Feed Mechanism Vibration Compensation Using Positional Frequency Analysis

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Solution Overview

Problem

Existing methods fail to effectively suppress vibrations in the second axis direction orthogonal to the first axis direction when a movement target is moved in the first axis direction, often amplifying vibrations independent of the first axis position.

Innovation Solution

A compensation quantity acquisition device and method that utilize a vibration acquisitor, positional frequency characteristic acquisitor, position independent frequency storage, and position dependent vibration acquisitor to acquire and cancel position-dependent vibrations by performing Fourier transformations and inverse Fourier transformations, allowing a feed mechanism control device to drive a second driver based on the acquired compensation quantity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If vibration cancellation is applied without considering position dependence, then control simplicity is maintained, but vibration suppression effectiveness is reduced

Engineering Contradiction:
Improvecontrol system complexityVSAvoidvibration suppression effectiveness
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism that detects the actual position of the movement target along the first axis and uses this information to adjust the vibration cancellation amount in the second axis direction. The feedback loop continuously monitors position and modifies the cancellation strategy accordingly, achieving effective vibration suppression without requiring overly complex predictive models or advance calculations

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively suppresses vibrations in the second axis direction, preventing amplification and ensuring stable movement by distinguishing between position-dependent and position-independent vibrations.

Implementation Method 1

a positional frequency characteristic acquisitor configured to acquire a positional frequency characteristic by performing Fourier transformation on the vibration in the second axis direction

Methodology Applied
Scientific EffectFourier transformation:

Implementation Method 2

a position dependent vibration acquisitor configured to perform inverse Fourier transformation on the positional frequency characteristic from which a component of the position independent frequency has been removed, to recover the vibration of the movement target

Methodology Applied
Scientific EffectInverse Fourier transformation:

Data Source

PatentEP3540538B1Compensation quantity acquisition device, feed mechanism control device, compensation quantity acquiring method and feed mechanism control method
Publication Date: 2021.09.08 FANUC LTD
  • EP3540538B1 patent drawingFigure 1
  • EP3540538B1 patent drawingFigure 2
  • EP3540538B1 patent drawingFigure 3

AI summary

A compensation quantity acquisition device (41) acquires vibration of the movement target (11) in a second axis direction, orthogonal to the first axis direction when the movement target (11) is moved in the first axis direction, acquires a positional frequency characteristic by performing Fourier transformation on the acquired vibration in the second axis direction, performs inverse Fourier transformation on the positional frequency characteristic from which the component of position independent frequency in the second axis direction (that occurs independently of a position of the movement target in the first axis direction) has been removed, to recover the vibration of the movement target (11) in the second axial direction as position dependent vibration, and acquires positional compensation quantity of the movement target (11) in the second axis direction that cancels the position dependent vibration.