High-speed structured light three-dimensional surface shape vertical measurement method

Abstract

The invention relates to a high-speed three-dimensional surface shape vertical measurement method adopting a projection single-frame structured light image. The high-speed three-dimensional surface shape vertical measurement method is characterized in that a special combined projection lens comprises an ordinary projection lens and a cylindrical lens and is adopted in a structured light projection device. The combined projection lens images a 1-frame orthogonal grating image on a measured object, and an image of a horizontal stripe of an orthogonal grating is separated from an image of a vertical stripe. A CCD (Charge Coupled Device) camera synchronously acquires the orthogonal grating image subjected to object height modulation from the same direction through a semi-transparent semi-reflection mirror. The acquired image is subjected to Fourier transform, filtering and inverse Fourier transform to obtain the distribution of modulation degree of horizontal stripe components and vertical stripe components of the orthogonal grating image on the object surface. An object three-dimensional surface shape is rebuilt through a corresponding relationship between the modulation degree obtained by calibration in advance and height. The high-speed three-dimensional surface shape vertical measurement method provided by the invention can realize the object three-dimensional shape reconstruction through single-frame stripe image shooting and has the characteristic of realizing high-speed vertical measurement.

Description

technical field [0001] The invention relates to a structured light projection optical surface shape measurement technology, in particular to a high-speed three-dimensional surface shape vertical measurement method in which the projection direction and the detection direction are coaxial. Background technique [0002] Three-dimensional object surface profile measurement, that is, three-dimensional surface shape measurement, is of great significance in the fields of computer vision, biomedicine, industrial inspection, reverse engineering, film and television special effects, product quality control and other fields. Optical three-dimensional sensing technology has been greatly developed due to its advantages of non-contact, high precision, and easy automatic control. Existing optical three-dimensional sensing methods mainly include: triangulation, Moiré Topography (MT for short), Fourier Transform Profilometry (FTP for short), and spatial phase detection (Spatial Phase Detecti...

AI Technical Summary

Problems solved by technology

[0003] In view of the deficiencies in the existing modulation degree measurement profilometry: the phase shift algorithm needs to collect a large number of pictures and the measurement speed is slow, and the measurement system using dual gratings to separate the object plane to obtain the orthogonal modulation degree curve is complex and will Spectral aliasing occurs in the frequency domain

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