Automatic surface inspection for S-PVC using a composite vision-based method

Appearance defect inspection is crucial for quality control in the context of Industry 4.0. This research introduces a joint surface defect inspection and classification framework for polyvinyl chloride (PVC) pipe based on the low-cost visual sensors and high-efficiency computer vision algorithms. First, we build a robust imaging system to acquire the surface of PVC (S-PVC) by considering its characteristics and the illumination condition into the modeling process. Second, we adopt the region of interest method to eliminate the background interference captured in the S-PVC imaging and design an efficient S-PVC defect inspection and classification method. Third, we build an automatic machine prototype to evaluate the efficiency of the proposed method. Experimental results demonstrate that our framework has the advantages of low latency, high precision, and robustness.