Large-angle Attitude Maneuver of Spacecraft using Reaction Control System with Consideration of Actuator Dynamics

Missions involving rapid and large-angle attitude maneuvers have been conceived for astronomical and Earth observation satellites in recent years. In light of the necessity for an actuator capable of generating large torque, it is imperative to consider the characteristics of an actuator when designing a control system. Actuators capable of generating large torques include the reaction control system (RCS). RCS provides an on/off input by using the reaction force of fuel injection from the thrusters, it can generate a large torque. This paper considers large angle spacecraft attitude maneuvers by RCS. To this end, a design model for controller design considering the characteristics of RCS is derived based on the relative motion equation of the spacecraft. Next, A nonlinear tracking controller based on sliding mode control is proposed to guarantee boundedness of the tracking error in the presence of system uncertainties and external disturbances. Then, we propose a method to appropriately change RCS injection threshold according to spacecraft attitude by solving an optimization problem.