JPH0764603A - Process control equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a process control device capable of performing an optimum manual operation according to the characteristics of a process different for each control loop. In a process control device that monitors a plurality of control loops under the control of the CPU 1 using a CRT display 4, a manual operation speed corresponding to the characteristics of each process is set for each control loop. It is set and stored in the table memory 2, and during manual operation, the operation amount is changed at a speed unique to each control group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process control device for monitoring a plurality of control loops by using display means such as one or a plurality of CRT displays.

[0002]

2. Description of the Related Art Generally, in a process control device, an operator may manually increase or decrease an operation amount. In this type of process control device, the manual operation speed of the operation amount should be originally determined from the following viewpoint. Ease of operation by the operator.

The operation amount (valve opening) is set to a speed at which a desired amount (speed) can be easily set. If it is too slow, the operation will take time, and if it is too fast, the desired amount will be exceeded. Process characteristics (responsiveness). The speed of the response of the control valve to the change of the manipulated variable and the responsiveness of the process amount to the change of the control valve are matched.

Conventionally, although the above is considered, even if there are a plurality of control loops, the manual operation speed of the operation amount is
It was the same for all control loops of the controller.

[0005]

From the viewpoint of the manual operation of manually operating the operation amount (valve opening degree) to set the process amount to a desired amount, the above viewpoints are important. . In manual operation, the amount of operation is increased / decreased (open / close of the valve opening) while watching the process amount. For example, if the manual operation speed is fast for processes with a slow response speed, the amount of operation will be too much. Causes an overshoot of the process amount. Since the characteristics of this process are different for each control loop, the manual operation speed needs to be different for each control loop. However, since the conventional process control device has the same manual operation speed in all control loops, even if the above-mentioned requirements can be satisfied, the above-mentioned requirements cannot be satisfied. Therefore, for example, for a process with a slow response speed, there is a problem that an overshoot of the process amount occurs, and as a countermeasure against this, inching operation, that is, the operation amount is not changed continuously. ,
I also take the method of doing this in small increments,
Even with this method, if the response speed of the process is different for each control loop, the inching operation cycle is different for each control loop, and there is a problem that manual operation is complicated and difficult.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a process control device capable of performing an optimum manual operation according to the characteristics of different processes for each control loop. There is.

[0007]

The process control device of the present invention has a display means for monitoring a plurality of control loops each having a manual operation means for adjusting the manipulated variable, wherein each control loop is provided. A manual speed setting means for setting the speed of the manual operation by the manual operation means is provided, and the operation amount is changed at a specific speed for each control loop.

In this process control device, when the manual operation means of a control loop is operated, the operation amount is changed at a speed set corresponding to the control loop.
Therefore, even when the operation amount of any control loop is manually adjusted, it can always be appropriately performed according to the characteristics of the process.

[0009]

The present invention will be described in more detail with reference to the following examples. FIG. 1 is a block diagram showing a schematic configuration of a digital distributed process control apparatus showing an embodiment of the present invention. This process control device uses C for supervisory control.
PU1, a manual operation speed table memory 2 for storing a manual operation speed for each control loop, an input unit 3 for setting and inputting a control loop No. and speed to the manual operation speed table memory 2, and a CRT for monitoring It is composed of a display 4 and an arithmetic control unit 5. C
There may be a plurality of RT displays 4. Each control loop is provided with a key button for increasing / decreasing the operation amount. Since the processes of each control loop have different responsiveness, the change in the manipulated variable when performing a manual operation, that is, the manual operation speed is preset for each control loop and stored in the manual operation speed table memory 2. There is. The storage mode is as shown in FIG. The set speeds t ₁ , ..., T _m , ... are set according to the characteristics of the process. For example, for a process having a fast response speed, it is fast (however, the operator's operation causes an excessive amount of operation. Limit so that it does not occur), and set slower for slow ones. As for the setting method, first, the speed is determined in accordance with the characteristics (responsiveness) of the process, and then the limit (upper limit) is added to the speed for ease of operation by the operator. Although various units can be considered at this time, here, (second / Fs) [the time when the manipulated variable changes to full scale (from 0% to 100%)] is taken as an example, and this value is t (t _{, 1} , ..., T _m , ...).

The CRT display 4 displays the loop name, process amount (PV), set value (S) of each control loop.
V), manipulated variable (MV), and loop status are displayed. Further, the arithmetic control unit 5 corresponds to each control loop,
Performs arithmetic control operation. Next, in the apparatus of the above embodiment,
The operation when a certain control loop is manually operated will be described with reference to the flowchart shown in FIG. Since the apparatus of the embodiment is a digital controller of fixed cycle operation, the change interval of the operation amount is set to "τ" (second).

When a manual operation is performed in the control loop 5- _m , this is taken in (step ST1), and the set speed t _m corresponding to the control loop Nom is loaded from the manual operation speed table memory 2 (step ST2). .
Then, the operation amount change amount per one time (one cycle) “Δm
v ″ = τ / t _m × 100 (%) is calculated (step S
T3). This Δmv is also unique to each control loop m because the manual operation speed t _m differs for each control loop.

Next, it is determined whether the manual operation is to increase or decrease the operation amount (step ST4). If the operation amount is increased, the sign of Δvm is positive (step ST5), If the manipulated variable decreases, the sign of Δvm is made negative (step ST6), and ΔMV _m is added to the previous (one cycle before) manipulated variable output “MV _m , _n−1 ” to output this manipulated variable. "MV _m , _n " is calculated (step ST
7). Finally, the manipulated variable "MV _m , _n " is output (step ST8).

As described above, the optimum manual operation (continuous operation) speed according to the characteristics of the process is realized for each control loop. Although the above embodiment has described the distributed control system in which a single control device monitors and operates a large number of control loops, the present invention is not limited to this, and is not limited to the control of one control loop. It is also applicable and effective when monitoring and operating a plurality of control loops by using a plurality of used one-loop controls.

[0014]

According to the present invention, for each control loop,
Manual operation speed setting means for setting the speed of manual operation by the manual operation means is provided, and the operation amount is changed at a speed unique to each control loop. , It is possible to slow down the speed of manual operation and prevent overshoot of the process amount. Further, the inching operation is unnecessary, and the manual operation can be easily performed. For those with fast process response speed, the speed of manual operation can be increased, and quick manual operation can be performed. Therefore, the optimum manual operation can always be performed according to the characteristics of the process.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a digital distributed process control device showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a data storage area of a manual operation speed table memory of the process control apparatus of the embodiment.

FIG. 3 is a flowchart for explaining an operation at the time of manual operation of the process control device of the embodiment.

[Explanation of symbols]

1 CPU 2 Manual operation speed table memory 3 Input section 4 CRT display

Claims (1)

[Claims] 1. A process control apparatus having a display means for monitoring a plurality of control loops each having a manual operation means for adjusting an operation amount, wherein a speed of manual operation by the manual operation means is set for each control loop. A process control device comprising a manual speed setting means for changing the operation amount at a specific speed for each control loop.