Motion-induced errors compensation for variant shifting-phase method using patterns sequence exchanged

doi:10.1016/j.optlaseng.2024.108346

2024-09-01

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DOI：10.1016/j.optlaseng.2024.108346

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摘要

En 中文

Phase shifting profilometry has found broad application in high-accuracy dynamic optical measurement. However, due to the nature of its multi-frame projection, motion-induced errors are unavoidable in dynamic scenarios. This paper proposes a patterns sequence exchanged method to suppress the motion-induced errors in variant shifting-phase methods (VSPM) which project four fringe patterns. For each of the three original methods in VSPM, a set of four encoded patterns is divided into two subsets by analyzing its computational characteristics. Patterns grouped into one subset should be adjacent when projected. To compensate for both the motion-induced shifting-phase errors and wrapped phase errors, an auxiliary patterns set, also containing four complete variant shifting-phase images, is constructed by extracting two different but adjacent subsets from two patterns sets captured consecutively. The essence of constructing the auxiliary patterns set is to change the projection sequence of patterns, and calculate another shifting-phase and wrapped phase with opposite errors tendencies. This is because the patterns sequence plays a crucial role in dynamic measurement. For different projection sequence of patterns, the object motion introduces different error order relative to the original projection sequence, thus causing different error forms. According to the original and auxiliary patterns sets, the motioninduced shifting-phase errors and wrapped phase errors of VSPM are compensated, then further get highaccuracy absolute phase. The experimental results confirm the effectiveness of the proposed compensation method without any iterative calculation, which further expands the application of VSPM in high-speed dynamic measurement, whether it is uniform or non-uniform motion.

Keyword:

Dynamic 3D measurement

Phase shifting profilometry

Variant shifting-phase methods

Patterns sequence exchanged

Motion-induced errors compensation