Adaptive time-varying sliding mode attitude maneuver control for multirotary-joint solar power satellite under constraints

This paper focuses on the problem of attitude maneuver for the Multirotary-joint Solar Power Satellite (MR-SPS) subject to the angular velocity and control torque constraints, mass parameter uncertainties, and external disturbances. The attitude dynamics and kinematics considering the mass parameter uncertainties and external disturbances are first established. Subsequently, a gain-scheduling disturbance observer is designed to eliminate the effect of the mass parameter uncertainties and the external disturbances. A novel nonlinear implicit time-varying sliding surface is constructed to eliminate the reaching phase and limit the angular velocity to a certain range. Based on the time-varying sliding surface, a sliding mode controller is designed in conjunction with the disturbance observer. The time-varying term in the sliding surface can be adjusted according to the control torques to restrict them within an appropriate range to avoid saturation. Lyapunov stability analysis demonstrates that the sliding mode controller can ensure the asymptotic stability of the system. Finally, numerical simulations are performed to illustrate the effectiveness of the proposed control scheme.