3D inspection for HDD production process using laser light sectioning

Abstract

This research proposes the automatic visual inspection from three-dimensional characteristics of Hard Disk Drive case tightening process by machine vision system using laser light sectioning. The machine vision camera captures a number of features of HDD perpendicular to a conveyor belt as seen by a laser strip light. The narrow band pass filter (650 nm.) was mouthed in front of lens in order to cut off the unwanted wavelength. After image pre-processing, the laser profiles were calculated the center of gravity to extract the image coordinate. The features used here are the laser strip profile at various locations along the HDD formulating the 3D data. The homography computation was used to transform the image coordinate to the real world distance (in metric system). This scheme can be used to inspect the completeness of screwing process of the HDD which the 2D visual inspection cannot perform on the top view.