Multivariate Time-Series Precursor Detection for Early Anomaly Prediction

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Solution Overview

Problem

Early anomaly detection in multi-variate time series data is challenging due to uncertainty in identifying the exact time when precursor symptoms occur, making it difficult to use user-provided labeled data effectively for predictive maintenance.

Innovation Solution

The method employs multi-instance learning with long short-term memory (LSTM) to identify precursor feature vectors from multi-variate time series data segments before an abnormal period, using contrastive loss and hinge loss to ensure the extracted features are robust and interpretable, even with limited labeled data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If user-provided labeled abnormal time periods are used for anomaly detection, then the detection can be performed with available data, but the exact timing of precursor symptoms remains uncertain and difficult to identify

Engineering Contradiction:
Improveanomaly detection accuracyVSAvoiduncertainty in precursor symptom timing
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the time series data into multiple instance sections within the abnormal time period. Each instance section is independently analyzed to identify precursor symptoms, allowing the system to pinpoint specific time segments where anomalies begin rather than treating the entire abnormal period as a single unit. This segmentation resolves the timing uncertainty by breaking down the ambiguous abnormal period into analyzable segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary analysis by extracting precursor features from instance sections that occur before the confirmed abnormal phase. By analyzing the time series data in reverse chronological order from the labeled abnormal period, the system identifies precursor symptoms in earlier time segments, enabling early detection before the full anomaly manifests. This preliminary action allows the system to detect anomalies at their earliest detectable stage.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multi-instance learning with LSTM is applied to extract precursor features, then early detection accuracy is improved, but the computational complexity and model requirements increase

Engineering Contradiction:
Improveprecursor feature extraction accuracyVSAvoidLSTM model complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the time series data into multiple instance sections and applies multi-instance learning, where each instance section is processed independently by the LSTM model. This segmentation allows the complex LSTM model to focus on smaller, manageable time segments rather than processing the entire time series at once, making the computational task more tractable while maintaining high detection accuracy through aggregated results from multiple instances.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies LSTM modeling selectively to extract only the relevant precursor features from each instance section, rather than attempting to model all aspects of the time series data. By focusing computational resources on identifying specific precursor patterns rather than comprehensive analysis, the system achieves high detection accuracy with reduced computational overhead compared to full-series modeling.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentUS11204602B2Early anomaly prediction on multi-variate time series data
Publication Date: 2021.12.21 NEC CORP
  • US11204602B2 patent drawing
  • US11204602B2 patent drawing
  • US11204602B2 patent drawing

AI summary

Systems and methods for early anomaly prediction on multi-variate time series data are provided. The method includes identifying a user labeled abnormal time period that includes at least one anomaly event. The method also includes determining a multi-variate time series segment of multivariate time series data that occurs before the user labeled abnormal time period, and treating, by a processor device, the multi-variate time series segment to include precursor symptoms of the at least one anomaly event. The method includes determining instance sections from the multi-variate time series segment and determining at least one precursor feature vector associated with the at least one anomaly event for at least one of the instance sections based on applying long short-term memory (LSTM). The method further includes dispatching predictive maintenance based on the at least one precursor feature vector.