用于地基望远镜的高分辨率倾斜镜设计

摘要

根据多镜面地基望远镜在近红外实现共相衍射极限成像的需求,提出了一种基于压电堆栈致动器的高分辨率倾斜镜设计方案.该方案以哑铃型柔性铰链和菱形位移缩小结构(RADS)作为倾斜镜的运动传递元件,压电堆栈致动器(PSA)作为动力元件,并使用电涡流传感器作为角度测量部件.介绍了高分辨倾斜镜的工作原理,并对哑铃型柔性铰链和菱形位移缩小结构进行设计.柔性铰链和位移缩小结构的关键结构参数均采用理论计算、实验和仿真进行优化.建立倾斜镜模型,利用理论计算和有限元仿真软件分别计算倾斜镜的倾斜角度和分辨率.实验结果表明:设计的倾斜镜角度分辨率达到0.017″,最大倾斜角度为14.6″,谐振频率为136.97 Hz,与有限元仿真结果相吻合,满足地基望远镜系统衍射极限成像的要求.%To meet the requirements of co-phase diffraction limit imaging,a high resolution tip/tilt mirror(TM)for multi-mirror ground-based telescope is proposed and designed.Three dumbbell-shaped flexible hinges and rhombus attenuated displace-ment structures (RADSs)were used in the TM system as the moving transmission devices,and three piezoelectric stack actuators (PSAs)were applied as driving components.The structure parameters of the flexible hinges and RADSs were optimized by theo-retical,experimental and simulative methods.The experimental results show that the TM has an extreme high angular resolution of 0.017″,and the mechanical excursion angle is larger than 0.24′with a natural frequency of 136.97 Hz,which accord well with the results of the theoretical estimation and finite element analyzing (FEA)simulation.The high angular resolution property indi-cates the multi-mirror telescope can achieve the imaging in diffraction limit.