Three-dimensional measurement method of modulation level phase at period edge

Abstract

The invention aims to provide a three-dimensional measurement method for a modulation level phase at a period edge, which comprises the following steps of: A, equally dividing a 2pi phase according to a total number of levels according to the total number of levels of the phase, and enabling the modulation level phase to be positioned at the period edge; b, generating N sine stripe patterns from modulation level phases to periodic edges according to the requirements of an N-step phase shift method; c, the projector projects N stripe patterns to the surface of the to-be-measured object, and sine stripe patterns of the to-be-measured object are obtained; d, solving the mean value intensity, the modulation intensity and the wrapped phase of the N sine stripe patterns obtained by the camera according to an N-step phase shift method; e, taking out edge coordinates of all periodic edges according to a periodic edge positioning pattern acquired by a camera; f, determining the fringe level of the pixel by using the level phase modulated by the edge coordinate, and unwrapping the pixels one by one to obtain an absolute phase; and G, reconstructing a three-dimensional point cloud according to triangulation ranging, and establishing a three-dimensional model of the object to be measured.

Description

technical field [0001] The invention relates to the technical field of three-dimensional measurement of structured light, in particular to a three-dimensional measurement method in which the modulation order phase is located at the edge of a period. Background technique [0002] Structured light measurement technology has the advantages of non-contact, full-field lossless measurement, high precision, and fast speed. It has been widely used in industrial inspection, machine vision, digitalization of cultural relics, and medicine. Among the existing structured light measurement systems, the structured light 3D measurement system consisting of a camera and a projector is widely used because of its simple structure and high efficiency of point cloud reconstruction. In a typical single-camera structured light 3D measurement system, the projection device projects the fringe pattern onto the surface of the measured object during the measurement process. After processing, the phase...

AI Technical Summary

Problems solved by technology

The spatial phase unwrapping method requires a small number of projection patterns and can be used for dynamic scene measurement, but the accuracy of phase resolution is relatively low; although the stereo phase unwrapping method can solve the problem of low accuracy of spatial phase unwrapping, it needs to add additional Camera device assisted unwrapping

The time phase unwrapping method is widely used because of its advantages of high precision, strong robustness, wide adaptability, and simple equipment. Need to project a large number of fringe patterns, increase the time to understand the package, and be sensitive to the movement of the object to be measured

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