| 摘要 |
PURPOSE:To recognize a hole accurately using a visual sensor. CONSTITUTION:A hole 3 having an outline 3' is made in a work 2 mounted on a work table 1. When the image thereof is picked up by means of a CCD camera 4, the work 2 is illuminated from different directions by lighting the light sources 5A, 5B sequentially thus picking up the image twice. The intensity of each image signal is then normalized and the lower image signal value is selected for each pixel thus forming an image where the shaded parts are collected and emphasized. In general, the images of objective holes are picked up sequentially under a plurality of illumination geometry conditions for shading the different positions thus acquiring the image signal under each illumination geometry condition. An image signal representative of minimum brightness is then selected for each pixel and the hole is recognized based on the selected image signals. |
