自适应光学系统倾斜校正技术研究

发布时间：2018-01-02 15:10

本文关键词：自适应光学系统倾斜校正技术研究　出处：《中国科学院研究生院(长春光学精密机械与物理研究所)》2016年博士论文　论文类型：学位论文

【摘要】：波前倾斜校正是自适应光学(AO)系统稳定图像、对目标进行高分辨率成像的前提。随着大口径望远镜衍射极限分辨率的提高,倾斜校正精度、即波前倾斜误差抑制带宽的要求将进一步提高。因此本文围绕提高AO系统波前倾斜校正误差抑制带宽展开了研究工作。定量分析了匹配1m~2m口径望远镜的AO系统的波前倾斜幅度和频率特性,得出了大气湍流导致的波前倾斜频率决定了波前倾斜的校正带宽需求,当对低轨卫星跟踪成像时,卫星运动引起波前倾斜变化速度加剧,波前倾斜频率增加至30Hz,AO倾斜校正系统误差抑制-3dB带宽需要达到80Hz左右。针对AO系统分光倾斜探测方法的能量损失问题,采用波前倾斜和高阶畸变共用一个哈特曼波前探测器(WFS)的波前探测方法,省去了单独的倾斜探测器,波前倾斜的探测和校正分两个阶段进行,在提高了AO系统能量利用率和波前探测能力的同时简化了系统。采用神经网络建立压电陶瓷驱动快速反射镜(TTM)的磁滞逆模型,在倾斜校正回路的前向通道中加入磁滞补偿,将快速反射镜的静态磁滞非线性由17%降低到5%,使得快速反射镜的开环到位精度提高70%以上。根据TTM和WFS的响应特性模型,对WFS探测到的倾斜残差信号进行修正,补偿了倾斜校正系统对于TTM响应动作的探测时间延迟,大幅度提高了倾斜校正能力,倾斜误差抑制-3dB带宽由61Hz提高到77Hz。增加了高采样频率的TTM位置反馈回路,利用PID结合惯性环节对TTM进行进一步闭环,减小TTM响应的相位滞后,提高了TTM响应带宽;利用TTM位置反馈回路和基于WFS的光学波前倾斜校正回路组成双闭环回路倾斜校正系统,在双闭环结构下,对时间延迟补偿方法做了进一步改进,实验室内测量倾斜校正系统的误差抑制-3dB带宽提高到86Hz,能够满足1~2m大口径望远镜对于低轨道卫星的跟踪成像要求。以上研究工作所取得的成果将对大口径望远镜空间飞行目标的高清晰成像技术起到一定的推动作用。
[Abstract]:Wavefront tilt correction adaptive optical (AO) system is the premise of stable image, high resolution imaging of the target. With the large aperture telescope diffraction limit resolution, tilt correction precision, i.e. wavefront tilt error suppression bandwidth requirements will be further improved. This paper focuses on improving AO system wavefront tilt correction error suppression bandwidth of research work is carried out. Quantitative analysis of the wavefront AO 1m~2m telescope system matching the tilt amplitude and frequency characteristics of the atmospheric turbulence induced wavefront tilt correction of wavefront tilt determines the frequency bandwidth requirements, when the low orbit satellite tracking imaging, satellite motion caused by wavefront tilt change speed increased, the wavefront tilt frequency increases to 30Hz, AO tilt error correction system inhibits -3dB bandwidth required up to about 80Hz. To solve the problem of energy loss in optical tilt detection method of AO system, The wavefront tilt and higher-order aberrations share a Hartmann wavefront sensor (WFS) detection method of the wavefront tilt detector eliminates the need for separate, tilt correction and wavefront detection is divided into two stages, the improved AO system energy utilization rate and the ability of wavefront detection with simplified system. Using neural network to build pressure PZT mirror (TTM) hysteresis inverse model, adding hysteresis compensation to channel in the tilt correction circuit, the static hysteresis nonlinear mirror decreases from 17% to 5%, the mirror ring opening position accuracy is improved by more than 70%. According to the response characteristics of TTM and WFS on the model. Tilt the WFS to detect the residual signal is modified to compensate the tilt correction system for TTM detection response action time delay, greatly improves the tilt correction ability, tilt error suppression bandwidth of -3dB by 61Hz To improve the 77Hz. adds high sampling frequency TTM position feedback loop, using PID combined with inertial link for further loop of TTM, reduce the phase lag response of TTM, improve the TTM bandwidth; using TTM position feedback loop and WFS optical wavefront tilt correction circuit of double closed loop tilt correction system based on the double loop structure. Next, on the time delay compensation method has been further developed in the laboratory measurement error correction system of tilt inhibition of -3dB bandwidth up to 86Hz, can meet the large telescope 1~2m for low orbit satellite tracking imaging. The above research work achievements of large telescope space flight target high resolution imaging technology to a certain role.

【学位授予单位】：中国科学院研究生院(长春光学精密机械与物理研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O439;TP391.41

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