JP3494082B2 - Time proportional control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time-proportional control device, in which an operation amount corresponding to a control output signal is turned on and off for a predetermined repetition period (time proportional period: cycle time). The present invention relates to an improvement of a time-proportional control device that outputs an AC operation signal that is output at a time ratio and is applied to a control target by using the time-proportional output signal.

[0002]

2. Description of the Related Art Conventionally, as a time proportional control device of this type, as shown in FIG. 9, a deviation e between a set value SV in a subtraction unit 1 and a measured value PV from a heater 13 as a control target, which will be described later, e. Is output, and the deviation e is calculated by the PID calculator 3
The feed-forward processing unit 5 corrects the PID calculation output with a feed-forward amount from a detection unit 15 to be described later, and the time-proportional output unit 7 changes from 0% to 100% in one time-proportional period, for example. The sawtooth wave and its corrected PID calculation output are compared (see FIG. 10), and the period during which the PID calculation output exceeds the sawtooth wave is ON period (TON), and the period when the PID calculation output does not exceed it is OFF period (TOFF).
) Is output to the zero-cross control type operating device 9, the operating device 9 switches the alternating-current operating signal from the alternating-current power supply 11 and supplies it to the heater 13, and the detecting section 15 outputs the alternating-current operating signal. For example, there is a configuration in which a voltage fluctuation is detected and output as a feedforward amount to the feedforward processing unit 5 described above.

The measured value PV in FIG. 9 is measured by a sensor (not shown) arranged in the heater 13, for example. Therefore, as shown in FIG. 10, for example, the PID calculation output is 4
ON when 0% and sawtooth wave time proportional period is 30 seconds
A time-proportional output having an OFF period of 18 seconds in a period of 12 seconds is output to the operating device 9, and an AC operation signal subjected to zero-cross control by the operating device 9 is applied to the heater 13 for heating control.

Moreover, the feedforward processing unit 5 feedforward-processes the PID calculation output so that the influence of the disturbance is reduced based on the feedforward amount from the detection unit 15, and the time proportional based on the PID calculation output. Since the heater 13 is heated and controlled by the output, stable control can be performed faster than the feedback control, even if the AC operation signal changes in voltage, for example. In addition, in FIG. 10, feed-forward processed P
The ID calculation output is shown by a broken line.

At present, however, the time proportional control device generally has a digital structure, and as shown in FIG. 10, when the sawtooth wave which is the comparison wave increases with a predetermined output resolution (ΔMV), the sawtooth wave is used. The time-proportional output is ON / OFF switched and output at discrete change timings of the ΔT interval.

Further, as shown in FIG. 11, a triangular wave varying from 0% to 100% to 0% in one time proportional period may be used as a comparison wave, and like the sawtooth wave, the PID is used in the time proportional period. ON period (TON1, TON2) when the calculation output exceeds the triangular wave, and OFF when it does not exceed the triangular wave
In some cases, the time proportional output unit 7 may be formed so as to output the time proportional output for the period (TOFF) to the operating device 9.

[0007]

However, in the above-described time proportional control device, as can be seen from FIG. 10, the feedforward processed PID operation output is compared with the sawtooth wave during the time proportional cycle, and the time proportional output is obtained. Even if is output, only the PID calculation output when the sawtooth wave changes from ON to OFF (or from OFF to ON) is reflected as a manipulated variable in the control target, and during the ON time that should affect the control stability. The changed power supply voltage fluctuation is not reflected, and there is room for improvement to perform more accurate control by the feedforward amount.

Further, as shown in FIG. 12, when the sawtooth wave increases with a predetermined output resolution (ΔMV), the sawtooth wave turns on / off the time proportional output only at the timing of ΔT intervals.
Since it cannot be switched OFF, it should be switched at the timing of T'ON and T'OFF originally, but it is switched at a delayed timing such as TON and TOFF, which causes an error. That is, there is a PID calculation output that is difficult to output due to the output resolution (ΔMV) of the time proportional output.

Further, when the PID calculation output suddenly changes as shown in FIG. 13 due to the influence of the input noise and the quantization error of the measured value PV, the PID calculation output temporarily falls below the sawtooth wave and the time proportional output is turned off. Switch to.

However, in a general time proportional control device,
Since it has a function to prevent chattering when switching the time proportional output ON / OFF, PI
Even if the D calculation output returns to the original level and exceeds the sawtooth wave, the time proportional output remains OFF and the time proportional output is originally O.
An error is likely to occur until switching to FF. Such a problem also occurs in a configuration in which a control output signal other than the PID calculation output is added to the feedforward processing unit 5.

The present invention has been made in order to solve such a problem, and it is possible to suppress the influence of the disturbance exerted on the controlled object to a small extent, and to accurately and stably obtain the control output result for controlling the controlled object. It is an object of the present invention to provide a time-proportional control device that can be applied to a controlled object.

[0012]

In order to solve such a problem, the present invention provides an adding section for adding a correction value to a control output signal for controlling a controlled object, and a disturbance affecting the controlled object. A feedforward process that inputs a feedforward amount that changes the process gain from the measurement result, and performs a feedforward process to suppress the influence of disturbance on the addition control output signal, and outputs the addition control output signal. Section, a time-proportional output section that outputs a time-proportional output obtained by converting a predetermined time-proportional cycle into an ON / OFF ratio to the controlled object side according to the feed-forward processed addition control output signal, and the time A control output signal average calculation unit for calculating an average value of the addition control output signal before the feedforward process in the proportional cycle,
ON to turn on a predetermined operation signal to operate the controlled object
An actual output calculation unit that calculates time based on the time-proportional output and the feedforward amount and calculates the actual output of the time-proportional output from the ratio of the time-proportional period to the ON time, and the addition control output signal average value and the actual output calculation unit. A correction value calculation unit that outputs the difference from the output as a correction value to the addition unit is provided. Moreover, the above adder is
The above correction value based on the
Is added to the control output signal.

Further, the present invention has a PID calculation unit for performing PID calculation of the deviation between the set value and the measured value from the controlled object, and the PID calculation output from this PID calculation unit is used as the control output signal for the correction value. It is also possible to form the adding section so as to add

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The same parts as those in the conventional example are designated by the same reference numerals.

FIG. 1 is a block diagram showing an embodiment of a time proportional control device according to the present invention. In FIG. 1, a subtraction unit 1 subtracts a set value SV and a measured value PV from a heater 13 described later at a predetermined sampling timing to output a deviation e, and is connected to a PID calculation unit 3.

The PID calculator 3 performs a PID calculation on the deviation e, and outputs a PID calculation output (solid line: M, for example, as shown in FIG. 2A.
V1 to MV10) are output at a predetermined control sampling period as a control output for controlling the controlled object, and are connected to the addition unit 17.

The addition unit 17 adds the correction value from the correction value calculation unit 21 to be described later to the PID calculation output, and outputs the addition PID calculation output (dotted line: MV1) as shown in FIG. 2B, for example.
1 to MV20), and is connected to the feedforward processing unit 5 and the PID output average calculation unit 19.

The feedforward processing section 5 outputs the addition PID calculation output (MV11 to MV) for each control sampling period.
20) is corrected by the feedforward process with the feedforward amount from the detection unit 15 which will be described later.
As shown by the broken line in the figure, it outputs an addition PID calculation output that suppresses the influence of disturbance, and is connected to the time proportional output unit 7.

Although FIG. 3 shows an example in which the feedforward processing is performed for each control sampling cycle, it is also possible to perform correction with the same feedforward amount for every arbitrary plurality of continuous control samplings.

Each addition PID calculation output as the operation amount after the feedforward processing in the feedforward processing unit 5 is a predetermined operation signal (for example, commercial power supply AC100V of a commercial power supply AC100V, which is set as an applied AC operation signal applied to the heater 13). ) Is Eo, and the measured voltage actually applied to the heater 13 and measured by the detection unit 15 is En,
It looks like this:

Operation amount after feedforward processing = (E
o) ² / (En) ² × (addition P before feedforward processing
ID calculation output)

Here, the sign n of the measured voltage En is the number of measurement samples, and the reason for performing the processing with the square of the voltage is that this equation is obtained from the electric power when the heater resistance is considered to be a constant value. is there. Note that the power changes the process gain
It has become a part.

The time-proportional output unit 7 compares the sawtooth wave that changes from 0% to 100% in a time-proportional cycle with the addition PID calculation output (broken line) after the feedforward processing, as shown in FIG. Within the time-proportional period (1 cycle), it is in the ON state (TON) when the added PID operation output exceeds the sawtooth wave, and in the OFF state (TOFF) when the added PID operation output is lower than the sawtooth wave. It forms an output, and is connected to the zero-cross type operation device 9 and the actual output calculation unit 23.

In FIG. 3, the discrete change timing of the sawtooth wave is shown largely, but in reality, since the comparison is made with the addition PID operation output at the fine discrete timing ΔT, the ON / OFF ratio also changes according to the feedforward processing. .
The time-proportional output unit 7 has a function of preventing chattering, and after the ON / OFF switching operation is once performed in the same cycle, the ON / OFF switching is not necessarily performed again.

The operation unit 9 has a function of switching the AC operation signal from the AC power supply 11 at a zero-cross point which comes after the OFF switching or ON switching timing of the time-proportional output and applying it to the heater 13 to be controlled. Have. The heater 13 is provided with a temperature sensor (not shown) and the like, and outputs the above-mentioned measured value PV.

The detection unit 15 uses, for example, the power supply voltage E of the AC operation signal actually applied to the heater 13 from the AC power supply 11.
It measures n and outputs the value as a feedforward amount that changes the process gain, and is connected to the feedforward processing unit 5.

The PID output average calculating section 19 adds all the addition PID calculation outputs before the feedforward processing within one cycle of each time proportional cycle and calculates the average value thereof. The correction value calculating section 21 is connected. For example, in FIG. 2, the average value obtained by adding MV1 to MV10 and dividing by the total number of samples (10) is output as a percentage.

The actual output calculation unit 23 outputs a predetermined AC operation signal as a reference signal for operating the heater 13 based on the time proportional output and the feedforward amount within one cycle for each time proportional cycle. The ON time to be turned on is calculated, and the actual output of the time proportional output is output, for example, as a percentage from the ratio of the time proportional cycle to the ON time, and is connected to the correction value calculation unit 21.

Although a predetermined AC operation signal as a reference signal should be applied to the heater 13, it actually fluctuates, and the time proportional output corrected by inputting this fluctuation amount as a feedforward amount. Is obtained, and the ON time at this time is converted into the ON time in the state where the reference signal is applied and output. The reference signal is the actual output calculation unit 2
3 is preset in advance, or is manually or automatically input from the outside at the time of turning on the power or at any other time.

Specifically, the actual output calculating section 23 outputs the actual output as follows, for example. First, an ON time is calculated when it is considered that a predetermined AC operation signal as a reference signal is applied.

ON time = (E1 ² / Eo ² ) Δt + (E2 ² / Eo ² ) Δt + ... + (En ² / Eo ² ) Δt = (ΣEn ² / Eo ² ) Δt = {(ΣEn ² / nEo ² ). Δt} × n = ΣEn ² / nEo ² (ON time)

Here, Δt is the time proportional output resolution, and the symbol n is the ratio of the ON time and the time proportional output resolution. That is, the ON time when it is considered that the predetermined AC operation signal as the reference signal is applied is calculated by adding (En / Eo) 2 and calculating the average value thereof to obtain the actual time proportional output O
It becomes the form which added to N period.

Using this ON time, the actual output is obtained as follows. Actual output = (ON time) / (time proportional cycle)

The correction value calculation unit 21 subtracts the actual output value within the same time proportional cycle from the average value of the addition PID calculation output,
Based on the difference, an output that is insufficient or deficient is obtained and is output as the correction value, and is connected to the adder unit 17 described above.

The above-mentioned addition unit 17 adds a correction value from the correction value calculation unit 21 based on the PID calculation output of the immediately preceding time proportional cycle to the PID calculation output from the PID calculation unit 3 in a certain time proportional cycle. And the ON / OFF of the time proportional output is brought closer to the average value of the added PID calculation output.

That is, as shown in FIG. 2, the adder unit 17 outputs all PID calculation outputs M in a certain time proportional cycle.
PI of the immediately preceding time proportional cycle for V11 to MV20
The correction values based on the D operation outputs MV1 to MV10 are added,
It has a function of outputting an addition PID calculation output as shown by a chain line.

Therefore, the ON / OFF switching timing of the time-proportional output output from the time-proportional output unit 7 changes according to the addition of the correction value, so that the ON / O
The FF ratio also changes. The correction value to be added is constant during the time-proportional cycle to be added, and another constant correction value based on the immediately preceding time-proportional cycle is held and added in the next time-proportional cycle.

However, since the correction value is not created in the first time proportional cycle of control, the PID calculation output input to the adder 17 and the addition PI output from the adder 17
The D operation output is the same, and feedforward processing is also performed on the PID operation outputs MV1 to MV10.

Next, the operation of the above-described time proportional control device according to the present invention will be briefly described. The set value SV and the measured value PV input to the subtraction unit 1 are subtracted at a predetermined sampling timing, and the deviation e is added to the PID calculation unit 3.

The PID calculator 3 performs a PID calculation on the deviation e at a predetermined control sampling cycle, and outputs PID calculation outputs MV1 to MV10 as shown in FIG. 2A to the adder 17.

In the adder 17, since the correction value is not input at the beginning of control, the same PID calculation outputs MV1 to M
V10 is output to the feedforward processing unit 5 and the PID output average calculation unit 19 as an addition PID calculation output.

In the feedforward processing section 5, the addition PID calculation outputs MV1 to MV1 for each control sampling period.
For 0, feedforward processing is performed with the feedforward amount from the detection unit 15 (see FIG. 3), and an addition PID calculation output that suppresses the influence of disturbance is added to the time proportional output unit 7.

The time-proportional output unit 7 compares the feedforward-processed addition PID calculation output with the sawtooth wave (see FIG. 3), and is in the ON state (TON) during the period when the addition PID calculation output exceeds the sawtooth wave. , In the period when the added PID calculation output is lower than the sawtooth wave, the OFF state (T
OFF), a time-proportional output is formed, and this is output to the manipulator 9 and the actual output calculation unit 23.

The operation device 9 switches the AC operation signal from the AC power supply 11 at the ZETH cross point next to the ON / OFF switching timing of the time proportional output, and actually applies it to the heater 13.

On the other hand, the PID output average calculation section 19 outputs all addition PID calculation outputs (MV1 to M) within the time proportional cycle.
V10) is added and the total number of samples (10)
The average value (percentage) divided by is added to the correction value calculation unit 21.

On the other hand, the actual output calculating section 23 obtains the ON period of the predetermined AC operation signal serving as the reference that should be applied to the heater 13, based on the time proportional output and the feedforward amount within the same time proportional cycle. The actual output value of the time-proportional output is calculated as a percentage from the ON time and the time-proportional period, and this is added to the correction value calculation unit 21.

In the correction value calculation unit 21, the actual output value is subtracted from the average value of the addition PID calculation outputs within the same time proportional cycle to form a correction value, which is added to the addition unit 17.

As shown in FIG. 2B, the adder 17 holds the correction value during the period next to the time proportional period which is the basis of the correction value, and adds it to the PID calculation output from the PID calculation unit 3. , An addition PID calculation output (MV11
~ MV20) is a feedforward processing unit 5 and PI
It is added to the D output average calculation unit 19.

From the feedforward processing section 5, FIG.
Feed-forwarded additive PID as shown in
The calculation output (broken lines: MV11 to MV20) is applied to the time proportional output unit 7, and the time proportional output unit 7 applies the time proportional output corresponding to the added PID calculation output to the manipulator 9, while the PID output average calculation unit. A correction value used for the next time proportional cycle is created from 19, the actual output calculation unit 23, and the correction value calculation unit 21. Thereafter, this operation is repeated.

As described above, in the time proportional control device of the present invention, the subtraction unit 1 outputs the deviation e from the set value SV and the measured value PV, and the PID calculation unit 3 calculates the PID calculation output based on the deviation e. Then, the PID in the time proportional cycle in the adding unit 17
The correction value is added to the calculation output, and the feedforward processing unit 5 inputs the feedforward amount as the disturbance measurement result. By this, the feedforward processing is performed to suppress the influence of the disturbance on the added PID calculation output, and the time proportional Addition PID that has been feedforward processed by the output unit 7.
The calculation output and the sawtooth wave are compared to output a time proportional output corresponding to the addition PID calculation output, while the PID output average calculation unit 19 calculates an average value of the addition PID calculation output before the feedforward process in the time proportional period. Then, the actual output calculation unit 23 calculates the ON time for turning on the predetermined AC operation signal for operating the heater 13 based on the time proportional output and the feedforward amount, and calculates the time from the ratio of the time proportional cycle to the ON time. The actual output value of the proportional output is calculated, and the correction value calculation unit 21 forms a difference between the average value of the added PID calculation outputs and the actual output value of the time proportional output as a correction value, and this correction value is calculated in the next time proportional cycle. Is added by the adder 17 to form the above-mentioned addition PID calculation output.

Therefore, even if the addition PID calculation output that has been subjected to the feedforward processing is output as a time proportional output by comparison with a sawtooth wave when it changes from ON to OFF (or OFF to ON), the control stability is improved. The fluctuation of the feedforward amount, which is the fluctuation of the power supply voltage that changes during the ON period that affects, is included in the correction value of the next time proportional cycle, and the feedforward amount during the OFF period is not included in the calculation of the correction value. .

Therefore, the appropriate feedforward amount in the time proportional cycle is reflected in the heater 13, the influence of the disturbance affecting the controlled object can be suppressed quickly, and stable control can be performed.

Further, as shown in FIG. 12, the sawtooth wave can switch ON / OFF the time proportional output only at ΔT intervals due to the output resolution (ΔMV), and as shown in FIG. Even if the switching timing is delayed, a correction value based on the addition PID calculation output of the time proportional cycle is created and added and reflected in the PID calculation output in the next time proportional cycle, so that the ON / OFF switching timing is set to the desired sawtooth wave. It becomes possible to approach the switching timing, and the influence of the PID calculation output, which is difficult to output due to the output resolution (ΔMV) of the time proportional output, is immediately corrected and controlled, and quick and accurate time proportional control becomes possible.

Further, even if the PID calculation output suddenly changes due to the influence of the input noise, the quantization error of the measured value PV, etc., and the time-proportional output is quickly switched to OFF as shown in FIG. 13, Since the PID calculation output of the next time proportional cycle is corrected with the correction value including the value of the PID calculation output after the sudden change, the time proportional control can be performed similarly quickly.

Further, in the conventional time proportional control device, the PID calculation output other than the PID calculation output when the time proportional output is turned ON / OFF is ignored, but in the above-described present invention, the PID calculation within each time proportional period. The output is effectively reflected in the next time-proportional cycle, and from this viewpoint, accurate time-proportional control is possible.

This means that, in the above-mentioned structure, the correction at the early stage by the feedforward process is ensured, and the time proportional output is obtained after the feedforward process to control the heating of the heater 13, that is, the time. It becomes possible to improve the fact that the fluctuation of the feedforward amount cannot be corrected except when the proportional output is turned ON / OFF, and it is possible to suppress the influence of the disturbance on the heater 13 to a small extent, thereby enabling quick and stable control.

In the above-described time proportional control device according to the present invention, the configuration using the sawtooth wave as the comparison wave has been described, but the configuration using the triangular wave is also possible. This triangular wave also changes discretely.

That is, as shown in FIG. 5, the time-proportional output unit 7 uses a triangular wave that changes from 0% to 100% to 0% in a time-proportional cycle, and in a half cycle of this time-proportional cycle, feedforward processing is performed. The added PID calculation outputs (MV11 to MV20) thus generated are compared with the triangular wave, and the addition PI is added.
ON state during the period when the D operation output exceeds the triangular wave (T
ON), the addition PID calculation output can be formed to have a function of forming a time-proportional output in the OFF state (TOFF) in a period in which the output becomes lower than the triangular wave.

The PID output average calculating section 19, referring to FIG. 5, shows all the addition P in the half cycle of the time proportional cycle.
The ID calculation outputs (MV11 to MV15) are added, and the average value (percentage) divided by the total number of samples (5) in the half cycle is formed to be output. It is formed to output the ON / OFF ratio (percentage) of the time proportional output of.

In the adding section 17, the correction value is held in the next half cycle of the half cycle which is the basis of the correction value in the time proportional cycle, and the addition value is added to the PID calculation output from the PID calculation section 3 to perform the addition PID calculation. The outputs (MV16 to MV20) are added to the time proportional output unit 7 and the PID output average calculation unit 19. Otherwise, the configuration is the same as described above. Note that the addition PID calculation outputs MV16 to MV20 in FIG. 5 are after addition.

As described above, in the configuration in which the triangular wave is used as the comparison wave, the correction value is created based on, for example, the PID calculation output of the first half cycle of the triangular wave, and the PI is calculated in the subsequent second half cycle.
It is possible to add and correct the D calculation output and output the time-proportional output, and there is an advantage that the quick correction can be performed within the same time-proportional cycle.

FIG. 6 is a characteristic diagram of a result of simulating the operation of the time proportional control device according to the present invention using a triangular wave as a comparison wave, and FIG. 7 is a conventional time proportional expression shown in FIG. It is a characteristic view of a result of simulating the control device. From these FIGS. 6 and 7, it can be seen that the time proportional controller according to the present invention is excellent in control accuracy and stability. The comparison wave used in the present invention may be a sawtooth wave or a triangular wave, and may be one that changes in a virtual linear manner with a predetermined repetition period of 0% to 100% or 0% to 100% to 0%.

In the configuration of the present invention described above, an example in which the PID operation output is used as the control output signal for controlling the controlled object has been described, but the present invention is not limited to this. For example, a configuration is possible in which the above-mentioned correction value is added to an output value fuzzy calculated from a set value (target value) and a measured value from a controlled object, or an output value that changes in a predetermined pattern over time is described above. It is also possible to add the correction values.

That is, in the present invention, the time-proportional output for controlling the AC or DC power applied to the controlled object for directly controlling the controlled object is the addition control output signal obtained by adding the above-mentioned correction value to the control output signal. The object of the present invention can be achieved by a structure formed on the basis of the above.

As described above, in order to configure the present invention corresponding to various control outputs, for example, as shown in FIG. 8, a control output signal is added to the adding section 17 and added to the above-mentioned correction value to perform addition control. Outputs the output signal and outputs the control output signal average calculator 2
The addition unit 17 and the control output signal average calculation unit 25 may be formed so as to calculate the average value of the addition control output signal in 5, and the other configurations are the same as those in FIG. 1 except for the PID calculation unit 3. However, it is also possible to consider the PID calculation unit 3 as a control output signal output unit. In FIG. 8, the control output signal average calculation unit is simplified to the control output average calculation unit.

By the way, in the above-mentioned configuration of the present invention, the time proportional output from the time proportional output section is the heater 13.
If the output is turned ON / OFF by being associated with the AC operation signal applied to the control signal, higher-precision control becomes possible.

For example, in the case where the operating unit 11 is of the zero-cross type, the half cycle of the predetermined AC operation signal as the above-mentioned reference signal which should be applied to the heater 13 or an integral multiple thereof is previously sent to the time proportional output unit 7 or the like. A configuration is also possible in which ON / OFF switching is performed at this timing to output a time-proportional output.

If such a structure is adopted, the heater 13
Although there is a time delay in the AC operation signal applied to the
The period from the F switching point to the zero-cross point of the AC operation signal is always the same, and the time-proportional output from the time-proportional output unit 7 and the heater 13 are actually reflected even if there is no zero-cross point information from the operation device 9. The output has the same time ratio,
The response in zess cross control becomes stable.

Further, the detection unit 15 or a detector (not shown) detects the zero-cross point of the AC operation signal to be actually applied to the heater 13 and fetches it into the time proportional output unit 7 (see the broken line in FIG. 1). 1/4 from the point
A configuration in which ON / OFF is switched at a timing delayed by about the cycle to output a time-proportional output is also possible.

According to this structure, even if the AC operation signal from the AC power supply 11 fluctuates or the operation device 9 has an operation error, the ON / OFF switching point of the time proportional output is the zero crossing of the applied AC operation signal. It becomes difficult to immediately before and after the point, and the heater 13 can be stabilized with a more accurate AC operation signal.
As a result, a good X-cross control response can be obtained. It should be noted that the present invention can use an operating device other than the zero-cross system.

Further, in the above-described embodiment, the fluctuation of the power supply voltage is taken as an example of the disturbance, but other than this, a disturbance that changes the process gain, such as the temperature of the cooling medium for cooling control, may be considered. In those cases, it is necessary to clarify how the process gain changes depending on the feedforward amount, and to change each expression in the feedforward processing unit 5 and the actual output calculation unit 23 in accordance with each feedforward amount. Needless to say.

The time proportional control device according to the present invention is generally a CPU that performs an arithmetic operation and a judgment operation by a predetermined program, a ROM that stores an operation program of this CPU, a RAM that temporarily stores the arithmetic operation result, and an external device. In many cases, it is composed of a microcomputer mainly composed of I / O which is the interface of the above, but it can be composed of an electronic circuit in which electronic parts are combined.
The digital signal handled by the PU becomes the above-mentioned control output signal, and the analog signal such as a voltage signal or a current signal becomes the control output signal in a device having an analog configuration.

[0073]

As described above, the time proportional control device of the present invention changes the process gain from the addition unit for adding the correction value to the control output signal for controlling the controlled object and the disturbance measurement result for the controlled object. A feed-forward processing unit that inputs a feed-forward amount to be input and feed-forward-processes the added control output signal, and a time-proportional time obtained by converting the time proportional period into an ON / OFF ratio according to the feed-forward processed control output signal. A time-proportional output unit that outputs an output, a control output signal average calculation unit that calculates the average value of the addition control output signal before feedforward processing for each time-proportional period, and control based on the time-proportional output and feedforward amount Calculate the ON time to turn on the predetermined operation signal to operate the target
An actual output calculation unit that calculates the actual output of the time proportional output from the ratio of the time proportional cycle to time, and a correction value calculation that outputs the above correction value to the addition unit from the difference between the addition control output signal average value and the actual output. Section and the repetition time cycle
Based on the above correction value in the next repetition time proportional cycle
The adder is formed so as to add to the control output signal.
It Therefore, with respect to the addition control output that has been subjected to the feedforward processing that changes the process gain, a time proportional output that takes into consideration the disturbance that changes during the ON period that affects the control stability, for example, the power supply voltage fluctuation is output, and the control target is It is possible to improve the problems caused by controlling and controlling the controlled object by obtaining the time proportional output after the feedforward processing by ensuring the correction at an early stage by the appropriate feedforward processing in the time proportional cycle. It is possible to suppress the influence of disturbance to be small. In addition, it is possible to correct a control output signal that is difficult to output due to the relationship with the output resolution (ΔMV) of the time proportional output, and to suppress the influence of a sudden change of the control output signal due to noise or the like to be small, It is possible to make a correction by effectively utilizing the control output signal. As a result, in the above configuration, stable and highly accurate time proportional control is possible. In addition, the PID is calculated by calculating the deviation between the set value and the measured value from the controlled object.
In the configuration in which the PID calculation unit that outputs the calculation output as the control signal is provided, in addition to the above-described effects, it is possible to correct the PID calculation output that is difficult to output in relation to the output resolution (ΔMV) of the time proportional output. , PID caused by noise, etc.
It is possible to suppress the influence of the sudden change of the calculation output, and to perform the correction by effectively utilizing the PID calculation output within the time proportional cycle. As a result, even in the configuration in which the PID calculation output is output as the control signal, similarly fast and stable time-proportional control can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a time proportional control device according to the present invention.

FIG. 2 is a diagram for explaining the operation of the time proportional control device of FIG.

FIG. 3 is a diagram illustrating an operation of the time proportional control device of FIG.

FIG. 4 is a diagram illustrating an operation of the time proportional control device of FIG.

FIG. 5 is a diagram for explaining another operation of the time proportional control device of FIG.

FIG. 6 is a characteristic diagram showing a simulation result of the time proportional control device of the present invention according to FIG. 1.

FIG. 7 is a characteristic diagram showing a simulation result of a conventional time proportional control device.

FIG. 8 is a block diagram showing another embodiment of the time proportional control device according to the present invention.

FIG. 9 is a block diagram showing a conventional time proportional control device.

FIG. 10 is a diagram for explaining the operation of the time proportional control device of FIG.

11 is a diagram explaining another operation of the time proportional control device of FIG. 9. FIG.

FIG. 12 is a diagram illustrating an operation of the time proportional control device of FIG. 9.

FIG. 13 is a diagram for explaining the operation of the time proportional control device of FIG. 9.

[Explanation of symbols]

1 Subtraction unit 3 PID calculation unit (control signal output unit) 5 Feedforward processing unit 7 Time proportional output unit 9 Manipulator 11 AC power supply 13 Heater (control target) 15 Detection unit 17 Addition unit 19, 25 PID output average calculation unit ( Control output signal average calculation unit) 21 Correction value calculation unit 23 Actual output calculation unit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koichi Sakakura 5-16-6 Kugahara, Ota-ku, Tokyo Rika Kogyo Co., Ltd. (72) Yukako Oyanagi 5-16-6 Kugahara, Ota-ku, Tokyo (56) Reference JP-A-55-3089 (JP, A) JP-A-4-205603 (JP, A) JP-A 1-251102 (JP, A) JP-A-10-285989 ( JP, A) JP 55-134404 (JP, A) JP 2-165303 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G05B 11/36 G05B 11/28 G05B 11/32

Claims (2)

(57) [Claims] 1. A and adder for adding the correction value to the control output signal for controlling the controlled object, flop from influencing the disturbance measurement result to an operation of the controlled
A feedforward processing unit that inputs as a feedforward amount for changing the process gain, thereby performing a feedforward process on the addition control output signal from the addition unit so as to suppress the influence of the disturbance, and outputting an addition control output signal, ON / OFF in a predetermined repetition time proportional cycle according to the feed-forward processed addition control output signal
A time-proportional output unit that outputs a time-proportional output converted to a ratio to the control target side, and a control output signal average calculation unit that calculates an average value of the addition control output signals before the feedforward processing within the time proportional cycle ON to turn on a predetermined operation signal for operating the controlled object
An actual output calculation unit that calculates time based on the time proportional output and the feedforward amount, and calculates the actual output of the time proportional output from the ratio of the time proportional cycle to the ON time; and the addition control output signal average value. A correction value calculation unit that outputs the difference from the actual output as the correction value to the addition unit , wherein the addition unit corrects the correction based on the repetition time period.
The value of the control output in the next repetition time proportional period
A time proportional control device characterized by being added to a signal . 2. A PID calculation unit for performing PID calculation of a deviation between a set value and a measured value from the controlled object, wherein the addition unit corrects the PID calculation output from the PID calculation unit as the control output signal. The method for adding a value
The time-proportional control device described.