Adaptive Backstepping Attitude Control for Liquid-Filled Spacecraft without Angular Velocity Measurement

The attitude tracking form quaternion measurements for a three-axis stabilized liquid-filled spacecraft are studied under uncertain parametric and external disturbances. The sloshing liquid inside the partially filled liquid tank is equivalent to a spherical pendulum model; thus, coupled dynamic equations are derived using the conservation of moment of momentum. Considering the failure of acceleration sensors, when the angular velocity information cannot be obtained, an adaptive robust backstepping control algorithm is proposed by combining the adaptive backstepping control technique with a passive control algorithm. A nonlinear damping algorithm is introduced to enhance the disturbance attenuation ability and robustness performance against lumped disturbances. Globally uniformly ultimately bounded (GUUB) stability of the entire closed-loop system is guaranteed based on the Lyapunov approach. The comparative simulations show that the control strategy is robust and effective for the spacecraft attitude maneuvers.