Machine Sound Anomaly Detection With Timbre Separation

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Solution Overview

Problem

Current anomaly detection methods using unsupervised machine learning fail to distinguish between different types of anomalies, treating all outliers similarly and lacking the ability to differentiate between relevant and irrelevant anomalous sounds in acoustic data from machines.

Innovation Solution

The use of a computer program product that employs a target autoencoder and an environmental autoencoder to reconstruct waveforms, with a neural network classifier determining whether an input waveform represents anomalous behavior of a target device by distinguishing between target device waveforms and unrelated sound events, enabling automatic response to anomalies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If unsupervised machine learning is used for anomaly detection, then the system can detect abnormal waveforms, but it cannot distinguish between different types of anomalies

Engineering Contradiction:
Improveanomaly detection capabilityVSAvoidanomaly type differentiation
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent divides the anomaly detection task into two separate autoencoders: one trained on target device waveforms and another on environmental sound waveforms. Each autoencoder specializes in reconstructing its specific type of waveform, enabling the system to distinguish between device-generated anomalies and environmental noise by comparing reconstruction errors from both models.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If a single anomaly detection model is used, then the system is simple to implement, but it treats all anomalies the same without distinguishing relevant from irrelevant sounds

Engineering Contradiction:
Improvemodel implementation simplicityVSAvoidanomaly relevance information
Core Design Contradiction:
Ease of manufactureVSLoss of information

Solution Approach 1:

The patent introduces an intermediary classification layer that takes the reconstruction errors from both autoencoders as inputs and determines whether an anomaly is relevant (device-related) or irrelevant (environmental). This intermediary component preserves anomaly relevance information while building upon the simple autoencoder framework.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If acoustic data is used to monitor machine condition, then insights about inner workings are obtained, but irrelevant environmental sounds create false anomalies

Engineering Contradiction:
Improvemachine condition insightVSAvoidenvironmental noise interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and isolates environmental sound patterns by training a separate autoencoder exclusively on environmental waveform data. This dedicated model reconstructs environmental sounds, allowing the system to identify and filter out environmental noise from the target device monitoring, thereby reducing false anomalies while preserving genuine machine condition insights.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS11443758B2Anomalous sound detection with timbre separation
Publication Date: 2022.09.13 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • US11443758B2 patent drawing
  • US11443758B2 patent drawing
  • US11443758B2 patent drawing

AI summary

Methods, systems, and computer program products for detecting anomalous behavior include reconstructing a waveform of a target device from an input waveform using a target autoencoder. A waveform of unrelated sound events is reconstructed from the input waveform using an environmental autoencoder. The input waveform is classified to determine that the input waveform is produced by anomalous behavior of the target device using a classifier, based on the reconstructed waveform of the target device and the reconstructed waveform of the unrelated sound events. An automatic response to the anomalous behavior is generated.