Visibility analysis of large assembly fixture measurement based on screen space transformation

To improve the accuracy of fixture installation, a visibility analysis method for large assembly fixture measurement based on screen space transformation was proposed. By studying practical visibility problems of large-scale assembly fixture, an approach to identify and simplify obstacles was proposed and a solving algorithm for minimum observation station based on visibility matrix was put forward. The proposed methods were verified through an experimental Boxjoint-based assembly fixture, and the result showed that the computation of the visibility analysis was reduced and the computational efficiency was increased significantly by converting 3D interference problem into 2D space intersection. It provided effective measure for visibility analysis and instrument layout of large volume metrology in complex shop-floor conditions.