JPH04102901A - Controller - Google Patents

Abstract

PURPOSE:To effectively maintain control characteristic even if characteristic variation is generated in a process by providing this controller with a differential output variation computing part for computing variation in the operation result of a differential operation part and an integrating operation regulating means for regulating the integrating operation value of an integrating operation part based upon the computed result of the differential output variation computing part. CONSTITUTION:The controller is provided with the differential output variation comput ing part 6 for computing variation in the operation result of the differential operation part 4 and the integrating operation regulating means 7 for regulating the operation value of the integrting operation part 3 based upon the computed result of the comput ing part 6. The computing part 6 inputs a differential operation result (D) and finds out its variation DELTA(D) by differential operation and the regulating means 7 regulates the integration value DELTA(I) outputted from the operation part 3 in accordance with variation DELTA(D) outputted from the computing part 6. Consequently, the influence of mismatching of parameters can be reduced, the tuning of the parameters can easily be executed, and even when characteristic variation is generated in a process, its control characteristics can be effectively maintained.

Description

[Detailed Description of the Invention] <Industry> 2 Field of Application The present invention relates to a controller suitable for controlling the temperature of electric furnaces, etc., and more specifically, the present invention relates to a controller suitable for controlling the temperature of electric furnaces and the like. This invention relates to a controller that has improved adaptability to changes in characteristics and changes in the controller's calculation parameters.

<Conventional technology> FIG. 8 shows the configuration of a conventionally known controller.

The deviation D V between the process amount PV and the target set value SP is applied to the proportional calculation section 11 and the integral calculation section 12, and the process amount Pv is also applied to the differential calculation section 13, The output calculation unit 14 adds the signals from the
An operation signal MV is obtained and outputted to an operation end such as a valve.

Now, when dealing with the variable range of the target set value SP as 0 to 100%, the reception range of the corresponding process quantity as 0 to 100%, and the operation range of the control manipulated variable (operation signal) MV as 0 to 100%. , transmission from the proportional calculation unit 11 to the operation signal MV;
10UT1 is as shown in equation (1).

0UT1= (SP-PV)* (100/PB)%・
...(1) However, PB is the proportional band constant in formula (1). For example, if PB = 10%, (SP
-PV) becomes 10% or more, the control output becomes 100% or more, that is, becomes saturated.

The integral calculation unit 12 calculates 1 of (SP-PV)*(100/PB) every time corresponding to the integral time constant, corresponding to the deviation DV of (SP-PV) and the proportional band constant PB.
I'm going to pile up.

Here, the internal calculation value of the integral calculation unit 12 is 100%, 20%
Conventionally, an output drugging method has been used as a method for preventing overintegration states such as 0% and 300%.

For example, this method transmits CV-11,0-((P)-1-('D)) to the integral calculation unit 12 for +(P)+(D))>=110%. , (I) = specifies the execution of CV.

Note that (P), (1), and (D) are proportional here.

This is the calculation output of the integral and differential calculation section.

<Problems to be Solved by the Invention> FIG. 9 is a diagram showing the difference in settling characteristics when some of the parameters of the controller are changed in a conventional device with the process characteristics fixed.

Based on the characteristics of (c), ((1), (b).

(a) shows the trends of the process amount Pv, operation signal (MV), and integral output (I) when the integral time (TI) in the parameter is increased by 2 times, 0.5 times, and 0.25 times, respectively. (a>) shows a tendency to oscillate with large overshoot, and (d) shows a tendency to have little overshoot but take time to settle.

FIG. 10 is a diagram showing the difference in settling time when the influence of parameter changes continued from FIGS. 9(a) to 9(d) was investigated.

In <a), in addition to the conditions shown in FIG. 9(a), the differential time is also multiplied by 0.5, indicating that the vibration tends to persist. 9(b) is based on the characteristic shown in FIG. 9(a), and the integration time is set to 0.125 times the standard shown in FIG. 9(c).

Figure 11 shows that the proportional band is 2 for the standard in Figure 9(c).
This shows the characteristics when doubled.

Here, each characteristic when a small change in the set value SP is given is shown.

Based on these various characteristics, according to the conventional device, the amount of overshoot at the time of rise varies depending on the difference in parameters, as shown in FIG. 11 for the standard of FIG. 9(C) and FIG. 9(b). This situation also occurs due to variations in process characteristics with fixed parameters.

This means that the characteristics of the process change, for example, due to changes in the physical quantities to be processed in the heat treatment furnace.

The present invention has been made in view of these points, and its purpose is to reduce the effects of parameter mismatch, facilitate parameter tuning, and maintain good control characteristics even when process characteristics vary. The aim is to realize a highly adaptable controller.

Means to solve problems〉 In order to solve the above problems, the present invention has the following features: Input the target set value and process amount and perform proportional calculation.

A controller that performs integral calculations and differential calculations and outputs a control operation amount to a process, comprising: a differential output change calculation unit that calculates the amount of change in the differential calculation result from the differential calculation unit; and an integral calculation unit that calculates the amount of change in the differential calculation result from the differential calculation unit. and integral calculation regulating means for regulating the amount based on the calculation result of the differential output change calculation section.

Effect> The differential output change amount calculating section receives the differential calculation result (D), performs a differential calculation on this, and obtains the change amount Δ(D).

The integral calculation regulating means is the product of output quantities from the integral calculation section.
The amount Δ(1) is regulated according to the change amount output Δ(D>) from the differential output change amount calculating section.

Further, when the amount of change Δ(D) is less than a certain level, the restriction on the output from the integral calculation section and the product 1Δ(1) is relaxed or lifted.

<Embodiment> FIG. 1 is a configuration block diagram showing an embodiment of a controller according to the present invention.

In Fig. 1, 1 is the input of the target setting [SP and the process amount P V from process 2, and the deviation D between the two is input.
A difference calculation circuit 2 which calculates V is a proportional calculation section which inputs the deviation signal DV and performs a proportional calculation, and outputs a proportional calculation result (P). Reference numeral 3 denotes an integral calculation unit which inputs the deviation signal DV and performs an integral calculation, and outputs an integral calculation result (I). 4 is the process amount P
A differential calculation section receives input and performs differential calculation, and outputs the differential calculation result (D). Reference numeral 5 denotes an output calculation unit that adds the calculation results from each calculation unit 2, 3.4, and outputs an operation signal MV for controlling an operation end such as a valve.

6 is the amount of change Δ of the differential calculation result (D) from the differential calculation unit 4
(D), a differential output change calculation unit 7 calculates the integral calculation amount (I) from the integral calculation unit 3, and a differential output change calculation unit 7
This integral calculation regulation means can change the regulation based on the calculation result Δ(D).

FIG. 2 is a block diagram showing the internal configuration of the integral calculation regulating means 7. As shown in FIG. Calculation result Δ from differential output change calculation section 6
Limiting circuit 7 that limits the output level L V according to (D)
1, and the coefficient K (-〇~1) according to the amount of differential operation (J))
．． 0).

FIG. 3 is a characteristic diagram set in the limiting circuit 71. If the calculation result Δ(D) from the differential output change amount calculation section 6 is small, the output level L V is limited so as not to exceed a predetermined value. As a result, the cumulative amount Δ(I) of the integral calculation amount is regulated within a predetermined range of the change Δ(D) in the differential calculation amount (effect ■)
.

When the amount of change Δ(D) is below a certain level, the restriction on the amount Δ(I) of the integral calculation amount is relaxed or lifted (action ①).

FIG. 4 is a characteristic diagram of the coefficient multiplication means 72.

As the amount of differential operation (D) increases, the coefficient K or 1
．． The coefficient gradually decreases from 0, and the coefficient K becomes 0 when (D) reaches 100%. As a result, the product 1Δ(1) of the integral calculation 1 is multiplied by a small/large coefficient K depending on the magnitude of the differential calculation amount (D) (action ■).

The operation of the apparatus configured in this way will be explained next.

The proportional calculation unit 2 performs a proportional calculation on the deviation signal DV of the process amount P■ and the set value Sl), and outputs the calculation result (P
) is output to the output calculation section 5.

The integral calculation unit 3 performs an integral calculation on the deviation signal DV and outputs the calculation result (I) to the output calculation unit 5 via the integral calculation regulation means 7.

The differential calculation section 4 performs a differential calculation on the process amount P■, and outputs the calculation result (D) to the output calculation section 5 as well as to the differential output change amount calculation section 6.

The integral calculation regulating means 7 restricts the integral calculation amount <1> based on the calculation result Δ(■)) from the differential output change amount calculating section 6. Also, based on the differential calculation result (D>,
], O to O are multiplied by a coefficient K and output to the output calculation section 5.

FIG. 5 is a diagram showing control characteristics when the present invention is applied.

(a) is a characteristic diagram similar to FIG. 9(a), and by applying the present invention, the tracking point of the integral operation amount (I) at the time of operation and saturation limited to - of tMV is lowered. There is. By lowering the tracking point l~ of the integral calculation amount (I), it is possible to increase the cumulative amount of the integral calculation amount (I).

Here, (b) is a characteristic showing the effect of the above-mentioned effects ■, ■, ■, (c) is a characteristic showing the effect of the above-mentioned effects ■, ■, and (d) is a characteristic showing the effect of the above-mentioned effect ■. This is a characteristic that shows the effect of

As is clear from the comparison of these characteristics, in (a), the integral calculation result (]) rises faster than the rise of the differential calculation result (D).

In the characteristic (c), due to the effect of regulating the level LV of the accumulation amount Δ■, the integral calculation result (1) is vertical -1, 0 in the range of speeds of the differential calculation result (I)) from vertical to vertical. - It's going up.

In the characteristic (d), due to the effect of multiplying by the coefficient K, the integral calculation result (I) is suppressed according to the differential calculation result (D).

As is clear from each of these characteristics, by applying the present invention, the process, i! : Excessive accumulation of integral calculation results (1) can be effectively suppressed at a stage before PV settles toward the set value SP.

<Effect of the invention> Figure 6 shows the process amount P when the present invention is applied.
FIG. 3 is a diagram showing the rise characteristics of v. FIG. Figure 9(a)-(
As is clear from the comparison with the characteristics of the conventional device shown in d), it can be seen that the effects of parameter changes are alleviated by application of the present invention.

FIG. 7 is a diagram showing each rise characteristic in the case of mismatch parameters when the present invention is applied. Here, (a) and (b) are cases where the present invention is applied, and (
c) and (d) are cases where the present invention is not applied.

= 11- In the conventional device, the integral calculation result (I) rises quickly, so by applying the present invention, appropriate intervention is performed on the integral calculation result (I), and the influence of parameter mismatch is eliminated. It has been recognized that this has been reduced.

As described in detail above, according to the present invention, it is possible to easily tune parameters, maintain good control characteristics even when process characteristics vary, and realize a highly adaptable controller.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the controller according to the present invention, FIG. 2 is a block diagram showing the internal structure of the integral calculation regulating means, and FIGS. 3 and 4 are diagrams showing the internal structure of the integral calculation regulating means. A diagram showing each characteristic, FIG. 5 is a diagram showing the control characteristics when the present invention is applied, FIG. 6 is a diagram showing the rise characteristics of the process amount P■ when the present invention is applied, and FIG.
The figure is a diagram showing each rise characteristic in the case of mismatched parameters when the present invention is applied, Figure 8 is a configuration diagram of a conventionally known controller, and Figure 9 is a conventional device with fixed process characteristics. Figure 10 is a diagram showing the difference in settling characteristics when some of the parameters of the controller are changed. Diagram showing the difference, Figure 11 is Figure 9(c)
FIG. 2 is a diagram showing the characteristics when the proportional band is doubled with respect to the standard. DESCRIPTION OF SYMBOLS 1... Difference calculation circuit, 2... Proportional calculation part, 3... Integral calculation part, 4... Differential calculation part, 5... Output calculation part, 6... Differential output change amount calculation part , 7... Integral calculation regulation means, O (D) R (D) * No. TL=lD L/7=, //q04B FB='/,
, 3”15 (CL) (b) 7T
=TT, 'i, 25 7T=rrt,, 5m Diagram T = 70 TD= 2.5 (C) (
d) Choshi = Cho 1181 T
T=TI*Z 7 TL= 5 L/T= , 0JAA3 FB
=Otsu8β((1) (b)TI=
TI no, 25 7””L=Trg, 5 □ Chim diagram TT2S 7D2 1.25 (C) (d) Tr=TLg, 25 TI=TIi, 5th 9th TL2/(J L/r= , n'?048Pβ=9
．． 375 ((L)
' (b) 7T=TTX, Z, S-Tr=Triangle, 5
Figure TI=/D TD=2.5 (C) (d) TI=74X/H=-Hz;z le 1O TL=10 L/T=,/IqO481'B=9. ,
:F74 ((L) rr, =rx*, zs TD2TD tree, 5 5 TI= IQ TD= Z,, 5(I)) TT=TTX, IZ5 →-mu□L

Claims (3)

[Claims] (1) Input the target set value and process amount, perform proportional calculation,
A controller that performs integral calculations and differential calculations and outputs a control operation amount to a process, comprising: a differential output change calculation unit that calculates the amount of change in the differential calculation result from the differential calculation unit; and an integral calculation unit that calculates the amount of change in the differential calculation result from the differential calculation unit. 1. A controller comprising: integral calculation regulating means for regulating the amount based on the calculation result of the differential output change calculation section. (2) The controller according to claim 1, wherein the integral calculation restriction means releases or relaxes restrictions on the integral calculation amount within a predetermined range of the amount of change in the differential calculation result. (3) The controller according to claim 1, wherein the integral calculation regulating means includes coefficient multiplication means for suppressing the amount of integral calculation based on the differential calculation result.