The use of laser structured light for 3D surface measurement and inspection

Computer aided inspection (CAI) systems need to be capable of integrating CAD, manufacturing and verification by automating the inspection process and moving it upstream in the manufacturing cycle. This paper discusses structured light systems that are used for obtaining range data of three-dimensional (3D) objects for verification and recognition using a triangulation method. The authors investigate field of view for three configurations of structured light systems and also describe visibility/occlusion for those configurations. Using a simplified camera calibration method, the authors describe how depth information of an object can be obtained using a closed-loop depth estimation method. Because of the system configuration and the properties of laser and camera this sensing method also generates errors. Thus in the paper, measurement errors are also analyzed