A Precise Connection Method for Surface Shape Data Measured by the Grating Projection Method

Abstract

A highly precise connection method for two sets of three-dimensional surface shape data measured by the grating projection method is proposed with the aim of capturing the full-field surface shape of a large space structures with high accuracy and spatial resolution. The coordinate transformation matrix that serves as an interface between the two sets of surface shape data is precisely calculated by feature-point matching of the virtual targets using the singular value decomposition algorithm, and the two sets of the surface shape data are connected by the coordinate transformation. In the verification experiment, the virtual targets are created from preliminary surface shape measurement of dedicated concave models using the grating projection method. The results show that the two sets of surface shape data can be connected with 40.2 © 10 ¹6 mRMS accuracy. This connection accuracy is roughly the same as that achieved with photogrammetry using the grating projection method, thus confirming the effectiveness of the connection method proposed.