JP7093603B2 - Drive response monitoring device - Google Patents

Description

An embodiment of the present invention relates to a drive response monitoring device that monitors the speed control response of a motor and a drive device in a process control system.

The production line of the plant is operated by the process control system. The process control system includes a motor for driving equipment, a drive system for controlling the motor, a programmable logic controller (hereinafter referred to as PLC), and the like. Various operation performance signals (control signals, sensor signals, operation signals, etc.) exist in the process control system. The data collection system can store these signals as time series data. The accumulated time series data can be effectively used and utilized by using an appropriate system. Therefore, there is a need to utilize these data for plant monitoring and maintenance.

Patent Document 1 describes a method of constantly evaluating the performance deterioration state of the equipment constituting the plant by dividing the time series data into clusters by principal component analysis and modeling the target for each cluster. ing.

In Patent Document 2, a model that estimates the other from one is created using two correlated time-series data, and the value output by the estimated model is compared with the actual time-series data. , A method for constantly evaluating the performance deterioration state of the equipment constituting the plant is described.

Japanese Patent No. 5048625 Japanese Patent No. 5669553

In the above-mentioned Patent Documents 1 and 2, etc., an abnormality of the equipment is detected by creating a model of the plant and making some judgment on the deviation from the estimated value by the model. However, such modeling requires a huge amount of data, and in order to obtain an accurate model with less error, it is necessary to determine in advance whether the data used for model creation is normal or abnormal. It takes a lot of time and effort.

An object of the embodiment is to provide a drive response monitoring device that determines an abnormality or deterioration from changes in the speed control response of a motor and a drive device without taking a lot of time and effort to model a plant. And.

The drive response monitoring device according to the embodiment drives a data collecting device for collecting a plurality of actual data including control signals and measurement data related to equipment and products operated by the process control system in chronological order, and a motor. The speed command value of the drive device and the measured value of the speed of the motor with respect to the speed command value are collected in time series, and the speed control response which is the delay of the measured value of the speed with respect to the speed command value at an arbitrary time is measured. The response measuring device and the time-series data of at least two actual data selected from the plurality of actual data are classified into clusters so that they have the same value at different times and have the same operating conditions . It is equipped with a cluster classification device. The cluster classification device associates the data of the speed control response having a time included in the at least two actual data classified in the cluster with the cluster, and the data of the speed control response associated with the cluster. The quality of the data of the speed control response is determined by comparing with the first reference value set in advance.

In the present embodiment, a drive response monitoring device that detects changes in the speed control response of the motor and the drive device and determines an abnormality or deterioration is realized without requiring a large amount of time and labor.

It is a block diagram which illustrates the drive response monitoring apparatus which concerns on Embodiment 1. FIG. It is an example of a schematic operation waveform regarding the drive response monitoring apparatus of Embodiment 1. It is a schematic diagram for demonstrating the operation of the drive response monitoring apparatus of Embodiment 1. FIG. It is a schematic diagram for demonstrating the operation of the drive response monitoring apparatus of Embodiment 3. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
It should be noted that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio of the sizes between the parts, and the like are not necessarily the same as the actual ones. Further, even when the same part is represented, the dimensions and ratios may be different from each other depending on the drawing.
In addition, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate.

(Embodiment 1)
FIG. 1 is a block diagram illustrating a drive response monitoring device according to the present embodiment.
As shown in FIG. 1, the drive response monitoring device 15 is connected to the communication network 4. A process control system 5 is connected to the communication network 4. The process control system 5 includes a programmable logic controller (PLC) 3. The PLC 3 controls the drive device 1 according to the set program. The drive device 1 drives the motor 2 according to a control signal and a command supplied from the PLC 3.

A plurality of sets of the drive device 1 and the motor 2 are provided in, for example, a steel rolling plant. A plurality of sets of drive devices 1 and motors 2 drive, for example, a rolling mill, a table roller, and a pump for cooling water.

The PLC 3 collects control signals for driving actuators and the like related to process control other than the drive device 1 and the motor 2, and measurement data from various measuring instruments including the measuring instruments provided in the drive device 1. The process control system 5 can accept manual operations by these operators from, for example, an operation panel (not shown), an HMI terminal, or the like connected to the communication network 4.

PLC3 handles these control signals, measurement data, and the like. These control signals, measurement data, and the like are referred to as operation record signal group 9. The operation record signal group 9 can include a process record value 6, an operation parameter 7, an operator operation signal 8, and the like.

The actual process value 6 means an actual value in each process of a product containing an intermediate product controlled and manufactured by the process control system 5. For example, PLC3 acquires rolling load data measured by a load cell provided in a rolling mill as a rolling load actual value. The PLC3 acquires the tension data obtained by directly measuring the tension of the rolled material with a tension meter or indirectly using actual measurement data such as speed and torque as the actual tension value. The PLC 3 acquires the data of the output torque recorded by the drive device 1 as the actual torque value.

The operation parameter 7 is data regarding the specifications of the product set by the upper process computer. The PLC3 can acquire these data via various measuring instruments provided during the process. For example, measuring instruments for measuring the plate thickness and plate width of the rolled material are provided before and after the rolling mill, and data is generated in real time from these measuring instruments. The steel grade is set by the process computer.

The operator operation signal 8 refers to an operation signal including a manual operation from a control panel, an HMI terminal, or the like connected via the communication network 4. The operator operation signal 8 includes, for example, a record of operation equipment intervention operation by an HMI terminal, a record of mode selection operation, and the like.

The above-mentioned operation record signal group 9 is an example when applied to the process control system 5 for a rolling process of steel or the like, and is not limited to these. Appropriate signal groups are set according to the production of non-ferrous metals and other production processes such as paper and film.

Further, the operation record signal group 9 is not limited to a single PLC, and may be collected via a plurality of PLCs constituting the process control system. Further, the operation record signal group 9 may be collected from other systems constituting the process control system, for example, a distributed control system (DCS) or the like.

The drive response monitoring device 15 collects each performance data of the operation performance signal group 9 handled by the PLC 3 via the communication network 4. The acquisition time is associated with each performance data of the operation performance signal group 9. That is, each performance data of the operation performance signal group 9 is collected as time-series data acquired in real time. Each actual data collected as time-series data is not associated with the final product, but is classified into clusters in units of time as described later, and changes in the speed control response of the drive device 1 and the motor 2. Used to monitor.

The configuration of the drive response monitoring device 15 will be described.
The drive response monitoring device 15 includes a data collecting device 10, a response measuring device 11, and a cluster classification device 12. The data acquisition device 10 and the response measurement device 11 can be connected to the communication network 4. The data acquisition device 10, the response measurement device 11, and the cluster classification device 12 are connected to each other.

The data collection device 10 collects each performance data of the operation performance signal group 9 handled by the PLC 3 in real time via the communication network 4. The data acquisition device 10 supplies all of the actual data of the operation actual signal group 9 or a plurality of actual data selected from the operation actual signal group 9 to the cluster classification device 12 as time-series data. When a plurality of actual data are selected from the operation actual signal group 9, the actual data to be selected in advance is set.

The response measuring device 11 collects time-series data regarding the response of the drive device 1 handled by the PLC 3 in real time via the communication network 4. The time-series data regarding the response of the drive device 1 is data representing the time change of the speed command value data generated by the PLC 3 and the actual speed data. The speed command value data is generated by the PLC 3 based on, for example, the rolling speed pattern data supplied from the upper process computer. The actual speed data is data measured by a rotation speed meter provided in the motor 2 when the drive device 1 operates according to the speed command value. More specifically, the difference between the speed command value and the measured speed value is defined as the speed control response, and the response measuring device 11 supplies the data of the speed control response to the data collecting device 10.

The cluster classification device 12 includes a cluster group 13 and a determination device 14. The cluster group 13 includes a plurality of clusters. The cluster classification device 12 classifies the actual data selected from the operation actual signal group 9 into a plurality of clusters. The cluster classification device 12 classifies selected actual data having the same value at different times into the same cluster. Associate the data of the speed control response at the same time contained in each classified cluster with that cluster.

As will be described in detail later, when the selected actual data takes the same value at different times, it means that the operating conditions are the same, so the speed control response at each time is compared with the reference value. Thereby, it is possible to determine the state of abnormality or deterioration of the drive device 1 or the motor 2.

In the determination device 14, a reference value (first reference value) relating to the speed control response for each cluster is set in advance. The determination device 14 compares the data of the associated speed control response with the reference value in the same cluster, and determines whether or not the predetermined value or range is exceeded. In a cluster, if the speed control response data exceeds a predetermined value or range of the reference value, it indicates that the drive device 1 or the motor 2 is abnormal or deteriorated. For example, a plurality of predetermined values or ranges of reference values may be provided to determine the degree of deterioration and abnormality.

The operation of the drive response monitoring device 15 of the present embodiment will be described.
FIG. 2 is an example of a schematic operation waveform regarding the drive response monitoring device of the present embodiment.
The drive device 1 uses a speed actual measurement sensor attached to the motor 2 or a speed actual value obtained from the speed actual estimator inside the drive device 1 according to the speed command value output from the PLC 3, and uses the motor. The speed of 2 is controlled.

PLC3 includes process performance values 6 such as rolling load performance, tension performance, torque performance, operation parameters 7 such as plate thickness, plate width, and steel type, and operator operation signals 8 such as intervention operation and mode selection from operation supplies. The signal group 9 is input as a control signal. The PLC 3 enables these control signals to be used by the data acquisition device 10 and the response measurement device 11 via the communication network 4.

The speed control response data measured by the response measuring device 11 is collected as time-series data by the data collecting device 10 together with the operation record signal group 9 via the communication network 4.

FIG. 2 shows a graph of the speed characteristics of the drive device 1 in which the horizontal axis represents time and the vertical axis represents the speed of the motor 2. In FIG. 2, the solid line shows the time change of the measured value Nm of the speed data of the motor 2 driven by the actual output of the drive device 1. The broken line indicates the time change of the speed command value Nref supplied from the PLC 3 to the drive device 1.

As shown in FIG. 2, in the drive device 1, the speed command value Nref is set to increase substantially linearly from 0 and reach the target value. The actual speed Nm of the motor 2 increases so as to follow the speed command value Nref, and reaches the target value. The actual speed Nm has a delay time with respect to the speed command value Nref, and this delay time is defined as a speed control response.

The speed command value Nref and the actual speed Nm are time series data. In this example, N1 is set to a value of k [%] of the actual velocity Nm. k [%] is preset, for example, 20%. The time of the actual speed Nm at the speed N1 is t2. Further, the time of the speed command value Nref when the speed is N1 is t1. In this way, the speed control response (t2-t1) is associated with the time t2.

FIG. 3 is a schematic diagram for explaining the operation of the drive response monitoring device of the present embodiment.
FIG. 3 shows time-series data of rolling load actual and tension actual as an example of the operation actual signal group 9 associated with the time. In this figure, the time is shown by t1 to tm + k, the rolling load actual data is shown by a1 to am + k, and the tension actual data is shown by b1 to bm + k. The actual rolling load data and the actual tension data are associated with each time, and the association is represented by the same subscript. It should be noted that each time the subscript becomes larger, the later time is indicated, and the interval between each time is constant. In this example, the data of the velocity control response ΔTi, ΔTm + i associated with a specific time are also shown.

The cluster classification device 12 classifies the clusters using the actual data selected in advance from the operation actual signal group 9. For example, the cluster classification device 12 creates a plurality of rolling load actual data and tension actual data for each steel type to form a cluster group 13. The cluster classification device 12 stores the speed control response converted into time-series data in the cluster having the same time as the time of the data stored in the cluster. The quality of the speed control response for each cluster is determined by the determination device 14.

Clusters classified as described above mean that they have the same operating conditions. Therefore, the speed control response data stored in the same cluster can be considered as the speed control response data under the same operating conditions.

Here, if the equipment controlled by the process control system 5 is normal, the speed control response under the same operating conditions should be the same. Therefore, if the speed control response in the same cluster deviates from a certain limited range, it can be determined that there is something wrong with the equipment. At this time, by making the cluster division finer, it becomes possible to improve the definition of the abnormality of the equipment and detect the sign of the abnormality.

As shown in FIG. 3, in this example, one cluster formed in the cluster group 13 contains time series data of two sections T1 and Tm + 1. The two sections T1 and Tm + 1 have the same length.

The time-series data a1 to ak and b1 to bk included in the interval T1 have values equal to the time-series data am + 1 to am + k and bm + 1 to bm + k included in the interval Tm + 1, respectively. In the figure, as shown by the broken line arrows, the data surrounded by the solid line frame in the section T1 is equal to the data surrounded by the solid line frame in the different sections Tm + 1. For example, the data a1 and b1 associated with the time t1 have values equal to the data am + 1 and bm + 1 associated with different times tm + 1, respectively. Similarly, the data a2 and b2 are equal to the data am + 2 and bm + 2, respectively, and the data ai and bi are equal to the data am + i and bm + i, respectively.

Each cluster in such sections T1 and Tm + 1 is treated as the same cluster. In the same cluster, the operating conditions are the same, and in each of the sections T1 and Tm + 1, the speed control response can be considered to be the same value under the operating conditions.

Here, when there are speed control responses ΔTi and ΔTm + i associated with time ti and time tm + i, respectively, the speed control responses are the same operating conditions. Therefore, unless there is a problem with the drive system, the speed control responses ΔTi and ΔTm + i are It is considered that they have the same value. Conversely, if there is a difference in the speed control responses ΔTi and ΔTm + i in the same cluster, it can be considered that some problem such as abnormality or deterioration has occurred in the drive system.

By presetting the same range of speed control response and comparing the speed control response at any time within the same cluster as a judgment standard with this judgment standard, abnormalities or deterioration of the drive device 1 and the motor 2 can be determined. The situation can be determined.

When classifying clusters, the above-mentioned section can be arbitrarily set. The determination may be made based on the presence or absence of the same data value in a wider section, or the determination may be made based on the presence or absence of the same data in a narrower range, for example, at a single time.

The effect of the drive response monitoring device 15 of the present embodiment will be described.
The drive response monitoring device 15 of the present embodiment includes a data collecting device 10 that collects time-series data of the operation record signal group 9 of the process control system 5 in real time. The drive response monitoring device 15 can collect time-series data related to the speed response of the drive of the motor 2 from the drive device 1 in real time. Therefore, the speed control response data can be associated with each data of the operation performance signal group 9 according to the data acquisition time.

The drive response monitoring device 15 includes a cluster classification device 12 that classifies each data of the operation performance signal group 9 and the data of the speed control response associated with each time into clusters by having the same value at different times. The cluster classification is executed so that all the time-series data of the operation record signal group 9 or the selected plurality of time-series data have the same data at the same time or the same period. Therefore, since the time-series data classified into the same cluster represent the same operating conditions, it is possible to determine whether the speed response is good or bad under the same operating conditions.

(Embodiment 2)
In the first embodiment described above, whether or not the speed control response is within a limited range is used as a determination criterion. However, since the speed control response may change due to the maintenance of the equipment, it is necessary to anticipate the change in the speed control response due to this maintenance in the judgment criteria used for the judgment of quality. In other words, it means that the range of the judgment standard of the speed control response is wider than the case where the change due to the equipment maintenance is not included. Therefore, in such a case, it is difficult to accurately determine the abnormality of the equipment even if the types of the actual data of the operation actual signal group 9 used for the cluster classification are increased and the cluster is divided finely. Become.

Therefore, in the second embodiment, the quality of the speed control response at a specific time is not limited to the judgment, and the judgment standard for the time change of the speed control response is introduced. The speed control response for each cluster is continuously collected, and its temporal change, that is, secular variation is focused on. More specifically, the steepness of the change between the speed control responses collected for each cluster at each time is calculated and compared with the preset judgment reference value.

For example, the cluster classification device 12 associates the speed control response ΔT1 at time t1 with the cluster C1 including time t1. Similarly, the cluster classification device 12 associates the speed control response ΔT2 with the cluster C1 at time t2. That is, the cluster C1 has a speed control response ΔT1 at time t1, a speed control response ΔT2 at time t2, ..., a speed control response ΔTi at time ti, a speed control response ΔTi + 1 at time ti + 1, ... Are classified, and each actual data is associated by time.

At this time, the change of the speed control response ΔTi, ΔTi + 1 with respect to the time change between the adjacent times ti and ti + 1 in the cluster C1 is compared with the determination reference value (second reference value) ΔTth.

(ΔTi + 1-ΔTi) / (ti + 1-ti)> ΔTth (1)

When the equation (1) is satisfied, the determination device 14 outputs the deterioration determination, assuming that the rapid deterioration determination is in progress.

In the drive response monitoring device of the second embodiment, since the cluster classification device 12 continuously acquires the speed control response data for each cluster, the time change of the speed control response corresponding to each of the adjacent times suddenly occurs. It can be determined whether or not it is a thing. Therefore, it is possible to eliminate the detection of a slow change in the speed control response, as in the case of recovering the speed control response that has decreased due to natural deterioration over time by maintenance or the like. Deterioration judgment can be performed.

Of course, the time change of the speed control response may be determined while determining the speed control response at each time (in the case of the first embodiment).

(Embodiment 3)
In the other embodiment described above, the cluster classification device 12 selects a plurality of actual data from the operation actual signal group 9 in advance, and classifies the clusters according to the selected actual data. However, selecting what kind of performance data from the operation performance signal group 9 may cause a problem that human judgment based on experience is required. Therefore, in the third embodiment, the selection of necessary performance data from the operation performance signal group 9 is automated.

In the drive response monitoring device of the third embodiment, the cluster classification device 12 automatically generates a cluster in order to determine the quality of the speed control response from the operation record signal group 9.

The data collection device 10 stores all the time-series actual data of the operation actual signal group 9. The speed control response data is stored in association with the time. When the speed control response data has the same value, the operating conditions are the same at the time when the speed control response data is acquired.

The same operating conditions will be classified into the same cluster. Therefore, by extracting common conditions from the actual data associated with the time when the same speed control response was acquired, the actual data required for cluster generation can be selected.

FIG. 4 is a schematic diagram for explaining the operation of the drive response monitoring device of the present embodiment.
FIG. 4 shows time-series data of all the actual data ai, bi, ci, ..., xi, yi, zi included in the operation actual signal group 9. The actual data ai, bi, ci, ..., Xi, yi, zi are associated with the time ti. Here, i is a natural number (integer of 1 or more), and represents the i-th time ti and the actual data ai, bi, ci, ..., Xi, yi, zi.

Further, the speed control response data is acquired at an arbitrary time, and the speed control response data is associated with the actual data via the time.

Here, when the speed control responses ΔTm and ΔTn acquired at different times tm and tun are equal values, the set of actual data am, bm, cm, ..., Xm, ym, zm and an, bn, cn, ..., xn, yn, Zn are considered to be actual data acquired under the same operating conditions. However, some of these actual data may not be related to the setting of the operating conditions. Therefore, it is necessary to search for a common condition from the set of actual data am, bm, cm, ..., Xm, ym, zm and an, bn, cn, ..., xn, yn, zn. A common condition is, for example, when the values of the actual data are equal to each other.

Of the set of actual data am, bm, cm, ..., xm, ym, zm and an, bn, cn, ..., xn, yn, zn, the set of data bm, cm and the data bn, surrounded by a solid line frame, If each set of cn has an equal value, it is determined that these actual data set this operating condition. The cluster classification device 12 extracts arbitrary actual data bi and ci from the operation actual signal group 9, and classifies the cases where the actual data bi and ci have equal values at different times into clusters. After that, the cluster classification device 12 operates in the same manner as in the case of the other embodiments described above.

Regarding the setting condition of the same operating condition, the time range associated with the data having the same value may be further expanded. For example, when the value of the set of data bm and cm is equal to the value of data bn and cn, the time is set back by one, and the data at time tm-1 and time tun-1 are compared and the same. The operating conditions may be determined.

According to the embodiment described above, it is possible to realize a drive response monitoring device capable of determining a change in the speed control response of the motor and the drive device without requiring a large amount of time and labor.

Although some 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 embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention and its equivalents described in the claims. In addition, each of the above-described embodiments can be implemented in combination with each other.

1 drive device, 2 motor, 3 programmable controller, 4 communication network, 5 process control system, 6 process performance value, 7 operation parameter, 8 operator operation signal, 9 operation performance signal group, 10 data collection device, 11 response measurement device, 12 cluster classifier, 13 cluster group, 14 judge, 15 drive responder

Claims (4)

A data collection device that collects multiple performance data, including control signals and measurement data , in chronological order for equipment and products operated by process control systems.
The speed command value of the drive device for driving the motor and the measured value of the speed of the motor with respect to the speed command value are collected in time series, and the speed control which is the delay of the measured value of the speed with respect to the speed command value at an arbitrary time. A response measuring device that measures the response, and a response measuring device
A cluster classification device that classifies time-series data of at least two actual data selected from the plurality of actual data into clusters so that the same operating conditions are obtained by having the same value at different times.
Equipped with
The cluster classification device is
The data of the speed control response having the time included in the at least two actual data classified in the cluster is associated with the cluster.
A drive response monitoring device that determines the quality of the speed control response data by comparing the speed control response data associated with the cluster with a preset first reference value. The drive response monitoring device according to claim 1, wherein the cluster classification device sets the first reference value at a single time and determines the quality of the speed control response data. The drive response monitoring device according to claim 1 or 2, wherein the cluster classification device compares changes in the actual data in two different time ranges with a preset second reference value. The cluster classifier extracts the speed control response of the same value, and among the plurality of actual data associated with the time of the extracted speed control response of the equal value, the actual data having the same value at different times. The drive response monitoring device according to claim 1, which classifies the data into clusters so as to form a set of data.

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