High-speed phase-shifting profilometry under fluorescent light

摘要

Phase-shifting profilometry (PSP) has been widely used in three-dimensional (3-D) shape measurement because of its attributes of high-accuracy and high-resolution. However, PSP typically works under fluorescent light, flickering with a double frequency of the alternating current frequency, which may generate a non-ignorable phase error, and result in a PSP's measurement error, especially for PSP using a high sampling speed. We first mathematically describe the fluorescent light problem, model the PSP's phase error, and state the problem in highspeed PSP. Next, a fluorescent light error suppression (FLES) algorithm is proposed to suppress the phase error. Both the phase error model and the proposed algorithm are theoretically analyzed, and then numerically and experimentally verified. The provided numerical and experimental results coincide with the theoretical analysis. The proposed algorithm can reduce the phase error from 0.12 rad to a comparable level with system noise of 0.02 rad, which is significant for the accurate measurement of 3-D shapes for high-speed PSP in a fluorescent light environment.