Observer-based robust preview control for tracking low Earth orbit targets of a 2.5-meter optical telescope with wind disturbance

Abstract

Fast and accurate tracking of low Earth orbit (LEO) targets is challenging in the presence of variable environmental wind disturbances and measurement noise. To deal with this challenge, a 2.5-meter optical telescope control system is designed in this paper. Based on the descriptor system augmented with the wind disturbance, a T-N-L observer is employed to estimate the extended system states. With these estimations and the preview trajectory information, a composite robust preview controller (TNL-CRPC) is designed and optimized by $H_{\infty }$ method to improve the tracking performance while compensating for wind disturbances. Two simulation experiments are conducted to evaluate the proposed control scheme against three traditional control methods, i.e., PID, ADRC and TNL-PID. Simulation results demonstrate that the developed control system achieves improved tracking performance and disturbance rejection capability, meeting the telescope’s design requirements.