High precision shape control of large deformable mirrors for adaptive optics

In this paper, we propose a novel control method for high precision position control of large deformable mirrors with voice coil actuators. The controller consist of a low frequency force feedforward and a high frequency local position feedback.using force feedforward control, the dynamics of mirror can be contolled in faster settling times, and the local position controller based on the active disturbance rejection control(ADRC) algorithm guarantee the final stability of the high precision shape. we present the progress of the unit construction with a 7-actuator sub-system used to test the control method. Finally, by using experimental test, results confirm the validity of the proposed control scheme.