The Study on the Application of the Stabilized Control System for the Tip-tilt Mirror Image in NVST

Because the dome of the New Vacuum Solar Telescope(NVST) is moved away from the telescope when it is at the operation,the tracking system of the telescope is largely affected by the wind.This effect manifests for the image jitter greatly in the low-frequency wind.In order to solve this problem,the design of an image stabilization system based on the two-dimensiontip-tilt mirror in the present TiO high-resolution image channel is made.This designation is based on the existing optical system of the telescope and the characteristics of the focal plane image jitter under the effects of the wind.According to the measured properties for the two-dimension tip-tilt mirror system,we established the transfer function of the system,and designed the controller.After in-depth analysis of the numerical simulation and the experiments,it is showed that in the five to six level wind effects,it be able to control the RMS value of the image jitter for the NVST below 0.5 arcsec when the Tip-tilt mirror image stabilization systems operating at the 25Hz.This indicates that the tip-tilt mirror image stabilization system can compensate the image jitter of the telescope caused by the wind.