Improve the performance of convolutional GAN using history-state
ensemble for unsupervised early fault detection with acoustic emission
signals
Abstract
Early fault detection (EFD) in run-to-failure processes plays a crucial
role in condition monitoring of modern industrial rotating facilities,
which are more and more demanding for safety, energy and ecology saving
and efficiency. To enable effective protecting measures, the evolving
faults have to be recognized and identified as early as possible. The
major challenge is to distill discriminative features on the basis of
only the ‘health’ signal, which is uniquely available from various
possible sensors before damage sets in and before the signatures of
incipient damage become obvious and well-understood in the signal.
Acoustic emission (AE) signal has been frequently reported to be able to
deliver the early diagnostic information due to its inherently high
sensitivity to the incipient fault activities, offering great potential
of the AE technique for EFD, which may outperform the traditional
vibration-based analysis in many situations. Up to date, the
‘feature-based’ multivariate analysis dominates the interpretation of AE
waveforms. In this way, the decision making relies heavily on expert’s
knowledge and experience, which is often a weak link in the entire EFD
chain. With the advent of artificial intelligence, people are seeking
for intelligent method to tackle this challenge. In this paper, we
introduce a versatile intelligent analysis method for AE signals. A new
architecture of convolutional generative adversarial network (GAN) is
designed to extract deep information embedded in AE signals. In order to
improve the robustness of the proposed EFD framework, a novel ensemble
technique referred to as ‘history-state ensemble’ (HSE) is introduced in
this paper. Primary merits of HSE are highlighted as: (1) it does not
require extra computing time to obtain the base models; (2) it does not
require special design on the network architecture and can be applied to
different networks. To evaluate the proposed method, a rolling contact
fatigue test monitored by AE sensors was performed, and experimental
results have demonstrated the proposed ensemble method largely improves
the robustness of GAN.