JP2003050603A - Controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a controller capable of monitoring control performance by extracting few data. SOLUTION: This controller is provided with a featured value extracting part 5 for calculating featured values indicating control performance in a real time based on feedback amounts, a storage part 6 for storing calculated featured values, and a communicating part 7 for outputting the stored featured values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to various types of regulators such as temperature regulators, and more particularly to regulators suitable for monitoring control performance.

[0002]

2. Description of the Related Art For example, in the case where a temperature controller controls the temperature of a production system to manufacture a product, the temperature controller is used to monitor whether or not desired control is performed. Control data such as detected temperature from the instrument is input to a recorder and recorded on paper, and if necessary, monitor items such as overshoot amount, dead time, etc. are calculated manually, and reference values are set. In general, it is judged whether the result is acceptable or not, or the control data from the temperature controller is input to a personal computer to calculate and calculate the monitoring item, and the result is compared with a reference value to determine whether it is acceptable or not. .

[0003]

At the production site, in order to shorten the tact time, reduce the defect rate, etc., it is required to increase the control speed and function in the production system.
Even in regulators such as temperature regulators, higher sampling frequency is required.

In such a situation, the former method using a recorder causes an enormous amount of data to be recorded,
There has been a problem that it becomes extremely difficult to analyze all data, and the cost required for data management and analysis also increases.

In the latter method using a personal computer, the control data can be automatically analyzed and managed, but since the speedup increases the data amount per unit time, the temperature controller and High-speed communication means with the personal computer is required, and a high-performance personal computer is required, which increases equipment costs.

The present invention has been made in view of such a point, and an object thereof is to make it possible to monitor a control performance by taking out a small amount of data from a regulator.

[0007]

In order to achieve the above object, the present invention is configured as follows.

That is, in the controller of the present invention, based on the target value and the feedback amount from the controlled object, in the controller which outputs the operation amount for the controlled object, the characteristic amount indicating the control performance is set to the feedback amount. Is stored on the storage unit.

Here, the characteristic amount indicating the control performance is, for example, the time until the feedback amount reaches the target value and stabilizes, the variation between channels in the control of a plurality of channels, the overshoot amount, the undershoot amount, The dead time, the maximum inclination, the hunting cycle, and the fluctuation range of the feedback amount in the settling state are included.

According to the present invention, not the feedback amount itself but the feature amount indicating the control performance extracted on the basis of the feedback amount is stored in the storage unit. Therefore, the feature amount is read from the storage unit and the production management or control is performed. It can be used for analysis etc., compared to the case of performing production management or control analysis using the feedback amount itself.
The amount of data to be managed can be greatly reduced.

In one embodiment of the present invention, a feature quantity extraction unit that extracts a feature quantity indicating control performance in real time based on the feedback amount, a storage unit that stores the extracted feature quantity, and a storage unit are stored. It is configured to include a communication unit that reads the characteristic amount from the storage unit and transmits the characteristic amount to the outside.

According to the present invention, the characteristic amount such as the time until the feedback amount reaches the target value and stabilizes, the dead time, or the overshoot amount is automatically extracted in real time by the characteristic amount extraction unit and is extracted. The feature amount is stored in the storage unit, and the stored feature amount is taken out to the outside through the communication unit as needed and used for production management or control analysis.

In another embodiment of the present invention, the feature quantity extraction unit starts the feature quantity extraction operation at the time when the target value is changed.

According to the present invention, the extracting operation of the feature quantity extracting unit, that is, the monitoring of the control performance is not continuously performed while the control operation is being performed, but while the target value is not changed. Is kept in a standby state. In other words, the extraction operation by the feature extraction unit is automatically started when control monitoring is required, so the amount of data read for monitoring can be small and the monitoring method can be small. This is effective in suppressing the equipment cost.

In still another embodiment of the present invention, the feature quantity extraction section starts a feature quantity extraction operation based on an external command.

According to the present invention, the extraction operation of the feature amount extraction unit, that is, the monitoring of the control performance is started based on an external command, and is in a standby state until the command for starting the monitoring is input. Maintained at. That is, the extraction operation by the feature amount extraction unit is started from the time when a command that requires control monitoring is input from the outside of the controller, so the amount of data read for monitoring can be small, and the monitoring means can be small. It is possible to suppress the cost of equipment.

In a preferred embodiment of the present invention, an alarm output unit is provided which compares the extracted characteristic amount with a predetermined threshold value and outputs an alarm when the characteristic amount exceeds the threshold value.

According to the present invention, when the characteristic amount exceeds the predetermined threshold value, an alarm is output because the control operation is defective.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to a temperature controller will be described below with reference to the drawings.

FIG. 1 shows a block diagram of this temperature controller. This temperature controller 1 has a target temperature (target value)
The setting unit 2 for setting and inputting SP and the detected temperature (control amount) PV, which is the feedback amount detected and input by the control target 3 such as a heating device, are controlled with respect to the control target 3 so as to match the target temperature SP. And a control calculation unit 4 for calculating and outputting the PID operation amount. Further, in order to monitor the behavior of the control, the characteristic amount indicating the control performance is based on the control data such as the detected temperature PV input to the control calculation unit 4. A feature amount extraction unit 5 for extracting the feature amount, a storage unit 6 for storing the extracted feature amount, and a communication unit 7 for transmitting the feature amount stored in the storage unit 6 to an external computer or the like as necessary. ing.

In this embodiment, in order to monitor the control performance, in order to reduce the amount of data to be managed by the user, not the control data itself such as the detected temperature PV, but the control data itself.
The feature amount extracted based on this is stored, and the feature amount is read out as needed to monitor the control performance. With this, a small amount of data can be extracted from the temperature controller 1 to monitor the control performance. I am trying. Which feature amount is extracted is set by the user from the setting unit 2 according to the control performance that the user intends to monitor.

Next, some specific examples of extracting the characteristic amount and monitoring the control performance will be illustrated.

(First Example) FIG. 2 shows a time T from when control toward the target value SP is started until the detected temperature PV (control amount), which is a feedback amount, reaches the target value SP and stabilizes. Is shown as a feature amount indicating control performance, FIG. 11A shows a change in the detected temperature PV (control amount), and FIG. 9B shows a flowchart for explaining the operation. .

The control is started when the power is turned on, but if the target value is not changed, the monitoring state is not activated and the system stands by (# 1 to # 2).

When the target value is changed, the monitoring state is activated (# 3), the deviation between the target value and the control amount is calculated (# 4),
It is determined whether or not the deviation is within a preset setting range (# 5). If the deviation is out of the settling range, the "waiting time" is cleared and the process returns to the beginning (# 6).

When the control amount approaches the target value and the deviation falls within the settling width, the measurement of the "waiting time" starts (# 7) and whether the measured "waiting time" is equal to or longer than the preset setting time. Judgment is made (# 8). When it is determined that the “waiting time” has reached the settling time or longer, the elapsed time from the start of monitoring is stored and stored in the storage unit as the stable time T.
(# 9), it returns to the standby state again (# 10) and prepares for the next target value change.

When the target value is changed as described above, the time T until the detected temperature PV (control amount), which is the feedback amount, reaches the target value SP and stabilizes,
It is stored in the storage unit as a feature amount.

(Second Example) FIG. 3 shows an example in which the variation δ of the detected temperature PV (control amount), which is the feedback amount between channels in the control of a plurality of channels, is extracted as a characteristic amount indicating control performance. In the figure, (a) shows a change in the detected temperature PV (control amount), and (b) shows a flowchart for explaining the operation.

The control is started when the power is turned on, but if the target value is not changed, the standby state is waited without being activated (# 1 to # 2).

When it is detected that the target value is changed, the monitoring state is activated (# 3), the maximum value of the control amount in each channel is read (# 4), and the maximum value in any channel is set in advance. It is determined whether or not the set threshold value has been reached (# 5). When it is determined that the maximum value of any channel has reached the threshold value, the minimum value of the control amount of the other channel is read (# 6), and the difference between the maximum value and the minimum value is calculated (# 6). 7) This is stored and stored in the storage unit 6 as the control variation δ between channels (# 8), and returns to the standby state again (# 9) to prepare for the next target value change.

As described above, when the target value is changed, the variation δ of the detected temperature PV (control amount), which is the feedback amount between the channels, is stored in the storage unit as a characteristic amount. .

(Third Example) FIG. 4 shows an example in which the integrated amount S while the detected temperature PV (control amount), which is the feedback amount, exceeds a predetermined threshold value P is extracted as a characteristic amount indicating control performance. The figure (a) shows the detected temperature PV (control amount).
FIG. 3B shows a flowchart for explaining the operation.

The control is started when the power is turned on, but the monitoring state is not activated until the control amount reaches the preset threshold P (# 1 to # 2).

When the control amount reaches the threshold P, the monitoring state is activated (# 3), the difference between the control value and the threshold P is calculated and integrated, and the area of the band where the control amount exceeds the threshold P is calculated. (# 4). When the control amount falls below the threshold value P, the integral calculation is terminated, and the total area S of the band where the control amount exceeds the threshold value P
Is stored and stored in the storage unit 6 (# 6), and the standby state is restored again (# 7).

In the case of the temperature controller 1, this area S
Corresponds to the amount of heat supplied at a temperature equal to or higher than the threshold value P, and is used, for example, in the case of managing whether or not the sterilization process is correctly performed by adding the required amount of heat at a predetermined temperature or higher.

(Other Examples) There are various other characteristic amounts indicating the control performance besides the above, for example, FIG.
As shown in (a) to (e), (a) overshoot amount O, (b) dead time D, (c) maximum slope K, (d) hunting period t, and (e) control amount in the settling state. The wobbling range w, etc. is appropriately selected according to the form of the controlled object, the operating condition, the management form, and the like.

The present invention can also be implemented in the following modes.

(1) As shown in the block diagram of FIG. 6, an alarm output unit 8 is provided which is activated when a predetermined feature amount stored in the storage unit 6 exceeds a preset threshold value, which impedes control. Before the state is reached, it is possible to avoid the control failure in advance by arranging for appropriate processing, for example, so as to raise the need for maintenance.

(2) It is also possible to start the feature quantity extracting operation by the feature quantity extracting section 5 in response to an ON / OFF signal input from the outside of the controller via the communication section 7 or a communication command. .

(3) It is also possible to detect the start of the original control of the controller and automatically start the feature quantity extracting operation by the feature quantity extracting section 5.

(4) Detecting that the controlled variable has changed from the settling state in which the controlled variable reaches the target value and stabilizes to a value equal to or larger than the preset settling band width, and the feature amount extraction section 5 automatically performs the extraction operation. Can also be configured to start.

(5) Of course, the present invention is not limited to the temperature controller, but can be similarly applied to other controllers for controlling pressure, flow rate and the like.

[0043]

As is apparent from the above description, according to the present invention, the following effects can be expected.

That is, according to the present invention, since only the predetermined feature amount necessary for monitoring the control performance is extracted and stored, the stored feature is read and desired by a small-scale monitoring means having a small capacity. Can be accurately monitored, which is effective in suppressing equipment costs.

Further, even if the speed of sampling in the controller itself is increased, the data amount of the feature amount itself does not significantly increase, so there is no particular need to update the monitoring means to a high capacity one. Can perform high-performance control and monitoring at low cost.

Further, since the calculated feature quantity is stored in the controller, it is possible to connect to a recorder or a computer without being connected.
It is also easy to use the display means provided in the controller itself so that the controller can be confirmed by itself.

[Brief description of drawings]

FIG. 1 is a basic control block diagram.

FIG. 2 is a diagram showing an example of a feature amount and a flowchart for extracting the feature amount.

FIG. 3 is a diagram showing another example of the characteristic amount and a flowchart for extracting the characteristic amount.

FIG. 4 is a diagram showing still another example of the characteristic amount and a flowchart for extracting the characteristic amount.

FIG. 5 is a diagram showing another feature amount.

FIG. 6 is a block diagram showing another embodiment.

[Explanation of symbols]

1 Temperature controller 2 setting section 3 controlled objects 4 Control calculation unit 5 Feature extraction unit 6 memory 7 Communication section 8 Alarm output section

Claims (5)

[Claims] 1. A controller that outputs an operation amount for the controlled object based on a target value and a feedback amount from the controlled object, wherein a characteristic amount indicating control performance is extracted and stored based on the feedback amount. A regulator characterized by being stored in a section. 2. The controller according to claim 1, wherein a feature quantity indicating control performance is extracted in real time on the basis of the feedback quantity, a storage section for storing the extracted feature quantity, And a communication unit that reads out the stored characteristic amount from the storage unit and transmits the characteristic amount to the outside. 3. The regulator according to claim 2, wherein the feature quantity extraction unit starts the feature quantity extraction operation at a time point when the target value is changed. 4. The controller according to claim 2, wherein the feature quantity extraction unit starts a feature quantity extraction operation based on a command from the outside. 5. The controller according to claim 1, wherein the extracted feature quantity is compared with a predetermined threshold value, and when the feature quantity exceeds the threshold value, an alarm is output. A regulator comprising an alarm output unit.