Research On Key Technologies Of Laser Scanning Projection System For Polychromatic Layer

With the improvement of China’s industrial level,advanced laser scanning projection technology is increasingly widely used in the manufacturing field.In Laser scanning projection,the deflection of the galvanometer is used to change the outgoing direction of the light beam,and the visual persistence effect of the human eye is utilized to form a continuous and clear pattern on the surface of the projected workpiece,staff is guided to position and assemble.In order to break through the limitations of conventional laser projectors due to the limitations of a single wavelength and achieve layered projection for different parts,materials,and assembly processes,in this paper,a multicolor layered laser scanning projection system was proposed;a receiving and projection optical path was designed;the three-dimensional scanning positioning technology of the system was researched;and a multicolor projection optical path to verify the projection performance of the system was established.Firstly,in this paper,the basic principle of laser scanning projection system was deeply researched;and two projection schemes were proposed,namely,multi color common optical axis and multi color split optical path.The corresponding projection optical path model was designed,and the lens group spacing was adjusted through the self-focusing function to achieve the focus of three colors minimum light spots on different distance working surfaces.The optical principle of two-dimensional galvanometers was analyzed;and the basis for selecting galvanometers was determined based on the key optical parameters.An optical receiving system based on avalanche diode(APD)was designed;The tolerance analysis and stray light analysis of the optical system were carried out.Secondly,the optical system was simulated using ZEMAX optical design software;and the reliability and projection effect of the optical system were analyzed.A polychromatic projection experimental optical path was built to verify the simulation results.The experimental results showed that on the projection surface at a distance of 3m,the diameter of the light spot at various wavelengths of the projection system was within 0.8mm and the size of the light spot was uniform,enabling the realization of the polychromatic self-focusing projection function.Finally,the three-dimensional positioning technology of the multi color layered scanning and projection system was researched;and the transformation relationship between the world coordinate system and the projection coordinate system was analyzed,as well as the corresponding relationship between the galvanometer scanning angle and the projection coordinate system were analyzed.The corresponding relationship between the galvanometer scanning angle and the world coordinate system was obtained.The observation values of the scanning angle of the galvanometer were achieved by using Newton iterative method,and the rotational translation matrices of the world coordinate system and the projection coordinate system were obtained by using Rodrigues matrix and Grey Wolf algorithm.Aiming at the problem of large spot size in large angle scanning systems,a solution based on self-focusing projection region division was proposed;1:1 correspondence between the CAD model and the actual workpiece is realized in the system.Compared to traditional laser scanning projectors,multi color self-focusing scanning projection systems can be applied to more and more complex assembling environments,which is higher practical value.