High-speed and high-accuracy fringe projection profilometry without phase unwrapping. (May 2021)

• Record Type: Journal Article
• Authors: Deng, Huaxia; Ling, Xing; Wang, Yuyu; Yao, Pengcheng; Ma, Mengchao; Zhong, Xiang
• Is Part Of: Optics and lasers in engineering. Volume 140(2021)
• Publication Date: 2021-05
• Subjects: Dynamic 3D measurement -- Speckle -- Phase-shift grating -- Binary defocusing projection technique -- High speed -- High accuracy; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2020.106518
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: A novel approach to balance the speed and accuracy of the reconstruction of Fringe Projector Profilometry (FPP). The approach is realized by the speckle matching function designed instead of phase unwrapping to improve the matching speed. Through the cyclic method, it is equivalent to achieve reconstruction with one picture Abstract: High-speed and high-accuracy measurement is the ultimate objective of fringe projection profilometry(FPP). However, improving measurement speed, especially without the reduce of measurement accuracy, poses a great challenge for the development of FPP. In contrast to the existing methods, which typically use phase unwrapping method, this paper proposes a high-speed and high-accuracy FPP without phase unwrapping. This approach is a specially designed speckle matching function based on digital image correlation, instead of phase unwrapping, to improve the matching speed. At the same time, the binary defocusing method can speed up the projection speed and the cyclic method can reduce the total number of gratings needed for reconstruction. In order to improve the accuracy, six-step phase shift method is used instead of the three-step phase shift method. Dynamic 3D measurement experiments demonstrate that this approach realizes high-speed measurement by 320 fps and high-accuracy measurement by a mean standard deviation of approximately 45 μ m. This approach provides a welcome boost to the development of high-speed and high-accuracy FPP.