A high-accuracy 3D projection system for fastener assembly

Matching a fastener with a hole in the assembly of large-scale structure is tedious and time consuming because the workers have to check the CAD drawing and process document manually in order to determine the needed fastener for a hole. To this end, this paper aims to develop a 3D projection system to display the assembly information directly onto the physical part without manual check, leading to improved assembly efficiency and quality. For large-scale structure, the perquisite of fastener assembly information projection is to register the physical part to its CAD model rapidly. To this purpose, first, a high accuracy and real time 3D profile measurement system for a physical part is proposed; second, the rapid registration based on multi-scale local geometrical feature is also formulated. The experiment shows the 3D projection system has a good measurement accuracy and rapid registration process; hence the proposed method can greatly increase the assembly efficiency and has a big impact in large-scale structure assembly.