Most scanning LiDAR sensors generate a sequence of point clouds in real-time. While conventional 3D object detectors use a set of unordered LiDAR points acquired over a fixed time interval, recent studies have revealed that substantial performance improvement can be achieved by exploiting the spatio-temporal context present in a sequence of LiDAR point sets. In this paper, we propose a novel 3D object detection architecture, which can encode LiDAR point cloud sequences acquired by multiple successive scans. The encoding process of the point cloud sequence is performed on two different time scales. We first design a short-term motion-aware voxel encoding that captures the short-term temporal changes of point clouds driven by the motion of objects in each voxel. We also propose long-term motion-guided bird's eye view (BEV) feature enhancement that adaptively aligns and aggregates the BEV feature maps obtained by the short-term voxel encoding by utilizing the dynamic motion context inferred from the sequence of the feature maps. The experiments conducted on the public nuScenes benchmark demonstrate that the proposed 3D object detector offers significant improvements in performance compared to the baseline methods and that it sets a state-of-the-art performance for certain 3D object detection categories. Code is available at https://github.com/HYjhkoh/MGTANet.git

本文提出了一种新的三维物体检测结构，该结构可以编码由多个连续扫描获取的LiDAR点云序列，并利用时空上下文实现较大的性能提升。通过短期运动感知体素编码和长期运动指导俯视图特征增强，可以对点云序列进行编码处理，结果显示，与基线方法相比，该模型在性能上显示出明显优越性，在某些三维检测类别方面表现出了最先进的性能。

MGTANet：使用长短期运动引导时间注意力编码顺序LiDAR点以进行3D物体检测