Sensor planning system for fringe projection scanning of sheet metal parts

Automatic sensor planning for 3D scanning with structured light scanners is a challenging task. That is true especially in the case of reflective surfaces that are typical for sheet metal parts. This paper describes a new sensor planning system for the automatic generation of scanning positions based on a computer model of the part for digitization of sheet metal parts. Compared to previous studies, visual properties of the scanned parts' surface can be simulated precisely by application of a reflectance model proposed by Nayar and simplified by Ellenrieder. This model is suitable for materials that are characterized by the combination of diffuse and specular reflections. Results of the scanning that were obtained using an ATOS III Triple Scan fringe projection 3D scanner and a KUKA KR 60 HA industrial robot were compared to the simulation. Results obtained for two test parts show 16 and 26% differences in correspondence of acquired polygonal areas between simulation and scanning.