Attitude Tracking Control of Liquid- Filled Spacecraft Based on Internal Model

This paper studies the attitude tracking problem of liquid-filled spacecraft with time-varying inertial matrix and unmodeled input disturbances. First we establish the attitude error system of liquid-filled sapceraft based on quaternions. Aiming at the dynamic characters of the system, a linear time-varying internal model is designed. After we attach the internal model to the original system and get the augmented system, a dynamic high-gain controller is designed to ensure the input-to-state stability (ISS) property of the closed-loop system. Simulation verifies the robustness and accuracy of the proposed controller.