Research On 3D Reconstruction Of Laser Based On Phase-shinting Method

With the development of science and technology,the demand of three-dimensional contour measurement technology is also increasing.In recent years,as the most widely used technology of structured light three-dimensional contour measurement,phase-shifted three-dimensional contour imaging technology has great application prospects in many fields,such as medicine,quality control,mechanical engineering,robot guidance and industrial detection.For three-dimensional contour measurement technology,measurement accuracy is a very important index,and the modulation of light source is an important factor affecting it.The research direction of this paper is to build a phase-shifted laser three-dimensional imaging system based on acoustooptic modulation and MEMS galvanometer scanning.On this basis,the influence of different sinusoidal modulation laser modes on detection accuracy is studied.1.Starting from three different fringe projection modes,this paper summarizes the research progress of phase-shifting imaging technology at home and abroad,expounds their advantages and disadvantages,and summarizes the advantages of using acousto-optic modulation and MEMS galvanometer scanning to build phase-shifting imaging system.2.Introduced the relative principle of phase-shift imaging,including phase-shift method,scanning projection principle and calculation model,phase unwrapping algorithm and system calibration principle;analyzed the accuracy of phase-shift three-dimensional imaging,determined the error calculation method to measure the detection accuracy;and determined the theoretical simulation and experimental research scheme of this subject.3.According to the imaging principle,the simulation experiments are designed and the plane and sphere surfaces are successfully restored to verify the feasibility of phaseshift imaging.On this basis,the effects of the storage format and depth of storage,noise,modulation depth of sinusoidal modulation,modulation frequency and non-sinusoidal error of CCD image on the detection accuracy are studied.The phase unwrapping algorithm is realized and its solution effect is tested.4.The parameters of the instrument needed for the system construction are tested,and the relevant parameters are determined according to the experimental requirements.On this basis,a phase-shifting laser three-dimensional imaging system based on acoustooptic modulation and scanning projection of MEMS is built,and the effect of modulation depth on detection accuracy is tested.Laser diode laser is used as light source to carry out experiments,and the influence of modulation frequency on the experiment is studied.The root mean square error of the measurement system can reach 6.0417 mm,and the detection system is used to detect different precision targets such as steps,surfaces and gypsum images,which can successfully restore their three-dimensional details.