Dynamic 3D shape measurement based on the phase-shifting moir\'e algorithm

TL;DR

This paper introduces a novel dynamic 3D shape measurement method using phase-shifting moire algorithm, enabling single-shot measurement of moving objects with improved accuracy and broader scope compared to previous techniques.

Contribution

The proposed method extends existing moire phase retrieval techniques to dynamic 3D measurement, allowing single-shot capture and enhanced measurement range and precision.

Findings

Successfully measured dynamic 3D shapes in experiments.

Demonstrated improved accuracy over Wang's method.

Expanded measurement scope for moving objects.

Abstract

In order to increase the efficiency of phase retrieval,Wang proposed a high-speed moire phase retrieval method.But it is used only to measure the tiny object. In view of the limitation of Wang method,we proposed a dynamic three-dimensional (3D) measurement based on the phase-shifting moire algorithm.First, four sinusoidal fringe patterns with a pi/2 phase-shift are projected on the reference plane and acquired four deformed fringe patterns of the reference plane in advance. Then only single-shot deformed fringe pattern of the tested object is captured in measurement process.Four moire fringe patterns can be obtained by numerical multiplication between the the AC component of the object pattern and the AC components of the reference patterns respectively. The four low-frequency components corresponding to the moire fringe patterns are calculated by the complex encoding FT (Fourier transform) ,spectrum filtering and inverse FT.Thus the wrapped phase of the object can be determined in the tangent form from the four phase-shifting moire fringe patterns using the four-step phase shifting algorithm.The continuous phase distribution can be obtained by the conventional unwrapping algorithm. Finally, experiments were conducted to prove the validity and feasibility of the proposed method. The results are analyzed and compared with those of Wang method, demonstrating that our method not only can expand the measurement scope, but also can improve accuracy.