| Active optics can actively change the posture of the mirror surface to correct the effects of temperature,wind,and other factors on optical imaging,and is widely used in deep space exploration and other fields.As a key part of the optical deflection mirror,it can achieve highprecision pose adjustment of the mirror surface,which is crucial in the fields of active optics,adaptive optics,satellite communications and biomedical systems.However,with the development of related technology fields,many fields pose new challenges to the size,operating space and dynamic performance of the optical deflection mirror.In the existing position and attitude adjustment schemes of optical deflection mirror,large actuators such as stacked piezoelectric ceramics or voice coil motors are often used to form deflection platforms with compliant mechanism.Such schemes have large assembly errors and are not suitable for applications with narrow operating space,which limits their applications in medical imaging and other fields.Although MEMS micro mirrors can serve as an alternative solution to meet the application of optical polarizers in compact environments,greatly expanding their applications in emerging fields,problems such as complex manufacturing processes and high cost are inevitable.In view of the challenges faced by the deflection platform in the emerging field,this paper designs a new flexible deflection mirror driven by piezoelectric wafers,and carries out research around the structural design,modeling analysis,finite element simulation and experimental verification of the deflection platform.The specific research contents are as follows:Firstly,considering the requirements of multi-disciplinary and cutting-edge technology for precision polarizing mirrors,such as more compact size,simpler structure,and faster response,a new type of flexible thin plate polarizing mirror driven by piezoelectric chips has been designed,which has the characteristics of compact structure,simple manufacturing,low cost,and good performance.The overall structure design is carried out,abandoning large-sized drivers and using small and precise thin plate piezoelectric drivers,By using nested connections,the coupling effect of mutual forces between various drive components is reduced,and the asymmetric effect of the two axes is achieved.The motion principle is analyzed and a feasible process preparation route is provided.Secondly,for the motion coupling of multiple piezoelectric actuators of the deflection mirror,the piezoelectric action of the piezoelectric actuators is one by one equivalent to the external force by using the separation method,and the relationship between the voltage and the output deflection is quantitatively analyzed.Simplify the flexible polarizing mirror with concentrated parameter characteristics into a concentrated parameter model,equivalent the actuator to a spring damping system,obtain the relationship between its shape variable and the output posture of the polarizing mirror,use the Lagrange equation to solve the dynamic model,and ignore damping and external forces to obtain the natural frequency of the piezoelectric flexible polarizing mirror.Then,the finite element method is used to analyze the statics output characteristics and dynamic characteristics of the flexible piezoelectric deflection mirror.Through statics simulation,the relationship and stress between the voltage and the pose of the flexible piezoelectric deflection mirror are obtained.Through modal simulation,the natural frequency and modal vibration mode of the deflection mirror are obtained.The dynamic and static characteristics of the deflection mirror are analyzed and the structural design is assisted.The finite element simulation results are compared with the theoretical analysis results to verify the validity and accuracy of the proposed theoretical model,which provides a reference for further prediction of statics characteristics and dynamic behavior in the movement process.Finally,based on theoretical research and simulation results,a flexible piezoelectric polarizing mirror was designed and fabricated,and a precision swing angle measurement experimental system was established.Based on the experimental system,the output performance of the applied signal of the pendulum mirror is tested,and the static characteristics of the pendulum mirror are tested.The comparison of theoretical and simulation analysis results verifies the effectiveness of the statics model in the open loop experiment.At the same time,the frequency sweep experiment is carried out,further verifying the accuracy of the dynamic modeling.And identify and fit the two axes,conduct closed-loop positioning and tracking experiments on the deflection mirror,and verify the good dynamic characteristics and feasibility of closed-loop application of the designed deflection mirror.The designed piezoelectric flexible thin plate polarizing mirror has good output performance and compact structure,and exhibits asymmetric characteristics of two motion axes.It has certain reference significance for beam manipulation applications in precision motion,biomedical,and optical fields that require compact operating space. |
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