 20c. In the example of Figure 5, part of the processing circuit 20 is formed as dedicated hardware 20a, and the processing circuit 20 also includes a processor 20b and a memory 20c. The processing circuit 20 may be at least one dedicated hardware 20a. In this case, the processing circuit 20 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. The processing circuit 20 may include at least one processor 20b and at least one memory 20c. In this case, each function of the overload avoidance support system 20 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in memory 20c. The processor 20b reads and executes the programs stored in memory 20c to realize the functions of the recording devices 21 to 25, the conversion device 26, the data aggregation device 27, the determination device 28, and the guidance device 29. The processor 20b is also called a CPU (Central Processing Unit), central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 20c may be, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM. In this way, the processing circuit 20 can realize each function of the overload avoidance support system 20 by hardware, software, firmware, or a combination thereof.

As described above, according to this embodiment, multiple pieces of past operational data recorded in databases 31-34 are aggregated for each steel sheet Pr's product information, and from among the aggregated multiple pieces of past operational data, past operational data for other steel sheets Pr that are similar to the past operational data for the target steel sheet Pr to be rolled is determined as similar past operational data. Prior to rolling the target steel sheet Pr, guidance including limit violations, alarms, and countermeasures contained in the similar past operational data is displayed on the display unit 13, thereby helping to avoid overload operation of the rolling equipment. In this way, according to this embodiment, it is possible to effectively utilize the rolling equipment's operational history to avoid overload operation of the rolling equipment. Moreover, because guidance is automatically displayed prior to rolling the target steel sheet Pr, there is no need for personnel in charge of operations, equipment, and control to work together to recover from overload operation after it occurs, as was the case in the past.

1...Rolling plant, 13...Display unit (operation screen), 20...Rolling equipment overload avoidance support system, 21-25...Recording means, 21...First recording device, 22...Second recording device, 23...Third recording device, 24...Fourth recording device, 25...Fifth recording device, 26...Conversion device, 27...Data aggregation device, 28...Determination device, 281...Similarity score calculation unit, 282...Overall determination unit, 29...Guidance device, 31...Time axis performance database, 32...Product unit database, 33...Machine unit database, 34...Electrical unit database, Cg...Center of gravity, D...Distance between centers of gravity, Pr...Steel plate

Claims (3)

1. A rolling equipment overload avoidance support system for supporting the avoidance of overload operation of rolling equipment installed in a rolling plant, comprising:
a recording means for recording a plurality of past operation data in a database, including product information of steel plates manufactured in the past, steel plate time unit information including the thickness and temperature of the steel plate in rolling time units, rolling equipment time unit information including the rolling load of the rolling equipment, steel plate length unit information and rolling equipment length unit information obtained by converting the steel plate time unit information and rolling equipment time unit information into length units in the rolling direction, and limit violations, alarms, and countermeasures that have occurred during rolling;
a data aggregating device that aggregates the plurality of pieces of past operation data recorded in the database for each piece of product information;
a determination device that determines, from the plurality of pieces of past operation data aggregated by the data aggregation device, past operation data of other steel plates that is similar to the past operation data of the target steel plate to be rolled, as similar past operation data;
a guidance device that displays, on a display unit, guidance including limit violations, alarms, and countermeasures that have occurred during rolling and are included in the similar past operation data, prior to rolling the target steel plate;
Equipped with
The determination device
a similarity score calculation unit that calculates a first similarity score indicating a similarity between a plurality of digital data included in the past operation data of the target steel plate and a plurality of digital data included in the past operation data of the other steel plate, and a second similarity score indicating a similarity between a plurality of analog data included in the past operation data of the target steel plate and a plurality of analog data included in the past operation data of the other steel plate;
a comprehensive determination unit that calculates a comprehensive similarity score by adding the first similarity score and the second similarity score calculated by the similarity score calculation unit, and determines that the comprehensive similarity score is similar to the past operational data if the comprehensive similarity score is equal to or greater than a reference value,
The similarity score calculation unit plots the multiple analog data of the target steel plate and the multiple analog data of the other steel plates to determine their centers of gravity, and calculates the second similarity score based on the distance between the determined centers of gravity . The recording means
a first recording device that records the steel plate time unit information, the rolling equipment time unit information, and time unit information of manual operation by an operator of the rolling plant in a time axis performance database in association with the product information;
a second recording device that records, in a product unit database, steel plate length unit information, rolling equipment length unit information, and manual operation length unit information, which have been converted from time units to length units by a conversion device, in association with the product information;
a third recording device that records the rolling plan of the rolling plant, the limit violation, alarm and response method of the rolling equipment in the product unit database;
a fourth recording device that records mechanical maintenance information of the rolling equipment in a machine unit database in association with the product information;
2. The rolling facility overload avoidance support system according to claim 1, further comprising: a fifth recording device that records electrical system maintenance information of the rolling facility in an electrical unit database in association with the product information . 2. The rolling equipment overload avoidance support system according to claim 1 , wherein the comprehensive judgment unit calculates the comprehensive similarity score by adding values obtained by multiplying the first similarity score and the second similarity score by different weighting coefficients.