Selection of Optimal Lighting Conditions

Optical methods are increasingly used for measurement of surface texture, particularly for real measurements where the optical methods are generally faster. In the evaluation of surface roughness by machine vision technique, the scattered light pattern reflected from the machined surface is generally captured and optical surface finish parameters from the images are correlated with the actual roughness. Capturing of the image at appropriate conditions is required for the good correlation of the optical parameters with the roughness. Lighting conditions is a major factor that influences the image pattern and hence the optical parameters. In this work the lighting conditions like light source angle to the workpiece, and the angle of the surface were varied and its influence on the optical surface finish parameter are studied.The present work investigates the effects of lighting conditions while correlating the Ra with amplitude parameters.This work also explains the effects of machined surfaces due to its position change. In this thesis an experimental study is presented for identifying optimal lighting conditions for inspecting the surface roughness based machined surface textures.