拼接主镜主动控制实验研究

Active Control Experiment of the Segmented Primary Mirror

对分块拼接主镜实现主动控制是拼接镜技术的难点之一。建立了拼接主镜主动控制系统的模型,采用静态解耦的方式,将传递函数矩阵对角化,系统从多输入多输出的形式简化为单输入单输出的形式,并且建立了简化后的控制系统模型。在此基础上,完成了控制系统的控制器设计。为了实现拼接镜的主动控制,在实验室中搭建了由四块正六边形子镜组成的拼接镜实验系统,由三个驱动器来控制每块子镜的倾斜和平移误差。结果表明,单位倾斜误差校正时间为2.6s,分析子镜倾斜的功率谱密度可知,动态倾斜误差校正带宽达到了0.34Hz,实现了静态拼接误差的高效快速校正和动态误差的实时有效校正。

It is difficult to realize the active control of block segmented primary mirror for splicing technique. The model is established based on the active control system of segmented primary mirror. The single-input single-output systems are obtained after the diagonalization of transfer function matrix of a multi-input multi-output system using the static decoupling. And the simplified control system model is designed. On this basis, the controller design of the control system is completed. We set up an experimental system of segmented mirror in the laboratory with four hexagonal mirrors to implement the active control technology. Three actuators control the tip and tilt error of each sub-mirror. The results show that the correction time of unit tilt error is 2.6 s. According to the power spectral density analysis of the tip of sub-mirror, the correction bandwidth of dynamic tilt error reaches 0.34 Hz. The efficient fast correction of static splicing error and the real-time effective correction of dynamic error are realized.