SPDP-Net: A Semantic Prior Guided Defect Perception Network for Automated Aero-Engine Blades Surface Visual Inspection

Automated surface defect detection is essential to manufacturing automation. However, automated inspection of aero-engine blades remains challenging due to tiny defects and weak features. To address this issue, we propose a semantic prior guided defect perception network, named SPDP-Net, which is ultimately integrated into an automated system to achieve efficient detection of defects. Firstly, a semantic prior mining module (SPM) is developed to capture finer-grained pixel-level location priors of defects by leveraging image feature mapping relations which facilitates the precise perception of tiny defects. Subsequently, we propose a defect enhancement perception module (DEP) to separate weak defects from complex backgrounds by utilizing defect location priors provided by SPM to enhance the features of defects while suppressing the values of non-defect regions, which makes the weak defects present as more obvious outliers. Finally, the global information extraction module (GIE) extracts the global features of defects, which helps to further improve the predicted results. When equipped with SPM, DEP and GIE, SPDP-Net can accurately identify and locate defects, exhibiting more competitive recognition and feature extraction capabilities for tiny defects and weak defects. To evaluate the effectiveness of our method, we construct an aero-engine blade surface defect detection dataset from real industrial scenarios called ABSDD with the collaboration of senior engineers. We achieve 95.9% precision, 94.0% recall and 94.9% F1 score on ABSDD. In addition, we also achieve state-of-the-art results on two public benchmark datasets, KSDD2 and DAGM. Finally, we have applied the developed SPDP-Net to an automated system and have conducted actual tests in collaboration with a well-known aero-engine production company.
Note to Practitioners
—At present, the automated detection system for surface defects in industrial manufacturing has not been well developed, which is particularly trailing behind in the field of aero-engine manufacturing. To the best of our knowledge, the surface defect detection of aero-engine blades is still carried out manually. To address this problem, we propose SPDP-Net for the automated detection of surface defects in aero-engine blades. It can accurately perceive and capture tiny and weak defects with excellent performance. SPDP-Net achieves state-of-the-art results on three tasks from different industrial manufacturing fields, which demonstrates its good transfer application capabilities. In addition, we integrate SPDP-Net into an automated detection system consisting of an autonomous imaging system and a high-performance computing server and conduct actual tests in an aero-engine production company. The test achieves remarkable results, indicating the good application prospects of the automated detection system.