# Open-source tool SONAR: an analysis of SGD-based online one-class joint anomaly detection

- Source: Reddit r/robotics
- Published: 2026-10-17T22:53:03.000Z
- RoboHot: https://robohot.news/en/items/w34u2nm2872vycoqq7mqgbk94
- Original: https://www.reddit.com/r/robotics/comments/1x8nlbr/opensource_oneclass_sgd_sonar/

## Summary

The Dense-Armor project has open-sourced the SONAR (SGD-based One-Class Novelty detection with Approximate RBFs) module, which uses random Fourier features (RFF) to approximate an RBF kernel and adds strongly convex regularization, allowing the one-class boundary to be updated per sample via online SGD to detect whether robot joint residuals deviate from a healthy state.