Height-information guided vision-language distillation for annotation-efficient bushing defect detection
摘要
Automated defect detection in automotive bushing components requires high accuracy for dimensional irregularities, low annotation costs, and efficient edge deployment. Height-information imaging captures variations that 2D images miss, yet existing methods require full annotation and produce heavy models. Vision-language models reduce annotation through pseudo-labeling but lack height-understanding and demand excessive computational resources. Here, we present HeightVL-Distill, a four-stage framework that integrates height-information imaging with vision-language capabilities and progressive knowledge distillation. The framework comprises Height-VLM Alignment that teaches models to interpret stratified height representations, Cross-Modal Height-Visual Uncertainty for strategic sample selection, Progressive Height-Aware Distillation that transfers knowledge to lightweight students, and a Height-Preserving Lightweight Architecture. Experiments on 20,000 bushing images demonstrate 97.3% mean Average Precision at IoU 0.5 (mAP@50) with only 12.8% annotation. The distilled model contains 42M parameters and processes 67 frames per second; this represents 95