On-orbit identification of disturbance torques acting on satellite with rotating payloads

This paper presents an approach to improve the stability of three-axis stabilized satellite with rotating payloads from a disturbance identification perspective. Based on steady-state output-only and the system transfer function, the unknown external and internal disturbance torques are identified in a closed loop without persistent excitation. The modified eigensystem identification algorithm (ERA) and the least-squares (LSM) method are employed to obtain the complete models of the disturbance torques. Finally, a feedforward control algorithm is proposed to achieve on-line compensation for the identified disturbance torques. Simulation results show that the approach proposed in this paper can reject the unknown and unwanted disturbance torques effectively, and improve the control performance of satellite with rotating payloads.