Method for evaluating surface detects of small-sized workpieces and flow for detecting unqualified workpieces

Abstract

The invention discloses a method for evaluating surface detects of small-sized workpieces. The method comprises the following steps of: acquiring surface images of small-sized workpieces under a specific light source with an industrial camera; detecting various defects such as unfilled corners, edge dropping, abnormity, pockmarks, cracks and the like of the small-sized workpieces based on image processing and profile analyzing methods; evaluating the severity and quantity of defects such as the unfilled corners, the edge dropping and the like of the small-sized workpieces by adopting a convexdefect evaluating parameter and a method for combining the convex defect evaluating parameter with a linearity evaluating parameter; and evaluating the degrees of the pockmark and crack defects with a threshold value segmentation method based on dimensional histogram statistic and the ratio of pockmark pixels. Based on the evaluation, the invention further provides a flow for detecting surface-unqualified workpieces. The flow has low false detecting rate, high detecting speed and wide application range, can meet the online detection requirement of the small-sized workpieces, and is suitable for detecting surface defects of various small-sized workpieces.

Description

technical field [0001] The invention relates to the technical field of surface defects of small workpieces, in particular to a method for evaluating surface defects of small workpieces and a process for detecting surface unqualified workpieces using the evaluation method. Background technique [0002] Surface defects are an important factor affecting the surface quality of small workpieces, directly affecting the appearance and performance of the final product. For example, on the one hand, the surface defects of small permanent magnet workpieces affect the surface magnetic distribution and uniformity of magnetic properties of permanent magnet materials that magnetic material users are concerned about, and on the other hand, they mainly affect the determination of the corrosion resistance of permanent magnet materials. Important characteristic of magnet life. The surface defects of small mechanical parts seriously affect their mechanical properties and product appearance. ...

AI Technical Summary

Problems solved by technology

However, most of the above-mentioned detection methods have deficiencies and cannot be popularized and applied in the industry. For example, the artificial visual inspection method has low detection efficiency, the detection quality is greatly affected by human factors, and it will increase the cost. Due to the limitation of the principle, the detection method is mainly used in the defect detection of ultra-micro cracks, and it is difficult to evaluate workpieces with multiple defects; the eddy current detection technology is suitable for the detection of large plates

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