Small satellite agile maneuver using control moment gyroscope and thruster

Abstract

Nowadays, the agile maneuver for the earth observation mission satellite is required from clients caused by the market’s demand such as multi-target performance for military strategy or disaster monitor and so on. In a small satellite system, the reaction wheel or momentum wheel have been mainly implemented to control and stabilize three-axis with a magnetorquer for preventing speed saturation. However, due to the characteristics of these actuators that generate a torque by wheel speed change, they cannot provide enough large amount of torque to rotate a small satellite with 3-4 deg/sec slew rate. In conclusion, the actuator such as CMG shall be implemented for a small satellite agile maneuver. In this paper, the CMG steering algorithms combined with a thruster is introduced in order to escape from the singularity problem which is the most critical issue in on-line CMG control algorithms. Moreover, simulation studies for the satellite attitude hold and multi-targe imaging mode is performed to prove the availability and advantage of the newly introduced algorithms in this paper over the existing steering laws.