Robust fringe projection measurement based on reference phase reconstruction

Abstract

Phase measurement profilometry plays an important role in industrial applications. Traditional fringe projection profilometry (FPP) requires a stable reference plane to record the reference phase for the 3D reconstruction, which makes it sensitive to the motion-induced error caused by the reference plane. Thus, it is challenging for the traditional FPP to implement a robust measurement in industrial scenarios though it exhibits high accuracy. To solve this problem, a phase reconstruction method is proposed where the reference phase is denoised and reconstructed from the background of the modulated phase by minimizing the total variation (TV) via the theory of Sylvester equation. Since this strategy achieves synchronous extraction of the reference phase and the object one, it can correct the reference phase in real-time and reduce the measurement error caused by deviation of the reference plane. The proposed method has been applied to measure the step-shape workpiece with different deviations of the reference plane and the gear workpieces on conveyer. The experimental results show competitive performance with traditional FPP in accuracy and more robustness in complex industrial scenes.