Abstract
Prognostics predicts future performance progression
and remaining useful life (RUL) of in-service systems
based on historical/contemporary data. One of the challenges for
prognostics is the development of methods which are capable of handling
real-world uncertainties that typically lead to inaccurate predictions.
To alleviate the impacts of uncertainties and to achieve accurate
degradation trajectory and RUL predictions, a novel sequence-to-sequence
predictive model is proposed based on a variational auto-encoder (VAE)
that is trained with Generative Adversarial Networks (GAN). A Long
Short-Term Memory (LSTM) network and Gaussian mixture model are utilized
as building blocks so that the model is capable of providing
probabilistic predictions. Correlative and monotonic metrics are applied
to identify sensitive features in the degradation progress, in order to
reduce the uncertainty induced by raw data. Then, the extracted features
are concatenated with one-hot health
state indicators as training data for the model to learn the end-of-life
(EoL) without the need for prior knowledge of failure thresholds. The
performance of the proposed model is validated by health monitoring data
collected from real-world aero-engines, wind turbines, and lithium-ion
batteries. The results demonstrate that significant performance
improvement can be achieved in long-term degradation progress and RUL
prediction tasks.