A novel measurement method based on the multiple sub-regions stitching technology is proposed to realize three-dimensional (3D) profile stitching for large aspheric surface.
The sub-regions stitching measurement is applying a four-axis fixture and a commercial small-range profiler.
A stitching algorithm including the multi-body theory, the invariability of curvature radiuses and the least square principle is established to reconstruct the full 3D profile.
The standard deviations of stitching errors of proposed method is verified by measuring the 3D profile of an off-axis parabolic surface and an axisymmetric aspheric surface within 0.16 μm and 0.42 μm respectively.