Noncontact profilometric measurement of large-form parts

A quick and efficient technique for automatic profilometric measurement of a large-form part is proposed and verified by experiment, When a laser stripe is projected onto an object, the deformed laser line image is detected by a solid-state array camera and automatically transferred to its space position using a least-squares mapping algorithm. Measurements can be executed on any surface of a 3-D object except the base. Large arrays of data points are acquired on each surface by means of a scanning mechanism. Since the measuring data from each laser stripe position can provide 2-D information concerning the surface contour, the laser stripe and the solid-state array camera are integrated into a measurement system for obtaining the entire 3-D information. Experimental results show that this technique can determine the 3-D profile of an object with an accuracy of 0.5 mm. (C) 1996 Society of Photo-Optical Instrumentation Engineers.