Effect Of Laser Modulation Technique On Distance Accuracy Of Structured Light Imaging

With the continuous development of structured light three-dimensional imaging technology,it has a huge application prospect in precision manufacturing,computer vision,medical imaging and other fields.Taking into account most of the mainstream probes,the phase-shift structured light imaging based on laser modulated light source has become one of the hot topics in this field,which benefit from its good beam quality,accuracy,rapid,non-contact,and little influence on the change of reflectivity.The research direction of this paper is to make analog modulation by two methods of laser direct modulation and external modulation of acousto-optic modulator.The phase shift is realized by MEMS scanning projection.The principle of detection and the modulation mode of the light source are elaborated in this paper.The mathematical model of 3D reconstruction is established,and the simulation analysis is made.The factors that affect the precision of the 3D image reduction by the imaging system,and the synchronous control system of the optical system are designed to meet the detection requirements,and the experimental system is set up to carry out the detection experiment.Firstly,the domestic development of structured light 3D imaging and abroad is reviewed,then the advantages and disadvantages of several projection methods are compared.Secondly,the principle of structured light imaging based on direct modulation and acousto-optic modulation is determined.Based on the principle of internal modulation and acousto-optic modulation,the MEMS mirror scanning projection principle,the three-step phase shift method and the time phase unwrapping method are used to establish the mathematical model of the detection system by using the camera imaging principle and the system calibration scheme.At the same time,the error and precision measurement methods are analyzed,and the error evaluation method is put forward.Finally,Finally,combined with actual measurement requirements,a set of structured light 3D imaging system is built based on imaging principle,and a synchronous control system is designed.The measurement of the plaster image of theplane and face is completed.The shape of face can be clearly identified by the reduction of plaster of face.The effects of laser modulation non-sinusoidal,modulated light intensity and modulation depth on imaging precision are analyzed by experiments.