Improved tip-tilt control for laser beam steering system utilizing modified disturbance observer-based controller

A tip-tilt control system is widely utilized in a laser beam steering system (LBS) utilizing a fast steering mirror (FSM) to improve its robustness in the presence of dynamic disturbances. The ultimate goal of the LBS system involves positioning a laser beam at an aiming location point on a target with minimal beam jitter in the presence of dynamic disturbances. This paper proposes an improved tip-tilt control method utilizing a disturbance observer (DOB) in the FSM motion system. To improve tip-tilt control capability for dynamic disturbances, the existing tip-tilt control system implements a modified DOB-based control scheme, which is an improved method for disturbance suppression. Experimental results show that the control error of the modified DOB-based controller is reduced, effectively improving the disturbance attenuation capatibility.