Development and characterisation of a novel optical surface defect detection system

The objective of this project was to develop and characterise a novel optical highspeed online surface defect detection system. The inspection system is based on the principle of optical triangulation and provides a non-contact method of determining 3D pro file of a diffuse surface. Primary components of the developed system consist of a diode laser, CCfl5 CMOS camera, and two PC controlled servomotors. Control of the sample movement, image capturing, and generation of 3D surface profiles was programmed in LabView software. Inspection of the captured data was facilitated by creating a program to virtually present the 3D scanned surface and calculate requested surface roughness parameters. The servomotors were used to move the sample in the X and Y directions with a resolution o f 0.05 jam. The developed noncontact online surface-profiling device allows for quick high-resolution surface scanning and inspection. The developed system was successfully used to generate automated 2D surface profiles, 3D surface profiles and surface roughness measurement on different sample material surfaces. This automated inspection facility has X-Y scanning area capacity of 12 by 12 mm. In order to characterise and calibrate the developed profiling system, surface profiles measured by the system were compared to optical microscope, binocular microscope, AFM and Mitutoyo Surftest - 402 measurement of the same surfaces