Research On Optimization Design And Simulation Analysis For The Key Components Of1m Aperture Photoelectric Theodolite

In order to satisfy the requirments of modern range measuring technology,photoelectric theodolite gradually develops towards large aperture, high-resolution,high tracking accuracy and high pointing accuracy. Clearly, large aperture theodolitebrought the following issues: the structure is too large and complex; servo trackingperformance decrease because the structure’s moment of inertia is large; lightweightdesign of large aperture primary mirror and the supporting means of primary andsecondary mirror; temperature adaptability of large aperture theodolite system, andso on. In order to meet the requirements of structural stiffness and stability, andensure system accuracy while reducing structural mass, it is need to optimize the keycomponents of theodolite using the finite element method. Besides, dynamic andstatic response analysis and thermal analysis is also indispensable for the wholesystem, so that the system structure can be comprehensive optimized.The development of the domestic and international large capture photoelectricdetection system is summarized. Current development of the finite element analysisfor photoelectric detection system at home and on board is introduced. The concept,theoretical basis and analysis method of finite element technique is explained indetail. Also, the theoretical basis of optimization design, especially topologyoptimization design, is summarized. Taking a1m aperture photoelectric theodolite as study object, its key componentsincluding four-way, turntable and base are structural optimized so as to improvestructural rigidity while reducing structural mass. First various components’ workingcharacteristics and relationships with the other parts are studied, based on these,reasonable finite element model of these components are established, then eachcomponent’s optimal material topology are obtained by continuum topologyoptimization. According to structural topology, lightweight truss structure modelsare constructed and the models’ key parameters are optimized in size. Finally, thestructures optimized are verified by finite element analysis.The basic theories of supporting primary mirror are studied. Design principle ofsupporting structure and method evaluating surface figure pricision are summedup. The disadvantages of existing axial and radial supporting structures are analyzedand improved composite supporting system including new axial and radialsupporting structures for1m aperture primary mirror are presented. Besides, therelevant parameters for radial and axial supporting structures are optimized.After simplified some structures, finite element model of whole theodolite areestablished. System-level static analysises for the whole theodolite are made,including studying object’s deformation and stress in working condition, the primaryand secondary mirrors in defocus and offset under gravity in various direction andstatic wind loads. Then system-level dynamic analysises for the whole theodolite aremade, including mode analysis, dynamic wind load analysis, random vibrationresponse analysis when theodolite is on truck and ship.When radial and axial temperature differences are existing, the deformation ofprimary morror is studied. Thermal environment of theodolite are analyzed, thentemperature field of main optical and mechanical system are calculated. Based onthese, the thermal structural coupling analysis is made for optical and mechanicalsystem, and we can obtain the main system’s optical performance when loaded bytemperature field mentioned above.