Output Feedback Decoupling Control of Deformable Mirrors for Adaptive Optics Applications

The deformable mirror (DM) is a critical component of adaptive optic systems. However, controlling and modeling it is challenging due to its nonlinear, coupled, and position-dependent dynamics, which arise from the interaction of actuators and mechanical coupling across multiple axes. This paper presents a decoupled control strategy for the DM that addresses the challenges of unknown system dynamics and position dependency. The proposed approach incorporates a proportional controller as an inner control loop and an output feedback controller as an outer control loop, combining state feedback with an extended high-gain observer (EHGO). The controller design does not require prior knowledge of the mirror’s dynamics and can be implemented independently for each actuator and axis. Simulations were conducted to evaluate the controller’s performance, demonstrating its effectiveness in tracking desired motions along both the X and Y axes, even in the presence of unknown dynamics.