16-step dual-frequency grating phase shift profilometry capable of absolute phase unwrapping

A dual-frequency grating and phase technology, applied in the field of optical three-dimensional sensing, can solve the problems that the measurement accuracy and measurement range cannot be guaranteed at the same time, and achieve the effects of suppressing the accumulation of error diffusion, strong adaptability, and high measurement accuracy
CN101655360AInactive Publication Date: 2010-02-24SICHUAN UNIV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
SICHUAN UNIV
Publication Date
2010-02-24
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides 16-step dual-frequency grating phase shift profilometry capable of absolute phase unwrapping in the three-dimensional sensor technology. The invention is characterized by usingcomputers to design codes to generate 16 dual-frequency grating patterns, using a digital light projector to image the grating patterns on the surface of an object instantaneously in sequence, using apick-up device to record the deforming fringe pattern of the object, subsequently using the functional relationship between the gratings with two frequencies, using the absolute phase unwrapping method to directly realize phase unwrapping of point to point in the whole field range and having no relation with the path for phase unwrapping, effectively inhibiting accumulative error diffusion, usingphase measuring profilometry to process the deforming fringes, accurately restoring the three-dimensional shape of the object and obtaining such digital information as deformation of the object and the like by further analyzing the data processing results. The method can be used for measurement study of the characteristics of the object surface with the characteristic of diffuse reflection. The method has the advantages of high measurement precision and strong adaptability to the surface topography of the object, etc.
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Description

1. Technical field

[0001] The invention relates to optical three-dimensional sensing technology, in particular to the three-dimensional surface shape measurement of an object by using a dual-frequency grating based on a phase measurement profilometry method. 2. Technical Background

[0002] Three-dimensional surface measurement is of great significance in the fields of machine vision, biomedicine, industrial inspection, rapid prototyping, film and television special effects, and product quality control. Optical three-dimensional sensing technology has been widely researched and applied due to its advantages of non-contact, high precision, large-area measurement, 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 Detection for short). SPD), phase measuring profilometry (Phase Measuring Profilome...

Claims

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