HyperDet: 3D Object Detection with Hyper 4D Radar Point Clouds
Yichun Xiao, Runwei Guan, Fangqiang Ding
TL;DR
HyperDet tackles the radar-only 3D detection gap by building a task-aware hyper 4D radar point cloud through spatio-temporal fusion, cross-sensor consensus validation, and a diffusion-based foreground enhancement guided by LiDAR supervision. The approach remains detector-agnostic and is compatible with standard LiDAR-oriented detectors, preserving radar-specific cues while densifying foreground geometry. Experiments on MAN TruckScenes show consistent gains over raw radar inputs with VoxelNeXt and CenterPoint, indicating effective input-level refinement that narrows the radar-LiDAR gap. This work demonstrates a practical path to deploy radar-enabled perception by leveraging existing LiDAR-oriented detectors with a refined radar front-end, particularly robust in adverse weather and cost-constrained scenarios.
Abstract
4D mmWave radar provides weather-robust, velocity-aware measurements and is more cost-effective than LiDAR. However, radar-only 3D detection still trails LiDAR-based systems because radar point clouds are sparse, irregular, and often corrupted by multipath noise, yielding weak and unstable geometry. We present HyperDet, a detector-agnostic radar-only 3D detection framework that constructs a task-aware hyper 4D radar point cloud for standard LiDAR-oriented detectors. HyperDet aggregates returns from multiple surround-view 4D radars over consecutive frames to improve coverage and density, then applies geometry-aware cross-sensor consensus validation with a lightweight self-consistency check outside overlap regions to suppress inconsistent returns. It further integrates a foreground-focused diffusion module with training-time mixed radar-LiDAR supervision to densify object structures while lifting radar attributes (e.g., Doppler, RCS); the model is distilled into a consistency model for single-step inference. On MAN TruckScenes, HyperDet consistently improves over raw radar inputs with VoxelNeXt and CenterPoint, partially narrowing the radar-LiDAR gap. These results show that input-level refinement enables radar to better leverage LiDAR-oriented detectors without architectural modifications.
