A 3D measurement method for rigid moving objects based on phase-shifted fringe projection

Abstract

The invention discloses a three-dimensional measurement method for a rigid moving object based on phase-shift fringe projection, which specifically includes the following steps: step S1: building a three-dimensional measurement system for fringe projection, including a projector and a camera; step S2: the projector sequentially projects N phases The shifted fringe pattern is projected onto the surface of the moving object, and the camera synchronously collects the deformed phase-shifted fringe image modulated by the moving object; Step S3: Use the N-step phase shift method to solve the truncated phase φ of the phase-shifted fringe 1 ; construct the combined phase; use histogram equalization to process the combined phase to obtain the corrected combined phase; step S4: build a spline interpolation function f(φ 1 ), to eliminate the introduced discrete phase error, then φ 3 =f(φ 1 ) represents the optimized truncated phase; step S5: for the optimized truncated phase φ 3 Perform phase unwrapping to obtain continuous absolute phase Φ 3 , the absolute phase Φ 3 Convert it to height information to reconstruct the three-dimensional shape of the moving object.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional measurement, in particular, the invention relates to a method for three-dimensional measurement of a rigid moving object based on phase shift fringe projection. Background technique [0002] The fringe projection method has the advantages of non-contact, high precision, fast speed, and low cost. It is widely used in the field of three-dimensional measurement. The key lies in how to accurately extract the phase distribution of fringes. The phase shift method is a commonly used phase extraction algorithm. However, when measuring a moving object, the phase shift amount between multiple phase shift fringes will change, thereby introducing periodic phase errors. [0003] In response to the above problems, domestic and foreign scholars have proposed some error compensation methods, all of which have achieved good results (Optics and Lasers in Engineering, 2021, 141: 106573). For example, feat...

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Problems solved by technology

For example, feature matching is used to estimate object motion information, but it is not suitable for moving objects with indistinct features (Optics Express, 2013, 21(25): 30610-22; Optics Express, 2020, 28(19): 28600-11) ; combined with Fourier and other frequency domain methods to compensate phase errors, but involves frequency domain operations, the amount of calculation is large, and the robustness is general (Optics Express, 2016, 24 (20): 23289-303; Optics Express, 2019 ,27(3):2713-31)

[0004] In summary, how to accurately restore the three-dimensional shape of moving objects is still facing great challenges

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