JPH03210605A - Plant controller - Google Patents

Abstract

PURPOSE:To always monitor the abnormality by using an inspecting simulator function functioning at production for diagnosis of the abnormality of a plant after the plant is actually installed. CONSTITUTION:The working of a plant 3 is simulated by a simulation means 2 after reception of the control output of a control means 1. Then the means 2 produces an answer signal of the same type as that obtained when an answer is received from a plant 3. A comparison means receives the answer signals of the means 2 and the plant 3 to be controlled and compares both signals with each other to produce an abnormality signal when no coincidence is obtained between them. If a switch means 9 is set in an inspection mode under such conditions, the working of the means 1 can be confirmed after reception of the answer result obtained by the means 2. When a plant control/monitor mode is set, the working of the plant 3 is simulated by the means 2 together with the controlled applied to the plant 3. Thus it is possible to always monitor the abnormality of the plant 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a plant control device for controlling various plants such as a chemical plant.

(Prior Art) For example, digital control devices are used for control in various plants such as chemical plants. This digital control device has a single input terminal and an output terminal at multiple points.
10 parts, a memory storing a plant control program, and a processor that executes the control program and sends and receives necessary control signals to and from the 110 parts;
Connect the control end of the plant to be controlled to the

A plant generally includes a plurality of on/off valves, motors, pumps, regulating valves, etc., whose operating ends are individually connected to a plurality of 110 output terminals. Also, these on-
The off valves, motors, pumps, and regulating valves are provided with limit switches, rotation detectors, etc. in order to detect their operating states, and their detection outputs are individually applied to the plurality of input terminals of 110 parts as answerback signals.

In a digital control device, the control program determines which output terminal outputs the control output and which input terminal receives the answerback when controlling which operation end. Whether or not to control the ends is determined and programmed sequentially in accordance with the necessary control procedures of the plant to be controlled.

Therefore, when this digital control device is connected to the plant to be controlled and control is started, the control output is generated to the operating end according to the program, and the next control is executed in response to answerback from the operating end. This can be performed sequentially to implement predetermined plant control.

By the way, when manufacturing a digital control device, it is necessary to test and verify the control program at the manufacturer's factory before installing it in an actual plant, and conventionally, testing has been performed using the following two methods.

■ As shown in FIG. 3, a simulator 2 that simulates a plant is connected to the control device 1, a control signal 3 is passed to the simulator, an answerback signal 4 for the control signal created by the simulator is input to the control device, Tests are performed by providing an environment as if the control device were applied to an actual plant.

(2) As shown in FIG. 4, a simulator program 12 is prepared separately from the control program 11 in the same control device, and the same function as (2) is obtained by exchanging control amount data 13 and answer back data 14.

This simulator program will be removed when installing an actual plant.

On the other hand, when diagnosing a plant, conventionally, abnormality detection may be performed by comparing answerback signals using a plant simulator program by individually handling only important parts. However, in this case, it is not used for control program testing in factory testing.

(Problem to be Solved by the Invention) As mentioned above, when manufacturing a digital control device, it is necessary to check whether the programmed control operation will reliably perform the intended control operation before installing it in an actual plant. It is necessary to test and verify the control program at the manufacturer's factory. Conventionally, a simulator that simulates the plant to be controlled is connected to the manufactured digital control device and the operation is confirmed by exchanging signals with the simulator, or the manufactured digital control Separately from the control program, a simulator program that simulates the plant to be controlled is prepared in the equipment, and operation is confirmed by running the control program and simulator program and exchanging control amount data and answerback data. .

In this case, it is necessary to prepare a simulator and simulator program that simulates the plant to be controlled, which is costly, and there is a problem that it is necessary to spend time and manpower to develop the simulator and simulator program. .

Moreover, this simulator and the simulator program become unnecessary after the operation confirmation verification is completed, which is extremely wasteful.

On the other hand, after a digital control device is installed in an actual plant, it becomes necessary to diagnose abnormalities in the plant, but conventionally, such abnormality diagnosis has been performed independently using a plant simulator program. This was done by back signal comparison and for each plant.

This is because the simulator program for factory testing is configured to answer back to the control processor.
It is not possible to detect abnormalities in an actual plant. Therefore, the function is to perform abnormality diagnosis by comparing the answerback signal from the simulator program that simulates the plant with the answerback signal from the actual plant. This is because a separate program for plant abnormality diagnosis is required.

Therefore, a program for diagnosing plant abnormalities had to be developed separately from a simulator program for factory verification, which was extremely wasteful.

In addition, in the case of diagnostic programs, a program for plant abnormality diagnosis must be developed separately from the simulator program for verification, so in order to reduce the cost and effort of development, it is necessary to You have to limit yourself to important elements, and it is difficult to check everything. Therefore, since the important element check is performed, items that are not included in the check items cannot be checked even if an abnormality occurs.

However, in order to ensure reliability and to be able to respond immediately to troubles, it is desirable to be able to constantly monitor abnormalities while the plant is in operation.

Therefore, the purpose of this invention is to create a plant that can use the simulator function for verification during manufacturing to diagnose abnormalities in the plant after installation in an actual plant, and that also enables continuous abnormality monitoring. The purpose is to provide a control device.

[Configuration of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention is configured as follows. That is, it has a plurality of input/output terminals, and the control end of each controlled element of the target plant and the response signal input terminal of the controlled element are connected to the required input/output terminal, and the control means controls the plant. According to the control procedure, a control output is generated to the operating end of the controlled element via the required input/output terminal, and upon receiving a response signal from the controlled element, the control means moves to control the operating end of the next controlled element. In the plant control device configured to perform plant control in this manner, simulation means receives a control output from the control means to simulate the operation of the plant and generates a response signal of the same type as when the plant responds. , a comparison means that receives the response signal of the simulation means and the response signal of the controlled plant, compares both response signals, and generates an abnormal signal when they do not match, and a verification mode and a plant control/monitoring mode. When in the verification mode, the response signal from the simulation means is given to the control means, and when in the plant control/monitor mode, the response signal obtained from the input/output terminal for the response signal input of the controlled element is given to the control means. and switching means for supplying a plant response signal to the control means.

(Function) In this device having such a configuration, the simulation means receives the control output of the control means, simulates the operation of the plant, generates the same type of response signal as when the plant responds, and in the verification mode, Since the switching means gives the response signal of the simulation means to the control means, during verification in a factory without an actual plant, the control operation of the device can be verified simply by setting the switching means to the verification mode.
After connecting to the actual plant, when the switching means is set to the plant control/monitor mode, the switching means outputs the control output of the control means to the simulation means and the plant, inputs the response results of each to the comparison means, and the response signal of the plant is On the other hand, when the comparison means receives response signals from both the simulation means and the plant, it checks whether they match or do not match, and when they do not match, it operates to generate an abnormal signal.

Therefore, if the switching means is set to the verification mode, the operation of the control means can be confirmed based on the response results from the simulation means, and if the switching means is set to the plant control/monitoring mode, the simulation means can be used while controlling the plant. It is possible to carry out simulations using
It is possible to monitor abnormalities by comparing the response results of both.

Therefore, according to the present invention, the simulator function for verification during manufacturing can be used for diagnosing plant abnormalities after installation in an actual plant. The simulator function can be effectively utilized.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings, taking as an example a case in which a control signal is given to an on/off valve. Note that a plant generally includes a plurality of on/off valves, motors, pumps, regulating valves, etc., and the simulator also simulates these operating ends.

FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a block diagram showing a specific example thereof, and 3 is a plant (actual plant) to be controlled.

As an example, the operating end of the target plant 3 is an air diaphragm type on/off valve 13 driven by a solenoid valve 12, as shown in FIG.

10 is a plant control device according to the present invention, and this plant! The 119Il device 10 includes a plant control section 1 which is a functional element (specifically, a software element 2 control program) for controlling the plant, a simulator section 2 which is a simulator element (simulator program) for simulating the plant, and a plant It consists of a switching section 9 that selects either the answerback signal of the simulator 2 by executing a simulation based on the control output of the control section 1 or the control ratio mode B of the plant control section 1.

Verification mode A is a mode for operation testing (for test verification during production) in which control signals/answerback signals are exchanged between the plant control unit 1 and the simulation unit 2, and monitor mode B is for plant control and The mode for monitoring (abnormality monitoring during actual operation) is to completely disconnect the plant 3 side,
Only the answerback signal from the simulation section 2 is returned to the plant control section 1, and when switching to monitor mode B, both the answerback signals from the simulation section 2 and the plant 3 are given to the comparison section 7. It also functions to return only the answerback signal from the plant 3 side to the plant control section 1.

Note that the plant control unit 1 outputs control signals for the plant to the output terminals of the plant control device input/output device unit, which supplies signals to the operating terminals of the controlled elements at each time.
A control signal is also supplied from the output terminal to the simulator 2, and a response signal (answer back) from the plant 3 or the simulator 2 is sent to the input/output device section of the plant control device corresponding to the control end of the controlled element. The configuration is such that this is done for a system of input terminals, and the output and input have a one-to-one correspondence with each input terminal and output terminal in the input/output device section of the plant control device.

Therefore, the input and output terminals for a control signal and its response signal for a certain control target element in a plant are determined to be specific, and as control progresses, control outputs are sequentially given to the output terminals of the control target element. It is possible to obtain a response signal separately from others and proceed with control.

The operation of this device having such a configuration will be explained.

In this device, by switching the switching unit 9, a verification mode A is used for operation tests (for test verification during manufacturing) in which control signals/answer back signals are exchanged between the plant control unit 1 and the simulation unit 2. and plant control and its monitoring (
You can select one of the monitor modes B for monitoring abnormalities during actual operation.

When the switching unit 9 is switched to verification mode A, the command signal from the plant control unit 1 is given only to the simulator 2, and the simulator 2 that receives the command signal performs simulation according to the command signal. The answerback signal which is a response signal is outputted by executing the answerback operation, and this answerback signal is given to the plant 1ill1 section 1.

As a result, the plant 1111m section 1 moves to the next control 8J and generates a control output, and in response to this, the simulation section 2 executes a simulated operation in accordance with the command signal,
Outputs an answerback signal.

By repeating such operations, the plant control device 1
0 can verify the control operation of the plant control section 1 using the function of the internal simulator 2.

As a result of verification of the control operation of the plant control unit 1, if it is confirmed that the desired control function can be obtained, then the control operation of the actual plant 3 is confirmed.
This plant control device 1O will be connected to the plant and actual operation will begin. At this stage, the plant control device IO switches the switching unit 9 from the verification mode A to the monitor mode B.

When the switching unit 9 is switched to the monitor mode B and the plant control device IO starts operating, the plant control unit 1 starts operating and starts controlling the plant.

Then, a command signal for plant control from the plant control section 1 is given to both the plant 3 and the simulation section 2. When a start command signal (opening control signal for the on/off valve 13) 4 is output from the plant control unit 1 as the control program is executed, the plant 3 that receives this signal
The on/off valve 13 is controlled to be open, and the limit switch 11 outputs an open response signal from the plant 3 as an answerback, which is input to the plant control unit Wt10.

On the other hand, the control signal 4 is also input in parallel to the simulator 2, and upon receiving the control signal 4, the simulator 2 simulates the operation of the on-delay timer element 2a as the on-off valve 13. This on-day
Due to the operation of the timer element, the control signal 4 is turned on,
After a specified time, outputs an answer back signal 6 that turns on (
(Generation of a response signal to open the limit switch 11 as a simulated operation).

Among these answerback signals 5 and 6, the answerback signal 5 from the plant 3 is input to the plant control device IO, and the plant control device IO moves to the next control operation based on the answerback signal 5 received from the plant 3. When a control output is generated and an answerback signal is output from the plant 3 in response, the next control operation is performed and the operation of generating the control output is performed. By repeating such operations, the plant control device flO controls the plant 3.

On the other hand, in monitor mode B, the answerback signals 5 and 6 from the simulator 2 and the plant 3 are also input to the comparator 7. Then, in the comparison section 7, in order to check whether the two match,
AN of both answer back signals 5 and 6 with AND logic element 7a
After taking the D logic and inverting the result with the NOT logic element 7b, the result is passed through the timer processing element 7c to perform on-red delay timer processing to guarantee errors between the actual plant and the simulator, and to determine abnormality. .

Note that the functions of the simulator 2 include the following.

■ Define a set of control signals and answerback signals.

This is a rule that determines which items should be compared.

■ Regulation of what the answerback signal should be (on or off) when the control signal is on. This is because depending on the on/off valve, the answerback from the limit switch may be off when the control signal (open command) is on.

Therefore, if the contents of the answerback signal 6 from the simulator 2 and the answerback signal 5 from the plant 3 do not match, the comparator 7 makes a logical judgment on this, and the result of the comparison by the comparator 7 determines whether the answerback signal 6 from the plant 3 Malfunctions due to abnormalities (for example, diaphragm failure, valve jamming, interface or driver failure, signal line disconnection, etc.) can be detected, and abnormality monitoring of the plant 3 can be carried out in parallel with the original control.

Furthermore, with this system, the simulator 2 used for verification at the factory can be used directly for diagnosing plant abnormalities after the plant is installed, making it possible to effectively utilize the simulator 2. . In other words, in the past, simulation programs used for verification in factories were used only for verification and could not be used for anything else, so diagnostic programs for plant diagnosis had to be created individually, which increased costs and Previously, this was only done on particularly important parts, but with the present invention, it can now be used for both verification and monitoring, increasing versatility and eliminating waste.
It will be possible to reduce costs and enhance functionality.

Furthermore, in the prior art, it has been difficult to diagnose input/output devices regarding digital output and digital input. The reason for this is that since the hardware of the digital input/output device itself is simple, equipping it with a diagnostic mechanism will lead to a decrease in reliability and an increase in cost. but,
Through comparison and verification in the present invention, the coverage range of plant diagnosis includes abnormalities in input/output devices, abnormalities in control terminals, abnormalities in sensors, etc., so even when an abnormality occurs in input/output devices, the operator can be confident that the abnormality has occurred. It becomes possible to make announcements while maintaining the information.

For example, as you can see from the configuration in Figure 2, the plant control bag Wlto is one of its multiple input/output devices.
Although signals are sent to the operating end of the plant 3 and answerbacks are taken in through predetermined input/output devices 14.15, even if any of the input/output devices t14.15 becomes abnormal, the comparator 7 Since the comparison results do not match, the comparison section 7 outputs an abnormality signal 8. Then, by issuing an alarm or lighting an alarm lamp or the like based on this abnormality signal 8, the occurrence of an abnormality can be detected.

In this way, this device has a plurality of input/output terminals, and connects the operating terminal of each controlled element of the target plant and the response signal input terminal of the controlled element to the required input/output terminal,
The control means generates a control output to the operating end of the controlled element via the required input/output terminal according to the control procedure of the plant, and upon receiving the response signal of the controlled element, the control means generates a control output of the next controlled element. In a plant control device configured to perform plant control by shifting control to an operating end, the operation of the plant is simulated in response to a control output of the control means, and a response signal of the same type as when the plant responds is provided. a simulation means that receives a response signal of the simulation means and a response signal of the controlled plant, compares both response signals and generates an abnormal signal when they do not match, and a verification mode and a plant control In the verification mode, the response signal from the simulation means is given to the control means, and in the plant control/monitor mode, one of the input/output terminals is used for inputting the response signal of the controlled element. and switching means for applying a response signal of the plant obtained from a terminal of the control means to the control means.

In such a configuration, the simulation means receives the control output of the control means, simulates the operation of the plant, and generates a response signal of the same type as when the plant responds, and in the verification mode, the switching means Since the response signal of the simulation means is given to the control means, during verification in the factory, the control operation of the device can be verified simply by setting the switching means to verification mode, and by setting the switching means to plant control/monitor mode, The switching means outputs the control output of the control means to the simulation means and the plant, inputs the respective response results to the comparison means, and manually inputs the response signal of the plant to the control means. When it receives both response signals, it checks whether they match or do not match, and when they do not match, it operates to generate an abnormal signal.

Therefore, if the switching means is set to the verification mode, the operation of the control means can be confirmed based on the response results from the simulation means, and if the switching means is set to the plant control/monitoring mode, the simulation means can be used while controlling the plant. It is possible to carry out simulations by
It is possible to monitor abnormalities by comparing the response results of both.

Therefore, with this device, the simulator function for verification during manufacturing can be used for diagnosing abnormalities in the plant after installation in the actual plant. The simulator function can be effectively utilized.

It should be noted that the present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope without changing the gist thereof.

〔Effect of the invention〕

As explained above, according to the present invention, the simulator function for verification during manufacturing can be used for diagnosing plant abnormalities after installation in an actual plant, and furthermore, it is possible to constantly monitor abnormalities. Therefore, it is possible to provide a plant control device that can also improve reliability.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a system block diagram showing a more specific embodiment of the invention, and Figs. 3 and 4 are control diagrams for explaining a conventional example. FIG. 2 is a block diagram showing an example of the configuration of the system. 1... Plant control section, 2... Simulation section, 3
...Plant, 4.Control signal, 5.Plant answerback signal, 6.Simulation section/answerback signal, 7.Comparison section, 8.Abnormal signal, lO. ...Plant control device, 11... Limit switch, 13... On/off valve, 14.15... Input/output device. Figure No. ■ 11411

Claims (1)

[Scope of Claims] The control means has a plurality of input/output terminals, and connects the operating terminal of each controlled element of the target plant and the response signal input terminal of the controlled element to the required input/output terminal. generates a control output to the operating end of the controlled element via the required input/output terminal according to the control procedure of the plant;
In a plant control device, the control means performs plant control by shifting to control of the operating end of the next controlled element upon receiving a response signal of the controlled element, wherein the control means receives a control output of the control means, and controls the operation end of the next controlled element. a simulation means for simulating the operation of the plant and generating a response signal of the same type as when the plant responds; and receiving a response signal from the simulation means and a response signal from the plant to be controlled, and comparing both response signals. and a verification mode and a plant control/monitoring mode, and when in the verification mode, a response signal from the simulation means is given to the control means, and a plant control/monitoring mode is provided. A plant control device comprising switching means for supplying a response signal of the plant obtained from a terminal for inputting a response signal of a controlled element among the input/output terminals to the control means when in the mode.