Dynamic graph convolution and mixed attention mechanism based ship point cloud target detection
摘要
In the practical inland-river freight scenarios, the ship point cloud encounters challenges such as uneven density, large-scale variations, and a tendency to lose structural information. To address these issues, a novel ship point cloud target detection method is proposed. The method adopts the point-voxel region-convolutional neural network (PV-RCNN) as the baseline and enhances it from three perspectives. Specifically, a density-weighted voxel-farthest point sampling method is proposed first for key point sampling. Subsequently, a coordinate-mixed attention mechanism is developed for feature extraction. Moreover, a dynamic graph convolution feature aggregation module based on the candidate bounding box is proposed, enabling adaptation to the characteristics of point clouds in the inland-river freight scenario. This work is validated using a ship point cloud dataset from a practical project deployed at BaiXian Lake in Zhouzhuang. Compared with the baseline network, the average precision of the LiDAR side-scan ship point cloud and the BEV-scan ship point cloud have been enhanced by 2.3% and 3.8%, respectively. Experimental results indicate that the proposed method compensates for the limitations of the baseline PV-RCNN in terms of extracting long-range and structural features of the target. Consequently, it boosts the precision and robustness in target detection of ship point clouds within the inland-river freight scenario.