Structure Design And Analysis Of Aerial Camera Reflector

Aerial reconnaissance to overcome the earth's curvature and the terrain obstacles on the ground reconnaissance equipment sight restrictions,to make up for the disadvantages of satellite reconnaissance and lack of details and poor timeliness,showing an indispensable position in the modern battlefield in changing circumstances.With aerial camera remote imaging on the details of the resolution needs to continuously improve the optical system focal length and diameter increases,surface mirror as an important part of the optical system,which use the following form accuracy to guarantee the environment of the system imaging effect more and more attention.Many researchers engaged in research work load and environment mirror deformation,points out that there is a certain proportional relationship between the degree of reflection surfaces shape change and the shape of the mirror,support,load and light weight,the proportion coefficient is generally given according to experience.With the popularization of computer technology,as integrated optical structural thermal analysis,by polynomial fitting as a bridge,the finite element analysis to optical design software,the optical system imaging quality evaluation conclusion,as judged by mirror structure design can meet the requirements of the overall design basis.This paper analyzes the methods to evaluate the imaging quality of the optical system,and points out that the MTF evaluation method has received wide attention due to the same evaluation results in the design and actual detection;and analyzes the application of finite element method in the modern machine design,it points out that the finite element analysis of the deformation data is discrete data,not direct application to optical analysis software;finally introduced the Zernike polynomial,because its coefficient and optical aberration have certain relation,in recent years,often as a finite element analysis data to convert to optical design software for image quality evaluation of the link.Based on the thin plate theory,the deformation reason of the reflector surface under the influence of gravity is analyzed.The influence of material,structure shape and support scheme on the shape of reflected mirror is discussed.The characteristics of common mirror material,support scheme and contrast of different weight reduction forms are enumerated.At the same time,it is pointed out that the service life of the aerial camera is long,and there is a hidden danger only through the adhesive bonded mirror and the structural support connected with it.Finally,the structure of a 420 * 280 oblong mirror is designed and analyzed.Objects in mirror geometry and surface shape error parameters were determined by optical design,the design index of processing capacity object mirror gives the final analysis;through the back open and closed support scheme of two lightweight form and the corresponding comparison design;through the method of finite element analysis components reflecting surface deformation analysis by Zernike polynomial fitting transfer to the optical design software.The extent of compliance to the design index of the evaluation,finally through the mirror after processing and assembling the optical properties of the tested and verified the correctness of the theoretical analysis,object reflector design can meet the precision requirement of mirror optical system.Because of the length of time and the length of the topic,the thesis does not analyze all the structural parts.After these parts are assembled,the stress and strain of the reflector are not discussed in detail.In addition,because the camera is in the state of ring control,the working environment at normal temperature is not designed.The design and analysis of the mirror shape change under the temperature change have not been carried out.These jobs will be in the days after the work of continuous improvement,and combined with the camera and photographic flight environmenttest,at the extremes of temperature,pressure,vibration and other conditions,the stability of mirror supporting structure changes and do detailed tracking and recording,quality assessment to design under practical conditions.