Radar Odometry Subject to High Tilt Dynamics of Subarctic Environments

TL;DR

This paper evaluates radar odometry methods in challenging subarctic terrains with high tilt dynamics and introduces a novel radar-inertial approach that improves accuracy in such demanding environments.

Contribution

It benchmarks existing methods under extreme tilt conditions and proposes a new radar-inertial odometry technique with tilt-proximity submap search.

Findings

The proposed method achieves a 0.3% accuracy improvement over the second-best.

Benchmark results show up to 13° pitch and 4° roll differences between scans.

The method performs well on complex sequences with high lateral slip.

Abstract

Rotating FMCW radar odometry methods often assume flat ground conditions. While this assumption is sufficient in many scenarios, including urban environments or flat mining setups, the highly dynamic terrain of subarctic environments poses a challenge to standard feature extraction and state estimation techniques. This paper benchmarks three existing radar odometry methods under demanding conditions, exhibiting up to 13{\deg} in pitch and 4{\deg} in roll difference between consecutive scans, with absolute pitch and roll reaching 30{\deg} and 8{\deg}, respectively. Furthermore, we propose a novel radar-inertial odometry method utilizing tilt-proximity submap search and a hard threshold for vertical displacement between scan points and the estimated axis of rotation. Experimental results demonstrate a state-of-the-art performance of our method on an urban baseline and a 0.3% improvement over the second-best comparative method on a 2-kilometer-long dynamic trajectory. Finally, we analyze the performance of the four evaluated methods on a complex radar sequence characterized by high lateral slip and a steep ditch traversal.