Research on Flight Control of High-Aspect-Ratio Unmanned Aerial Vehicles Based on L1 Adaptive Control

The geometry nonlinear aeroelastic problems of the high-aspect-ratio unmanned aerial vehicles (UAV) are prominent, which will bring many adverse factors to flight control. A high-aspect-ratio UAV flight controller design technique in accordance with the L1 adaptive control algorithm is therefore suggested to increase the flight control system's robustness. First, the adverse effects brought by the aerodynamic lift surface model to the static aeroelastic problem of UAV are analyzed. Then, a longitudinal channel in accordance with L1 adaptive controller is designed, including the design of adaptive law, control law, and state observer. Next, the stability of the designed controller is analyzed to prove its stability. Finally, simulation validation is carried out, and the results show that the designed controller can still achieve good tracking performance of instructions under the adverse effects of static aeroelasticity and has strong robustness against uncertain disturbances caused by model and environment interference.