Three-dimensional measuring method for complex large object based on stripe period correction

Abstract

The invention discloses a three-dimensional measuring method for a complex large object based on stripe period correction. The measuring system comprises a projector, a measuring bracket, a camera, a computer and a reference plane, wherein the projector and the camera, on the same level, are placed on the measuring bracket, and are connected with the computer through wires respectively; an object to be detected is placed on the reference plane. The three-dimensional measuring method has the advantages that (1) a five-step phase moving method based on stripe period correction is proposed; (2) a time phase expansion method based on stripe period correction is proposed; (3) the operation is convenient and practical, and the high-accurate three-dimensional measuring of the complex and large object is realized.

Description

technical field [0001] The invention relates to a measurement method, in particular to a three-dimensional measurement method for complex large objects based on fringe period correction. Background technique [0002] The grating projection method is widely used in the three-dimensional measurement of objects. The three-dimensional measurement technology is one of the key basic technologies of the modern manufacturing industry. It is a high-tech integrating optical, mechanical, electrical and computer technologies. It provides the necessary three-dimensional data for product manufacturing, and is widely used in the fields of three-dimensional measurement, quality control, digital manufacturing, reverse engineering and virtual manufacturing of various complex workpieces, and has high practical value. Using the grating projection method to measure the three-dimensional shape of the object has become an important measurement method for detecting the three-dimensional shape of th...

AI Technical Summary

Problems solved by technology

However, the intersecting axis system has the following problems: when performing three-dimensional measurement, the period of the sinusoidal grating stripes on the reference plane is a very important parameter, which directly affects the measurement results

[0006] When the grating projection method is used to measure the three-dimensional profile of the object using the intersecting axis system, the period of the grating stripes on the reference plane will be broadened due to the oblique projection, resulting in a non-fixed period. When the measured object is large, it will bring a large error to the measurement.

At present, there is no measurement method at home and abroad that can generate a series of sinusoidal grating fringes (period non-uniform) with five-step phase shifts at each frequency on the projector plane, and project the fringes onto the reference plane to obtain a series of five-step phase shifts at each frequency Sinusoidal grating fringes (uniform period), each frequency satisfies the fringe frequency change law of the time phase expansion method of the exponential sequence, and realizes high-precision three-dimensional measurement of complex and large objects

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