Fuzzy ADRC-Based Motion Control for a Star Tracker

Aiming at the problem that star trackers' motion tracking accuracy is directly affected by external disturbances such as vibration, attitude changes, and environmental factors, as well as internal disturbances such as assembly inaccuracy, friction, and sensor noise, a control approach is adopted to suppress these disturbances, improve tracking accuracy, and ensure their navigation performance. By establishing a dynamic model of the star tracker'sgimbal motion, a composite control strategy combining a fuzzy controller with an active disturbance rejection controller (ADRC) is designed. The fuzzy controller is utilized to adaptively adjust the parameters of the ADRC, thereby estimating the total disturbance. Simulation tests show that for \sin usoidal signal under random disturbances, the proposed method achieves mean absolute errors of 0.062 6° and 0.063 8° in the yaw and pitch directions, respectively, and root mean square errors of 0.071 1° and 0.073 3°, respectively. Compared with traditional PID and ADRC methods, its error is the smallest. It can be concluded that the fuzzy active disturbance rejection control (FADRC) method possesses superior disturbance rejection capability, can effectively improve the tracking performance of the star tracker, and holds significant value for engineering applications.