Adaptive attitude maneuver control for liquid-filled spacecraft with angular velocity and torque constraints

In this article, the large-angle attitude maneuver control problem for liquid-filled spacecraft systems with external disturbance and nonlinear uncertainties is considered, while the angular velocity and control torque constraints are taken into account to suppress the liquid sloshing amplitude. Firstly, the rigid-liquid coupling system is modeled based on the existing pulsating ball model. Different from the existing fuzzy disturbance observer, an adaptive fuzzy neural network disturbance observer is proposed to estimate the lumped disturbance consisting of the nonlinear certainties and external disturbance, which can track the lumped disturbances quickly and has better observation performance. Then, in order to handle the constraints on angular velocity and control torque, two auxiliary systems are developed to stabilize the rigid-liquid coupling systems in finite time under the backstepping algorithm. Finally, numerical simulation results are presented to demonstrate the effectiveness of the proposed disturbance observer and control law.