Disturbance Utilization-Based Alignment Control for Laser Communication Satellites With Multiple Disturbances

The alignment control of laser communication satel-lites is influenced by multiple disturbances such as alignment mechanism vibration and external disturbance, which makes the control design of the alignment system more challenging. To address this difficulty, an alignment control scheme based on disturbance utilization is proposed. Firstly, considering the influence of alignment mechanism vibration and external distur-bance, the deep coupled alignment model of laser communication satellites is established. Subsequently, a disturbance observer is designed to estimate the mechanism vibration and external disturbance. Based on the disturbance observer, a disturbance discrimination operator is constructed to distinguish the ben-eficial and detrimental disturbances. Finally, according to the disturbance observer and disturbance discrimination operator, a disturbance utilization controller is designed to compensate for detrimental disturbances and utilize beneficial disturbances, thereby achieving high-precision alignment control for laser communication satellites. Furthermore, prescribed performance function is introduced to ensure that the alignment error of satellites converges according to the predefined convergence rate and residual set. The feasibility of the designed control scheme is verified in simulation.