Vision-based quality inspection for components with small diameter and deep hole

Focusing on the long-thin cylindrical component with small diameter and deep hole, we present an internal structure inspection method based on micro vision. A camera consisting of CCD sensor and endoscope is used to get clear images of the component's internal structure. The curves in the image are extracted to represent the internal structure. A search strategy based on Kalman filter is proposed to detect the internal wire. Then, the quality of the component is inspected according to the extracted curves. Experimental results show that the proposed search strategy could reliably and precisely extract curves, occupying the capacity of overcoming the restrictions such as low-contrast conditions, emergencies of noises and shadows. Moreover, experiments are well conducted to verify the effectiveness of the proposed methods.