Design And Finite Element Analysis Of Background Objective Measurer

Background-objective measurer is a kind of precise optical instrument applying in the space environment; which is mainly used to measure the parameters of the globe and atmosphere to provide the basic reference data for the missile forewarning satellite. Background-objective measurer is a real-time infrared reconnaissance camera mounted on satellite platform; it can simultaneously reconnoiter, discriminate and track the enemy missile. As a result of the above, the missile's flight parameters are obtained. It is an essential to develop background-objective measurer in our country in order to strengthen national defence.It is required to be reliable and compact in terms of the load on the satellite. Taking into account the process of launching, system is subject to the severe mechanics environment, the structure designed should be great stiffness, high strength and smaller mass. In this thesis according to the optical system specifications and environmental requirement, the best material for the lens tube is adopted, and two sets of lens tube structure are designed. All design thought and the implementation key about the main components are detailed in scheme. Cross-compared two schemes proposed, and the combined lens tube scheme is finalized accordingly; simultaneously the structure of the bottom board is desgined in details which is the bear weight bearing component of the camera to satisfy the performance of the entire camera.Using 3D structure design software UG to build the accurate shape and simulation assembly for the lens tube components and the bottom board respectively, and thus the important structure parameters of lens tube components and the entire camera system are obtained, such as mass, centroid and moment of inertia etc. Based on interference checking carried on lens tube components 3D modal, the unreasonable part in design is optimized. On the base of 3D modal of background-objective measurer, finite element analysis software ANSYS is applied to do the static analysis of the lens tube structure and the whole machine. In order to imitate parameters in the launch environment, loading at acceleration of 15g on the modal, the maximum deform and stress of lens tube structure on static force condition is acquired, by which demonstrated the stiffness and strength of the structure developed.Using the modal analysis on lens tube structure and the whole machine carried out, the inherent frequency and modal shapes of structure system is obtained, which demonstrates the structure not only to be reliable, but also to set foundation to improve the measurer of dynamic characteristic further. To imitate sinusoidal vibration during the process of launching, the harmonic response on the lens tube structure analyzed to get the homologous displacement and acceleration graphs. Taking into account the high stability of the optical system, in order to further decrease the deformation of the lens tube structure, the flexible damping lamella set on lens tube support positions is developed, which demonstrated good shock absorption effect in imitate analysis.Finally, the thermodynamics analysis on the whole machine structure are carried out; analyzing the influence of heat source and thermal expansion upon the structure systems, which provides theory basis for the implementation of the heat controls.