An optical triangulation method for non-contact profile measurement

In this paper we present a triangulation based range sensor for non-contact profile measurement. The sensor measures distances and orientations of objects and surfaces, based on the triangulation principle. This method is highly independent from optical surface properties and allows significant range measurements. Then a polynomial approximation based direct calibration method of this sensor is described. Next we present a prototype of the measuring system where the object is illuminated with laser sheet of light and viewed with the camera. The illumination angle, viewing angle and baseline between laser source and camera gives the triangulation geometry from which the depth information and 3D shape of the object is to be measured. A simple method for obtaining depth information using least square method is explained next. A comparison with range sensor results with standard calibrated results is performed to judge the suitability and accuracy of the system.