Safe Robot Navigation via Multi-Modal Anomaly Detection

Presentation at ICRA 2020: Safe robot navigation in the presence of unknown obstacles using anomaly detection.

Paper: https://doi.org/10.3929/ethz-b-000392927
Code & Dataset: https://github.com/leggedrobotics/ano...

Video & Presentation by Lorenz Wellhausen

Paper Abstract:
Navigation in natural outdoor environments requires a robust and reliable traversability classification method to handle the plethora of situations a robot can encounter.
Binary classification algorithms perform well in their native domain but tend to provide overconfident predictions when presented with out-of-distribution samples, which can lead to catastrophic failure when navigating unknown environments.
We propose to overcome this issue by using anomaly detection on multi-modal images for traversability classification, which is easily scalable by training in a self-supervised fashion from robot experience.
In this work, we evaluate multiple anomaly detection methods with a combination of uni- and multi-modal images in their performance on data from different environmental conditions.
Our results show that an approach using a feature extractor and normalizing flow with an input of RGB, depth and surface normals performs best. It achieves over 95% area under the ROC curve and is robust to out-of-distribution samples.