JPS59191601A - Output tracking control system - Google Patents

Abstract

PURPOSE:To perform the mode switching with no sudden fluctuation of control quantity for a control system where a controlled system is controlled in two types of modes, by making the manipulated variable of one mode follow the manipulated variable of the other mode when the controlled system is controlled in either one mode. CONSTITUTION:A tracking arithmetic part 10 is set by a control meter 300 between a feed-forward arithmetic part 2 and a switch 3. The part 10 performs an operation of MVA=Z+B, where the value B is added to the output Z of the part 2 in an automatic mode A. When the operation is switched to the mode A, the manipulated variable MVA equal to the hitherto manipulated variable MVM is set at a manipulated variable MV in response to the action of a switch 3. For this purpose, the manipulated variable MVM of a manual control part 4 is also supplied to the part 10. In a manual mode M the tracking is carried out to satisfy B=MVM-Z. For this purpose, the part 10 accepts the output MVM from the part 4 and performs an operation in response to the action of the switch 3. Thus no fluctuation is produced with the manipulated variable even though the manual mode M is switched to the automatic mode A.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an output dragging control method, and in particular to an output dragging control method for switching the route of a signal supplied to a controlled object without variation (bumpless) in an instrumentation system. Regarding.

[Prior art]

Figure 1 shows a controller 100 and a controlled object (process) 200.
FIG. 3 is a Pronk diagram showing an example of a control system of a conventional instrumentation system, which further includes a feedforward calculation element. Here, 1 is a control calculation unit, which performs, for example, proportional integral derivative (PID) control calculation. 2 is a feedforward calculation unit, which applies feedforward pathology f(X, Y) to the input signal X and feedforward input signal Y supplied from the control calculation unit 1 to obtain an output Z; Let the manipulated variable be MVA. 3 is a switch, a4
Switch between automatic mode A and manual mode H of the installation system, and set the manipulated variable MV8 and the manipulated variable MV gate to the manipulated variable M, respectively.
V to the process 200. 4 in the figure is a manual adjustment section. Further, Sv is a set value, Pv is a control amount, and these Sv and PV are supplied to the mixer 5, and 5v-
pv is obtained, and this 5v-pv is supplied to the control calculation section l.

In such a control system, it is naturally required that the manipulated variable MV for the process 200 does not vary (bumpless) when the switch 3 is changed over. Here, when switching the switch 3 from automatic mode A to manual mode A method is adopted in which the manipulated variable MV is made to track the manipulated variable MVA in advance, or alternatively, in manual mode X, the manual adjustment section 4
is the operation MMV so as to give the change to the operation amount MV.
By adopting a method of outputting -, fluctuations can be easily removed.

On the other hand, when switching switch 3 from manual mode to automatic mode A, feedforward calculation f(
X, Y) and calculates the number Iha, the manipulated variable MVA becomes the manipulated variable MV1. H must be tracked. That is, the signal X must be determined by performing the inverse calculation of the calculation f(X, Y) so as to satisfy the following equation (1).

f(X, Y) = MVrl
(1) In this case, feedforward operation f(X, Y)
Or, for example, f(X,Y)=X+Y
In the case of simple addition as in (2), the signal X is obtained as follows: X=MV Yaw (3), and the tracking signal can be easily obtained.

However, the feedforward calculation unit 2 performs a complicated calculation f
When performing (X, Y), it is difficult to perform the inverse calculation, so in the conventional control system, it is difficult to perform accurate tracking, which causes a problem in which the manipulated variable MV for the process 200 fluctuates. there were.

〔the purpose〕

SUMMARY OF THE INVENTION It is an object of the present invention to provide an output trucking control method that eliminates such conventional problems and allows switching of the route of a signal supplied to a controlled object without any change.

[Key points of the invention]

In order to achieve such an object, the present invention provides first and second signal generating means for generating the first and second signals, respectively, and a selection method for selecting one of the first and second signal generating means. a calculation means for calculating the first signal and the second low dimension to generate a difference signal; a holding means for holding the difference signal; and a holding means for passing the difference signal held by the holding means. switching means switchable between a first position and a second position for supplying a difference signal to the holding means; The difference signal is used to correct the first signal, and when the second signal generation means is selected, the difference signal from the calculation means is used to correct the first signal and the second signal is converted into the first signal. The present invention is characterized in that it includes a correction means for following.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the output docking control method of the present invention. Here, corresponding parts of the controller 300 that can be configured in the same manner as before are designated by the same reference numerals. Explanation will be omitted.

Here, lO is a tracking calculation unit, and this tracking calculation unit IO is arranged between the feedforward calculation unit 2 and the switch 3. This tracking calculation unit lO
is the operation of adding the value B to the output Z of the feedforward operation unit 2 in the automatic mode^, that is, the following equation (4)
Perform the calculation shown in

MVA=Z+B (4
) Here, when switching to automatic mode A, in conjunction with the operation of switch 3, the operation amount M in manual mode A until then is changed.
The manipulated variable MVA having a value equal to v, 1 is set as the manipulated variable MV. For this purpose, the operation amount Mv1 of the manual adjustment section 4.
l is also supplied to the tracking calculation unit lO.

On the other hand, in the manual mode, tracking may be performed as shown in the following equation (5).

B-MV, 1-2 (
5) For this purpose, in conjunction with the operation of the switch 3, the tracking calculation unit IO adjusts the output MVi from the manual adjustment unit 4.
is accepted and the calculation of equation (5) is performed.

Thereby, switching from manual mode to automatic mode A can be performed without causing a change in the amount of operation.

FIG. 3 shows an example of the configuration of the tracking calculation unit 10 that calculates equations (4) and (5). Here, 11 is a switch, which is switched between automatic mode A and manual mode X in response to switching of switch 3. 12 is an adder, and 13 is a subtracter, which satisfy equations (4) and (5), respectively.
) expression is calculated. Reference numeral 14 denotes a follow-up value holding section, which stores and holds the value B determined by equation (5) during the manual mode. When switching from manual mode output to the device 12.

In the manual mode, when tracking the value B in the tracking calculation unit 1O, it is preferable to reset the integral operation so that the output value of the control calculation unit 1 does not fluctuate. Furthermore, upon initial startup of the instrumentation system, it is preferable to reset the value B up to that point or to set the follow-up value holding unit 14 so as to output a minus value. Holding, setting, etc. of these values B can be easily performed in an instrumentation system using a microprocessor.

FIG. 4 shows another embodiment of the present invention in which the feedforward input signal Y is switched between use (on) and non-use (off) without causing any fluctuation in the manipulated variable. An example of a controller 400 is shown below. Here, 2
0 is a tracking calculation unit, which outputs a signal YO to the feedforward calculation unit 2 in response to the input of the feedforward signal Yl. S is a mode switching signal, which controls switching between feedforward mode F in which feedforward control is applied to the control system and tracking mode T in which tracking is performed without feedforward control.

FIG. 5 shows an example of the configuration of such a tracking calculation section 20. Here, 22 and 23 are switches, which are switched between feedforward mode F and tracking mode T in accordance with mode switching signal S. 24 is an adder, 2
5 is a subtracter, and 26 is a follow-up value holding section that stores and holds the follow-up value. A setting section 27 outputs the tracking input signal YT to the subtracter 25.

The output value Y of the adder 24 and the output value B1 of the subtracter 25 are given by the following equations (6) and (7), respectively.

Y=YI÷a+ (8)
B1=YT-Yl
- (7) When switching to tracking mode T, switches 22 and 23 are set to the T side in the figure,
According to equation (7), the value B1 can be set as the follow-up value, and the value of the signal YO becomes equal to the value of the signal YT. On the other hand, when switching from the tracking mode T to the feedforward mode F, the tracking value holding section 2B outputs the held value B1 immediately before the switching to the adder 24 as a tracking value, so that the switching can be performed without fluctuation. can.

During the feedforward mode F, the switches 22 and 23 are set to the F side, so the value Bl held in the follow-up value holding section 26 is output as a constant value, and the value B1 is determined by equation (8). The value obtained by adding the feedforward input signal YI to the feedforward input signal YI is supplied to the feedforward calculation unit 2 as the output signal YO.

From feedforward mode F to tracking mode T
When switching to , if the setting section 27 sets the value of the signal YT equal to the value of the signal YO immediately before the switching,
Since the output signal YO retains the value of the signal YO immediately before switching, the output signal YO without fluctuation is supplied to the feedforward calculation section 2, and therefore the feedforward mode F can be turned off. Further, by setting the signal YT to a desired value by the setting section 27, the signal YT having the desired value can be supplied to the feedforward calculation section 2.

〔effect〕

As explained above, according to the present invention, in a control system in which a controlled object is controlled in two modes, when controlling the controlled object in one mode, the amount of operation in that mode is changed to that in the other mode. Since the manipulated variable can be tracked, the mode can be switched without sudden fluctuations in the manipulated variable.

It should be noted that the present invention is not limited to control systems including the above-mentioned feedforward calculation elements, but can of course be widely applied to control systems that switch signals for controlled objects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the configuration of a conventional instrumentation system, FIG. 2 is a block diagram showing a first example of the configuration of an instrumentation system according to the control method of the present invention, and FIG. 3 is a block diagram showing the main components thereof. FIG. 4 is a block diagram showing a second example of the configuration of the instrumentation system according to the control method of the present invention, and FIG. 5 is a block diagram showing an example of the configuration of the main part thereof. It is a line diagram. DESCRIPTION OF SYMBOLS 1... Control operation initial part, 2... Feedforward calculation part, 3... Switch, 4... Manual adjustment part, 5... Mixer, lO... Tracking calculation part, 11... - Switch, 12... Adder, 13... Subtracter, 14... Tracking value holding section, 20... Tracking calculation section, 22... Switch, 24... Adder, 25...・j subtractor, 26...following value holding unit, 2? ...Setting section, 100, 200, 300...Adjustment system, 200...
・Controlled object (process), SV...set value, X...control calculation unit output signal, Z...feedforward calculation unit output signal, Y, Yl
...feedforward input signal, YO...tra...
Linking operation unit output signal, MV, MV8, MVM
・"Manipulated amount, pv...Controlled amount. A...Automatic mode, H...Manual mode, F...Feed forward mode, T...Tracking mode. Patent applicant: Fuji Electric Manufacturing Co., Ltd. Company Representative Patent Attorney Yoshi Tani −

Claims (1)

[Claims] first and second signal generation means for generating a dark signal and a second signal, respectively; selection means for selecting one of the first and second signal generation means; a calculation means for calculating the difference between the two signals and generating a difference signal; a holding means for holding the difference signal; a first position through which the difference signal held by the holding means passes; and a first position for passing the difference signal; switching means capable of switching between a second position and a second position for supplying the signal to the holding means; When the second signal generation means is selected, the difference signal from the calculation means is used to correct the first signal and the second signal is generated.
and a correction means for causing the first signal to follow the signal.