空间反射镜面形校正技术实验系统设计

Development of Experiment System for Surface Correction Technology for Space Reflecting Mirror

摘要:

针对空间相机主镜面形在轨主动校正的工程需求，设计了用于验证空间反射镜面形校正技术的实验系统。该实验系统将一面口径为676mm的SiC反射镜面形作为被控对象；将9只基于无刷直流电机的力促动器作为执行机构；将基于PXI总线的工控机和基于虚拟仪器技术的测控软件作为控制器；将干涉仪作为面形检测模块；可实现对反射镜面形的闭环控制。实验结果表明：所研制的力促动器达到了输出范围不低于-320N +320N，输出精度优于0.1N的指标需求；基于面形响应函数的校正方法可以有效地校正反射镜面形。针对幅值为0.5 像散和0.5 三叶两种像差，一次校正后的校正偏差分别为6%和4%。利用该实验系统，力促动器的单机性能指标得到了测试与评估；面形校正方法得到了有效验证。

Abstract:

Aiming at the engineering requirement of active correction for surface shape of the primary mirror of space camera in orbit, an experiment system verifying the technology of surface shape correction for space reflecting mirror was designed. The experiment system took the surface shape of a SiC reflecting mirror with a diameter of 676mm as the controlled object, nine force actuators based on brushless DC motor as the operating device, the industrial computer based on PXI bus and the measurement and control software based on virtual instrument technology as the controller, the interferometer as the surface shape detection module, and was able to realize the closed-loop control of the mirror surface shape. The experiment showed that the developed force actuator had met the requirements of the output range greater than -320N 320N and the output accuracy better than 0.1N and the correction method based on surface shape influence function was able to correct the mirror surface shape effectively. Tasking the correction of 0.5 wave astigmatism and 0.5 wave trefoil as two examples, the correction deviations after one correction by the nine force actuators array were 6% and 4% respectively. Utilizing the experiment system, the performance of a single force actuator was tested and estimated and the correction method was also validated.