扫描镜动态面形变化和模态分析

为了分析某热像仪帧扫描镜在工作状态下的面形变化和产生2000Hz共振的原因，并提供改进设计依据,根据帧扫描镜运动曲线计算了帧扫描镜的扫描角速度和角加速度，用有限元分析软件I DEAS计算了扫描镜在扫描、加速、减速过程中面型的变化和前10阶固有模态，分析了扫描镜在试验中产生2000Hz共振的原因，并对扫描镜结构进行了改进，重新计算了面型变化和前10阶模态，试验证明消除了共振现象。最后提出了扫描镜设计时应注意动态下的面型变化是否满足要求，以及固有模态要避开驱动力矩中的干扰频率等要点。

Modal analysis and dynamic deformation of scanning mirror

In order to analyze the surface deformation of the frame scanning mirror of a certain thermal imager in operation mode,the cause of the 2 KHz resonance was investigated for improving the design basis. The scanning angular velocity and angular acceleration of the frame scanning mirror were calculated based on the moving curves of the frame scanning mirror,the acceleration,deceleration,the surface deformation as well as the first ten orders of the natural modal of the scanning mirror in the process of scanning were calculated with FEA software(I-DEAS),and the cause of 2 KHz resonance of the scanning mirror was analyzed in the experiment.Based on the experimental results,the surface deformation and the first 10 orders of the natural modal were calculated,and the structure of the scanning mirror was improved.It was proved that the resonance phenomenon was eliminated.At last,the important details are given in designing the scanning mirror,care shall be given to the deformation of the facet and efforts shall be made to avoid the jitter from driving torquer, which will interfere the natural modal.