JPH03262002A - Pulse width output controller - Google Patents

Abstract

PURPOSE:To perform optimum control and to shorten the time required until a control deviation is reduced to zero by outputting a 1st or 2nd continuous signal when the absolute value of the control deviation exceeds a specific value. CONSTITUTION:An output signal switching part 20 outputs the 1st or 2nd continuous signal 13a or 14a as an operation signal when the absolute value ¦E¦ of the control deviation E exceeds the specific value alpha regardless of the proportional gain of negative feedback control arithmetic performed by a control arithmetic part 8. The proportional gain of the control arithmetic part is so set that the best control result based upon the operation signal is obtained when ¦E¦ < alpha, and then continuous driving is performed with the 1st or 2nd continuous signal 13a or 14b so that the deviation E is reduced toward zero. Consequently, the optimum control over the controlled variable is performed when ¦E¦ < alpha, and if such a large deviation E that ¦E¦ >= alpha is generated, a settlement time which is the time from the deviation E to the reduction of this E to zero can be made extremely short.

Description

[Detailed Description of the Invention] [Industrial Applicability] The present invention is applicable to negative feedback systems, when driving an electric operating part in IVc, etc. (pulse width output controller used, fie[
The present invention relates to a controller that can shorten the settling time for weight control.

[Traditional time]

FIG. 2 is an explanatory diagram of the configuration of a flow rate side (2) device 2 as a negative feedback constant value side device using a conventional pulse width output controller 1.

w, In Figure 2, 3 is attached to a pipe 5ff through which fluid 4 flows, and detects the instantaneous flow rate Q of this fluid 4.

As a result of this flow rate detection, a flow rate signal 3 representing ff1fQ
Flow rate transmitter configured to output a, 6 a flow rate setting device 7
The flow rate setting signal 7a and the flow rate signal 3a output by are input, and the limiting deviation between the flow rate setting value Q$ represented by the signal 7a and the flow rate value Q represented by the signal 31 is calculated. Control that outputs a control deviation signal 6a representing the control deviation E! ! I] The deviation calculation section 8 has built-in relay contacts 81 and 82, and the control 4M difference signal 6a is input, and this signal 6a is
A control calculation unit that performs a predetermined negative feedback control calculation including at least a proportional control calculation such as an ID calculation and outputs a pulse train signal 8a, which will be described below. A rectangular pulse 81a having a positive pulse polarity outputted by the relay contact 81 when it is positive is a signal outputted from the ms point 81 at a predetermined force synchronization τ, and when the deviation E is negative, the relay A rectangular pulse 82m having a negative pulse polarity outputted from the contact 82 is a signal outputted from the # contact 82 at the above synchronization τ.

Both of these rectangular pulses gla and 82at are pulses having a pulse width corresponding to the result of the above-described negative feedback control calculation performed in the control calculation unit 8VC.

Reference numeral 9 denotes an electric flow rate control valve that opens and closes the valve in response to the input pulse train signal Ba'tc to adjust the flow rate Q of the fluid 40 flowing through the pipe line 5.
is composed of the above-mentioned control deviation calculation section 6, flow rate setting device 7, and control calculation section 8.

The flow rate control device 2 is composed of the controller 1, the flow rate transmitter 3, and the control valve 9. In this case, the controller 1 performs constant value control on the flow rate Q by applying the signal 8a to the valve 91'c. It looks like this.

Then, when the controller 11c8 is turned on, the control calculation unit 8 starts to perform at least the proportional control calculation as described above.
Therefore, in this case, the square pulses 81a or 82a (these pulses may be collectively referred to simply as pulses X) constituting the pulse train signal 8a are generated according to the absolute value of the deviation E, for example, as shown in FIG. By exhibiting the pulse width B shown in the figure, this pulse @ B +1 usually increases as the absolute value of E increases.

Further, the larger the proportional gain Kp in the above proportional control calculation, the wider it becomes.

Problem to be Solved by the Invention C] Now, in FIG. 2, the controller 1 is configured as described above, so in this case, the above-mentioned ratio 4 in the controller Hc is
For example, if the proportional gain Kp of the control calculation is increased, this controller 1
Strong pullback control is performed for Ew such as +i, but in this way general VCl5! ! The control performance for the flow rate QK is poor because it is easy to cause 11 ng or extreme overshoot in the control result, so in Fig. 2, the control effect of the flow rate Q to set value changes and disturbances is shown to have the best 11i response. As shown, the gain described above is usually set relatively small. However, when the gain Kp is small, as mentioned above, the time 111B of the pulse
It is clear that the settling time Tr becomes longer until it becomes equal to , and such a longer settling time T increases the operating speed for a controlled object such as a flow control system using an electric control valve 9 [12]. This is especially true for slow controllers.

In other words, the above-mentioned pulse Ill! For output controller 1.

Since it is not possible to set a large proportional gain,
There is a problem that when a large control deviation E occurs, the settling time Tr of the flow rate Q becomes very long.

An object of the present invention is to continuously drive an electric operation part such as the electric control valve 9 when a large control deviation E occurs, so that the settling time Tr of a controlled variable such as the IVtt amount Q is shortened. so that (can be)

Another objective is to obtain a pulse width output controller that can perform proportional control operation with an appropriate proportional gain for the controlled amount when the deviation E is small.

[Means to solve the problem]

To achieve the above purpose, one shot F! According to AK, a predetermined negative feedback control calculation is performed on the input control deviation, and the pulse polarity is either positive or negative depending on the polarity of the control deviation, and the result of the negative feedback control calculation described in 1. V
a control calculation unit that outputs a pulse train signal consisting of synchronous pulses having a pulse width according to C, a first signal value equal to the pulse value of the pulse of the positive pulse polarity, and a polarity equal to the positive pulse polarity; and said w, 1
a first continuous signal generator that outputs a first continuous signal whose signal value does not change over time; W! equal to the pulse value of the pulse of the negative pulse polarity; , a second continuous signal generator that outputs a second continuous signal having two signal values and a polarity equal to the negative pulse severity and in which the second signal value does not change over time; When the first and second continuous signals and the control deviation are input and the absolute value of the control deviation is less than a predetermined value, the pulse train signal is output as an operation signal, and the absolute value of the control deviation of the previous control deviation is The pulse width output controller is configured to include an output signal switching section that outputs the first continuous signal or the second continuous signal as the operation signal depending on the control side differential force polarity when the differential force is equal to or greater than a predetermined value. .

[Effect]

With the above configuration, regardless of the magnitude of the proportional gain Kp in the negative feedback control calculation performed by the control calculation section,
When the absolute value IEI of the control deviation E becomes equal to or greater than the predetermined value α, the output signal switching unit outputs W, l or the second continuous signal as the operating signal, so the drive is driven by the operating signal output from the output signal switching unit. When the control amount controlled via the operating unit is controlled via the upper operating unit by a pulse train signal output as an operating signal from the output signal switching unit when +E+<α, This control result is an Il that does not cause hunting or extreme overshoot.
If the proportional gain in the control calculation section is set so as to obtain an appropriate control result, when the state of IE1Σα occurs, the operation section will adjust the deviation E using the first or second continuous signal.
is therefore to be driven continuously to pull it back to zero.

When IEl<α, 1 for control t: Optimal control can be performed, and when a large deviation E such as IE1Σα occurs, the time required from the occurrence of the even difference E to reduce this E to zero This results in a pulse width output controller that can significantly shorten the settling time Tr.

〔Example〕

FIG. 1 is an explanatory diagram of the configuration of a flow rate control device 11 as a negative feedback constant value control device using a pulse width output controller lO as an embodiment of the present invention. Components that are the same as those shown in Figure 2 are given the same reference numerals as in Figure 2.

Now, in figure g1, 8F and 8N are connected to output the square pulses sla and 82a, respectively. The output terminal of the controller 10 is capable of giving a valve opening command signal 12a that causes the valve 9 to perform an opening operation.

1ON is the output terminal of the controller 10 that is connected to the valve 9 so that the valve opening command signal 12b that causes the C# valve 9 to perform a closing operation can be given.

Reference numeral 12 denotes an operation signal of the controller 10 representing either a valve opening command signal 12a or a valve opening command signal 12b that the controller IO gives to the valve 9 as an operating section of the flow rate control device 11. 13 has a first signal value AI equal to the pulse value of the square pulse 81a of positive pulse polarity and a polarity equal to this positive pulse polarity, and the first signal value A does not change over time. Constantly outputting 1 continuous signal 13g @
The continuous signal generator 14 has a second signal value AI equal to the pulse value of the square pulse 82a of negative pulse polarity and a polarity equal to this negative pulse polarity, and the second signal value A is A second continuous signal generator 15, which constantly outputs a second continuous signal 14a that does not change over time, receives the flow rate setting signal 7a and the ii-signal 3a and generates a control difference signal 15a representing the control deviation E. 16 is a control deviation calculation unit similar to the control deviation calculation unit 6 described above, which outputs the signal 1.
5a is input and this signal 15a represents the control deviation E=
Qs When Q is EΣα with α as a positive predetermined value, the coil 17a of relay F is excited, and when E<α, coil 1 is excited.
A first comparator configured to demagnetize 7a.

18, when the signal 15a is input manually, the control deviation E represented by the signal 15a in parentheses is E, so that when E<(-α), the coil 19a of the relay 19 is energized, and when E>(-α), the coil 19a is demagnetized. This is the second comparator.

Then, 171 is the b contact of the relay 17 which is driven by the relay coil 17a to open and close the connection between the °C terminal 8P and IOP, and 172 is the b contact of the relay 17 which is operated in conjunction with the contact 171 to close the circuit. First continuous signal generator 1 during operation
3 outputs the first continuous signal 13m from the output terminal 10P.
At the ali point of relay 17, which seemed to output 191
is driven by relay coil 19a to connect terminals 8N and I.
b of relay 19 that opens and closes the connection between ON and
The first point, 192, seems to open and close the circuit in conjunction with the contact 191, and when the circuit is closed, the second continuous signal 14a output by the second continuous signal generator 14 is output to the output terminal 1ON. This is the a contact point of sea 19. The above-mentioned pulse width output controller 1O includes the control deviation calculation sections 6 and 15, the flow rate setting device 7, the control calculation section 8, the first and second comparators 16.
18 and + 17 and 19 and output terminal 10F and ION
and first and second continuous signal generators 13 and 14, and the aforementioned flow rate control device 11 is composed of such a controller 10, a flow rate transmitter 3, and a flow rate control valve 9. There is.

In FIG. 1, the controller 10 is configured as described above, so if the absolute value 1 of the control deviation is less than α, both the relay coils 17a and 19a are in a non-eal state! Is there one?
, - all relay contacts 171 and 191 are turned on and both relay contacts 172 and 192 are turned off, resulting in this result.

The pulse train signal 8a outputted by the control calculation unit 8 is outputted from either the controller output terminal 10F or 1ON to the outside of the controller lθ as an operation signal 12, and the valve 9 opens and closes based on this signal 12.

In addition, when the control a and the i4 difference E are E4α, the relay coil 17a is excited by the comparator 16 and the contact 17 is
1 is turned off and contact 172 is turned on, but
At this time, since the condition E>(-α) is satisfied, the comparator 18 demagnetizes the coil 19a, so the contact 191 is on and the contact 192 is off. , E>0, so that the control calculation unit 8 outputs the pulse train signal 8a consisting of pulses 81a and does not output the pulse train signal 8a consisting of pulses 82a.VC! Since the arithmetic unit 8 is configured at ℃, N station, E
If Σα, the first continuous signal 1311 is input to the control valve 9VC via the output terminal 10F as a valve open finger→signal 12m.

Then, the deviation E is E4 (-α) again! IIvC
When the coil 19a is excited by the comparator 18, the contact 191 is turned off and the contact 192 is turned on. At this time, since the condition E<α is satisfied, the comparator 16
is demagnetizing the coil 17a, so the li point 171 is on and the contact 172 is off. Furthermore, since E<O at this time, the calculation unit 8 outputs the pulse train signal 8a consisting of the pulses 82a. Since the calculation unit 8 is configured so as not to output the pulse train signal 8a consisting of the pulse 81a, the second continuous signal 14a will close the valve via the output terminal 1ON if E4 (-α). Finger → Signal 12
It will be inputted to the control valve 9 as b.

That is, in FIG. 1, the operation signal 12 in the manner described above is output to the terminals 10P and IO according to the value of the control deviation E.
In this case, the first
The pulse train signal 8a, the first and second continuous signals 13a and 14a, and the control deviation E represented by the control deviation signal 15a are inputted to the second comparators 16 and 18, the relays 17 and 19, and the terminals 10P and ION. If the absolute value IEI of the deviation E is less than the predetermined value α, the pulse train signal 8a is changed to the operation signal 12.
and the absolute value IEI is greater than α, the deviation E
The first continuous signal 1 depending on the positive or negative of the deviation E as the polarity of
3a or the second continuous signal 14a as the operation signal 12. Therefore, the controller 10 includes the control deviation calculating sections 6 and 15 and the setting device 7. and control performance J [Part 8 and 1
and second continuous signal generation sections 13 and 14 and output signal switching section 2
It can also be said that it is composed of 0.

1: In Fig. 1, τ is 1g4 nodes 1O are configured as described above, and furthermore, when IEl(α), the pulse train signal 8arc output from the terminal 10P and ION as the operation signal 12 Therefore, fluid 4 via valve 9
The above-mentioned proportional gain Kp in the calculating section 8 is set in control-1 so that when controlling the flow rate Q of , an optimum control result that does not cause overflow or extreme overflow can be obtained.

Therefore, according to the lever controller 10, a good constant for Q is obtained when IEl<α! Naturally, the tBIJ m1ll result will be obtained, but since the controller 10 is configured as described above, if the IE1Σα state occurs, the gain will be
A continuous signal 13a or 14a corresponding to the positive or negative of the deviation E is outputted from the controller 10 regardless of the set value of E, and therefore, the valve 9 continuously opens or closes depending on these signals 13ae and 141. Therefore, a flow rate control operation is performed to return the deviation E to zero.

Therefore, according to the controller IO, when a large control deviation E such as IE1Σα occurs, KRiQ can be returned to the set value Qs[ during a very short settling time T.

Although the controller 10 is provided with two control deviation calculating sections 6 and 15, it is obvious that these two calculating sections may be combined into one.

〔Effect of the invention〕

As described above, in the present invention, a predetermined negative feedback control calculation is performed on the input control deviation to determine whether the control deviation has a positive polarity or a negative polarity depending on the polarity of the control deviation. a control operation s that outputs a pulse train signal consisting of periodic pulses having a pulse width according to the result of the negative feedback control operation, and a first @ value equal to the pulse value of the pulse of positive pulse polarity and positive polarity. a first continuous signal generation s that outputs a first continuous signal having a polarity equal to the pulse polarity and whose first signal value does not change to f over time; a second continuous signal generator that outputs a second continuous signal having two signal values and a negative pulse polarity VC equal to each other and whose second signal value does not change over time;
If a continuous signal and the control deviation are input and the absolute value of this control deviation is less than a predetermined value, a pulse train signal is output as an operation signal, and if the absolute value of the control deviation is greater than or equal to the predetermined value, the polarity of the control deviation is changed. depending on the first continuous signal or the second
The pulse width output controller was configured to include an output signal switching section that outputs a continuous signal as the operation signal.

Therefore, when configured as described above, the proportional gain K in the negative feedback control calculation performed by the control calculation section.

Regardless of the magnitude of , when the absolute value IE of the control deviation E exceeds the predetermined value α, the output signal switching unit outputs the first or second continuous signal as the operation signal.
When the control amount controlled by °C through the operating section driven by the operating signal output from the output signal switching section is IEl<α, the operating section is controlled by the pulse train signal output as the operating signal from the output signal switching section. When controlled through
IE1
When the state α occurs, the operating section is continuously driven by the first or second continuous signal so as to return the deviation E to zero.
If <α, optimal control can be performed for the control amount,
In addition, when a large deviation E such as l:4α occurs, the pulse width output adjustment can greatly shorten the settling time Tr, which is the time required from the occurrence of the even difference E to the time when this E becomes zero. It has the effect of increasing the meter.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of an embodiment of the present invention. FIG. 2 is an explanatory diagram of the configuration of a conventional pulse width output controller. FIG. 3 is a functional explanatory diagram of the main parts in FIGS. 1 and 2. 1, lO...Pulse width output controller, 8...
...Control calculation unit, 8a...Pulse train signal,
12...operation signal, 13...first
Continuous signal generator, 13a...first continuous signal.

Claims (1)

[Claims] 1) A predetermined negative feedback control calculation is performed on the input control deviation, and the pulse polarity is either positive or negative depending on the polarity of the control deviation, and the pulse polarity is determined according to the result of the negative feedback control calculation. a control calculation unit that outputs a pulse train signal consisting of periodic pulses having a pulse width, a first signal value equal to the pulse value of the pulse of the positive pulse polarity, and a polarity equal to the positive pulse polarity; a first continuous signal generator that outputs a first continuous signal in which the first signal value does not change over time; and a second signal value equal to the pulse value of the pulse having the negative polarity pulse and the negative pulse. a second continuous signal generating section that outputs a second continuous signal having a polarity equal to the polarity and in which the second signal value does not change over time; the pulse train signal, the first and second continuous signals, and the second continuous signal; If a control deviation is input and the absolute value of the control deviation is less than a predetermined value, the pulse train signal is output as an operation signal, and if the absolute value of the control deviation is greater than or equal to the predetermined value, the polarity of the control deviation is changed. A pulse width output controller comprising: an output signal switching section that outputs the first continuous signal or the second continuous signal as the operation signal, depending on the operation signal.