A synergistic coordinate and attention module for pipeline weld surface defect detection

To improve the efficiency and reliability of pipeline inner-wall defect inspection, this study proposes an enhanced YOLOv8n-based detection method. A synergistic coordinate and attention module (SCAM), integrating ECoordA and L-SimAM, is introduced to strengthen spatial localization and salient defect representation. A hybrid CIoU–NWD loss is further employed to improve the localization of small and low-contrast defects. On the ROC-DET dataset, the proposed YOLOv8n + SCAM model achieved a Precision of 88.3%, a Recall of 76.2%, an mAP@0.5 of 79.2%, and an mAP@0.5:0.95 of 60.6%, outperforming the baseline YOLOv8n by 3.5 and 2.7 percentage points in the two mAP metrics. On NEU-DET, the model achieved an mAP@0.5 of 79.9%. An integrated pipeline inspection crawler was also validated in an industrial production environment, reducing the average inspection time by approximately 10 min per pipeline. These results demonstrate the effectiveness and practical applicability of the proposed method for intelligent pipeline defect inspection.