Structured light projection-based high-speed three-dimensional measurement system

Abstract

The invention is applied in the technical field of three-dimensional sensing, and provides a structured light projection-based high-speed three-dimensional measurement system, which comprises a set of phase shifting image projection unit and a high-speed camera, wherein the phase shifting image projection unit comprises a multi-color LED point light source array; and along the emergent direction of the multi-color LED point light source array, the phase shifting image projection unit further comprises a collimating lens, a grating, a pair of reflection gratins arranged in parallel or a pair of inversely-arranged triple prisms, and a projection lens which are sequentially arranged. The structured light projection-based three-dimensional measurement system further comprises a drive circuit for driving the multi-color LED point light source array. The high-speed camera is used for shooting a projection image of the grating on the surface of a measured object, and has shutter frequency synchronous with the frequency of stroboflash of the multi-color LED point light source array. The structured light projection-based high-speed three-dimensional measurement system realizes the high-speed phase shift of the grating image by utilizing the quick frequency response characteristics of LEDs and the dispersion effect of the triple prisms or the reflection gratings, and then performs synchronous shooting by using the high-speed camera to realize high-speed three-dimensional measurement.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional sensing, in particular to a high-speed three-dimensional measurement system for structured light projection. Background technique [0002] Real-time 3D scanning is the development direction of 3D sensing technology. At present, there are two main methods to realize real-time 3D scanning. One is the use of Fourier transform 3D measurement profilometry. This method only needs one frame of image to obtain the object Therefore, the measurement speed is very fast, but because its measurement accuracy is extremely dependent on the quality of the stripes, when the shape of the object is complex, its measurement accuracy drops sharply, so its measurement field is very limited. The other is the use of phase-shift three-dimensional measurement profilometry. The advantage of this method is that it has high measurement accuracy and can be used to measure the surface of complex objects. However, sinc...

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Problems solved by technology

[0002] Real-time 3D scanning is the development direction of 3D sensing technology. At present, there are two main methods to realize real-time 3D scanning. One is the use of Fourier transform 3D measurement profilometry. This method only needs one frame of image to obtain the object The three-dimensional profile information, so the measurement speed is very fast, but because its measurement accuracy is extremely dependent on the quality of the stripes, when the shape of the object is complex, its measurement accuracy drops sharply, so its measurement field is very limited

The other is the use of phase-shift three-dimensional measurement profilometry. The advantage of this method is that it has high measurement accuracy and can be used to measure the surface of complex objects. However, since more than three fringe images with accurate phase shift need to be projected, its measurement speed greatly affected

Restricted by the projection system, the fastest measurement speed using this method can only reach 667 frames per second, which is far from meeting the requirements of high-speed 3D measurement

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