Takeoff Control for Variable-Sweep Wing Trans-Medium Aircraft Based on ADRC Extended State Observer and Backstepping Method

Addressing the challenge of low post-splashdown velocity and insufficient lift leading to potential water re-entry, a controller is designed using a backstepping approach enhanceed by an active disturbance rejection technique. This design enables the aircraft to maintain a set target angle of attack post-splashdown to sustain sufficient lift. Within the control strategy, the variations induced by wing deployment are treated as disturbances, effectively mitigated through observation using an extended state observer designed for active disturbance rejection, thereby addressing aerodynamic coefficient changes due to wing deployment. Simulation results confirm that the designed angle of attack tracking controller ensures successful take-off of the variable-sweep wing trans-medium aircraft post-splashdown.