Calibration of the Active Control System of Segmented Mirror

Active control of the segmented primary mirror is one of the key technologies. The control performance of the active optics of the 8m ring solar telescope mainly depends on the accuracy of the tip/tilt detection and the accuracy of the control model.When developing an active control system, it is necessary to calibrate the tip/tilt detection accuracy and establish a more accurate control model, that is, to calibrate the active control system. A Shack-Hartmann wavefront sensor for detection of the tip/tilt of the segmented mirrors is built in the experimental system, and the repeating measurement accuracy is scaled to 0.014arcsec, which is close to the 8m RST shape control requirement. Then the edge sensor and Shack-Hartmann wavefront sensor are used to measure the control matrix of the two-segment mirror's active control system, and a more accurate control model is established.