A defects detection system for the surfaces of stampings

Detecting defects on the surfaces of stampings plays a critical role in the manufacturing process. Many methods have been proposed to detect and identify simple defects on stampings. However, these methods suffer from large system size, high cost, and low speed for inspection. This paper proposes a new visual system for detecting defects on the surfaces of stampings. A set of LED bar lights are used to illuminate the stamping surface from the four sides. This can ensure that the irradiation directions are parallel to the surface. Thus, it can enhance the imaging of the defects and punching edges in the vertical orientation of the surface, which facilitates the location of the defects such as scratch and pitting and the measurement of the punching sizes. Thereby, the defects can be classified using simple shape and dimension analysis. The proposed system is a part of the automated sorting system. Practical operations verify the effectiveness of the proposed system.