| In the process of laser propagation,frequency fluctuations can arise because of vibration of emissive source or atmospheric turbulence,in order to stabilize the light path,it is necessary to make use of Fast Steering Mirror(FSM)system to eliminate the fluctuation of light path via fast and high-frequency vibration.It is usually combined with the great inertia mechanical structure to form a compound shaft tracking system for pointing and stabilizing in large angle range and high precision and it is widely used in areas such as laser communication intersatellite,Laser weapon precision targeting,and space remote sensing.Based on the great innovation initiative of Changchun Institute of Optics,Fine Mechanics and Physics,that is the “laser carrier measurement and control &communication” project,the two-axis Fast/Fine Steering Mirror system(FSM)was studied in this paper.Application requirement and integral structure of FSM as well as its key components,especially the lightweight design and elastic support of FSM were studied in detail.The main content of this paper includes parts as follows.Typical products and theory studies of FSM were summarized at home and abroad.On the basis of analyzing the feature of mechanical structure and function in several relative equipments both at home and abroad,this study mainly put its emphasis on the mechanical structure,lightweight design,elastic support,and whole system's experiment validation of FSM.Considering from aspects including clear aperture,rotation range,angular resolution and bandwidth control,this paper proposed the requirements of each key component of FSM,including mirror,elastic support,actuator and sensor.The lightweight design of the mirror.The mirror was generally designed in the beginning.Then the structure of the lens body was optimally designed,which includes topological optimum design and sizing optimum design.The influence of stiffener width and thickness of lens on surface precision was examined and then optimized design was applied to mirror bracket.After the model and parameter of mirror bracket was confirmed,simulated analysis was made on the lens body and bracket of the mirror,from which resonant frequency was got.This provided the basis for the design of FSM system later.Elastic support design of fillet triangle.The equation of rotational compliance and rotation accuracy of flexure hinges was deduced by use of castigliano second theorem,according to which the impact of fillet radius(r)and minimum thickness(t)on its rotational compliance,rotation accuracy and maximum stress was analyzed.Based on the requirement of FSM system,this study analyzed and established the basis parameter of flexure hinges of fillet triangle and two-axis elastic support,built a model,made the analysis using software of finite element analysis and got the simulation results.The error analysis of FSM system.Quantative analysis was made on major errors such as compliance error of FSM system,resonant frequency error of vertical directions,rotation offset error,and deviation effects of gravity load on elastic support.the analysis of impact factor of each error was finally put together to get the expected error result.Methods to lower the random error in practical processing and assembling were also mentioned.The FSM test detection platform was established.Experiment was designed and taken to test the process,compliance and resonant frequency of designed FSM.Experimental value and simulation results were compared with the theory calculation value,coming to the conclusion that this paper shares a common feature in design and analysis method,which could provide theoretical basis for relevant engineering research later. |
PDF Full Text Request