Optimal three-dimensional morphology measurement method

Abstract

Disclosed is an optimal three-dimensional morphology measurement method. First of all, according to actual measurement requirements, a measurement system composed of a projection system and a camera is well arranged; then according to measurement needs, a fringe pattern is designed and is projected to the surface of a measured object by the projection system, and the fringe pattern reflected by the object is sampled by the camera; then a wrapping phase is demodulated from the sampled fringe pattern, and a real phase value of the fringe pattern is obtained after unwrapping; then X-axis and Y-axis coordinates of the measured object are obtained through magnifying power of a telecentric lens, the pixel size of the camera and image coordinates of the sampled fringe pattern; and finally, correlation parameters of the projection system are obtained through calibration, and through combination with a fringe phase, according to a triangular relation, Z-axis coordinates of the measured object are solved. The calibration process is simple, the solving speed of three-dimensional coordinates is improved and higher measurement precision can be realized; and application of all subsequent measurement can be ensured through calibration once, and the efficiency is quite high.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional measurement, and in particular relates to an optical three-dimensional shape measurement method. Background technique [0002] Three-dimensional measurement has a wide range of requirements in rapid prototyping and quality inspection. At the same time, it is also widely used in reverse engineering, medical and other fields. The traditional three-dimensional measurement method is mainly contact measurement, such as three-coordinate measuring machine. With the advancement of optical technology, optical three-dimensional measurement technology has been greatly developed, and is more and more widely used in three-dimensional measurement. Typical optical three-dimensional measurement methods include laser scanning measurement, line laser scanning measurement, structured light projection measurement and interferometry. Among them, the structured light projection three-dimensional measuremen...

AI Technical Summary

Problems solved by technology

The existing sinusoidal fringe projection three-dimensional measurement profilometry has the following characteristics: the phase of the projected sinusoidal fringe pattern changes linearly along a certain direction in the entire image plane; in the measurement system composed of a single camera and a single projector, the phase to The transformation of the three-dimensional shape of the measured object always uses the triangular relationship between the projection light and the camera sampling light. In many cases, a reference surface is required, and the three-dimensional solution process is complicated.

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