The Study Of Application About The Tip-tilt Mirror Image Stabilized Control System In NVST

The One Meter Solar Telescope(or named New Vacuum Solar Telescope, NVST for short) is located at the northeast side of Fuxian Lake, Yunnan, and its main goals are high resolution imaging and spectral observations. In order to ensure good dome seeing while observation, NVST uses open observation mode by moving dome away from the telescope. In addition, because of the station’s lake breeze is obvious along with the telescope structural characteristics, the telescope tracking system is impacted greatly by the wind. These leads to the sun image substantial jitter in low frequency, and seriously affects observations, such as the terminal spectrometer system. To solve this problem, this thesis performed the study on image stabilization control system based on two-dimension tip-tilt mirror.Firstly, the second part of this thesis analyzes the image jitter characteristics of auto guide unit and TiO high resolution imaging system under random wind loads. And then proposes two schemes about stabilizing image jitter caused by random wind loads. The third part describes the major hardware parameters and tests the tip-tilt and drive controller’s performance. Base on the performance of tip-tilt mirror, the fourth part establishes the transfer function of the tip-tilt mirror image stabilization control system, and made numerical simulation analysis on two schemes. Comparative analysis of the results of the numerical simulation under two schemes, the fifth part focuses on experimental analysis of tip-tilt mirror image stabilization closed-loop control system’s performance on stabilizing the image jitter under random wind loads.By in-depth numerical simulation analysis and part of experiment, this thesis shows that in five to six wind action, the focal plane image of the One Meter Solar Telescope can be controlled within 0.5 arcsec when the tip-tilt mirror image stabilization closed-loop system is woking at 25 Hz, which indicates that the twodimension tip-tilt mirror image stabilization closed-loop system can stabilize the image jitter causing by random wind load.