Raster projecting three-dimensional outline measuring apparatus and method based on phase shift

Abstract

A method for measuring three-dimensional outline based on raster projection of phase shift includes projecting raster picture with sine distribution on measured object; finalizing phase shift procedure by controlling projective fring with computer; using CCD camera, image collecting card and computer to work out trans shaped raster pictures and three-dimensional face shape of the object. The device for realizing the method is also disclosed by the present invention.

Description

technical field [0001] The invention belongs to the field of three-dimensional sensing and measurement, in particular to a grating projection type three-dimensional profile measurement device and measurement method based on phase shift. Background technique [0002] Three-dimensional object surface profile measurement technology is one of the hotspots of three-dimensional sensing and measurement research at home and abroad. It is widely used in aerospace, on-line inspection and quality control, machinery manufacturing, medical diagnosis, computer-aided design / manufacturing, robot vision systems, etc. field. At present, there are mainly the following measurement methods: 1. Laser single-point measurement method. Since this method can only measure one point at a time, although the measurement accuracy is high, the efficiency is extremely low; 2. Laser line scanning method (abbreviated as optical section method), This method is single-line scanning, which is more efficient and...

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Problems solved by technology

At present, there are mainly the following measurement methods: 1. Laser single-point measurement method. Since this method can only measure one point at a time, although the measurement accuracy is high, the efficiency is extremely low; 2. Laser line scanning method (abbreviated as optical section method), This method is single-line scanning, which is more efficient and accurate than single-point measurement, and is easy to realize in engineering. It is a relatively mature method at present. However, when this method realizes full-field scanning measurement of the measured object, it must use three-coordinate The movement of the measuring machine can only be realized; 3. Moiré fringe method. This method is to superimpose the deformed grating image with the reference grating with the same period, and use the observed pattern to draw the contour line of the object. It belongs to the whole field measurement and can be used. Measuring dynamic objects, but the measurement accuracy is not high, the device is complicated, and there is still a distance from the actual application; 4. Grating projection method, which is also a full-field measurement, generally requires that the line connecting the optical center of the projection lens and the optical center of the camera lens be parallel It is difficult to meet this condition in actual measurement, and the phase shift function is completed by mechanical movement, and the precision is not high; the most important thing is that the traditional grating projection method must perform phase shifting on the entire system after obtaining the phase information of the object. The calibration of the corresponding coordinates of the height is very complicated, and the calibration accuracy directly affects the measurement accuracy

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