Yin Zihao, Qin Rongjie, Du Haoting, Zhou Weiyinuo, Sun Jialin, Sun Dexin, Liu Yinnian
Key Laboratory of Infrared System Detection and Imaging Technologies, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Micromachines (Basel). 2023 Mar 23;14(4):713. doi: 10.3390/mi14040713.
An active optical system with three segmented mirrors was proposed to verify the co-focus and co-phase progress. In this system, a kind of large-stroke and high-precision parallel positioning platform was specially developed to help support the mirrors and reduce the error between them, which can move in three degrees of freedom out of plane. The positioning platform was composed of three flexible legs and three capacitive displacement sensors. For the flexible leg, a kind of forward-type amplification mechanism was specially designed to amplify the displacement of the piezoelectric actuator. The output stroke of the flexible leg was no less than 220 μm and the step resolution was up to 10 nm. Further, a linear model was established to identify the amplification ratio between the actuator and the flexible leg, which can increase the precision of the positioning platform. Moreover, three capacitive displacement sensors with a resolution of 2.5 nm were symmetrically installed in the platform to accurately measure the position and attitude of the platform. To improve the stability and precision of the platform, particle swarm optimization algorithm was applied to identify the control matrix, which can help the platform achieve ultra-high precision positioning. The results showed that the theoretical matrix parameters had a maximum deviation of 5.67% from the experimental ones. Finally, abundant experiments verified the excellent and stable performance of the platform. The results proved that while bearing the heavy mirror, which is no more than 5 kg, the platform can realize a 220 μm translation stroke and 2.0 mrad deflection stroke, with a high step resolution of 20 nm and 0.19 μrad. These indicators can perfectly cater to the requirements of the proposed segmented mirror system's co-focus and co-phase adjustment progress.
提出了一种具有三个分段镜的有源光学系统来验证共聚焦和共相位过程。在该系统中，专门开发了一种大行程、高精度的平行定位平台，以支撑镜子并减少它们之间的误差，该平台可在平面外的三个自由度上移动。定位平台由三个柔性支腿和三个电容式位移传感器组成。对于柔性支腿，专门设计了一种前向型放大机构来放大压电致动器的位移。柔性支腿的输出行程不小于220μm，步长分辨率高达10nm。此外，建立了线性模型来识别致动器和柔性支腿之间的放大比，以提高定位平台的精度。此外，在平台上对称安装了三个分辨率为2.5nm的电容式位移传感器，以精确测量平台的位置和姿态。为了提高平台的稳定性和精度，应用粒子群优化算法来识别控制矩阵，这有助于平台实现超高精度定位。结果表明，理论矩阵参数与实验参数的最大偏差为5.67%。最后，大量实验验证了平台优异且稳定的性能。结果证明，该平台在承载不超过5kg的重镜时，可实现220μm的平移行程和2.0mrad的偏转行程，步长分辨率高达20nm和0.19μrad。这些指标能够完美满足所提出的分段镜系统共聚焦和共相位调整过程的要求。
