Surface Control of Primary Mirror for Deployable Diffractive Telescope

The deployable diffractive telescope can achieve an expansion aperture more than 20m, which is an important way to realize high-precision remote sensing detection in the future. In order to accurately adjust and maintain the primary mirror shape of the deployable diffractive telescope, this paper presents a primary mirror control scheme and presents a new type of actuator. The proposed actuator has the 20mm range and 0.1 $\mu$ m accuracy to be suitable for the surface control scheme. This paper designs a surface control frame consisting of surface control units and each surface control unit is equipped with six actuators. The scheme can achieve 6-DOF control of the mirror support unit, thus achieving sub-micron control of the telescope surface. This paper gives the design parameters of the actuator and simulation of the surface control. The simulation results show that the proposed control scheme and actuator can meet the requirements of the primary mirror surface control for the deployable diffractive telescope.