The Tolerance Analysis And Alignment Path Optimization Of Coaxial Optical System

The design and alignment of the optical system is the key factor in determining the quality of optical system imaging,and also critical parts of the field of optical research.In the current optical machine design process,Computer aided tolerance analysis often involves only the analysis and distribution for the part of optical tolerance,and there is no systematic consideration of the integrated effects of mechanical parts tolerances and optical components tolerances when the lens is assembled in an incomplete positioning way.On the other hand,for coaxial optical systems,Due to the large number of lenses and the complicated assembly relationship,the current computer-aided assembly(CAA)technology has been difficult to accurately solve the offset amount(machining error and assembly error)of coaxial optical system,which led to the increase of the number of times of alignment and lower the efficiency of alignment.Therefore,it is of great significance to study the tolerance analysis and the appropriate alignment method of the coaxial optical system for improving the optical system image quality and the precision of manufacturing and assembly.The research of this paper was divided into two parts:research on assembly success rate analysis based on tolerance synthesis of optical machine system and alignment path optimization method based on tolerance sensitivity analysis.This paper is based on the most basic unit in coaxial optical systems——lens system,the influence of various tolerances on assembly error when the lens is assembled in the form of spherical contact and plane contact was analyzed,a solution model of lens tilt assembly error and decentration assembly error was established.Based on the solution model of assembly error,a assembling success rate analysis method based on Taugchi orthogonal test method and Monte Carlo method was proposed,the statistical method was applied to the tolerance analysis of the optical system.By means of the optical element division technology and the angle of rotation around the center axis,the method of quantifying assembly position of lens and barrel and description method of the alignment path was put forward.Through analysing the tolerance sensitivity based on MTF by using optical design simulation software ZEMAX,the optimization methods of alignment path based on the error weighting factor was further proposed.The rationality of this research method was verified by an example of the alignment of telephoto objective system.