JPS60176104A - Process controller - Google Patents

Abstract

PURPOSE:To improve the tracking characteristic of the control when a large external disturbance takes place by quickening or slowing down a response to a device to be controlled in response to a magnitude of deviation through the operation of a multiplier so as to prevent the overshoot of the control. CONSTITUTION:If a deviation a-b is changed largely because of generation of an external disturbance, a value, e.g., a-b is multiplied to the deviation a-b by the multiplier 4 and the sensitivity becomes the unity with an operation signal c=K1(a-b), where K1=K(a-b). Through the operation above, when the deviation a-b is large, the input to a controller 3 is larger in comparison with a system without any multiplier 4, the response at the final control element is fast and the restoring operation of the final control element is quickened. Thus, the deviation of the signal (c) is made smaller than a conventional signal (c), the response of the final control element slows down and the overshoot of the control is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process control device that improves control followability when a large disturbance occurs.

2. Description of the Related Art Conventionally, there is a process control device configured as shown in FIG. That is, in FIG. 1, I is the set value a
This is a subtractor that calculates the deviation a - b between the measured value from the controlled device (, 76 runt). 2 is a sensitivity adjuster for adjusting the sensitivity of this deviation a-b. Reference numeral 3 denotes a controller which multiplies the deviation a-b outputted through the sensitivity adjuster 2 by a constant r-in and provides an operation signal C to the controlled device.

In the above configuration, for example, if a large disturbance does not act and the deviation a - b between the set value a and the measured value is small,
The operation signal C becomes C=K.(a-b), and the controlled device is controlled in a prescribed manner by this operation signal C. However, in the above configuration, r in, which is multiplied by the deviation, is constant (sensitivity 1) as shown in Fig. 2. For example, when a large disturbance occurs, the deviation a-b becomes large, and this Therefore, the controlled device may be over-controlled.

On the other hand, if the sensitivity is made high in order to cope with the above-mentioned large disturbance, hunting will occur during normal operation, which poses a problem.

The present invention has been made based on the above-mentioned circumstances, and an object thereof is to provide a process control device that improves control follow-up characteristics when a large disturbance occurs.

The process control device according to the present invention includes a subtracter that calculates the deviation between a measured value and a set value, a multiplier that multiplies the deviation from the subtracter by a multiplication amount based on the deviation, and a multiplier that calculates the deviation between the measured value and the set value. It consists of a sensitivity adjuster that adjusts the sensitivity with respect to the control dyne of the controller, and a controller that receives the output of the sensitivity adjuster and generates an operation signal to the controlled device. When the deviation becomes large, the response to the controlled device is made faster, and when the deviation becomes small, the response to the controlled device is delayed to prevent overcontrol. It is characterized by

The process control device according to the present invention will be explained below according to an embodiment shown in FIG. In FIG. 3, the same parts as those in FIG. 1 are given the same reference numerals, and the explanation thereof will be omitted, and only the newly added blocks will be explained here. That is, in this embodiment, a multiplier 4 for multiplying by a multiplication amount based on the deviation a-b is inserted between the signal lines of the subtracter 1 and the sensitivity adjuster 2 in FIG. As shown, C=1 (ab) and sensitivity 1, C=K.

(a-b), the sensitivity is 1/9, and C=3 (a-b), the sensitivity is 1/25.

Next, the operation of this embodiment configured as described above will be explained. In normal times, that is, when the deviation a-b does not change significantly, the multiplication amount of the multiplier 4 is 1, and therefore the operation signal C becomes C=Ko(&-b). , 1 In addition, when the deviation a-b changes greatly due to the occurrence of a large disturbance, the multiplier 4 changes the deviation a-b to (a-b
) is multiplied by the operation signal C = 1 (a b) where Kl
=K (a b ).

By performing the above-mentioned operations, for example, FIG.
), when the deviation (a-b) is large, the controller 3
The input is larger than that shown in FIG. 1, and the response at the operating end becomes faster (the operating end is pulled back faster), thereby causing the signal C of this embodiment shown in FIG. The deviation of the conventional signal C shown in FIG. 4(b) can also be reduced, and slow response of the operating end and excessive control can be prevented.

The present invention is not limited to the above-mentioned embodiments, but can be implemented with various modifications without departing from the gist of the present invention.

As described above, according to the present invention, there is provided a subtracter that calculates the deviation between the measured value and the set value, a multiplier that multiplies the deviation from the subtracter by a multiplication amount based on the deviation, and the multiplier that calculates the deviation between the measured value and the set value. It consists of a sensitivity adjuster that adjusts the sensitivity with respect to the control dyne from the multiplier, and a controller that receives the output of the sensitivity adjuster and generates an operation signal to the controlled device, and due to the action of the multiplier, When the above deviation becomes large, the response to the controlled device is made faster, and when the deviation becomes small, the response to the controlled device is slowed down to prevent excessive control. As a result, it is possible to provide a process control device that can improve control followability when, for example, a large disturbance occurs.

[Brief explanation of drawings]

FIG. 1 is a Zorock diagram showing a conventional process control device, FIG. 2 is a characteristic diagram showing the relationship between deviation and operation signal, and FIG. 3 is a block diagram showing an embodiment of the process control device according to the present invention. FIG. 4 is a characteristic diagram for explaining the operation of this embodiment. 1... Subtractor, 2... Sensitivity adjuster, 3... Controller, 4... Multiplier. Applicant’s sub-agent Patent attorney Takehiko Suzue□゛−

Claims (1)

[Claims] A subtracter that calculates the deviation between the measured value and the set value, a multiplier that multiplies the deviation from this subtracter by a multiplication amount based on the deviation, and a sensitivity to the control input from this multiplier. What is claimed is: 1. A process control device comprising: a sensitivity regulator that adjusts the sensitivity regulator; and a controller that receives the output of the sensitivity regulator and generates an operation signal to a controlled device.