Saturation Backstepping Controller for Spacecraft Attitude Agile Maneuvering

Agile spacecraft with rapid rotational maneuverability still attracts considerable attentions due to the increasingly complex space missions. Input saturation and low energy consumption are taken into consideration in the design of the attitude agile maneuvering controller. This paper aims to address the above problems using a saturation backstepping based attitude controller for rapid rotational maneuver. The backstepping attitude controller is designed at first for the maneuvering only includes acceleration phase and deceleration phase. After considering input constraints of attitude angular velocity and control torque, the backstepping controller is modified into a two-layer cascade-saturation backstepping controller using saturation control method. The attitude angular velocity and the control torque constraints are satisfied respectively by designing the one-layer cascade-saturation based virtual control input and the control torque saturation function. The resulted maneuvering is divided into three phases: acceleration phase, coast phase and deceleration phase. In the coast phase, the energy cost for attitude maneuvering is reduced. Finally, simulations are carried out to verify the performance of the proposed controller. The maximum control torque and attitude angular velocity are constrained and the energy cost is greatly reduced with high control accuracy.