Research on real-time vibration-insensitive inspection and classification algorithms for automatic online vision-based inspector

In the automatic online vision-based inspector on pharmaceutical production line, vibration disturbance from electromechanical system mostly leads to failure using traditional inter-frame difference algorithm. In this paper, a real-time vibration-insensitive inter-frame difference inspection algorithm for online impurities detection is proposed to overcome the disturbance. The inspection algorithm employs an efficient subpixel image registration method (based on a mountain-climbing searching strategy) and adaptive local threshold segmentation. Inspection can be finished in no more than 0.93 second. Experimental inspection results of false alarm rate 4.51% and omission rate 0.14% show detection validity even if vibration amplitude increases to five pixels. Then impurity classification based on Relevance Vector Machine (RVM) is carried out as feedback to monitor and improve the manufacture process. Classification accuracy above 97% satisfies the requirements for automatic production line.