Modified adaptive backstepping control for micro-satellite attitude stabilization

In this paper, a modified adaptive backstepping controller is proposed for the micro-satellite attitude control system in the presence of external disturbances from the space environment. Firstly, adaptive control is employed to estimate the upper bound of the disturbance. Then, the whole attitude controller is synthesized by using backstepping technique with two special continuous functions introduced. Due to the utilization of these two continuous functions, the designed controller can be guaranteed to be continuous. Moreover, attitude control accuracy can be adjusted by selecting proper control parameters online. Lyapunov stability analysis shows that the resulting closed-loop system is globally stable, and simulation results are also presented to verify the effectiveness of this approach to the high accuracy attitude control and robust to external disturbances.