Filter Observer-Based Attitude Control for Moving Mass Satellites Under Strong Aerodynamic Torques

Moving mass technology offers a promising solution to counter strong aerodynamic torques despite inherent inertial disturbance challenges. This paper proposes a filter observer-based attitude compensation scheme for low Earth orbit (LEO) moving mass satellites. The scheme integrates a moving mass device (MMD) with the traditional reaction wheel actuator to mitigate aerodynamic torques while maintaining effectiveness at varying orbital heights. By employing a filter-based disturbance observer for attitude control and a discrete algorithm for mass motion control, inertial disturbances are markedly reduced, thereby enhancing attitude control stability. The impact of aerodynamic model uncertainties on attitude control is evaluated, and to balance inertial disturbances with internal structural constraints, a dual-symmetric MMD layout is adopted. The proposed filter observer-based control algorithm allows for independent filter design tailored to specific system characteristics, with its stability validated via the Lyapunov approach. Additionally, an incremental discrete PID (proportional-integral-derivative) algorithm is introduced for mass motion control, taking observed disturbances as feedback and eliminating the need for direct measurement. Numerical simulations conducted on a real CubeSat, NJUST-2, reveal that the proposed algorithm outperforms other control strategies in terms of attitude control stability and actuator jitter, thus validating its effectiveness for attitude control applications.