Study Of The Optical 3-D Measurement Based On Modulation

In mutually optical three-dimensional of a phase-approach method measure, currently to measure the complex surface of a testing object, measure ineffective, and need to unwrap. This paper studies measure techniques based on modulation, which do not need to unwrap. It depends on the biggest contrast degree value of the sinusoidal fringes projected on objects in the position of imaging plan and the perpendicular diagraph principle to recover the high information of the object. It has the advantages of simple equipments, non-contact and be subjected to the small effects on outside environment and so on. It will be applied widely in the future.This paper discusses the difference of the 3D measuring techniques based on between Fourier transform and Phase shift. Because of the simple calculation and little background influence in phase shift measurement, this paper researches the modulation measurement based on phase shift techniques and gets a good modulation image.In the course of the research of modulation measurement based on phase shift techniques, this paper gives the programs on error margin analysis of the phase shift and the function analysis of grating, and analyzes facts that phase shift error has some effects on obtaining modulation value. To decrease the influence of non-sinusoidal signal in structured light on the modulation measurement precision, this paper presents a method to make grating from the angle of economy and function. Through 0. 618 methods, calling the gold partition method again, we found out the best expose time, and so a sine grating with high accuracy and high contrast has been developed.At the foundation of discussing several algorithms of depth retrieval, some of the programs and all flow charts are given, and studied a few vertical scanning ways at the same time, and pointed out that the type of whole scanning is better.Finally, this paper studies system parameter which has a significant effect on scanning accuracy, and we built up the experiment system on the basis of system parameter, and given the scanning partition value. Through the program calculating a series of modulation value, we get the depth information, and recover a testing object goodly, and show the accuracy and validity of the result.