Robust Control of a Deformable Mirror for Adaptive Optics Systems

摘要

To improve the robust stability of adaptive optics system, H_∞ synthesis has been introduced to design the controller. H_∞ synthesis has advantages to deal with unmodelled dynamic of plant and to ensure the optimal performance in tracking the desired input. To simplify the design of controller, Singular Value Decomposition is adopted to uncouple the channels. This paper first analyzes the frequency responses of the H_∞ synthesis and integrator in uncoupled channels. The results indicate that H_∞ synthesis can increase the phase margin, which explain that the stability of adaptive optics is improved. Then the simulation of atmospheric turbulence correction is analyzed to testify the performance of adaptive optics. The results show that both integrator and H_∞ synthesis can obtain a nearly same satisfying performance, but the former achieves a lower control voltage to correct wavefront than the latter. It validates that H_∞ synthesis has a better robustness to deal with the disturbance than integrator. That is to say, H_∞ synthesis is able to improve the stability of adaptive optics system.