JPH01243101A - Digital controller - Google Patents

Abstract

PURPOSE:To obtain a control system to quickly respond and not to overshoot by linearly changing the gain of the control system according to the quantity of a deviation. CONSTITUTION:When a set gain is made into G and a deviation signal is made into epsilon, for the gain of a digital controller equipped with an absolute value converter 8 and a gain arithmetic device 9, the deviation signal is made into ¦epsilon¦by the absolute value converter 8, the gain computing element 9 function- converts the output value of the absolute value converter 8 to 1+DELTA, and GX(1+DELTA) is obtained with the set gain G. By the arithmetic gain of the gain computing element 9, when the deviation is large, the gain is made high, and a response is made quick, and as the deviation is made small, the gain is made low, and the response is slow. Thus, the system can be obtained which responds quickly and does not overshoot.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a digital control device having a feedback control system.

(Prior Art) An example of a control device having a conventional feedback control system will be described with reference to FIG. In this conventional example, a detector 2 connected to the controlled object 1 detects the actual value of the controlled object 1. The reference circuit 3 outputs a reference value that is a control target value of the controlled object 1. The deviation detector 4 reads the reference value of the reference circuit 3 and the detected value of the detector 2 at regular intervals, and calculates a system suitable for controlling the reference value and the object 1 by proportional calculation, integral calculation, and differential calculation. etc., and outputs the product multiplied by the output of the gain setter 5. The energy control converter 7 provides energy controlled by the output signal of the control system 6 to the controlled object 1.

(Problem to be Solved by the Invention) However, in the conventional control device described above, in the case of sampling control, when trying to shorten the response time by increasing the gain, due to the relationship between the response time and the number of samplings, The number of times the reference value and the detected value can be sampled decreases, and the step response waveform becomes an overshoot waveform as shown in FIG. 3(a). Furthermore, in order to eliminate overshoot, the gain must be lowered to create a waveform with a longer response time, as shown in FIG. 3(b).

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a control device that does not cause overshoot even if the response time is shortened.

[Structure of the invention]

(Means for Solving Problem 711) Therefore, in order to achieve the above object, the present invention provides a reference setting means for setting a reference value that is a control target value of a controlled object, and a method for detecting an actual value of the controlled object. a detection means, a deviation calculation means for calculating the deviation between a reference value and an actual value, a coefficient setting means for setting an arbitrary coefficient based on the deviation, a conversion means for converting the deviation into an absolute value, and a conversion means for converting the deviation into an absolute value; A digital control device is provided that includes a coefficient setting means for performing a function conversion on an output value and multiplying the function-converted value by a coefficient from a coefficient setting means, and a conversion means for converting the deviation into an absolute value.

(Function) In the digital control device configured as above,
When the difference between the reference value and the output value of the detection means is large, that is, when the output value of the deviation calculation means is large, the gain becomes large and the response becomes fast. Further, as the actual value of the controlled object approaches the target value and the difference between the reference value and the output value of the detection means becomes smaller, the gain gradually becomes smaller and the response becomes slower.

In this way, the gain changes linearly according to the output value of the deviation calculation means, that is, the amount of deviation from the reference detected value, and when the deviation is large, the gain increases and approaches the target value quickly. When the gain approaches the target value, the gain is lowered to prevent overshoot.

(Embodiment) Hereinafter, the same components as those of the control device in which an embodiment of the present invention will be described based on the drawings will be denoted by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 1, the absolute value converter 8 is connected to the deviation detector 4.
Convert the output value of to absolute value. The gain calculator 9 performs a function conversion on the output of the absolute value converter 8, multiplies the function-converted value by the output value of the gain setter 5, and further multiplies the result by the output of the deviation detector 4. . These absolute value converters 8,
The gain of the digital control device equipped with the gain calculator 9 is:
Assuming that the set gain is ε for the G deviation signal, the deviation signal at the absolute value converter 8 becomes 1ε1. The gain calculator 9 converts the output value "h" of the absolute value converter 8 into 1+Δ, and calculates GX (1+Δ) from the set gain G. Reference value,
FIG. 5 shows the relationship among the detected value, deviation, and control gain. Due to the calculation gain of the gain calculator 9, when the deviation is large, the gain becomes high and the response becomes fast, and as the deviation becomes small, the gain becomes low and the response becomes slow, as shown in Fig. 3(c). It is possible to create a system that has a quick response and does not overshoot.

〔Effect of the invention〕

As described above, according to the present invention, the gain of the control system is changed linearly according to the amount of deviation.

=4- As a result, when the deviation is large, the gain is high, and as the deviation becomes small, the gain is low, so that a control system with quick response and no overshoot can be realized.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing an embodiment of the present invention, FIG. 2 is a waveform diagram showing each signal of the digital control device shown in FIG. 1, and FIG. 3(a) is a conventional control diagram. Waveform diagram showing the step response when the gain in the device is high, Figure 3(b)
is a waveform diagram showing the step response when the gain is low in the conventional control device, and FIG. 3(C) is a waveform diagram showing the step response in the digital control device shown in FIG.
FIG. 4 is a circuit configuration diagram showing a conventional control device. 1... Controlled object 2... Detector 3... Reference circuit 4... Deviation detector 5... Gain setting device
8...Absolute value converter 9...Gain calculator agent Patent attorney Rule Ken Chika Yudo Ken Daishimaru Figure 2 Figure 3

Claims (1)

[Claims] a reference setting means for setting a reference value that is a control target value of a controlled object; a detection means for detecting an actual value of the controlled object; a deviation calculating means for calculating a deviation between the reference value and the actual value; a coefficient setting means for setting an arbitrary coefficient based on the deviation; a conversion means for converting the deviation into an absolute value; and a coefficient for converting the output value from the conversion means into a function and multiplying the value converted by the function by the coefficient. A digital control device characterized by comprising a calculation means.