JP2002236502A - Method and unit for process control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a unit for process control which can improve controllability. SOLUTION: Process control is for the process having the long dead time like a polymerization process and a manipulated variable by feedback control is corrected with a manipulated variable by feedforward control to perform the control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a process control method and a control device. More specifically, the present invention relates to a process control method and a control device that have improved controllability in a process having a large dead time, such as a continuous polymerization process in which a raw material made of a prepolymer is continuously polymerized.

[0002]

2. Description of the Related Art Conventionally, a control method in a polymerization process for polymerizing a prepolymer, which is a raw material of a chemical fiber, to have a desired viscosity, is mainly a batch control (sequence control). there were.
However, in recent years, a control system (hereinafter, referred to as a continuous polymerization system) for continuously polymerizing a prepolymer, which is a raw material, has been attracting attention instead of the batch control.

In such a continuous polymerization treatment system,
The liquid raw material is continuously supplied from an inlet of a reaction vessel called a reactor, and is allowed to flow in a piston flow over a predetermined time (for example, 20 minutes) toward a reactor outlet while a polymerization reaction proceeds. Is controlled to have a desired viscosity. This control usually involves controlling the amount of CTA (chain terminate acid), which is a polymerization terminator,
This is performed by feedback control that adjusts according to the deviation between the detected value (control amount) of the viscosity at the reactor outlet and the target viscosity (target value).

FIG. 12 shows an example of a control system for controlling the polymerization process.

The control system 100 controls the _{manipulated variable} F _CTA with respect to the amount of CTA mixed by the PI controller 101 so that the prepolymer viscosity V _inc ′ at the reactor outlet matches the set target viscosity X _Bset ′. .
In the control system 100, a load (operating amount), that is, a raw material prepolymer supply amount G is applied to a control target 104 represented by a first-order lag element 102 and a dead time element 103.
It is assumed that the change in _PP acts as a disturbance.

In such a control system 100, since the movement of the raw material in the reactor is a piston flow, until the V _inc value as the control amount changes in response to the change in the F _CTA value as the operation amount. A waste time L is generated which is almost equal to the time required for the raw material to move inside the reactor (about 20 minutes in the above example). Further, the dead time L is almost inversely proportional to the value of G _PP , so that the smaller the load G _{PP, the} longer the dead time L.

[0007] From the above, such a control system 100
, The load G _PP changes and the prepolymer viscosity V at the reactor outlet changes.
_The change in _inc causes a delay corresponding to the ^dead time element e- ^Ls , and the control operation is necessarily delayed.

As a result, when the load G _PP is large, that is, when the dead time L is short, the PI controller 1
When the control parameter of 01, that is, the proportional gain K _P and the integration time T _I are set, the system becomes unstable such that hunting occurs when the load G _PP decreases. In order to avoid this, when the control parameters of the PI controller 101 are set based on the load G _PP being small, that is, when the dead time L is long, the response becomes slow when the load G _PP becomes large, and the control accuracy becomes poor. There is a problem that it gets worse.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the prior art, and has a long dead time and a process control method capable of improving controllability in a process in which a large load variation occurs. And a control device.

[0010]

A first aspect of the process control method of the present invention is a process control method for a process having a large dead time, such as a polymerization process, wherein the operation amount by feedback control is controlled by feedforward control. The control is performed by correcting the amount of operation by the operation amount. That is, the first method of the process control method of the present invention
The mode is a process control method for a process having a large dead time, such as a polymerization process, and includes a feedback control procedure for outputting an operation amount for eliminating a deviation between a target value and a control amount, and an operation amount according to a load. And a correction procedure for correcting the operation amount obtained by the feedback control procedure with the operation amount obtained by the feedforward control procedure.

In the first embodiment of the process control method according to the present invention, it is preferable to compensate for the dead time by using the operation amount obtained by correcting the operation amount by the feedback control by the operation amount by the feedforward control.

Further, the first aspect of the process control method of the present invention includes a feedforward manipulated variable correction procedure, and the feedforward manipulated variable correction procedure is calculated based on the manipulated variable obtained by the feedback control procedure. It is preferable that the operation amount obtained by the feedforward control procedure is corrected by the operation amount correction amount. In that case, it is more preferable to hold the operation amount correction amount as necessary.

A second embodiment of the process control method according to the present invention comprises:
A process control method for a process having a large dead time, such as a polymerization process, wherein feedback control including at least a proportional operation is performed, and the proportional gain is adjusted according to a load.
That is, a second embodiment of the process control method of the present invention includes a proportional gain adjustment procedure, and the feedback control procedure performs at least a proportional operation, and the proportional gain adjustment procedure loads the gain of the proportional operation with a load. It is characterized in that it is adjusted according to

Further, in the process control method according to the present invention, the controlled object is approximated by a first-order lag element and a dead time element, and an operation amount obtained by the correction procedure based on a model approximating the controlled object. It is preferable to compensate for the dead time by using the correction amount obtained by the Smith method. In that case, it includes a dead time compensation gain correction procedure, and the feedback control procedure is assumed to execute at least a proportional operation, and the dead time compensation gain correction procedure includes:
More preferably, the gain of the proportional operation is adjusted based on the correction amount obtained by the Smith method.

A third embodiment of the process control method according to the present invention comprises:
A process control method for a process having a large dead time such as a polymerization process, the method comprising: outputting an operation amount for eliminating a deviation between a target value and a control amount; a feedback control procedure for executing at least a proportional operation; And a proportional gain adjustment procedure for adjusting the gain of the operation according to the load.

On the other hand, a first embodiment of the process control apparatus of the present invention is a process control apparatus for a process having a large dead time, such as a polymerization process, and is an operation amount for eliminating a deviation between a target value and a control amount. And a feed-forward control means for outputting an operation amount according to the load, wherein the operation amount obtained by the feedback control means is corrected by the operation amount obtained by the feed-forward control means. The control target is controlled by the operated amount of operation.

According to a first aspect of the process control apparatus of the present invention, there is provided a feedforward manipulated variable correcting means, and the feedforward manipulated variable correcting means determines the manipulated variable correction based on the manipulated variable obtained by the feedback control means. It is preferable that the manipulated variable generated and obtained by the feedforward control means is corrected by the manipulated variable correction quantity. In that case, the feedforward manipulated variable correction means
More preferably, the operation amount correction amount is held.

Further, in a first embodiment of the process control device of the present invention, the process control device has a proportional gain adjusting means, the feedback control means has a PI adjuster or a PID adjuster, and the proportional gain adjusting means corresponds to a load. Preferably, a proportional gain adjustment coefficient is generated, and the proportional gain of the PI adjuster or the PID adjuster is adjusted by the adjustment coefficient.

Further, the first aspect of the process control apparatus of the present invention is as follows.
In an embodiment, it is preferable that a dead time compensating unit is provided, the dead time compensating unit generates a correction value by a Smith compensation method based on the corrected operation amount, and the deviation is corrected by the correction value.

Further, the first aspect of the process control apparatus of the present invention is as follows.
In the embodiment, a dead time compensation gain correction unit is provided,
And the feedback control means is a PI controller or a PID
A dead time compensation gain correction means for generating a proportional gain adjustment coefficient based on the correction value from the dead time compensation means, wherein the proportional gain of the PI adjuster or the PID adjuster is adjusted by the adjustment coefficient Is preferably adjusted by the following formula.

A second embodiment of the process control device of the present invention is as follows.
A process control device for a process having a large dead time such as a polymerization process, wherein the feedback control means includes a PI controller or a PID controller, and outputs a manipulated variable for eliminating a deviation between a target value and a control variable. ,
A proportional gain adjusting means for adjusting a proportional gain of the PI adjuster or the PID adjuster according to a load.

[0022]

Since the present invention is configured as described above, even in a process having a large dead time, such as a polymerization process, the manipulated variable can be changed immediately in response to a change in load.
Further, since the control parameters of the feedback control means are automatically adjusted according to the fluctuation of the load, highly accurate control can be realized.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments with reference to the attached drawings, but the present invention is not limited to only such embodiments.

Embodiment 1 FIG. 1 shows a schematic configuration of a control device for implementing a process control method according to Embodiment 1 of the present invention.

The control device A is a control device for controlling a polymerization process in which, for example, a prepolymer as a raw material of a chemical fiber (hereinafter, referred to as a raw material prepolymer) is polymerized until a desired viscosity is obtained. Is a polymerization apparatus B
The amount of the polymerization terminator CTA (chain terminate acid) mixed into the raw material prepolymer in FIG.
By adjusting by I control or PID control,
It controls the raw material prepolymer to have a desired viscosity. That is, the polymer has a desired viscosity.

FIG. 2 schematically shows a polymerization apparatus to which the control device A is applied. The polymerization apparatus B includes a tank 81 for injecting a raw material prepolymer and a polymerization terminator CTA, and a reactor 82 as a reaction vessel.

The injection tank 81 has an inlet 83 for the raw material prepolymer and an inlet 84 for the CTA. The raw material prepolymer and CTA charged into the inside of the tank 81 via the charging ports 83 and 84 are supplied to the reactor inlet by the screw type fluid conveyor 85 in a relatively short time (for example, 20 to 30 seconds). It is fed into the reactor 82 via 86.

The raw material prepolymer fed into the reactor 82 in this way takes a predetermined time (for example, about 20 minutes, referred to as a reactor passage time) while the polymerization reaction is proceeding, and is subjected to a piston flow by the fluid conveyor 88. To the reactor outlet 87.

The reactor outlet 87 is provided with a viscosity detector 89 for detecting the viscosity of the polymerized prepolymer, that is, the polymer. A predetermined process such as a noise removal process is performed on the output of the detector 89. The control is executed and output to the control device A as the detected viscosity value V _inc .

The dynamic characteristic (hereinafter referred to as plant characteristic) of such a polymerization process in the polymerization apparatus B is a control object model (hereinafter simply referred to as a plant element) including a first-order lag element 1 and a dead time element 2 substantially corresponding to the predetermined time. , Called a controlled object)
It is possible to approximate with M. In order to control the polymer viscosity with high accuracy in the polymerization apparatus B having such a large dead time (about 20 minutes in the above example) in the plant characteristic, the control apparatus A has the following configuration.

That is, the control device A performs the proportional operation and
Viscosity detection value V by integration operation_inc(Control amount) is the target viscosity
X_BsetThe manipulated variable (signal
No.) F_CTAOutput PI controller (feedback
Control means) 10, load (operating amount),
The effect of fluctuations in the supply amount of the polymer is the viscosity detection value V
_incManipulated variable F so that it does not appear in_CTATo correct forward
Output the feedforward manipulated variable (signal) a of
And a feedforward control means 20.
You.

The PI controller 10 has control parameters
Proportional gain K as_PAnd integration time T_IIs adjustable
For example, K set in advance based on a low load condition_PValue
And T_IAccording to the value, the viscosity detection signal value (control amount) V
_incViscosity value V while referring to _incTarget viscosity with
X_BsetManipulated variable F such that_CTAIs output.

The feed-forward control means 20 controls the feed
The set value of the prepolymer supply amount (hereinafter, the set prepolymer
G)_PPsetOptimum amount of operation according to changes in
Give in advance in the form of tables, formulas and graphs
G according to the feedforward gain
_PPsetOutput feedforward manipulated variable a according to value
You. The feedforward manipulated variable a is calculated by the PI
Output signal F of the controller 10 _CTAIs added to This
The operation amount F obtained by the PI controller 10._{C TA}
Is the operation obtained by the feedforward control means 20.
Corrected operation amount F that is corrected by working amount a_CTA´ is obtained
You.

Thus, in the control device A having such a configuration, the load, that is, the set prepolymer supply amount G _PPset
At the time when the supply amount of the raw material prepolymer supplied to the reactor 82 via the prepolymer pretreatment plant C (hereinafter, referred to as the actual prepolymer supply amount) G _PP changes, the viscosity detection value due to this change Since the manipulated variable a that cancels the influence on V _inc is applied to the control target M, even when the load fluctuates on the control target M having a large ^dead time element e- ^Ls , the fluctuation of the viscosity detection value V _inc Can be suppressed, and controllability can be improved.

The feedforward gain in the feedforward control means 20 is approximately a constant K
It can be given as a _CTA . In this case, in the equilibrium state, the output signal value F _CTA of the PI controller 10 becomes a signal value for compensating the approximation error, and such a compensation operation is performed by the integration operation of the PI controller 10.

The load referred to by the feedforward control means 20 for generating the feedforward manipulated _variable a may be the actual prepolymer supply amount G _PP instead of the set prepolymer supply amount G _PPset. . In this case, the correspondence between the G _PP value and the a value is set in the feedforward control means 20 in advance.

Embodiment 2 FIG. 3 shows a schematic configuration of a control device that executes a process control method according to Embodiment 2 of the present invention.

The control device A1 is a modification of the control device A of the first embodiment. The control device A1 controls the feedforward operation amount a output from the feedforward control means 20 as follows.
The feedforward manipulated variable correcting means 30 for correcting based on the feedback manipulated _variable F _CTA is provided in addition to the control device A.

Feedforward manipulated variable correction means 30
When the feedforward gain of the feedforward control means 20 is given, for example, as a constant K _CTA , the integrator corrects an excess or deficiency of the feedforward manipulated variable a by an integration operation. The gain K ₁ of the integration operation is set to occupy performed several times slower than the response of the entire control system of the modification operation.

The feedforward manipulated variable correcting means 30 receives an ON / OFF signal X for turning the operation on and off. When the operation is instructed to be turned off by the signal X, the output of the feedforward manipulated variable correcting means 30 always takes the value 0, and the control device A1 operates in the same manner as the control device A of the first embodiment. On the other hand, when the operation is instructed by the ON / OFF signal X in a state where the system is in an equilibrium state and the steady-state error due to the approximation error remains, an output signal of the feedforward manipulated variable correcting means 30 (hereinafter referred to as feed The absolute value of c (referred to as the forward correction amount) gradually increases, whereby the viscosity detection value V _inc changes and the absolute value of the feedback manipulated variable F _CTA gradually decreases. Eventually, the F _CTA value becomes the value 0, and the c value becomes equal to the F _CTA value at the start of the operation, and becomes stable.

When the operation of the feedforward manipulated variable correcting means 30 is turned off by the ON / OFF signal X when the feedforward corrected quantity c is stabilized, the feedforward manipulated variable modifying means 30 holds the output value c at that time. I do.

Thus, for example, even when the polymerization apparatus B is temporarily stopped and the power supply of the control apparatus A1 is turned off, the output value c of the feedforward manipulated variable correction means 30 is retained, thereby restarting the operation. PI at time
The excess or deficiency of the output value b of the controller 10 can be compensated for by the output value c of the feedforward manipulated variable correction unit 30, and a better result can be obtained in obtaining a static balance of the system.

Note that, instead of the above-described configuration in which the feedforward operation amount a is corrected by the feedforward correction amount c, a configuration in which K _CTA is changed by the c value may be of course possible.

Also, as in the first embodiment, the feedforward control means 20 can refer to the actual prepolymer supply amount G _PP as a load.

Third Embodiment FIG. 4 shows a schematic configuration of a control device for performing a process control method according to a third embodiment of the present invention.

The control device A2 is the same as the control device A of the first embodiment.
The feedforward control means 20 is abolished, and the proportional gain adjustment means 40 for adjusting the proportional gain K _P of the PI controller 10 is provided. Correspondingly, the proportional gain K _P is automatically adjusted, thereby improving the stability of the system.

That is, in the control object M, the load,
That is, the set prepolymer supply amount G _PPset(Or real
Prepolymer supply amount G_PP) Decreases when wasted time
Element e^-LsBecomes larger. In this case, keep the stability of the system
In order to control the PI controller 10,
Proportional gain K_PNeeds to be adjusted smaller. Control device
In A2, such adjustment is performed by a proportional gain adjusting means.
40 is given, for example, in the form of graphs, formulas and tables.
A gain adjustment coefficient d is generated according to the load,
Proportional gain K_PCan be configured to adjust
To automatically perform proportional gain adjustment.
I have.

That is, the proportional gain adjusting means 40
From the characteristic curve, the load, G _PPsetValue or G_PP
Automatically generates gain adjustment coefficient d based on value
It is said.

FIG. 5 shows an example of a characteristic curve representing the relationship between the gain adjustment coefficient d and the load applied to the proportional gain adjustment means 40.

However, in the control device A2 of the third embodiment having such a configuration, the proportional gain K _P is adjusted according to the load, so that the stability of the system is substantially constant regardless of whether the load is large or small. As a result, it is possible to reduce the deviation caused by disturbance.

As described above, the control devices A and A1 of the first and second embodiments are intended to suppress the deviation at the time of a load change mainly by emphasizing a static balance. In contrast, the control device A of the third embodiment
No. 2 has an advantage in preventing the system from becoming unstable when the load decreases and the dead time L increases.

Embodiment 4 FIG. 6 shows a schematic configuration of a control device for implementing a process control method according to Embodiment 4 of the present invention.

The control device A3 is the same as the control device A of the first embodiment.
And the feedback manipulated variable F
Correction value F _CTA ′ based on _CTA feedforward manipulated variable a
For example, a dead time compensating means 50 for performing the dead time compensation by the Smith method using the above method is added to the control device A.

In the Smith method, the system is configured such that the dead time is apparently eliminated from the control target by outputting the dead time outside the control loop. Embodiment 4
In the control device A3, the compensation by the Smith method is performed by the feedforward operation amount a and the feedback operation amount F.
_This is performed on the output signal F _CTA ′ of the adder p for adding _CTA . That is, F _CTA ′ of the adder p is input to the dead time compensating means 50, and the output signal value f is X
_The value is subtracted from the added value of the _Bset value and the V _inc value and input to the PI controller 10.

With this configuration, the control device A3 can suppress the change in the viscosity detection value V _inc even when the load largely changes and improve the responsiveness by the synergistic effect of the feed forward control and the dead time compensation. So you can
Controllability can be greatly improved.

In the control device A3, a dead time compensation gain correcting means 60 for correcting the proportional gain K _P of the PI controller 10 based on the output signal f of the dead time compensating means 50 is provided.

The dead time compensation gain correcting means 60 outputs a dead time compensation gain coefficient α which is given in advance in the form of an equation, a table, a graph, or the like, according to the output signal f of the dead time compensation means 50.

FIG. 7 shows an example of a characteristic curve representing the relationship between the dead time compensation gain coefficient α and the value of the output signal f of the dead time compensation means, which is given to the dead time compensation gain correcting means in advance.

This characteristic curve rises to the right when the output signal value f of the dead time compensating means 50 is large, that is, when the degree of dead time compensation is large, the influence of the dead time is small and the system is stable. Therefore, while the proportional gain K _P is set to a relatively large value and the control with emphasis on quick response is executed, when the output signal value f of the dead time compensating means 50 is small, that is, when the degree of the dead time compensation is small, the waste Since the influence of time is large, the control is performed with emphasis on stability by setting the proportional gain K _P to a small value.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 In order to show the effect of the first embodiment shown in FIG. 1, a mathematical model was created for each of the parts corresponding to the control object M and the pretreatment plant C, and the set prepolymer supply amount was set. G
_The results of a computer simulation of the behavior of the plant when the _PPset and the target viscosity _XBset were changed are shown.

FIG. _6A shows the target viscosity X _Bset (the unit of the vertical axis is pois), and FIG. 6B shows the load, here the prepolymer supply amount G _PPset (the reference supply amount Value 1
). That is, in this example, in the initial state (t
= 0), the load that had a value of 1 was sequentially changed to 0.6,
1, 1.4, 1 and stepwise, and 600
Minutes later, the manipulated _variable F when the target viscosity X _Bset is changed
_{Changes in the CTA} (FIG. (C)), the CTA concentration X _aden (FIG. (D)) and the control amount Vi _SC (FIG. (E)) at the reactor inlet are shown.

The manipulated variable F _CTA changes simultaneously with the change in the load (set prepolymer supply amount) G _PPset , and as a result, C
The TA concentration X _aden also changes at the same time as the load changes. As a result, the viscosity change _Visc appearing after 20 minutes was obtained without the feedforward control means 20 of FIG. 1 (corresponding to FIG. 11).
It turns out that it is much smaller.

Further, the control amount _ViSC is _{calculated by changing} the load (set prepolymer supply amount) G _PPset from the value 1 in the initial state to the value 0.7.
After a lapse of the dead time L from the time when the step change to 5 is performed,
It fluctuates once, but then returns to the specified value.

Example 2 FIG. 9 shows a simulation result of Embodiment 3 shown in FIG.

FIG. 14 is a view similar to FIG.
, The change amount of the control amount _ViSC is the same, but the convergence to the steady-state value is fast, and hunting is hardly observed.
In addition, the _ability to follow the change in the target viscosity X _Bset is fast.

Embodiment 3 FIG. 10 shows a simulation result in the case of Embodiment 4 shown in FIG.

This figure is also similar to FIG.
It can be seen that the fluctuation range is further smaller than that of No. 2 and that there is almost no hunting, and a good control result can be obtained.

Example 4 FIG. 11 shows a simulation result in the case of Embodiment 2 shown in FIG.

It can be seen from the simulation that the change in _Visc decreases _slightly with time.

[0071]

As described in detail above, the present invention performs feedback control and load-based feedforward control in combination with a process having a large dead time, such as a polymerization process. Therefore, the operation amount can be adjusted in advance so as to suppress the influence of the load fluctuation on the control amount, and highly accurate control can be performed for a process having a large dead time such as a polymerization process. An excellent effect is obtained.

Further, according to a preferred embodiment of the present invention, the dead time is compensated for by using the operation amount by the feedback control and the feedforward control.
Further, an excellent effect that controllability can be improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a control device for performing a process control method according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a schematic configuration of a polymerization apparatus to which the control device is applied.

FIG. 3 is a block diagram illustrating a schematic configuration of a control device for performing a process control method according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a schematic configuration of a control device for performing a process control method according to a third embodiment of the present invention.

FIG. 5 is a graph showing a characteristic curve referred to when a proportional gain adjustment unit generates a proportional gain adjustment coefficient.

FIG. 6 is a block diagram illustrating a schematic configuration of a control device for performing a process control method according to a fourth embodiment of the present invention.

FIG. 7 is a graph showing a characteristic curve referred to when a dead time compensation gain correction unit generates a dead time compensation gain correction coefficient.

FIG. 8 is a graph showing a simulation result of Example 1 of the present invention.

FIG. 9 is a graph showing a simulation result of Example 2 of the present invention.

FIG. 10 is a graph showing a simulation result of Example 3 of the present invention.

FIG. 11 is a graph showing a simulation result of Example 4 of the present invention.

FIG. 12 is a block diagram illustrating a schematic configuration of a conventional process control device.

[Explanation of symbols]

 Reference Signs List A control device B superposition device M controlled object 10 PI controller (feedback control means) 20 feed forward control means 30 feed forward manipulated variable correction means 40 proportional gain adjustment means 50 dead time compensation means 60 dead time compensation gain correction means

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoichi Oike 3-1-1 Higashikawasakicho, Chuo-ku, Kobe Kawasaki Heavy Industries, Ltd. Kobe Plant (72) Inventor Yosuke Suezawa 3-1-1 Higashikawasakicho, Chuo-ku, Kobe-shi No. 1 Kawasaki Heavy Industries, Ltd. Kobe Plant F-term (reference) 5H004 GA10 GA16 GB02 HA04 HB04 KB02 KB04 KB06 KB33 KC24 KC27 KC56 LA01 LA03

Claims (17)

[Claims] Claims: 1. A process control method for a process having a large dead time, such as a polymerization process, wherein the control amount is corrected by controlling an operation amount by feedback control by an operation amount by feedforward control. Method. 2. The process control method according to claim 1, wherein dead time is compensated for by using an operation amount obtained by correcting an operation amount by feedback control by an operation amount by feedforward control. 3. A process control method for a process having a large dead time, such as a polymerization process, wherein feedback control including at least a proportional operation is performed, and a proportional gain is adjusted according to a load. Process control method. 4. A process control method for a process having a large dead time, such as a polymerization process, comprising: a feedback control procedure for outputting an operation amount for eliminating a deviation between a target value and a control amount; A process control comprising: a feedforward control procedure for outputting an operation amount; and a correction procedure for correcting an operation amount obtained by the feedback control procedure with an operation amount obtained by the feedforward control procedure. Method. 5. A feed-forward operation amount correction procedure including a feed-forward operation amount correction procedure, wherein the feed-forward operation amount correction procedure is obtained by an operation amount correction amount calculated based on an operation amount obtained by a feedback control procedure. 5. The process control method according to claim 4, wherein the operation amount is corrected. 6. The process control method according to claim 5, wherein the operation amount correction amount is held as needed. 7. The method according to claim 1, further comprising a proportional gain adjustment procedure, wherein the feedback control procedure performs at least a proportional operation, wherein the proportional gain adjustment procedure adjusts a gain of the proportional operation according to a load. Claim 4
Or the process control method according to 5. 8. A control object is approximated by a first-order lag element and a dead time element, and is obtained by a Smith method using an operation amount obtained by the correction procedure based on a model approximating the control object. 8. The process control method according to claim 4, wherein dead time is compensated for by a correction amount. 9. A feedback control procedure including a dead time compensation gain correction procedure, wherein the feedback control procedure performs at least a proportional operation, and wherein the proportional gain adjustment procedure adjusts a gain of the proportional operation by a Smith method. 9. The process control method according to claim 8, wherein the adjustment is performed based on: 10. A process control method for a process having a large dead time, such as a polymerization process, which outputs an operation amount for eliminating a deviation between a target value and a control amount.
A process control method comprising: a feedback control procedure for executing at least a proportional operation; and a proportional gain adjustment procedure for adjusting a gain of the proportional operation according to a load. 11. A process control apparatus for a process having a large dead time, such as a polymerization process, comprising: a feedback control means for outputting an operation amount for eliminating a deviation between a target value and a control amount; Feedforward control means for outputting an operation amount, wherein a control target is controlled by an operation amount obtained by correcting the operation amount obtained by the feedback control means with the operation amount obtained by the feedforward control means. A process control device. 12. A feedforward operation amount correction unit, wherein the feedforward operation amount correction unit generates an operation amount correction amount based on the operation amount obtained by the feedback control unit, and feedforward operation is performed based on the operation amount correction amount. The process control device according to claim 11, wherein the operation amount obtained by the control means is corrected. 13. The process control apparatus according to claim 12, wherein the feedforward operation amount correction means holds the operation amount correction amount. 14. A proportional gain adjusting means, wherein the feedback control means includes a PI adjuster or a PID adjuster, wherein the proportional gain adjusting means generates an adjusting coefficient of a proportional gain corresponding to a load, and 13. The process control device according to claim 11, wherein a proportional gain of the controller or the PID controller is adjusted by the adjustment coefficient. 15. A waste time compensating means, wherein the waste time compensating means generates a correction value by a Smith compensation method based on the corrected operation amount, and the deviation is corrected by the correction value. 15. The process control device according to claim 11, wherein: 16. A method for modifying a dead time compensation gain, comprising:
And the feedback control means is a PI controller or a PID
The dead time compensation gain correcting means generates an adjustment coefficient of a proportional gain based on the correction value from the dead time compensation means, and the proportional gain of the PI adjuster or the PID adjuster is adjusted by the adjustment. The process control device according to claim 15, wherein the process control device is adjusted by a coefficient. 17. A process control device for a process having a large dead time, such as a polymerization process, which outputs an operation amount for eliminating a deviation between a target value and a control amount.
A process control device comprising: feedback control means having a PI adjuster or a PID adjuster; and proportional gain adjuster adjusting a proportional gain of the PI adjuster or the PID adjuster according to a load.