Research On Integrated Analysis Method Of Missile-borne Imaging Optical System In Complex Thermal Environment

The missile-borne optical imaging system works inside the optical hood of a high-speed vehicle.The external environment and the internal heat source of the hood will cause the thermal effect of the optical detection system.The external heat source that affects the optical hood internal optical imaging system is mainly derived from the aerodynamic thermal effects of the aerial hood and the atmospheric friction during the high-speed flight and the solar radiation,The internal heat source is mainly the heat generated by the electronic device during operation,and these heat sources are transferred to the optical system by means of thermal convection,heat conduction and heat radiation,which can caus e the imaging performance of the optical system to change.In this paper,the optical carrier system is used as the research object,and the imaging performance of the optical system is analyzed.The key technology of the integrated analysis process is analyzed deeply.The main contents of this paper include:(1)The thermal theory involved in the thermal integration analysis of the optical machine is studied deeply.The heat transfer problem between the hood and the light machine system and the optical system is analyzed deeply;the heat conduction calculation model,the thermal convection calculation model and the thermal radiation calculation model are established in the thermal analysis of the optical system.(2)The finite element analysis method of adaptive meshing of light machine system is studied deeply.According to the characteristics of the geometric model of the optical machine system,such as the characteristics of curvature change and angle,the adaptive meshing based on geometric features is a dopted,the density of the mesh is automatically determined according to several characteristics,which improves the precision of the finite element analysis and improves the efficiency of the solution.(3)The algorithm for fitting the surface of the optical element with thermal deformation.The surface fitting algorithm based on Zernike polynomial is discussed in detail,and the problem of Zernike polynomial fitting precision is analyzed.The influence of the fitting degree and the different grid division on the fitting accuracy of the face is analyzed.The face fitting program based on Zernike polynomial is written.(4)Simulation and calculation of the aerodynamic thermal environment of high speed aircraft.When the aircraft is flying at high speed,the optical hood and the atmospheric violent friction produce the aerodynamic thermal effect,the resulting heat will not only cause the hood itself to undergo thermoelastic deformation,while the heat generated by the friction of the optical hood will cause t he internal temperature of the hood to change by conduction and convection,thereby causing the internal imaging optical system to produce a corresponding thermal effect.In this paper,the aerodynamic thermal environment of the thermal analysis of the airborne light machine system is established by simulating the outflow field characteristics and the thermal response of the optical hood generated by the high speed flight.(5)Based on the aerodynamic thermal environment,the integrated analysis of the spacecraft system was carried out.The thermal deformation of the optical system under aerodynamic thermal environment is studied.The image quality is evaluated by using the transfer function and the point chart.The image quality of the optical system is determined.