A three-dimensional measurement method in which the modulation order phase is located at the edge of the period

Abstract

The object of the present invention is to propose a three-dimensional measurement method in which the modulation order phase is located at the edge of the cycle, comprising the following steps: Step A: According to the total number of orders of the phases, the 2π phase is equally divided according to the total number of orders, and the modulation order phase is located in the cycle edge; step B: generate a sinusoidal fringe pattern with N amplitude modulation order phase to the periodic edge according to the requirements of the N-step phase shift method; step C: the projector generates N fringe patterns on the surface of the object to be tested, and obtains the fringe pattern of the object to be tested. Sinusoidal fringe pattern; Step D: Calculate the mean intensity, modulation intensity and wrapping phase of N sinusoidal fringe patterns obtained by the camera according to the N-step phase shift method; Step E: According to the periodic edge positioning pattern collected by the camera, take out the edges of all periodic edges Coordinates; Step F: Use the order phase modulated by the edge coordinates to determine the fringe order of the pixel, and unpack each pixel to obtain the absolute phase; Step G: Reconstruct a three-dimensional point cloud according to triangulation ranging, and build a three-dimensional model of the object to be measured.

Description

technical field [0001] The invention relates to the technical field of structured light three-dimensional measurement, in particular to a three-dimensional measurement method in which the modulation order phase is located at the edge of the period. Background technique [0002] Structured light measurement technology has the advantages of non-contact, full-field lossless measurement, high precision, and fast speed, and has been widely used in industrial inspection, machine vision, cultural relic digitization, medicine and other fields. Among the existing structured light measurement systems, a structured light 3D measurement system consisting of a camera and a projector is widely used because of its simple structure and high point cloud reconstruction efficiency. 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, and at the same time, the ...

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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