JPH01259334A - Servo-controller - Google Patents

Abstract

PURPOSE:To automatically eliminate a zero adjustment shift and to execute a servo-control by obtaining correction data of the zero adjustment shift, based on the deviation of a position set value and a position feedback value and bringing the data to subtracting correction from the deviation. CONSTITUTION:The deviation DELTAS of a position set value set by a position setting device 1 and a feedback value obtained from a position feedback value output device 2 is allowed to pass through a dead band means 13, and it is detected to exceeds the reference value of a prescribed zero adjustment shift. Subsequently, DELTAS' allowed to pass through the means 13 is multiplied by the adjustment gain of a zero adjustment shift of an adjustment gain output device 14 by a multiplier 15, and its multiplied value is subtracted from DELTAS by a subtracter 4. As a result, the zero adjustment shift accumulated stably is eliminated and the state that the position feedback value is equal to the position set value can be held. In such a way, the correction of the zero adjustment shift can be performed automatically and continuously and a servo-control is executed with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to a servo control device that automatically corrects 5-zero adjustment deviation in a control system such as a hydraulic pressure reduction device.

[Conventional technology]

FIG. 2 is a block diagram showing a conventional servo control device for a hydraulic pressure reduction device. In the figure, 1 is a position setting device that sets the operating position of the controlled device, and 2 is a position setting device that outputs a feedback value of the position of the controlled device. position feedback value output device,
3 is a subtracter, and 5 is a deviation (ΔS) between the position setting value and the feedback value. 6 is a control gain output device, T is a multiplier, 8 is an adjustment point IJ for correcting the zero adjustment deviation of the control system,
9 is an output amplifier, 10 is a servo amplifier, 11 is a servo feedback output, and 12 is a servo valve as a controlled device.

Next, the operation will be explained. First, in controlling the operating position of the servo valve 12, the subtractor 3 takes the deviation ΔS between the position setting value set by the position setting device 1 and the feedback value obtained from the position feedback value output device 2, and the deviation ΔS is calculated based on this deviation. The control gain from the gain output device 6 is multiplied, and the multiplication result is output to the servo amplifier 10 via the adjustment polyne 8 and the output amplifier 9. The servo amplifier 10 takes the deviation from the servo feed pack output 11 and outputs it to the servo valve 12. Also, during servo control, the character of the control system may deviate (hereinafter referred to as character deviation) due to the characteristics of each amplifier 9, 10 or element. , and adjust the zero point of the entire control system.

[Problem to be solved by the invention]

Conventional servo control devices are configured as described above, so in order to perform stable servo control, it is necessary to constantly monitor the control system for deviations. There were problems such as having to readjust the adjustment volume 8 each time the adjustment was made.

This invention has been made to solve the above-mentioned problems, and aims to provide a servo control device that can monitor character deviations in a control system and automatically eliminate the character deviations.

[Means to solve the problem]

The servo control device according to the present invention uses deadpan means to detect the amount by which the deviation between the position setting value and the position feedback value exceeds a preset reference value, and uses the detected amount to adjust the deviation by using the multiplier. The structure is such that the multiplication result is multiplied by a gain, the multiplication result is subtracted from the deviation by a subtracter, and the result is output to the controlled device.

[For production]

The subtracter according to the present invention calculates the deviation between the position setting value and the position feedback value by using the correction data for the offset obtained based on the output amount of the deadpan means, that is, the multiplication value of the output amount and the gain for the offset. Subtractive correction automatically removes character deviations due to changes in characteristics of various parts of the control system.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, 1 is a position setting device, 2 is a position feedback value output device, 3 is a subtracter, 4 is a subtractor, and 5 is a deviation (ΔS
), 6 is a control gain output device, 7 is a multiplier, 8 is an adjustment volume, 9 is an output amplifier, 10 is a servo amplifier, 11 is a servo feedback output, 12 is a servo valve, 13 is a deviation ΔS from a predetermined basic setting value 14 is an adjustment gain output device for the adjustment gain for character deviation, and 15 is a multiplier.

Next, the operation will be explained. Here, the basic control operation is the same as that of the conventional circuit, and a redundant explanation thereof will be omitted here. In this invention, first, the deviation ΔS is passed through the deadpan means 13 to detect that it exceeds a certain reference value for character deviation.

Generally, when the position set value fluctuates greatly, there is a delay in the position feedback, that is, it takes time for the position feedback signal to be received by the position value output device 2. The output deviation ΔS' of the deadpan means 13 increases, but decreases with time, so the deadpan set value is set so as not to depend on this temporary value.
A multiplier 15 multiplies the ΔS′ after passing through the ΔS′ by an adjustment gain for character deviation from an adjustment gain output device 14, and a subtracter 4 subtracts this multiplied value from ΔS. As a result, the stably accumulated character deviations are removed, and the position feedback value can be kept equal to the position setting value.

Expressing this in a formula, △5 SERVO: Servo output SRmr: Position setting value 5FIK: Position feedback value △S': ΔS゛GN after deadpan: Adjustment gain for character deviation V RN* Adjustment value by tone adjustment sole G: This is the gain of the entire servo system, and items that were conventionally adjusted with adjustment volume 8 will be automatically corrected with -(ΔS'XGN).

Note that in the above embodiment, the servo valve 12 is used as the controlled device.
Although a servo system under hydraulic pressure using a servo system has been described, it can be applied to any other servo system that prevents such misalignment, and the same effects as in the above embodiment can be achieved.

〔Effect of the invention〕

As described above, according to the present invention, the adjustment value for the keynote shift is obtained based on the deviation between the position setting value and the position feedback value, and this is subtracted from the deviation.
It is possible to automatically and continuously correct the base tone deviation without manual intervention, and there is an effect that a high base tone accuracy, that is, a high servo control accuracy can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a servo control device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional servo control device. 4 is a subtracter, 12 is a controlled device, 13 is a deadpan means, and 15 is a multiplier. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Patent applicant Mitsubishi Electric Corporation Representative Patent attorney 1) Hiroshi Sawa 1,'. (2 others) Figure 1 Figure 2

Claims (1)

[Claims] A servo control device that automatically controls the operation of a controlled device based on a deviation between a position setting value and a position feedback value, a deadpan means for detecting the amount by which the deviation exceeds a preset reference value, and a deadpan means for detecting the amount by which the deviation exceeds a preset reference value; A servo control device comprising: a multiplier that multiplies an adjustment gain for zero adjustment; and a subtracter that subtracts the multiplied value from the deviation and outputs the subtracted value to the controlled device.