Design Of Laser Triangulation Measurement System Based On PSD

The rapid development of modern industry put forward increasingly high demands on ranging measurement. As short range, high-precision, high-speed, dynamic measuring, compact volume, etc., which belong to traditional ranging measurement are hard to satisfied by nowadays measuring techniques. Thus, it is strategic and pragmatic to research on short range dynamic laser measuring.The precision of non-contact measuring based on the principle of optical triangulation is improving; meanwhile, the measuring system has been frequently used in the measurement of object surface outline, geometry dimensions, and so on. Additionally, it has become an important method in measuring.The paper discussed the design of laser triangulation measuring system. Based on the theory of laser triangulation and the requirements of project, we analyze measuring principle, and design one kind of advanced laser triangulation measuring system, through mathematic simulation and analysis, we prove the feasibility of the system. Besides that, we analyze the factors including parameters of optical construction and characteristics of object surface, which may have influence on the measuring precision. Then we discuss the positional difference between radiation centroid and center of diffusion spot on PSD, and analyze the influence on system measuring precision from positional difference and receiving optical power.According to theoretical calculations on systematical measuring ability, we find interrelation among systematical parameters. Taking full account of the project size limits, we choose the multipass as optical structure, then choose systematical components and design mechanical prototype.Finally, we have experiments on the prototype. By changing receiving lens aperture, optical power, and target color, we verify that the system has the ability of target range measuring. The measuring precision of the prototype can satisfy the requirements of the project, through signal processing circuits and optimizing algorithm.