JPH01201704A - Controller for servo system - Google Patents

Abstract

PURPOSE:To suppress oscillation by deciding the condition of the oscillation of the preceding action and changing a target value string when it is decided to be the oscillation. CONSTITUTION:The controller of a servo system 1 decides the output of the servo system 1 by an oscillation deciding device 2 and changes the interval of a target value decided by an oscillation factor interval deciding device 3 into the target value of the servo system 1 by a target value converter 4. This device decides whether a overshoot (a) of response is larger than a certain value or not and decides the oscillation. When it is decided to be the oscillation, the oscillation factor interval deciding device 3 refers to a knowledge base for deciding the oscillation factor interval, decides which interval should be changed and instructs the target value changing device 4 about the interval.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a method for changing a target value for a servo system.
A servo system control bag #l that suppresses undesirable vibrations is involved.

(Prior art) Conventionally, in a servo system, in order to accurately follow the target value, the gain of the J control law is changed to adjust the amount of feedback, and the output is made to match the target value as much as possible.
If the target value is not smooth enough - the target value l
There was a problem in that vibrations occurred due to trying to make the object follow the object, and that the tracking accuracy deteriorated when trying to suppress the vibration.

[Structure of the invention]

(Means for Solving Problem a) The present invention includes means for determining vibration of a servo system, means for determining a section of a target value that is a cause of vibration, and means for smoothly changing the target value. , when it is determined that vibration is occurring, the corresponding section of the target value is changed so that it runs more smoothly.

(Function) The vibration state of the previous operation is determined, and if it is determined to be a perturbation, Dream ζ converts the target value sequence in the section that induces vibration to a smoother target value sequence #C to suppress the vibration.

(Embodiment) FIG. 1 is a diagram showing one embodiment of the present invention. The output of the servo system 1 is determined by the vibration determining device 2, and the target value interval determined by the vibration factor interval determining device 3I is changed by the target value converting device It4I to become the target value of the servo system 1.

FIG. 2 is an example of the target value and the response of the servo system.

In contrast to the target value l, the response oscillates after time te.

For example, the vibration determination device of FIG.
It is determined whether or not δ is larger than a certain value δ, and vibration is determined. When vibration 2 is established, the vibration factor interval determination device refers to the knowledge base for vibration factor interval determination, determines which interval should be changed, and instructs the target value change device to the interval. For example, there is too much knowledge base - jjJ, a
and the vibration period t and the ratio of the first and second overshoot amounts b/a
etc., and the relationship between the target value interval that causes vibration is set as n.

FIG. 3 is an explanatory diagram of the operation of the target value changing device.

For example, as shown in FIG. 2, a time that is an appropriate time T before time te is set as (C), and the target value of the interval (tc, te) determined by the vibration factor interval determination device lζ is changed. How to change it For example, if the previous target value is f (t) and the new target value is g (t), then the target value before time te can be smoothed as shown in the diagram. Suppress vibration.

(Effects of the Invention) According to the present invention, vibrations in the response of the servo system can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a response characteristic diagram showing a response example, and FIG. 3 is a characteristic diagram showing an example of changing a target value. 2... Vibration determining device, 3... Vibration factor section determining device, 4... Target value converting device.

Claims (1)

[Claims] In a servo system that is controlled to follow a target value, there is a means for monitoring the output of the servo system and determining vibration in the output, a means for determining a section of the target value that is a cause of vibration, and a means for determining the vibration. A control device for a servo system, comprising means for changing the corresponding section of the target value accordingly.