JPH01175604A - Controller - Google Patents

Abstract

PURPOSE:To control an output value for controlled system to a control reference value while an output value for controlled system is maintained within a limited value by selecting either a selector for control reference value specified control circuit of a selector for limited reference value specified control circuit. CONSTITUTION:When the output value A for controlled system 5 exceeds a lower limit reference value Amin, for example, the selector 27 for control reference value specified control circuit 27 of the control circuit and a logic circuit selector 29A are selected and a switch 9 is turned ON, whereby the output value B for controlled system 6 is constant-controlled so that the output value B for controlled system 6 shows a control reference value Bref. When the output value B is below the control reference values Bref, for example, an upper limit reference value Amax is set as the limited reference value Aref for controlled system 5, the selector 28 of control reference value specified control circuit 28 and a logic circuit selector 29D are selected, and a switch 12 is turned ON, whereby the limited reference value is constant-controlled so that the output value A does not exceed the upper limit reference value Amax. Thus, the output value B is stably controlled to the control reference value Bref while the output value A is maintained within the limited value.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to controlling the output value of a controlled object to a control reference value while keeping the output value of a limiting object within a limit value consisting of an upper limit reference value and a lower limit reference value. The present invention relates to a control device for controlling.

[Conventional technology]

FIG. 5 is a block diagram showing a conventional control device.
A control reference value setter for setting f, 2 is a control reference value B r
3 is an amplifier, 4 is an adder that adds the output signal of amplifier 3 and the output signal of amplifier 8, 5 is the limit target of transfer function a, 6 is transfer function 7 indicates the upper and lower limiters of the controlled object 5.

Next, the operation will be explained.

The control reference value Bref of the controlled object 6 is set in the control/reference value setter 1, and the output value B of the controlled object 6 is controlled, and the output value of the restricted object 5 is set to the upper limit reference value Amax and the lower limit reference value Ami. When controlling within the range of n, that is, within the limit value, the upper and lower limit Mitsutaf outputs a negative signal when the output value A exceeds the upper limit reference value Amax, and the output value A falls below the lower limit reference value Amin. and outputs a positive signal.

Then, the output signals of the upper and lower limits are amplified by the amplifier 8 so as to obtain a predetermined limiting effect.

Next, the output signals of the amplifiers 3 and 8 are added by an adder 4, and the output value A of the limiting object 5 is controlled within the limit value, and the controlled object 6 is controlled to the control reference value Bref.

[Problem that the invention seeks to solve]

Since the conventional control device is configured as described above, even if the output value A of the restricted object 5 is outside the limit value, the control is performed using the added value with the output value B of the controlled object 6. There is a problem in that it is difficult to determine the transfer function of the amplifier 7 so as to maintain the restriction target 5 within the limit value while maintaining stability.

This invention was made to solve the above-mentioned problems, and an object of the present invention is to obtain a control device that can stably control a controlled object while maintaining the output value of the limited object within the limit value. .

[Means for solving problems]

The control device according to the present invention compares the detected value of the controlled object with the limit value in the first comparing circuit, and compares the detected value of the controlled object with the control reference value with the output signal of the first comparing circuit. The third comparison circuit performs a comparison, and the first. The configuration is such that the constant control reference value control circuit selector or the constant limit reference value control circuit selector is selected based on the output signals of the second and third comparison circuits.

[For production]

In the control device according to the present invention, when the constant control reference value control circuit selector is selected, the constant control reference value control is performed to set the output value of the controlled object to the control reference value, and the constant limit reference value control circuit selector is When selected, limit reference value constant control is performed to keep the output value of the controlled object within the limit value.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, parts that are the same as those in FIG.
This figure shows a limit reference value setter for setting an upper limit reference value Amax and a lower limit reference value Am1n, and outputs the upper limit reference value Amax or the lower limit reference value Am1n as the limit reference value Aref.

Reference numeral 11 denotes a subtractor that subtracts the output value A of the restriction target 5 from the restriction reference value A r e f, and 12 represents a switch that is turned on in conjunction with selection of a constant limit value control circuit selector, which will be described later.

FIG. 2 is a circuit diagram showing a limiting circuit of the control device. In the figure, 21 indicates a first comparison circuit, which compares the output value A of the limiting object 5 (FIG. 1) with the upper limit reference value Amax. Comparators 22A and 22B, output value A and lower limit reference value Am1n
It is composed of comparators 23A and 23B for comparing. 24A to 24F are OR circuits, 25A and 25B are second
．． A comparator as a third comparison circuit is shown, and comparator 25A
is the output value B of the controlled object 6 (Fig. 1) and the control reference value B re when the output value A exceeds the upper limit reference value A max
f, and the comparator 25B determines that the output value B is the lower limit reference value A.
Output value B and control reference value B re when the value is less than m1n
It is compared with f. 26A is a first setting device for setting the control reference value Aref of the restriction target 5 to the upper limit reference value Amax, and 26B is a first setting device for setting the restriction reference value Aref of the restriction target 5 to the lower limit reference value Amin. A second setter 27 sets the control target 6 to the control reference value B ref
28 is a limit reference value constant control circuit selector that controls the restriction target 5 only with the limit reference value A r e f; 29A to 29D are first control reference value constant control circuit selectors;
- shows a fourth logic circuit selector, each comparator 22A, 22
B, 23A, 23B.

This is to ensure that the output signals of 25A and 25B pass through the same logical route as long as they maintain the same state.

Each of the above-mentioned comparators 22A, 22B, 23A, 23B.

25A and 25B are 1 comparison input example No. X1. as shown in FIG. Depending on the magnitude relationship of X2, the output signal Y1. Output Y2.

Next, the operation will be explained.

When the restriction and control operations are started, first, the first logic circuit selector 29A is selected, and the comparator 22A compares the output value of the restriction target 5 with the upper limit reference value Amax, and the output value A is the upper limit. When the value falls below the reference value Amax for h, the comparator 23A compares the output value A with the lower limit reference value A min. As a result, if the output value A exceeds the lower limit reference value Am1n, the control reference value constant control circuit selector 27 is selected, the switch 9 is turned on, and the output value B is set to the control reference value Href.
Control reference value constant control is performed so that. At the same time, the first logic circuit selector 29A is selected, and the output value A at the comparators 22A and 23A is the upper limit reference value A m a
If there is no change in the magnitude relationship between x and the lower limit reference value Am1n, selection by both selectors 27.29A is continued.

Next, the comparator 22A compares the output value A with the upper limit reference value Amax, and if the output value A exceeds the upper limit reference value Amax, the comparator 25A compares the output value B of the controlled object 6 with the control reference value. Compare with B ref. As a result, if the output value B is lower than the control reference value B ref, the upper limit reference value Amax is set as the restriction reference value Aref of the restriction target 5,
When the limit reference value constant control circuit selector 28 is selected and the switch 12 is turned on, the output value A becomes the limit reference value Aref,
Limit reference value constant control is performed so that the limit reference value is below the upper limit reference value Amax. At the same time, the fourth logic circuit selector 29D is selected, and if there is no change in the magnitude relationship between the output value B of the comparator 24A and the control reference value Bref, the selection of both selectors 28 and 29D is continued. Ru. Similarly, both selectors 27, 29B or 28, 290 are selected, and the control reference value or limit reference value constant control is performed.

Tonoyo 5fk control is shown in chart 7a of FIG.

As described above, depending on the magnitude relationship of the output value A, the upper limit reference value Amax and the lower limit reference value A m t n% or the output value B and the control reference value Bref, the first to fourth logic circuit selectors 29A to 29D are selected. Since the control reference value or limit reference value constant control is performed while changing the selection, the output value A of the limit object 5 is maintained within the limit value, and the output value B of the control object 6 is stabilized to the control reference value B ref. Easy to control,
And it can be done quickly.

In the above embodiment, the limit reference value Aref has been described as the upper limit reference value Amax or the lower limit reference value Amin, but it may be a correction value that takes into account the detection error and limit error of the output value A.

〔Effect of the invention〕

As described above, according to the present invention, the first. Since the configuration is such that the constant control reference value control circuit selector or the constant limit reference value control circuit selector is selected based on the output signals of the second and third comparison circuits, the output value to be limited is maintained within the limit value. This has the effect that the output value of the controlled object can be stably controlled to the control reference value easily and quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a control device according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing a limiting circuit of the control device according to an embodiment of the invention, and FIG. 3 is an input signal and output of a comparator. FIG. 4 is a flowchart showing the operation, and FIG. 5 is a block diagram showing a conventional control device. 1 is a control reference value setter, 5 is a restriction target, 6 is a control target,
9 and 12 are switches, 10 is a limit reference value setter, 21 is a first comparator, 25A and 25B are comparators, 27 is a control reference value constant control circuit selector, and 28 is a limit reference value constant control circuit selector. shows. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] The output value to be limited is compared with a limit value consisting of an upper limit reference value and a lower limit reference value, and the output value is within the limit value.
a second signal, the output value of which is greater than the upper reference value;
or a third signal whose output value is smaller than the lower limit reference value, and a first comparison circuit that outputs a signal of , a second comparison circuit that outputs a fourth signal in which the output value of the controlled object is larger than the control reference value, or a fifth signal in which the output value of the controlled object is smaller than the control reference value; A third signal is used to compare the output value of the controlled object with the control reference value, and a sixth signal indicates that the output value of the controlled object is larger than the control reference value, or the output value of the controlled object is larger than the control reference value. a third comparison circuit that outputs a seventh signal smaller than the control reference value;
A control device comprising: a constant control reference value control circuit selector selected by the signal; and a constant limit reference value control circuit selector selected by the fifth or sixth signal.