Predictive Control for Large Angle Attitude Tracking Maneuver of Spacecraft with Reaction Control System and Reaction Wheel

Abstract

Missions involving rapid and large angle attitude maneuvers have been conceived in astronomical and earth observation satellites in recent years. As an actuator capable of generating a large torque is also going to be required, it will also be necessary to consider characteristics of an actuator in designing a control system. Actuators capable of generating a large torque include reaction control system (RCS). RCS gives an on/off input as it uses the reaction force from fuel injection by thrusters, it can generate a large moment. In addition, the control system of current application satellites normally uses both RCS and reaction wheel (RW) conventionally used for attitude control. This paper considers large angle attitude maneuver of spacecraft by a combination of RCS and RW. To this end, characteristics of RCS and RW are defined, and a discrete-time model (Euler approximation model) for the control system design is derived. Next, we design a discrete-time nonlinear tracking controller so that the closed-loop system consisting of the Euler approximation model becomes input-to-state stable (ISS) using the concept of backstepping approach. Then, we propose a method to appropriately change the threshold of RCS injection corresponding to the attitude of spacecraft by model predictive control. Finally, the effectiveness of proposed control method is verified by numerical simulations.