Chatter Prediction Neural Network Stability Model

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Solution Overview

Problem

Current methods for predicting chatter in machine tools are limited by inaccurate measurement of machining parameters, especially in real production environments, leading to insufficient accuracy in stability lobe diagrams and chatter prediction.

Innovation Solution

An artificial neural network is used to predict chatter by feeding input data and adjusting weights based on comparison with measured stability data, in conjunction with a stability model like the Zero Order Solution, to improve the accuracy of chatter prediction and stability lobe diagram generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If experimental methods are used to obtain stability data, then measurement accuracy can be improved, but the complexity of the measurement system and time consumption increase significantly

Engineering Contradiction:
Improvestability data measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical measurement systems with an artificial neural network-based computational model. Instead of using extensive sensors and measurement equipment to directly measure stability lobes, the system uses a neural network trained on available data to predict stability boundaries, thereby substituting physical measurement infrastructure with an intelligent algorithmic approach.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent creates a virtual model (neural network) that copies and simulates the complex relationship between machining parameters and chatter stability. Rather than physically measuring all parameters, the system learns from available data and generates predictions that replicate the behavior of the actual machining system, eliminating the need for direct physical measurement of difficult-to-access parameters.

Inventive Principle:
Principle #26Copying

2Measurement precision

If comprehensive measurement data is collected in real production environment, then prediction accuracy can be improved, but the difficulty of detecting and measuring all required parameters increases

Engineering Contradiction:
Improvechatter prediction accuracyVSAvoiddifficulty of measuring machining parameters
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces an artificial neural network as an intermediary that bridges the gap between easily measurable parameters (spindle speed, feed rate, depth of cut) and difficult-to-measure parameters (tool center point dynamics, chatter stability). The neural network learns the complex relationships from training data and acts as a mediator that predicts the hard-to-measure quantities based on readily available measurements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system replaces direct physical measurement of complex parameters like tool center point dynamics with computational prediction through neural networks. This substitution eliminates the need for sophisticated sensors and measurement systems while maintaining prediction accuracy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If traditional stability models are used without neural network, then the system complexity remains low, but the accuracy of chatter prediction for varying machining conditions deteriorates

Engineering Contradiction:
Improveprediction system complexityVSAvoidchatter prediction accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transforms the static, fixed-parameter stability models into dynamic, adaptive models through the neural network. The system continuously learns from new data and adjusts its predictions based on varying machining conditions, tool wear, and workpiece characteristics, enabling the model to adapt its behavior rather than relying on predetermined fixed parameters.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The neural network enables dynamic parameter adjustment by learning optimal stability predictions from training data. Instead of using fixed theoretical parameters, the system adjusts its internal parameters (weights and biases) based on actual machining outcomes, allowing accurate predictions across varying conditions without increasing physical system complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3742244A1A method for predicting chatter of a machine tool
Publication Date: 2020.11.25 UNITED MACHINING MILL AG
  • EP3742244A1 patent drawingFigure 1
  • EP3742244A1 patent drawingFigure 2
  • EP3742244A1 patent drawingFigure 3

AI summary

The present invention is directed to a method for predicting chatter of a machine tool. The method comprises the following steps: Feeding first input data into an artificial neural network, which includes a plurality of weights; Determining first output data at the output of artificial neural network based on the first input data and the plurality of weights; Providing the first output data into a stability model to generate prediction data; Comparing the prediction data with measurement stability data and adjusting the plurality of weights of the artificial neural network.