Robust Attitude Control of Near Space Vehicles with Time-varying Disturbances

In this paper, the robust attitude control scheme is developed for near space vehicles (NSVs) with time-varying disturbances based on backstepping technique. To efficiently handle the time-varying disturbance and the system uncertainty, the disturbance observer is employed to estimate them. Using backstepping technique and the disturbance observer output, the robust attitude control is firstly developed for the NSV. And then, considering the actuator dynamics, another robust attitude control scheme is proposed for the NSV based on the disturbance observer. The uniformly ultimate boundedness of all closed-loop signals are guaranteed via Lyapunov analysis under both developed robust attitude control schemes. Finally, simulation results are presented to illustrate the effectiveness of the proposed attitude control schemes.