Micro-Doppler Based Human-Robot Classification Using Ensemble and Deep Learning Approaches

TL;DR

This paper explores real-time human-robot classification using micro-Doppler radar signatures, comparing classical, ensemble, and deep learning methods, with deep CNN achieving 99% accuracy on single R-D maps.

Contribution

It introduces a real-time classification approach using 25 GHz FMCW radar with direct analysis of R-D maps, demonstrating the effectiveness of deep learning over traditional methods.

Findings

Deep CNN achieves 99% accuracy in human-robot classification.

Ensemble classifiers outperform classical feature-based approaches.

Direct analysis of R-D maps is effective for real-time classification.

Abstract

Radar sensors can be used for analyzing the induced frequency shifts due to micro-motions in both range and velocity dimensions identified as micro-Doppler ($\boldsymbol{\mu}$-D) and micro-Range ($\boldsymbol{\mu}$-R), respectively. Different moving targets will have unique $\boldsymbol{\mu}$-D and $\boldsymbol{\mu}$-R signatures that can be used for target classification. Such classification can be used in numerous fields, such as gait recognition, safety and surveillance. In this paper, a 25 GHz FMCW Single-Input Single-Output (SISO) radar is used in industrial safety for real-time human-robot identification. Due to the real-time constraint, joint Range-Doppler (R-D) maps are directly analyzed for our classification problem. Furthermore, a comparison between the conventional classical learning approaches with handcrafted extracted features, ensemble classifiers and deep learning approaches is presented. For ensemble classifiers, restructured range and velocity profiles are passed directly to ensemble trees, such as gradient boosting and random forest without feature extraction. Finally, a Deep Convolutional Neural Network (DCNN) is used and raw R-D images are directly fed into the constructed network. DCNN shows a superior performance of 99\% accuracy in identifying humans from robots on a single R-D map.