Vehicle Power Electronics Prognostics Using Contextual Autoencoders

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Solution Overview

Problem

Power electronic (PE) modules in vehicles experience degradation and early failure due to high power densities and temperature conditions, making it difficult to predict imminent failures without advanced data analysis.

Innovation Solution

The use of autoencoders trained with datasets including contextual information to generate clusters representing operating conditions, allowing for prognostics of PE devices by determining the minimum distance of encoded features from these clusters, thereby predicting current and future operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If basic sensed data (current, voltage, temperature) is used to detect anomalies, then anomaly detection capability is improved, but the ability to predict imminent failure of specific PE modules deteriorates

Engineering Contradiction:
Improveanomaly detection capabilityVSAvoidimminent failure prediction accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent transitions from analyzing basic sensed data in the original feature space to using autoencoders that map data into a compressed latent feature space. This dimensional transformation enables the system to capture complex patterns and relationships that are not apparent in the original data, thereby improving failure prediction capability while maintaining anomaly detection accuracy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The autoencoder acts as an intermediary between the raw sensed data and the failure prediction logic. By introducing this intermediate processing layer with contextual information integration, the system can bridge the gap between basic anomaly detection and sophisticated imminent failure prediction, resolving the contradiction between the two capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If autoencoders are trained with contextual information to improve prognostics accuracy, then failure prediction capability is improved, but system complexity increases

Engineering Contradiction:
Improveprognostics accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-training autoencoders with contextual information from healthy PE devices before deployment. This offline training phase captures operational patterns and relationships, allowing the system to achieve high prognostics accuracy during operation without requiring complex real-time processing. The contextual information is integrated in advance, reducing the computational burden during actual failure prediction.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If K-means clustering is applied to encoded features to generate condition clusters, then operating condition classification is improved, but processing time increases

Engineering Contradiction:
Improveoperating condition classification accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts the most relevant features through the autoencoder's latent space representation before applying K-means clustering. By taking out only the essential compressed features that capture the critical variations in operating conditions, the system achieves accurate condition classification while reducing the dimensionality and computational complexity of the clustering process, thereby minimizing processing time.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS11353861B2Autoencoder utilizing vehicle contextual information
Publication Date: 2022.06.07 TOYOTA JIDOSHA KK
  • US11353861B2 patent drawing
  • US11353861B2 patent drawing
  • US11353861B2 patent drawing

AI summary

A method, system, and non-transitory computer readable medium describing an autoencoder that creates a reduced feature space from healthy power electronics devices for training. Devices under test are then encoded and compared to the encoded features of the healthy devices to determine health of the other devices. Contextual information is used to build multiple models that compare power electronics devices from similarly operated vehicles with one another.