| Fast steering mirror is a key component, which works between the light source or the receiver and the target. It is used to adjust and stabilize the optical axis or light beam. It has the advantages of small size, compact structure, high accuracy, high bandwidth and high speed. It has been widely used in space laser communication, astronomical telescope adaptive optics, aerial photography image motion compensation, high-precision laser processing and the launching laser system. Developed countries have produced mature products of fast steering mirror in many fields, but it is quite difficult to import this technology. Therefore, we need to study the fast steering mirror oriented to high-end applications, to provide the product with market competitiveness and independent innovation.Based on a star laser communication test platform laboratory system, an overview and comparative analysis of the existing various types of fast controlling mirrors were presented. After a comparative analysis, the research of the rapid control of the three-piezoelectric ceramic driving mirror had been performed.The contents of this dissertation were mainly constructed as follows: the structure design and optimization of the FSM system, the deduction and verification of the approximation formula for the single flexible elliptic hinge, the modeling and verifying of the supporting platform stiffness and the simulation analysis of system kinematics, dynamics and fatigue life. The performances of the FSM system were tested by experiment. Each content was described respectively as follows:According to the requirements of the fast steering mirror system used in the star laser communication test laboratory platform, a scheme design of the system was analyzed and presented. The project adopted three piezoelectric ceramics as the driving element, the built-in piezoelectric ceramic strain sensor and the two degrees of freedom supporting platform composed by four same elliptic flexure hinges and the system worked by the elastic deformation of flexible supporting platform. The whole system was compact and stable with no clearance and friction.Study on the the structure, Performance Indicators and compliant matrix of flexure hinge is done. The right-angle flexure hinge has the advantage of large moving range while the circular flexure hinge owes high precision. Elliptic flexure hinge has both the advantage of right angle flexure hinge and circular arc flexure hinge. On the premise of calculation precision, the elliptic arc flexibility matrix of flexure hinge is simplified. The simplified calculation formulas for elliptic arc are used in optimization design, which greatly reduced the optimization time.The bandwidth of the FSM is limited by mechanical resonance frequency. When the load cases is constant, the mechanical resonance frequency mainly depends on the size and the material characteristics of the flexible supporting platform. The formulas of the low ordert natural frequency for the flexible supporting platform are deduced and the formulas are verified by finite element simulation and experimental method. The optimal design of the structure parameters for the flexible supporting platform was finished.The simulation analysis of kinematics, dynamics and fatigue life of the whole system was carried out. First of all, the theoretical mathematical model of the FSM system was deduced and the driving moment was calculated under certain working conditions. Then, the rigid-flexible coupling model was established by the software Ug, Patran and Adams. On the basis of the coupled model, the simulation analysis of the FSM system’s fatigue life was done according to the linear cumulative damage theory and the nominal stress-life method. The results error between simulation analysis and the theoretical calculation was within 2%, which verified the consistency and reliability of the theoretical analysis and simulation.In order to test the static stiffness of the flexible supporting platform, the output-displacement characteristicof the piezoelectric ceramic actuator, dynamic and static characteristics of the FSM system, the experiments were set up, respectively. The experimental results showed that: the theoretical analysis for the stiffness of the flexible supporting platform was accurate, which can satisfy the demand of engineering design; the piezoelectric ceramic actuator will loss displacement under the action of changing force, especially when the force is large, the displacement loss should be considered at the beginning of the design; the performance of the FSM system meet the requirements of the design. |
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