Laser-based Non-Contact Dimension Measurement of an Object

Abstract

This paper presents an optical technique to measure the dimensions of a hexagonal object having cylindrical cavity at the centre. A red line diode laser has been used as the light source which scans the object with the help of a manually operated mechanical arrangement. The images captured by a camera during scanning are subjected to preprocessing. 3-D coordinates of all the laser illuminated points on the surface of the object are calculated using optical triangulation method. Delaunay triangulation algorithm is applied for surface reconstruction from the acquired point set so that dimensions of the object can be extracted. The extracted features are compared with that of the original object and the results are found to be satisfactory.