A cascaded group attention mechanism-based object detection algorithm for construction and demolition waste

Accurate object detection is crucial for managing construction and demolition waste (CDW). However, existing deep-learning models often exhibit limited performance in detecting small objects within complex environments. This study proposes a YOLOv11-based detection algorithm integrated with a novel Cascaded Group Attention (CGA) mechanism to enhance the model's ability to capture fine-grained features while significantly reducing computational and memory costs. First, we propose a transformer backbone based on CGA to improve long-range dependency modeling while substantially reducing redundant computations. Second, we employ a bidirectional multi-scale interaction module in the neck to integrate fine-grained details from high-resolution features with semantic context from low-resolution features, enabling accurate detection of CDW objects across scales. Finally, the proposed method is evaluated on two datasets. For comparison, we have reproduced several similar YOLOv11-based algorithms to validate the effectiveness of our approach. The results demonstrate a clear advantage of our approach, achieving mAP scores of 0.938 and 0.962, respectively, thereby surpassing the current state-of-the-art methods. Additionally, visualization of prediction results on test samples further confirms the high accuracy of our model. The data and code for this research can be obtained at the following link: https://github.com/jzp-csust/CDW.