PhD defense Anton Emelchenkov: Anomaly Detection in Non-Stationary Time Series
Télécom Paris, 19 place Marguerite Perey F-91120 Palaiseau [getting there], amphi 5 and in videoconferencing
Jury
- Reviewer: Jean-Yves Tourneret, Professor, INP Toulouse
- Reviewer: Jean-Marc Bardet, Professor, Université Paris 1 Panthéon-Sorbonne
- President: Romain Serizel, Professor, Université de Lorraine, LORIA
- Examiner: Ekhine Irurozki, Associate Professor, Télécom Paris, Institut Polytechnique de Paris
- Director: François Roueff, Professor, Télécom Paris, Institut Polytechnique de Paris
- Invited: Mathieu Fontaine, Associate Professor, Télécom Paris, Institut Polytechnique de Paris
- Invited: Hervé Mahé, Valeo, France
Abstract
Anomaly detection is critical for ensuring the reliability of industrial systems, yet remains particularly challenging for complex mechanical assemblies such as electric powertrains due to their non-stationary and multi-component dynamics. This thesis presents two complementary pipelines applied to anomaly detection in electric powertrains, combining interpretable signal-level modelling with data-driven temporal analysis.
The first pipeline builds on a non-linear chirp signal model to accurately track multiple time-varying amplitudes at predefined frequencies, enabling reliable and interpretable monitoring of individual mechanical components. We introduce novel amplitude-tracking methods and demonstrate their robustness through extensive numerical experiments and rigorous statistical validation. The second pipeline adopts a holistic view of vibrational signals and leverages deep learning architectures to capture complex temporal dependencies that are difficult to isolate using amplitude-based tracking alone. Within this framework, we propose ALERT, a novel anomaly detection method for non-stationary time series based on a linear autoregressive latent space. To enable systematic development and evaluation, we introduce a comprehensive experimental testbench, first large-scale dataset of non-stationary vibrational signals with synchronized rotational speed measurements, further enriched with diverse expert-guided degradation scenarios derived from real-world operating conditions. Together, these contributions advance the state of the art toward deployable, real-time anomaly detection systems for long-horizon monitoring in complex industrial environments.